Another celebration of insects that are not good enough nor bad enough nor beautiful enough nor bizarre enough to have fan clubs, or common names, or even much of a biography.
The BugLady thinks that this lovely little micromoth looks a bit skunk-ish. It’s LANDRYIA IMPOSITELLA (no common name, and no explanation of its interesting species name). It’s in the Flower moth/Teardrop moth family Scythrididae, a family with only 43 species in North America. Not a lot is known about the biographies of these small, dark, moths. Their caterpillars, described in one old text as having tufts of hair growing from small warts, tend to be miners or skeletonizers of leaves of plants in the aster, goosefoot, stonecrop, and grass families. Adults are diurnal (day-flying).
Heart-leaved aster is the host of Landryia impositella’s caterpillar. It creates mines/tunnels in the leaves, one caterpillar per leaf, overwinters as a caterpillar and pupates in the next spring. Adults often nectar on yarrow flowers. The BugLady photographed this moth in mid-July.
Landryia impositella has the dubious honor of having the lowest internet profile of any insect the BugLady can recall researching – four pages of hits, some of them faux, and most others annotated checklists.
As seasoned BugFans know, the BugLady is inordinately fond of crab spiders, a.k.a Flower spiders, family Thomisidae, and she thinks these MECAPHESA CRAB SPIDERS are beauts. Crab spiders’ hunting style is described as “sedentary” – rather than build a trap web, they sit still, front pairs of legs poised, and wait for their unwary prey. They are so-named because of their shape and stance and sideways movements.
male
Spiders in some of the crab spider genera are chunkier-looking, but the more commonly seen flower-top crab spiders, like the goldenrod crab spider, are a bit more svelte (and, of course, male crab spiders have a smaller abdomen and are “leggier” than females). Because there is a lot of variation within species, it can be hard to tell the difference between the various genera unless you look them right in the eyes (for a great visual, see http://bugguide.net/node/view/4999). Mecaphesas tend to look a bit translucent, and they have reddish bands on their legs, and some books say that spiders in the genus Mecaphesa are spinier (thanks, as always, to BugFan Mike for the ID). Some of the spiders listed Misumenops in older books are now in Mecaphesa. There are about 18 species in the genus in North America.
Mecaphesa likes to hang out in fields and grassland edges on flowers and on the tips of branches that are in bud. They are preyed upon by some species of mud dauber wasps, who stun them and stuff them into molded mud brood cells to be food for their young.
ROVE BEETLES (family Staphylinidae) are one of those “wait – that’s a beetle??” groups. Why? Because most beetles have a hard elytra/wing covers over the whole, or almost the whole abdomen. Elytra are actually the front pair of wings, highly modified to protect the soft flying wings underneath. The elytra of many (but not all) species of rove beetles are very short, and the flying wings that they protect must be unfolded when needed and then carefully refolded (like a road map) when not needed, a task that the beetle may use its abdomen and legs to accomplish. The exposed abdomen is somewhat susceptible to drying, so rove beetles favor humid environs, mainly on the ground, under leaves, rocks, and logs. Without full-sized elytra, the remarkably-flexible rove beetle can squeak into some pretty small spaces (without full-sized elytra, they are often mistaken for earwigs). There’s a nice overview of the family in the University of Florida’s excellent “Featured Creatures” series at http://entnemdept.ufl.edu/creatures/misc/beetles/rove_beetles.htm. Rove beetles have graced these pages in the form of the Hairy and the Shore rove beetles.
The rove beetle du jour is in the genus Platydracus and the BugLady thinks it’s either P. zonatus or P. mysticus (she’s leaning toward the latter), beetles of woods and grasslands and the windrows of beaches. Both species feed on other insects as larvae and as adults, and they may be effective biological controls of some “problem” insects. According to one source, Platydracus mysticus may be suffering a population decline since the mid-twentieth century, possibly due to habitat change and competition with non-native rove beetles.
Today’s episode celebrates the Carolina Saddlebags, the third saddlebags species to grace these pages; but first, a brief commercial message.
Birders (and non-birders) are urged to tune in to the Great Wisconsin Birdathon (wibirdathon.org), which will be heating up any minute now. Teams take pledges from donors and then head out for a day of birding in May in order to raise money for bird conservation initiatives in Wisconsin. The number of teams has exploded this year, and the BugLady gets a kick out of some of the team names.
Fans of the Great Lakes should check out the Walk to Sustain our Great Lakes, in which Julia and Alyssa will, starting in August, take a little stroll from the Milwaukee harbor to Lake Superior. A number of classroom teachers have already signed on to follow their progress/interact with them when school resumes in fall. See http://www.wsogl.com/.
While you’re at it, read all about the 2017 SEWISC Garlic Mustard Pullathon at https://sewisc.org/.
We now return to our regular programming.
First of all, a little about the saddlebags genus Tramea. It’s in the skimmer family Libellulidae, a genus with seven species known from North America, four of which have been recorded in Wisconsin. They’re named for the dark patches at the base of the hind wings, conspicuous when they fly overhead (they‘re tireless flyers and can circle overhead for far longer than you and your camera feel like waiting). Striped Saddlebags http://wiatri.net/inventory/odonata/SpeciesAccounts/SpeciesDetail.cfm?TaxaID=175, the latest addition to Wisconsin’s saddlebags list, are in a subgroup called the “narrowsaddle” saddlebags, because the saddle is only about as wide as the dragonfly’s abdomen. Our other three species (Red, Black, and Carolina) are “broadsaddle” saddlebags.
They are often called “dancing gliders” because of their unusual reproductive behavior. A male patrols a territory, and when a female nears, he accosts her, using his legs to grab her and manipulate her so that he can get his claspers onto the back of her head. Saddlebags mate for about 10 minutes, perched on vegetation (she can store sperm and need only mate once), and then they fly out over the water in tandem at about knee height or lower (our knees), looking for an area with lots of emergent vegetation. When she is ready to oviposit, he releases her (http://bugguide.net/node/view/654958/bgimage, demonstrated here by Black Saddlebags) but continues to guard her from above (hover guarding). She drops to the water’s surface, tapping it gently to loosen some eggs, and then dances back up to rejoin the male, and then they do it again. Paulson, in Dragonflies and Damselflies of the East, says (about Black Saddlebags) that the dance is observed from underwater, and that bass and other predatory fish have been known to follow a preoccupied couple (needless to say, saddlebags prefer fish-free ponds). Unattached males may follow, too, and take advantage of the brief uncoupling to steal the lady. She may oviposit solo, but if she does, she moves ten times faster than she does when a male is guarding her.
These are largish dragonflies, around two inches long, with broad hindwings, a slim abdomen, and a round head. And they are fast, reaching speeds of 17 mph. They may rest high in a tree or near the ground, invisible either way (the BugLady is always inadvertently kicking them up out of the grass). In hot weather, they may droop their abdomens as they perch, a reverse “obelisk” position that has the similar result of averting overheating by minimizing the amount of sun that strikes the abdomen http://bugguide.net/node/view/96096/bgimage, and they do the same thing in flight. Not surprisingly, the majority of internet hits for saddlebags are photo sites.
The books say that the genus Tramea is considered one of the most highly evolved genera of dragonflies. The BugLady saw that statement a number of times, without elaboration, in connection with the saddlebags and also with the rainpool gliders (genus Pantala). In the case of the gliders, it seemed to be associated with physiological and behavioral adaptations that allow them to fly for huge distances, feeding in the air (they even have the ability to store fat and use it for energy on long flights), and that allow their naiads to develop quickly in very temporary bodies of water. Of course, gliders are also famous for ovipositing on car windows in parking lots, thinking they are over water, so they lose a bit of credibility there.
We’re near the northern edge of saddlebags’ ranges here in Wisconsin (check species ranges at the Wisconsin Odonata Survey http://wiatri.net/inventory/odonata/SpeciesAccounts/), and have fun with the maps at the really cool national dragonfly range-finder at http://www.odonatacentral.org/index.php/MapAction.windowed (type the genus of your dragonfly into the “Taxa” box (in this case, Tramea) and select your species from the drop-down list).
Carolina Saddlebags (Tramea carolina) have been recorded in about 15 counties in Wisconsin, scatter-gunned throughout the state. These are primarily eastern/southeastern dragonflies that range from Nova Scotia to Texas, and they’re listed as a rare migrant here in God’s Country, but sightings seem to have been on an uptick in recent years (more dragonfly watchers? climate change?). Carolinas prefer shallow ponds, swamps, and lakes, and very slow streams as long as there is plenty of emergent vegetation and the water is not muddy, and they are a bit more tolerant of the presence of fish than their confreres.
They are one of two red broadsaddle saddlebags on the Wisconsin scene, but neither of the red species is as widely distributed in the state as the Black Saddlebags. How can you tell them apart? Short answer – sometimes you can’t (so maybe there are more Carolinas out here than we think).
Black saddlebags
Another name for the Carolina Saddlebags is the Violet-masked Glider. Typically, the Red Saddlebags has a lighter, redder-colored face, and the Carolina’s is described as “metallic violet” (males’ faces and abdomens are more intensely-colored than females’). Another big difference lies at the other end of the dragonfly; a Red Saddlebags has a few black marks across the top of the eighth and ninth abdominal segments, but in the Carolina, the black is much more extensive and wraps around the sides of the abdomen. And then there’s the shape of the saddle itself. Some saddlebags are remarkably cooperative and will sit still for photographs, but they often hold their wings in a way that hides the tell-tale perimeters of those red saddles. For a great comparison, see http://dragonfliesnva.com/My%20Documents/KevinPDF/pdf/identify/species/CarolinaSaddlebags-FINAL.pdf. And just for fun, some younger individuals can be almost as dark as Black Saddlebags http://bugguide.net/node/view/789608/bgimage.
Red saddlebags
The naiads (aquatic young) are green, with five, short “tails” at the end of their abdomen http://bugguide.net/node/view/224444/bgimage. They excel at mosquito control – in one test, consuming 38 in two days. When their final transformation into an adult occurs on land, they leave behind an empty shell (exuvia) as witness https://waltersanford.wordpress.com/tag/carolina-saddlebags-dragonfly/. Adults continue to feed on mosquitos, catching and consuming their prey on the wing. They feed all day, until dusk, and they may be found in smallish feeding swarms in company with others of their species.
Yes, they migrate to the North Country in small numbers in early summer. The BugLady has photographed juvenile/teneral Carolinas in Southeastern Wisconsin, so they breed here, too. They are not among the five species censused in a Citizen Science project run by the Xerces Society/Migratory Dragonfly Partnership (http://xerces.org/dragonfly-migration/migration-monitoring/) (don’t forget Dragonfly Woman at https://thedragonflywoman.com/dsp/report/). Carolina Saddlebags are less migratory than the phenomenal Black Saddlebags, but they do make up a small percent of the southward migration along the Atlantic, where they help to fuel the fall raptor migration.
At the very beginning of April, the BugLady received an email with pictures from her sister, BugFan Molly (who also mails interesting little packages containing six-legged critters). Seems that Molly spied something moving when she was out in her yard, looked closer, and then snagged her camera-wielding husband to record it. In her own words, “about 11:00 this a.m. I found this moth. It was crawling through the leaf litter in the garden. You could see only tiny buds of wings, barely visible on its back. In the time it took me to run into the house to get Steve & camera, the wings had exploded out…and kept on going… o my!”
If you’re having trouble finding it in the first shots, that’s the point of emerging as a leaf-colored moth on a leaf-covered substrate – good spotting, Molly!
It’s a Green-spotted fruitworm moth a.k.a Speckled green fruitworm moth and Speckled Green Quaker (Orthosia hibisci), a totally non-green moth that was obviously named after its caterpillar (unless it’s a Subdued Quaker Moth, Orthosia revicta, but the BugLady doesn’t think so).
Brief Aside – in recent years, the BugLady has not used abbreviations for insect names as frequently as she did in the early years, because she started checking what other meanings her abbreviations might have, lest she offend. She likes using the abbreviations, because some insect names are long and are repeated multiple times during an episode, and the BugLady, let’s face it, is a three-fingered typist. Corporate, military, geo-political, and academic acronyms are usually harmless, but, oh my, those people at the Urban Dictionary need to wash their brains out with soap! Ick!! Anyway, this one gets the Good Housekeeping Seal of Approval.
The SGFM/GSFM/SGQ is in the Owlet moth family Noctuidae, and in the subfamily Noctuinae, some of whose caterpillars, often called cutworms and armyworms, target agricultural crops. Noctuidae is a big family with more than 2,500 species in North America and about 12,000 worldwide, one of those “pardon our dust” groups whose taxonomy is constantly under review. The SGFM (not Surface Green Function Matching) is found from coast to coast in North America, but, since it likes woods and water, is found more sparsely in the desert and Great Plains.
There are a bunch of shots of unidentified caterpillars in the BugLady’s “X-files,” and by chance, a few of them look like they might be the GSFM (not Synthesis Gas From Manure). Caterpillar colors vary http://mothphotographersgroup.msstate.edu/species.php?hodges=10495. The caterpillars are catholic eaters – you can’t be picky if you burst upon the scene this early in the year. Their menu includes trees and shrubs in the rose, willow, maple, birch, honeysuckle, ash, heath (blueberry), and buckthorn families. The caterpillar pictured here was feeding on glossy buckthorn – BugFan Jim says that eventually, insects will discover that this aggressive, invasive shrub is a vast, unused food resource and will help to keep it in check.
The caterpillars, common in woodlands early in the season, make a welcome bit of protein for returning songbirds. Caterpillars start feeding on the leaves, then move to the flowers, and then to the fruits. The GSFM (not the Government Statistics Finance Manual) is on USDA Wanted Posters, because its nibbling on young fruit causes aborted fruits or deep, scarring/malformations https://entomology.ca.uky.edu/ef214, https://content.ces.ncsu.edu/green-fruitworm, and because when they are present in large numbers, they cause some defoliation (though they’re such early feeders that trees have time to put out new leaves). Their numbers vary from year to year and location to location; in big years, they’ll eat anything, and when populations are low they’re not considered much of a pest.
Adults, in the early days of spring, visit birch and maple sap drips for nourishment, and then switch to nectar from maple and willow flowers. They are considered pollinators.
SGQs (not the Scottish Guitar Quartet) overwinter as pupae in minimalist cocoons in the soil http://bugguide.net/node/view/894463/bgimage , ready to go when the ground warms. Females lay eggs (100 to 300 of them) in trees as the leaves emerge; their caterpillars are on the job by the end of April and have disappeared by the end of June, tucked away under the soil until the following year. There’s only one generation per year.
Although Molly’s moth emerged in the daylight, they are nocturnal. The BugLady needs to start turning her porch light on.
The BugLady has been hanging out at the ephemeral pond again; what follows is a revision of a BOTW from 2012 (different pictures, somewhat different cast of characters). By now, many of these critters have whole BOTWs of their own at http://uwm.edu/field-station/category/bug-of-the-week/.
She celebrated Easter at the Church of the Ephemeral Pond this year – a choir of peepers, wood frogs, and leopard frogs gave witness that there were, indeed, Easter eggs, but the BugLady didn’t see any. In past years, Belted Kingfishers have gathered at the pond to enjoy the frog spectacle, too, but they’re a bit late this year, or maybe the pond is early.
Ephemeral ponds are (most years) just that – ephemeral (they’re also called vernal or spring ponds, but because some hold water in fall instead of spring, “ephemeral” is a more inclusive term). These are the here-today-gone-tomorrowponds, the gather-ye-rosebuds-while-ye-may wetlands. The wonder of ephemeral pools is that they are populated by animals that take this annual disappearing act in stride – animals that are prepared to dry up with the pond or to get out of Dodge (timing is everything), and therein lie many tales.
An astonishing array of animals use ephemeral ponds as a place to drink, hunt, and breed, but an ephemeral pond is a challenging place to call home. The still, shallow water warms quickly (which encourages speedy metamorphoses) but contains little oxygen. As the water evaporates, its inhabitants squeeze into increasingly smaller spaces; water quality declines as waste products, including carbon dioxide, increase; and food gets harder to find. The handwriting is on the wall. The annual drought makes these ponds unsuitable for fish, which wreak havoc if they find their way in from nearby waterways in flood time. Do animals live there because they’ve developed adaptations that let them survive drought, or do they live there because the pond’s cycles give them something they need – a dry period?
Not every puddle that disappears seasonally is an ephemeral pond; the presence of certain indicator species verifies its status. Wood frogs, blue-spotted salamanders and fairy shrimp are considered obligate species (direct indicators) in Wisconsin, and finding empty caddis fly cases or encysted fairy shrimp eggs in the leaf litter of a dry depression in fall also identifies an ephemeral pond. A massive Citizen Science project to identify and census ephemeral ponds in southeastern Wisconsin is written up here: http://greentier.wisconsin.gov/topic/Wetlands/documents/reportEphemeralPondsMappingAccuracyAssessment.pdf.
Who lives there?
DRAGONFLIES – The BugLady photographed ovipositing (migrant) common green darners across a crowded pond on Easter, but they’re not the only dragonfly species that will use it, and damselflies do, too. Some young Odonates hatch and develop quickly, “goosed” by the warming water temperatures, and they emerge as adults before their pond disappears. Other dragonfly and damselfly species lay eggs in summer or fall, and their eggs go through a period of diapause (suspended animation), restarting when the pond fills again.
MOSQUITO larvae feed by filtering tiny stuff (bacteria, protozoa, algae) out of the water, and they are food for a host of carnivorous aquatic insects and for larval salamanders. The very-active larvae are called “wigglers;” the also-active pupae are called “tumblers.” The BugLady read that some species of mosquitoes lay eggs on damp mud near the pond’s edge – these enter diapause and can be dormant for years until the water rises again.
Mosquito larva
WATER TIGERS (a BugLady favorite) are the larvae of Predaceous diving beetles (family Dytiscidae), and their name is richly deserved. They grab their prey (lots of mosquito wigglers, fairy shrimp, and the odd tadpole) and inject meat-tenderizing enzymes through their sickle-shaped mandibles. Although they are aquatic as both larvae and adults, the winged adults can escape to a wetter spot when the ephemeral pond dries, but they may also overwinter in the mud and litter of the dry pool. This one shared the plastic spoon with a daphnia.
Water tiger and daphnia
GIANT WATER BUG NAIAD- The BugLady loves these bugs (the front end is very sharp – handle with care), and not just because the male is caregiver for the eggs that his lady glues onto his back. Its strategy for drought is to find permanent waters until the ephemeral pond opens up for business next spring. In the low oxygen of the ephemeral pond, he rocks his body back and forth, sloshing water on the eggs and keeping them wet and oxygenated.
Giant water bug
WATER MITES are a diverse bunch both in appearance and habit. Many nymphs (and some adults) are predators or parasites of aquatic insects, and they are commonly seen on dragonflies and damselflies. They move by scrambling through the water, and they can survive in low oxygen concentrations.
Water mite
CADDISFLIES creep around the vegetation of the pond wearing shelters made of bits of plants that they fasten together using homemade silk. Some species are herbivores that, while feeding, break down large pieces of plant material into smaller ones that smaller critters can eat. Others are carnivores – the BugLady read of one species that feeds on larval salamander embryos from un-hatched egg masses. Their eggs overwinter.
Caddis fly
PLANERIA, flatworms, are not related to leeches, which they somewhat resemble. Most scrounge bacteria, algae, and dead stuff from the pond floor, ingesting it through a ventral siphon. They get through the winter as eggs, and the adults of some species can encyst themselves. These dazzling green planeria are ephemeral pond specialists that carry around a bunch of photosynthesizing algae in their tissues. The planaria get oxygen and some sugars from the deal; the algae gets shelter and carbon dioxide.
Planeria
FAIRY SHRIMP – In the early days of the pond, females produce soft-shelled “summer” eggs (some fertile, some infertile but parthenogenic that hatch into more females). If you zoom in on the female, you can see eggs. The summer eggs hatch quickly. As the pond winds down, they form “winter eggs” that have a thick shell that protects them from desiccation and that can withstand years of drought (up to 15 years), and that must be dried and re-hydrated in order to hatch. Maybe 3/8 of an inch long, the male has claspers on his “face” and the female’s face is hammerhead shark-shaped.
Fairy shrimp female
Fairy shrimp male
These tiny guys, which are either SEED SHRIMP OR CLAM SHRIMP (the BugLady isn’t sure which) do look like seeds and clams, but they are Crustaceans, (very) distantly related to crayfish. Most are well under ¼” in length, which means they are targeted by many of the pool’s predators. The eggs of both are drought-resistant.
DAPHNIA are another BugLady favorite, partly because she can’t believe that she can actually photograph them. These tiny Crustaceans eat minute bits of algae, bacteria, and debris, and everybody eats them. Their jerky progress through the water gives them an alternate name – water flea. They overwinter as drought-resistant eggs. Daphnia eggs hatch within the female’s brood chamber and are released when she molts, and the BugLady is wondering if this shot captures a few young daphnia within the brood chamber.
Daphnia
PHANTOM MIDGE LARVA – a predaceous (sometimes omnivorous) larva that floats through the water column like a tiny dirigible, its paired air sacs fore and aft revealing its presence. Its stillness and transparency afford it camouflage; it grabs its prey with specially adapted antennae. It’s on the menu of larval salamanders and other predators.
Phantom midge larva
WATER SOWBUG – Yes, related to the guys that peer up at you when you pick up a flowerpot in the summer. They don’t swim, exactly, but they paddle-walk slowly along on the pond bottom, feeding on detritus that they find along the way. Their young hatch from eggs within the female’s pouch, and they don’t have any special adaptations to survive the drought.
Water sowbug
SCUD – these amphipods scoot around the pool (or the BugLady’s plastic spoon) on their sides, demonstrating their alternate name “sideswimmer.” In a fish-free habitat, they can be plentiful. Like water sowbugs, they are omnivore-detritivores, chewing on organic detritus while they hold onto it with their front legs. When the water dries up, they bury themselves in the mud.
Scud
The BugLady recommends the nifty booklet A Guide to the Animals of Vernal Ponds by Kenney and Burne, Massachusetts Division of Fisheries and Wildlife. And check out Massachusetts’ Vernal Pool Association at http://vernalpool.org/vernal_1.htm, where they describe ephemeral ponds as “wicked big puddles.” Pictures of animals can be found at http://vernalpool.org/sci_x.htm.
Most insects begin their lives inside an egg that’s been deposited near/onto/into the correct food source, in the correct habitat for the eventual young. The BugLady often photographs these eggs, but she didn’t know much about them. Here are some Selected Short Subjects about insect eggs (and the BugLady apologizes in advance, she couldn’t help herself).
Insect eggs come in all sizes and shapes and colors (and some change colors between the time they are deposited and the time they hatch). For some eggsquisite pictures, see http://www.atlasobscura.com/articles/the-blobby-dazzling-world-of-insect-eggs (ignore the text, which has a major eggsample of a “publish-in-haste-and-repent-at-leisure” boo-boo). Some eggs are laid alone, some in clusters, and some en masse, enclosed in a webby or gelatinous protective case. In some species, females detect pheromones left by recent, egg-laying females that tell them “This space is taken.”
Like an onion, an insect egg is layered, the layers manufactured within the female’s reproductive system via a process called oogenesis. In general, the outer layer/egg shell/chorion is made of lipo-proteins, sometimes covered with a waxy coat. The chorion may be sticky initially, so it will adhere to the surface it’s placed on. There are several layers between the chorion and the inner layer, which is called the cell wall or vitelline membrane and which wraps the nucleus and yolk. The surface of the shell has one or more tiny openings called micropyles, usually located on the top of the egg, and it may be minutely textured.
The egg that is manufactured within the female contains at its core an unfertilized female gamete/germ cell. Fertilization happens when sperm find their way through one of the micropyles/micropylar canals after the egg shell is formed around the nucleus. After fertilization, division of cells in the nucleus will result in an insect embryo that eats the yolk particles.
Seems like a lot of fuss – what’s the advantage of this system? Only that developing a weatherproof egg allowed insect ancestors to emerge from life in the sea about 400 million years ago, that’s all (although aquatic insects still lay their eggs in water – more about that in a sec). An inner membrane called the serosa restricts water flow through the egg shell; holding inside the moisture that Mom put there so her little bug wouldn’t desiccate, and keeping eggscess water outside. This has allowed insects to eggspand into almost all environments. Silverfish and a few groups of flies don’t have a serosa, but they lay their eggs in moist habitats, and their embryos develop really fast.
Too much of a good thing? Turns out that the qualities that allow the egg shell to protect the developing bug from drying out and from getting squished and (with varying success) from predation are not quite so good for oxygen eggschange. The answer – more “pyles” or pores. Though some air can be absorbed through the shell itself, the main ingress area(s) is/are other pore(s) called aeropyles. (older references say that the micropyle also allows oxygen to enter; others differentiate and use the term “aeropyle” for pores involved in gas exchange). The number and arrangement of these pores depends on the species.
Insect eggs face big swings in air temperature, and although embryos have higher metabolisms at higher temperatures (needing more oxygen), the rate of diffusion of oxygen through the chorion doesn’t necessarily keep up. This can result in low oxygen concentrations (hypoxia) within the egg (one source said that the hatching of common green darner eggs is triggered by hypoxia). In the recent BOTW about millipedes, the BugLady mentioned that arthropods were bigger 400 million years ago, when temperatures were cooler and atmospheric oxygen concentrations were higher. Information about the interseggtion of temperature, metabolism, and oxygen diffusion through the chorion suggests that arthropod eggs may also have been super-sized.
How about aquatic insects that still lay their eggs under water? Blogger Dragonfly Woman, an eggspert on giant water bugs in the family Belostomatidae, tells us that “Many aquatic insect eggs don’t have aeropyles at all and depend on oxygen flowing directly through the shell.” She continues “[Abedus herberti eggs] have a structure called a plastron network. Plastron networks are meshworks made up of many tiny projections of the chorion. This meshwork is thought to trap air against eggs when they are underwater so that they don’t drown. Many terrestrial eggs have these plastron networks and this structure may allow them to survive accidental submersion for some time. Water bugs also usually have plastron networks that may be responsible for their survival while they are underwater. Lots of other aquatic insects that lay their eggs in water don’t have these structures at all.” Read her full eggsplaination at https://thedragonflywoman.com/2011/02/07/the-anatomy-of-insect-eggs/. Amazing pictures.
How long does it take for an egg to hatch? Anywhere from a few days to months. Many months, in the case of insects that overwinter in the egg stage.
Eggs, it seems, don’t move, so they’re sitting ducks for predators. Like their parents, many eggs are chemically protected against egg grazers and egg parasites. The operative chemicals may be manufactured by Mom, or she may sequester them from plants that she eats (or both) before incorporating them into the shell. Though direct paternal care of eggs is rare in insects, males of some species gift the female with toxic chemicals during courtship, and these are built into the egg. Her eggs may have a toxic shell, be decorated with toxic hairs, be disguised with camouflage colors or brilliant with aposematic colors, or be unpalatable because of a layer of eggscrement. In the “Very Cool” department, a female (herbivorous) stinkbug dots the outside surface of each of egg with feces that contain bacteria needed by her offspring to digest plant materials. The newly-hatched bugs hang around the egg mass for a while, ingesting the bacteria.
Honeybees are the only insects that incubate their eggs and young (by using body heat to keep the temperature in the nursery between 92 and 97 degrees) (they flap their wings like crazy). Other insects are at the mercy of the temperature of air or water around them. Warmer surroundings = faster hatching.
What do the plants think of all this? Most than you’d eggspect. The BugLady recalls the days when living things were divided firmly into two Kingdoms, Plant and Animal (eggcept for some pesky flagellated, unicellular, chlorophyll-bearing organisms lurking uneasily in between). Plants were defined as organisms that didn’t move and didn’t have a sensory system and that produced their own food. More and more studies show that plants not only receive signals, but they also communicate with other plants chemically (great Ray Bradbury short story about a man who designs a machine that lets him hear plants). Research shows that plants recognize, react to, and communicate with plants downwind about grazing by caterpillars like gypsy moths, and that tomato plants are aware of oviposition by a moth and mobilize defensive proteins in their leaves before the caterpillars even hatch.
Gypsy moth egg case
Write researchers Kim Jimwon et al, “Thus far, plants appear to recognize at least three events as indicators of future herbivory. First, some plants increase resistance against insects when a neighboring plant suffers insect herbivory. In this case, plants appear to “eavesdrop” on volatile organic compounds released by the neighboring plant under herbivory and elicit their defenses. Moreover, the volatile-receiving plants showed priming of defenses, meaning the receiver plants activated faster or stronger defenses upon the anticipated herbivory. Second, insect footsteps can induce defensive responses in plants…. Third, oviposition, one of the most common events preceding insect larval herbivory, can induce a variety of direct and indirect defenses of plants.”http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0037420. For more about plant “senses”, see https://www.pri.org/stories/2014-01-09/new-research-plant-intelligence-may-forever-change-how-you-think-about-plants. And, of course, in the eggscalating chemical battle, a few insects can secrete chemicals that moderate the plant’s anti-herbivore tactics. The BugLady’s head may eggsplode.
After last week’s episode on Common green darners, BugFan Linda, whose eggstraordinary videos of pond life were featured in a January BOTW, responded that she had posted this video just a few days before https://www.youtube.com/watch?v=SgsEMAKUeX8. AWESOME, Linda, thanks!
A common green darner was reported near La Crosse (WI) on March 24 of this year, and a few others have been seen since then (and even though the winter of 2016-17 has been “Winter Lite,” the BugLady is ready for spring and dragonflies). The BugLady wrote very brief biographies of the green darner in 2010, in BOTWs about spring dragonflies and about dragonfly swarms, but there’s much more to the common green darner story.
They are in the darner family Aeshnidae, a group of large, powerful dragonflies (“darner” because their long, darning needle-like abdomen has led to folk tales about their sewing people’s lips or ears shut).
Most of our Wisconsin darners are in the famously-confusing mosaic darner genus Aeshna. Common green darners (Anax junia) (“Lord of June”) are one of two species of Anax darners found in the state. Common green darners are, well, very common, not just here but across the country. And Central America. And Hawai’i. And Canada. And there are populations in Tahiti and the West Indies. And strong winds have blown individuals to Great Britain, China, and Russia. The other Anax, the stunning Comet darner (Anax longipes) is a rare visitor and even rarer breeder in Wisconsin.
Green darners have a 3” long body and a 3 ½” wingspan; their striking “wrap-around” compound eyes may be made up of as many as 50,000 simple eyes, apiece. They practice sexual dimorphism – both males and females have a green thorax, but males have a predominantly blue abdomen with a purple stripe, and females have a rust-colored abdomen with a darker stripe. Tenerals (newly-emerged adults) may take a week or more to solidify their adult color patterns and have female-ish coloration in the interim, and a chilly darner is a darker-colored darner. Both males and females have prominent cerci (claspers) at the abdomen’s tip. Common green darners have a characteristic bull’s-eye spot on their “forehead” that comet darners lack. They can move each wing independently, which lets them hover, and even fly backwards. They perch vertically, frequently in low vegetation, so they usually spot the BugLady before she spots them.
Male Common Green Darner
Female Common Green Darner
Newly emerged Common Green Darner terneral
The long, slim, immature green darners (naiads) are found in still or very slowly-moving, shallow waters, preferably without sunfish and bass (nice set of naiad pictures here http://bugguide.net/node/view/238726/bgimage). Adults frequent the air above those habitats but may be seen far from water.
Two populations of common green darners – one migratory, the other resident – form tag teams in the air over Wisconsin. Migrants from the south arrive early, often in late April, as their prey (small, aerial insects) start to appear. They are the offspring, or the offspring’s offspring, of the darners that flew south in the fall (no, they apparently do not return to their natal ponds). “Shivering” their wing muscles to heat up the thorax allows them to be active in cool weather, and they also bask in the sun. This is so effective that temperatures as high as 110 degrees have been measured inside the thorax (which challenges the whole definition of cold-bloodedness). The picture of the female with the battered wings was taken in early July, suggesting that she was a migratory female who was reaching the end of her trail.
The migrants mate and die by the end of June, leaving their eggs in the water, just as the naiads of the resident population emerge as adults. These residents live a month or two as adults, depositing their eggs in late summer as the migrant adults emerge. Resident naiads overwinter under the ice in a state of suspended animation called diapause and take 10 or 11 months to mature (possibly more, in the chilly waters “Up North”), while the migrant naiads need less than half that time.
Mating commences when a male clasps a female at the back of her head in mid-air (one source said that she can reject his advances), then they retire to a perch to mate. Females oviposit in the open, in woody and herbaceous plant material below the water’s surface.
The books say that these are the only darners that oviposit in tandem. The books also say that a couple flying in tandem may be strafed by rival males. The attendant male doesn’t have many options; he may flap his wings at the intruder, shake his abdomen, land in vegetation, and even bite his challenger. According to Paulson, in Dragonflies and Damselflies of the East, females may curl their abdomen under and close their wings when under attack. The BugLady photographed (badly) an unattached male as he dive-bombed a second male whose abdomen was deeply submerged (presumably with an ovipositing female at the other end of it).
The BugLady once found a female stuck in an especially dense and sticky, dragonfly-eating patch of blanket algae. Did the female attempt to perch on the algae as she oviposited and get her wings stuck, only to be abandoned by her mate? Or, alternatively, did she get thirsty and then get stuck? Dragonflies “drink” by immersing their abdomen – water enters through the exoskeleton (the BugLady was able to fish her out with a stick).
The naiads are active predators that will eat anything they can grab using their foldable “lower lip” (labium) – zooplankton, other aquatic insects (including dragonfly naiads), tadpoles, larval salamanders, and fish fry are all fair game. In his wonderful write-up of the common green darner, Kurt Mead (Dragonflies of the North Woods) muses that “If dragonfly larvae were eight to sixteen inches long, as they probably were 300 million years ago, we would dare not swim in fresh water for fear of being attacked” (read the whole account at http://www.mndragonfly.org/html/behavior.html). Despite their spiny exteriors and their ability to shoot forward by expelling a spurt of water forcefully from their abdomen, they are eaten by frogs, fish, and by other aquatic insects. There’s even an “aquatic” parasitic wasp that lays its eggs in those of the green darner. Aprostocetus polynemae, apparently walks down a twig or leaf stem into the water to find dragonfly eggs.
Adults catch insects in the air and may eat them in mid-flight or on a perch. They can also pick prey from a leaf or from the ground, and they’ve been known to stake out bee hives, to the distress of the bee-keeper. At least one ambitious common green darner killed a hummingbird, and this fact is mentioned every darner write-up, though the BugLady suspects it’s pretty uncommon. Adults are preyed on by robber flies, birds, spiders, and by other dragonflies; the people who monitor the fall raptor migration tell us that the southward movement of American Kestrels synchs with that of the darners, and that kestrel migration is fueled by darners.
So, green darners migrate. Like birds, they respond to a suitable weather front – cold fronts for the southern flight and warm fronts for the far less conspicuous northern trip. The journey south may take several weeks of stop-and-start flying (averaging 7 miles a day but capable of far more, depending on the wind), and they may be accompanied by black saddlebags and variegated meadowhawk dragonflies. They migrate dramatically, sometimes in huge swarms that may take hours or days to pass a fixed point. Bluffs on the west edge of Lake Michigan are great places to catch the show at eye level. Dragonfly swarms are a late summer phenomenon, so tuck this address away for reporting swarms and contributing to Dragonfly Woman’s database: https://thedragonflywoman.com/dsp/report/.
The common green is the State Insect of Washington – so much more exciting than Wisconsin’s honeybee (and you thought the state insect was the mosquito!).
The BugLady took a walk on the first day of spring along a nearby dirt road. Automobile drivers are seldom happy with that road, but masses of millipedes, spiders, dragonflies, and butterflies enjoy its damp and dappled surface, and frogs, snakes, and other small animals cross from upland to lowland there. With Sandhill Cranes providing a sound track, the BugLady shared the road with a wolf spider, a six-spotted fishing spider and some small (but colorful) millipedes.
Millipedes, a.k.a rain worms, are fascinating critters – the BugLady wrote about them in the early days of BOTW (April, 2008) – see http://uwm.edu/field-station/millepede/ for Millipedes 101). They seem to be in need of a good PR campaign, so here are the basics. They don’t bite. They’re not slimy. Most of them are not carnivores. Most of them shun living plants and feed on rotting organic material (many practice coprophagy, though). They don’t give us diseases. They don’t want to come inside for the winter. If your home experiences a Biblical scourge of millipedes (which are humidity-seekers) it could be a First Alert that your plumbing needs a look. See – all good! Yet, many millipede hits on-line are exterminators (you don’t need one, because your house is way too dry for millipede comfort and will kill them all by itself. Caulk the cracks to keep them out).
Millipedes are under the umbrella of the great phylum Arthropoda; along with centipedes and a few others, they’re in the subphylum Myriapoda (from “myrias,” the ancient Greek word for 10,000). They’re in the class Diplopoda (for taxonomic comparisons, Insecta and Arachnida are also classes). When you say “diplopod,” you’re also speaking Greek (“diplos” means “double,” and “pous” means “foot”). Millipedes (Latin for “thousand feet”) have two legs on each sideof most segments (centipedes, also pictured here, have one on each side; for centipede info, see http://uwm.edu/field-station/house-centipede/). No actual 1000-leggers have been found, and the present record belongs to an individual with 750 legs. However many legs they have (and they have far more than any of the rest of us), those legs are short, and millipedes don’t disperse far or fast without help.
Millipede
Centipede
According to bugguide.net, there are 12,000 described species of diplopods worldwide, divided into two sub-classes, 16 orders, and 145 families, but there may be 70,000more species out there waiting to be described!! North America has just under 1,000 species in 52 families; bugguide.net illustrates members of 10 orders, including a few non-native species that have made it to our shores. They speculate that there could be hundreds of undescribed species in North America.
They’ve been around for a long time – one of the first groups of animals to adapt to life on land 400 million years ago (in the days when oxygen levels were higher than they are now and therefore arthropods grew bigger – six-foot long millipedes). Millipedes, whose exoskeleton lacks a protective, waxy cuticle, like to stay undercover where the humidity is high – in leaf litter, rotting wood, and soil. Powered by all those legs, most are good diggers, though some very large and very small species don’t tunnel.
Millipedes are, figuratively speaking, exactly what one of their common names claims they are – “thousand-legged worms.” They are cylindrical (except when they’re flat), many-legged, worm-ish critters. Most have chewing mouthparts, simple eyes, and sensory organs on their antennae that help them detect light levels and possibly humidity. An enlarged segment behind the head is called the collum. Air passes through pores near the legs on each side of the body on its way into the tracheal system, and a millipede’s heart is as long as its body. Their legs are seven-jointed, and males have longer legs than females.
An alarmed millipede tends to roll up in a tight disc, curling hard shell around soft legs. Many also make bad-smelling or irritating defensive chemicals (including cyanide) (lemurs tease millipedes into expressing those chemicals and then rub the liquid on their fur to discourage mosquitoes). Some chemical defense is less passive – a few tropical millipedes can spray chemicals about 20 inches. Wash your hands, don’t rub your eyes.
In spring, a young millipede’s fancy turns to love. For most species, courtship is minimal. He may walk along her back to get her in the mood (different strokes), he uses modified legs toward the front of his abdomen to hold her as he inserts a spermatophore (sperm packet) into the operative opening, and they often embrace for a while afterward. She lays her eggs (a few hundred to a few thousand) in an underground nest she shapes from excreted dirt, and in some species, she dies soon afterwards. The young have six legs when they hatch and add more each time they molt http://bugguide.net/node/view/168292. They grow and leave the nest, feeding on plant material and on the microorganisms their guts require to digest plant fibers. They may take a few years to mature and may live a few more years after that.
What ecosystem services do millipedes perform? As detritivores, they assist in the natural recycling process by making big pieces of organic material into smaller ones (for use by even smaller organisms). They are an important determiner of soil composition, and in areas where earthworms are scarce, they may fill the earthworm’s niche, capable of creating, according to a scientist named F. H. Colville, two tons of fertilizer per acre per year.
The BugLady has photographed a variety of millipedes in her neighborhood, but no one has ever accused her of being a Myriapodologist, so the following identities are “approximate.”
She has a color slide, but not a digital image, of Wisconsin’s largest species (up to 4”), the millipede formerly known as Spirobolus marginatus, now reclassified as part of the Narceus americanus–annularis species complex http://bugguide.net/node/view/832866/bgimage. It’s in the order Spirobolida and family Spirobolidae. She finds it around fallen logs on leafy forest floors. Interesting Narceus fact: the female lays a single egg in a cup formed from regurgitated food (bugguide.net). See http://www.hiltonpond.org/ThisWeek030522.html for some nifty pictures.
The dark, curled-up millipede is Cylindroiulus caeruleocinctus (probably), in the order Julida and family Julidae. The experts say that North American members of the family Julidae all originated in Europe.
The cute little guy semi-coiled on the leaf is a tough one. The BugLady thinks it’s in the order Julida and the family Parajulidae, and possibly in the genus Ptyoiulus, but she wouldn’t bet the farm on it. These are native millipedes and bugguide says that Parajulidae is the dominant millipede family in North America, from Canada to Guatemala. You can really see the dome-shaped collum right behind the head. Some millipedes burrow by pushing the tough collum down through the soil.
The very colorful millipede (burnished burgundy with purple bands) that shared the road with the BugLady looks like another Parajulid.
OK – the BugLady staged the shot of the millipede lying semi-curled on the green leaf with its feet up; it was on a stony parking lot and she thought it would be easier to photograph on a leaf. It’s a Flat-backed millipede in the order Polydesmida (the largest order of millipedes, all chemically defended), a Pleuroloma flavipes (“flavipes” means “yellow foot”), in the family Xystodesmidae (unless it’s Apheloria virginiensis). There are about 300 known species in the family, and a third of them live in the Appalachian Mountains (low mobility and geographic isolation make for some interesting species-rich regions). They are famous for “swarms,” which are sometimes migratory.
The small, pinkish millipede with square plates in its back is another Flat-backed millipede, but this one is a foreigner. The Greenhouse/ Hothouse/Short-flange millipede (Oxidus gracilis) hails from Asia but is well-established here. It is in the order Polydesmida and the family Paradoxosomatidae. It’s in reproductive mode all year.
Why did the millipede cross the road? More precisely, why do they congregate on the BugLady’s front porch, and in her basement and garage? They assemble and move around in response to heavy rain and to cooling temperatures (the seal on the BugLady’s garage door is not millipede-proof, and scores came in out of the cold last fall). Reportedly, train tracks can become slippery with flattened millipedes.
Interesting millipede facts:
Some of the larger species are sold as pets;
Millipedes have been used in rituals, in folk medicine to treat fevers, hemorrhoids, wounds, and earache, among others, and to make poison-tipped arrows, but they are not part of many cuisines.
This bug is so exquisite that it’s hard to remember that it’s an aphid. It’s the winged phase; non-winged individuals are, depending on the species, blob-shaped, sesame seed-shaped, or spidery-looking insects seen en masse, sucking juices from the tender parts of plants http://bugguide.net/node/view/638959/bgimage. Species of aphids are often associated with specific host plants.
The BugLady is going to go way out on a limb here, where taxonomists fear to tread, (she’s so far out that she can’t even see the tree trunk) and guess that this might be in the genus Euceraphis, and she’s going to pretend that the species is papyrifericola (to see just how far out, note that the expert at bugguide.net says “Tree aphids are not my strongest area, but I have collected off Betulaceae [birch] enough to know that what I think might be Euceraphis often turns out to be Calaphis when seen mounted on slides. I have little experience with them in the field, and cannot confidently recognize the genera from photos…… So, my recommendation is to not put a genus name on many of them in any confident way.”).
But, for the sake of argument, Euceraphis will open a door onto the tree aphids. The family Aphidae has about 4,700 species (so far), many of which are not major plant pests. Tree aphids are in the subfamily Calaphidinae (a bunch of deciduous tree feeders) and Euceraphis is in the tribe Calaphidini (mainly birch/alder-feeders, and there were birches nearby) (quick aside – Google offered to find for the BugLady some words that rhyme with Calaphidini, and the BugLady couldn’t resist, but they turned out to be words like “eeny,” “teeny,” “weany,” “meany,” and “beany”). There are lots of hits for “tree aphid,” but most sites lump them, discussing generic aphid lifestyles, symptoms of their presence, and bug control, rather than who’s who.
Generic aphid lifestyle: Aphids are poised to take over the world. Their reproductive strategy involves legions of females that move around on plants, popping out female young (already nymphs – they skip the egg stage) parthenogenetically (with no male “input”). These clones mature quickly and soon produce their own young. This is why naturalists joke that a female aphid who starts at the bottom of a stem is a great, great grandmother by the time she reaches the top (one species of rose aphid has been clocked at up to 15 generations per growing season). Aphids are designed to cash in quickly on the nutritious new spring growth.
Aphids are generally wingless until an overcrowded plant/deteriorating plant quality signals them to produce winged forms that can migrate to nearby vegetation. They have no “search image” – finding their host species is a matter of chance – so they often wind up on non-host plants accidentally. They are all female until, at the appointed time of the year for each species (usually fall), females will produce winged male and female nymphs. Romance ensues, and so does genetic diversity. Females subsequently lay eggs that overwinter and produce more females in spring, and the beat goes on.
Symptoms: They suck juices from leaf veins, buds, and new twigs. A healthy tree can shrug off the usual level of feeding, but a large infestation can cause brown/curled/wilted leaves and dieback of new shoots and even kill a plant, especially if aphid numbers are high for several years. Excess sap flows out the other end of the bug; it’s sugary, and other insects congregate to feed on the “honeydew” that falls on leaves. Humans are less enthusiastic about the sticky, hard-to-remove-once-it’s-dried stuff on their cars and patio furniture. And honeydew is a great growth medium for an unsightly “sooty mold” that grows on the leaves. With honeydew as a pay-off, some kinds of ants “farm” the nymphs of many kinds of aphids, but not those of Euceraphis.
This individual looks a bit fuzzy. Many adult Calaphidini are initially a lovely, pale green, but, says the Report by the State Entomologist of Minnesota to the Governor, Volume 17 (1919), “Some of the species [of Calaphidini], at least, are further characterized by wax glands on the body, legs, and antennae, which secrete an abundant, white waxy substance in tufts or bands that give them a very peculiar appearance and may serve as protection against some of their enemies” http://bugguide.net/node/view/638961/bgimage.
Members of the genus Euceraphis have divvied up the birch species and do not poach, even when a tree and its aphid are relocated to a different country. Euceraphis is notable among the tree aphids because all adults, not just a dispersal generation, are winged. According to one source, Euceraphis stops reproducing in mid-summer as leaves mature, and then resumes in fall as sugars in the leaves are being broken down and sent to the roots.
Tree aphids are kept in check by birds, crab spiders, a variety of insect predators like lacewings, syrphid fly larvae, and ladybugs (both adults and larvae). Several small wasps parasitize them, and they are subject to (vocabulary word of the day) entomopathogenic (“bad for insects”) fungi.
And what about Euceraphispapyrifericola? Large for an aphid at just under three-eighths of an inch, it specializes in paper birch (Betula papyrifera), though it’s unusual because it may sip on gray birch and, when in Rome, on a European alder.
A funny thing happened on the way to this BOTW. The BugLady spent the morning on-line, trying to discover the identities of a few moths. Suddenly, a screen popped up (and a voice came from her speakers) saying that this was a Microsoft Alert!!! That her Internet was Blocked (it sure was – frozen solid, had to turn the computer off, and the screen came back when she restarted), that her Credit Card Info was At Risk, and Also her Photos (Yikes!!!), etc., and please call an 877 number immediately. Yeah, right. She always tries to practice safe surfing, but her tech guru, BugFan Becca, told her that internet evildoers sometimes plant their little bombs on obscure sites because the security there may be lax compared to bigger sites. No surprise, if you call them back, they’ll be happy to take your credit card number in exchange for fixing the problem. The BugLady was also assured that no bad stuff will travel with this post.
So – microlepidoptera are, as you’d expect, a big group of small moths. It’s not exactly a scientific classification; there’s no single structure or life style that definitively says micro or macro. To some extent, it’s a grouping that’s determined by the size of the moth; there are some families that include both macro and micro species, and the families of the micros tend to be more primitive than those of the macros. As Wikipedia says, “Plans to stabilize the term have usually proven inadequate.” The group is very diverse and includes a bunch of day-flying species, and the biographies of many have not been written. Remember – of the 18,000 or so species of Lepidopterans in North America, more than 11,000 are moths. Here are three (and a half) of them.
SYNCOPACMA NIGRELLA (no common name) is on the BugLady’s “porch bug” list; it showed up on a fine evening in late August. It belongs to the Twirler moth family Gelechiidae, a large family with about 4,500 species globally (650 in North America). The family contains species that are agricultural pests and species that are biological controls of agricultural pests.
Syncopacma nigrella one of about five species in its genus in North America; this species is mostly found in the eastern US, but it also occurs in California, Wyoming, and Washington. It’s about a half-inch long, and the slim, fringed wings are typical of the family.
Gelechiid larvae often feed under cover, on the insides of their host plants – Syncopacma nigrella prefers lupines (of which the BugLady has none).
We have met Crambid moths/Grass moths/Crambid snout moths (family Crambidae) before, in the form of the orange mint moth, the white-spotted sable moth, and the eastern grass veneer moth. Crambids have wingspreads of ½” to 1 ¼” and have tympanal organs (ears) on their abdomens and hairy mouthparts that extend forward (and that put the “snout” in “snout moth”) (the hairs are sensory and give the moth information about its surroundings). According to bugguide.net, the larvae are stem borers, root feeders, leaf tiers, and leaf miners, and the larvae of one group is only found in the nests of arboreal ants! Adults of some species seek nectar on flowers and probably do a little pollinating.
The BugLady gets a kick out of the subtle patterns and silvery accents that are sported by some grass veneers, and by the way they sit, wings rolled up instead of folded over their backs. The grass veneers are said to be twig mimics.
The VAGABOND CRAMBUS (Agriphila vulgivagellus) is also called the Vagabond sod webworm, which gives us a clue to what the larvae do for a living. The species can be seen in late summer and early fall around grasslands and gardens, from the Atlantic coast to the Great Plains and north into Canada.
Adults are found perched in the grass by day, and are crepuscular (dawn/dusk) and nocturnal flyers. They fly over the grass-tops in September, sometimes in large numbers, drinking dew from the blades, and females lay eggs (60 per day for two weeks) by dropping them into the grass as they fly. The larvae feed on a variety of grasses and grains. They overwinter as immature larvae that awaken in spring and feed on grasses from a webbed tube they construct on the ground. The vagabond sod webworm has a single generation per year and is not considered as serious a pest as other species of sod webworms because the grass blades they eat in fall and in spring are growing fast.
JULIA’S DICYMOLOMIA (Dicymolomiajulianalis) led the BugLady on a merry chase through moth books and websites. She found this lovely creature (and another species to be named later) on composites in early summer. It is also in the Crambid family and is also found over the eastern side of North America. The moth could perch on the BugLady’s thumbnail with plenty of room to spare.
The larval menu is diverse and includes cattails, the primary host, but also Opuntia cacti, a few composites, and the egg clusters of evergreen bagworms. Eggs are inserted into cattail heads in mid-summer, and the larvae feed on fresh and then dried flower parts and on the seeds, digging deeper into the cattail head as they get older (a little lump on an otherwise-smooth cattail shows where they are feeding). The larvae spin silk through their chambers to hold the cattail head together and keep the seeds from scattering. Half-grown larvae overwinter in the cattail head, and they also pupate there in early summer.
And the half-moth?
The BugLady chased these beautiful rust and silver moths around the Riveredge prairie, and when she put her pictures up on the screen, she (eventually) noticed some variation in pattern that hadn’t registered out in the field (and this is why her field identification skills are going south – she can sit and stare, with a book in her hand, at insects on a screen, and they don’t fly away (except, see paragraph one)). She realized that one species (which turned out to be Julia’s Dicymolomia) had silver “suspenders” across the top of its wings, and the other had a horizontal silver band across the wings, about a quarter of the way south of the head. Same patch of prairie, same time of day, same time of year, same composites.
Spring is coming, and home gardeners have had a gleam in their eyes ever since the first seed catalog landed in the mailbox. Sheaves of asparagus shiver on beds of ice in grocery stores, and foragers are anxious for those first stalks of “volunteer” asparagus to peek up along the roadsides. They’re not the only ones who are waiting.
Asparagus beetles, in the leaf beetle family (Chrysomelidae), are asparagus specialists. They’re lovely little beetles, and two species grace our area, the asparagus/common asparagus beetle (Criocerus asparagi) and the spotted/12-spotted asparagus beetle (Crioceris duodecimpunctata) (yes – Latin for “12-dotted”). The common is, well, more common. We tend to talk about them generically, but there are some important distinctions.
Both beetles are aliens – Eurasian natives that arrived here in the second half of the 19th century and now occupy anyplace in North America where asparagus is grown. The common asparagus beetle has even made its way to Hawaii. The two species don’t look much alike – the 12-spotted asparagus beetle can be mistaken for a ladybug at a quick glance (one source points out that they even have spots on their “kneecaps”), and the spotting on the common asparagus beetle is variable.
The “what” and the “when” of their feeding makes the common asparagus beetle the less welcome of the two. Both chew on asparagus spears, which can cause stunting and other cosmetic damage that make the asparagus unmarketable (and consumers don’t enjoy picking up a spear with a bunch of eggs glued to it or a smear of frass (bug poop) on it, either) http://bugguide.net/node/view/16283/bgimage.
Both species overwinter as adults in hollow asparagus stems, or under leaf litter, garden debris, or loose bark – that way, when the sun warms the soil and the asparagus spears poke their heads up in spring, the beetles are already in the neighborhood. The common asparagus beetle is the first to wake up, and it also feeds on the lacy leaves, which can defoliate and weaken the plant, a perennial (no leaves = no photosynthesis = no food storage) and can make it susceptible to fungal infections. Its larvae also eat the spears and leaves.
After some fun in the sun, http://bugguide.net/node/view/17260/bgimage the common asparagus beetle lays its eggs in rows of 3 to 8 on the new spears, leaves or flower buds http://bugguide.net/node/view/1109490. There’s not much of a courtship, but she may parry his moves by turning her abdomen aside or by kicking. To protect their genetic investment, males guard females after mating, remaining piggyback during ovipositing. Female Chrysomelids have the ability to favor the sperm of a suitor by keeping eggs fertilized by a male if they like the cut of his jib and ejecting the sperm of previous males. The young hatch within a week and start feeding http://bugguide.net/node/view/170240. There may be two generations of common asparagus beetles each summer here in God’s Country, and up to five generations a year where the growing season is longer.
The 12-spotted gets out of the gate a little later in spring, and it also eats the spears and leaves, but its larvae concentrate on the fruits and don’t damage the plant (not a problem unless you raise asparagus for seed, and most growers don’t – they’re in it for the vegetable and they cultivate higher-yield, (seedless) male plants). It lays one egg at a time on the leaves; the larvae hatch, head for the fruits, and burrow inside. There are two generations per year, and they generally finish their life cycle by mid-summer. The larvae of both species pupate in cocoons in the soil.
What eats asparagus beetles? Ladybugs, ground beetles, wasps, flies, predaceous stinkbugs, dragon and damselflies, damsel bugs, lacewings, and a variety of birds including farmyard fowl. Its most efficient predator seems to be a small, blue-black wasp, Tetrastichus asparagi, that is a parasitoid of the beetle larvae and that must develop a taste for them, because as an adult, it eats the egg masses. One study in Massachusetts showed the wasp demolishing a hefty 50% of beetle eggs in an area and then parasitizing half of the remaining eggs. It uses its antennae and/or ovipositor to detect hosts that are already parasitized and doesn’t waste its time on them, and it targets only the common asparagus beetle (alas for the 12-spotted; a different species in the wasp’s genus goes after them).
What does an asparagus beetle do when it’s alarmed? Common asparagus beetles have several arrows in their quivers. They may scoot over and hide on the other side of the stalk, may do the classic Chrysomelid drop to the ground, or may resort to secretions from defensive glands. The 12-spotted beetles escape by flight. Both species use stridulation – making noise by rubbing two body parts together (in the case of asparagus beetles, a part of the abdominal exoskeleton rubs against teeth on the hard wing covers), both to scare predators and to communicate with other beetles.
