As their name suggests, clubtails (family Gomphidae) have clubbed tails (but sometimes just barely). The club is formed by three segments at the end of the abdomen that are flared to various degrees – males have larger clubs, club size varies by species, and in some species, clubs are pretty dramatic https://bugguide.net/node/view/184077/bgimage, and https://bugguide.net/node/view/186075/bgimage.
As a group, clubtails are medium-sized (1 ¾” to 2 ½” long) with green, blue or gray eyes that do not touch on the top of the head https://bugguide.net/node/view/403422/bgimage, and with clear, unpatterned wings and a striped body (the Wisconsin Odonata survey tells us that “Clubtail species are very similar to each other in some aspects, careful inspection is needed to identify them.”). They tend to perch on the ground and on rocks and lily pads.
The BugLady has been kind of easing into the Clubtails, starting with the local, fairly club-less Dusky, Ashy, and Lancet Clubtails and moving on to the Lilypad, Midland, and Arrow Clubtails. Seeing the more exotic members of the group will require some road trips.
Depending on how the spring progresses, she’ll have to wait about a month to see a Midland Clubtail (Gomphurus fraternus) (formerly in genus Gomphus); she usually stalks them as they bask on trails near the river in early June. Their range is “V-shaped,” stretching from Maine to Tennessee to Manitoba, centered around the Great Lakes https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.114745/Gomphurus_fraternus.
They’re are powerful flyers and avid hunters that can grab other dragonflies out of the air. In his 1901 report Aquatic Insects in the Adirondacks, J. G. Needham wrote “This vigorous species seems to prefer the larger bodies of water. The imago [adult] is a very strong flyer. It skirts the edges of streams with dashing sweeps which seem to proclaim it master of the situation. I have several times seen it feeding on other dragon flies as large as Mesothemis simplicicollis [now Erythemis simplicicollis, the Eastern Pondhawk].” There’s a picture in Kurt Mead’s Dragonflies of the North Woods of an immature female Midland Clubtail that nabbed an immature male, and Mead says that they’re agile enough to capture butterflies, too.
For their eggs Midland Clubtails prefer moving water – sunny, well-oxygenated rivers and large streams with some vegetation, a moderate-to-fast current, and a fine sand, mud, or clay bottom, but they’re also found at the edges of large lakes with waves. The female has no ovipositor and can’t insert her eggs in vegetation, so she uses waves or water currents to wash them from the tip of her abdomen, sometimes partially submerging in order to accomplish this. Many Gomphids enclose their eggs in a gelatinous wrap that glues them to rocks and logs.
Their chunky naiads https://programs.iowadnr.gov/bionet/Inverts/Taxa/813 are burrowers. Needham wrote of the genus “The nymphs form the most important part of the bottom fauna in all clear waters. They are active burrowers, taking their prey either on or beneath the surface of the bottom silt. They are very rapacious, and will eat almost any living animal small enough to be held by their powerful, grasping labia.”Many species spend two or three years in the aquatic, naiad/nymph stage.
Midland Clubtails are, overall, yellower in the north part of their range, and darker at the southern edge of their range. In 1958, the species was divided into two subspecies, Gomphurus fraternus fraternus and G. f. manitobanus, separated by differences in size and color and, to some extent, geography. Overall, G. f. manitobanus is smaller and paler, with more extensive yellow markings http://www.naturenorth.com/dragonfly/list/Gomphus_fraternus.html, and its range has been thought to be limited to north-central Canada. But, according to Gary Paulson in Dragonflies and Damselflies of the West “Populations on the Red and Assiniboine Rivers in southern Manitoba named as separate subspecies of G. f. manitobanus, smaller and paler than elsewhere, with yellow stripe down tibiae and prominent dorsal yellow spots on S9-10. These attributes may occur elsewhere on the Great Plains. “
The larger and darker Gomphurus fraternus fraternus has a generally more southern and eastern range. The two overlap in eastern Manitoba.
The BugLady found an interesting paper that documented a period of oxygen depletion and pollution in Lake Erie during warm weather in the mid-1950’s. This led to a die-off of burrowing mayflies (whose naiads are also aquatic), and within five years, the once-abundant Midland Clubtails that preyed on them were gone. John Muir nailed it – “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.”
The BugLady visited Riveredge Nature Center recently looking for adventure, and she found it even before she hit the trails. A dozen or so mining bees were flying around over a dirt bank near a bench – they were either nesting there or thinking about it (she came back a week later, and nesting was well-established). Mining bees are solitary, ground-nesting bees in the family Andrenidae, a large family with about 3,000 species, almost half of which are in the genus Andrena (there are 450 Andrenas in North America).
Most of them are small (a half-inch-ish), fuzzy, black and tan/black bees with a striped abdomen (or not). There are some gorgeous exceptions like this spectacularly orange Milwaukee mining bee, (Andrena milwaukeensis), a woodland bee that was discovered in 1903 by a Milwaukee entomologist https://bugguide.net/node/view/1690382/bgimage. Andrena genus members have hair on their faces between the eyes and antennae (like a mini crew-cut), and they have long hairs on the upper sections of their back legs where they stash pollen (pollen-carrying equipment is called scopa/scopae, from the Latin for “broom”). Pollen also sticks to hairs on the rest of their body.
Mining bees are important native pollinators. Like bumble bees, they are “buzz pollinators – the vibration caused by their buzzing loosens pollen from a flower, and the difference in electrostatic charges between the bee and the pollen causes the pollen to stick to them. Many species specialize on particular groups of flowers. They are present throughout the growing season, but they’re famous for being among the earliest pollinators out of the box (they often emerge before the flowers do and bask on sunny surfaces until they warm up enough to fly). Azalea, waterleaf, dogwood, violet, hawthorn, spring beauty, cranesbill, trout-lily, cherry, and golden alexanders mining bees kick off the wildflower season; and evening primrose, aster, sunflower, coneflower, and blazing star mining bees finish it off. There are also vernal pool, miserable, frigid, unpolished, mournful, lonely, neighborly, well-armed, and nude mining bees.
[Nota Bene – BugFan Andrea recently asked the BugLady a question about Cellophane bees, aka Plasterer bees (family Colletidae) https://bugguide.net/node/view/1605422/bgimage, small bees that were not on the BugLady’s radar. They’ve got an interesting story and she needs to figure out the secret handshake for distinguishing the slightly-smaller mining bees from the almost-honeybee-sized cellophane bees so she can tell it. Bugguide.net calls them “Virtually indistinguishable from some of the Andrenidae mining bees.”]
Female mining bees excavate tunnels in soil and sand that they waterproof and make into nursery cells, each provisioned with a ball of pollen and nectar for their offspring. For mining bee basics, see https://uwm.edu/field-station/mining-bee-rerun/. They’re not social, like honey bees, but they tolerate other bees tunneling nearby.
Turns out that there were more than one species of mining bee at Riveredge that day – a spectacular little bee with a red abdomen, and some generic-looking mining bees to be named later (or maybe never, as bugguide.net says, “Identification to species level usually requires an expert.”). They didn’t like each other much, and at first the BugLady thought that the red interloper might be a cuckoo/blood bee.
A few years ago, she photographed a small bee with a red abdomen, a sweat bee (family Halictidae) in the genus Sphecodes, the “blood bees” or cuckoo bees (https://uwm.edu/field-station/sphecodes-sweat-bee/). Blood bees (named for their color) are kleptoparasites that wait until another female sweat bee prepares a chamber for her eggs, and then move in and insert their own egg. Sometimes there’s a dust-up between the blood bee and the tunnel’s rightful owner. This recent Riveredge bee looks similar to a Sphecodes bee https://bugguide.net/node/view/973711, but because the blood bee doesn’t collect food for her larvae, she doesn’t have/need scopae. The Riveredge bee was pretty hairy, stem to stern, and the BugLady thinks it’s a “Red-tailed Andrena” (Andrena erythrogaster).
RTAs are (new vocabulary word) “oligolectic” – they are an oligolege of willows – which means that they specialize in willows, and the pollen balls formed by female RTAs are made of willow pollen. Makes sense, because willows bloom early and prolifically (see this episode from March of 2012, that freakishly early, warm spring https://uwm.edu/field-station/pussy-willow-pollinators/). Males RTAs patrol plants, keep an eye on the nesting sites, and mix it up with other bees; they likely encounter females on willows and mate there. RTAs dig their tunnels in bare-ish sites that have some vegetation/debris on top to hide the nest holes and shelter them from rain, and they can be found in mixed-species groups.
The BugLady, who is accustomed to finding scant information about the insects she researches, was delighted to come across a paper published in the Illinois Natural History Survey Biological Notes in 1988 called “Observations on the Bionomics of the Bee Andrena {TyIandrena) erythrogaster Ashmead (Hymenoptera: Andrenidae)” by Eugene R. Miliczky. For those of us who don’t exactly hit the ground running in the morning, the BugLady offers Miliczky’s description of emerging RTAs:
“’Prior to leaving on foraging trips, bees spent variable lengths of time sitting in their nest entrances. Especially long periods were spent there before the first departure of the day and on days with poor weather. Usually a bee sat just below ground level, facing outward with her antennae directed forward at a slight, diverging angle. Over the next several minutes or up to an hour’ or more, the bee gradually emerged from the nest a step or two at a time. Often she moved her head from side to side prior to a short advance. Not infrequently a bee retreated down her burrow for a few seconds to a minute or more. Very small (2—3 mm) beetles and ants passing the entrance were at times sufficient to induce a hasty retreat. At other times, the bee backed slowly and methodically down the burrow for no apparent reason. Eventually, however, the bee emerged completely.”
Sometimes a female returns from her foraging trips with pollen and sometimes with nectar, and she probably provisions only one egg chamber each day. Eggs hatch in eight to ten days, and when an RTA larva emerges into its sealed chamber atop its bed of pollen, it simply inclines its head downward into the center of the cache and starts to feed.
So in the end, the BugLady found out the part of the “Who?” “What?” and “Why” of her mining bee encounter, but the rest will have to wait for another day.
Here are some pictures of Red-tailed Andrenas and of unidentified mining bees enjoying the earthen bank and the willows and a spring day.
The BugLady was visited by another moth recently, this time a Tufted Bird-lime/Tufted Bird-dropping Moth/Cherry Agate (Cerma cerintha) that appeared in her bathroom and, later, in her kitchen. It’s a lovely little moth with a one inch-ish wingspan, in the Owlet moth family Noctuidae.
Noctuids are called Owlet moths because of the way the light reflects off the eyes of the (often drab) adults. Many of the moths are nectar feeders and are pollinators; many of the caterpillars are omnivores, relishing both foliage and their fellow invertebrates, and sometimes are cannibalistic. These are the fruit worms, cutworms, and armyworms that feed on the leaves of agricultural crops. Caterpillars of many Noctuid species have chemical defenses, gleaned from the foods they eat, and others use camouflage, mimicry or spines to protect themselves. Adults have tympanal organs (“ears”) that allow them to detect bat radar.
Depending on whose field guide you have, TBLMs are in the subfamily Acronictinae, or in the subfamily Eustrotiinae. About the confusion, Sogaard, in Moths and Caterpillars of the North Woods says “The taxonomy of the superfamily Noctuoidea (which includes…… Noctuidae) is in disarray. It will likely take a decade or more of work before the smoke clears from a truer, more stable taxonomy.” About the Eustrotiinae, David Wagner, in Caterpillars of Eastern North America, says “members of this subfamily were formerly classified with the bird-dropping moths (subfamily Acronictinae). Eustrotiines are a heterogeneous (unnatural) assemblage without any shared diagnostic adult or larval characters.” You get the picture. There are three members of the genus Cerma; here’s an even fancier one https://bugguide.net/node/view/926560/bgimage.
TBLMs are found in the US east of the Great Plains and across southern Canada east of Manitoba. Wagner says that they favor “barrens, fields, sandy openings, and woodland edges.” They are fairly common, but their lifestyle hasn’t been studied much.
TBLM caterpillars eat the leaves of fruit trees in the rose family, especially cherries and hawthorns. West Virginia blogger/photographer “Squirrel” (squirrelsview.blogspot) observes that the moths are found around fruit trees, and so are fruit-eating birds, so the bird poop strategy is a good one. Their camouflage is so good that, Sogaard says “I once brought a specimen home from the lighted side of a building only to find myself fooled by a bird dropping!”
There are two generations of TBLMs in the south, but probably only one here in Wisconsin. The BugLady couldn’t find much about their reproduction, only that a mature caterpillar creates a pupal chamber by chewing a tunnel into wood, turning around, and sealing the entrance with wood chips and silk, making it, says Wagner, “virtually undetectable.”
Two cool things about Tufted Bird-lime Moths:
First, Wagner, et al tell us in Owlet Caterpillars of Eastern North America, that “upon disturbance, caterpillars of the Cherry Agate…..may shake rapidly from side to side. Cerma caterpillars will wriggle violently if handled and are quick to hurl themselves from their purchase.”
Second, female Noctuids summon males with chemical scents called pheromones, and males preform courtship “dances.” Males of many nocturnal species of moth, including the Noctuidae, produce scents that are disseminated by various configurations of “scent brushes” that are associated with eversible glands. When a female emits pheromones to call to males, the males respond by approaching the female from upwind and sending out their own perfume. This, in some species at least, prompts the female to stop calling. His scent may serve to confirm a species match as well as to turn her head. In the lovely science language of a century-plus ago, “Scent fans are the perquisite of the males of many of the Noctuina whose eyes shine at night like those of the barn owl as they winnow the dewy flowers” (A.H. Swinton, 1908).
And, for the BugFan who has everything, a TBLM mousepad is waiting for you on the internet.
First, a short detour into the world of the non-flowering:
The BugLady’s message to people who are pining for the wildflower season to begin is this: Get thee to a wetland and watch the non-flowering plants. Mosses, especially, are going crazy these days, their green leaflets (the gametophyte part of the plant) bristling with the stalks of sporophytes, topped by variously-shaped spore capsules. They’re happier now than when the canopy above leafs out and casts them into shade. Ground-hugging liverworts are covered by reproductive pits and umbrellas, and any day now, cinnamon ferns will push up through the dead leaves and dried fronds that top the wetland hummocks. It’s beyond life-affirming.
On a recent wetland walk, the BugLady noticed some moss that was growing on a very rotten stump. Stiff leaves at the tips of many of the moss plants had formed a cup-shaped rosette. Turns out that these are called gemmae cups (cups for gemmae), and they’re part of the moss’s reproductive strategy. According to Dr. Jessica Budke, Herbarium Director at the University of Tennessee-Knoxville, “The moss makes little discs of plant tissue inside the cups called gemmae. These gemmae are moved away from the parental plant via a splash-cup dispersal mechanism. It sounds high tech, but really is just using the power of rain. When rain droplets land in the cup the gemmae are dislodged and can be carried in the water as it splatters away from the moss plant. The gemmae may not be dispersed very far, but it is far enough that this structure is advantageous for the plant to have. This is a form of asexual or clonal reproduction. The plant has made a mini copy of itself that can grow into a new moss plant.”
So, gemmae, the little “eggs” in the Easter basket, are like tiny buds that are ready to grow if they land on a favorable substrate when they’re washed from the gemmae/splash cup. Apparently, Four-tooth moss (which this moss probably is) likes to grow in the company of more Four-tooth moss. One researcher found that sparse populations were more likely to use gemmae, which land and grow close to the parent moss, while dense thickets of the moss are more likely to reproduce via spores, which travel through the air away from the clump. This may be a strategy to stabilize their punky substrate. The BugLady also found gemmae cups on some lichens.
Without further ado, the spider.
It is, almost certainly Theridion frondeum, the Eastern long-legged cobweb spider (BugFan Mike’s “best guess” is way better than the BugLady’s). It’s a small, dainty spider in the Cobweb spider family Theridiidae. Theridiidae is a large family (maybe 2,500 species globally and 234 in North America) whose numbers include the Common house spider, of former BOTW fame (https://uwm.edu/field-station/common-house-spider/) and the notorious Black widow spider.
The BugLady didn’t find a huge amount of info about this particular species, but there’s lots about the family.
Theridiidae are also called Cobweb spiders (because of their web style), and Tangle web spiders and Comb-footed spiders. Comb-footed because most species have a bristly comb near the tip of the rear set of legs that is used to draw silk from the spinnerets and, said one source, to roughen the surface of the silk a bit. Tangle-web because of the creative ways some species deploy sticky silk (remember, not all spider web silk is) (sticky). They’re found in woods, fields, edges and buildings across North America, more in the eastern half than in the west.
As usual with spiders, courtship is cautious. The BugLady found some tantalizing tidbits about male Theridids using nuptial feeding to show females what a great catch they are. Some family members secrete chemicals from various knobs on their head, and the female imbibes the liquid during courtship (although it’s not actually known what benefit she receives from it). Others are kleptoparasites – stealing prey from the webs of other spiders and presenting it to their prospective mates.
It’s a big family, and there’s lots of variety in the webs. These are not the tidy, two-dimensional, spiral webs of the orb weavers – these are (mostly) tangled, messy, “cob-webby,” tent-like structures. Lines made of sticky “gumfoot silk” may stretch from leaf to leaf or reach all the way from the web to the ground; when tripped by unlucky (pedestrian) prey, the line releases from the ground, hoisting the prey into the air (picture Wile E. Coyote stepping into a rope trap attached to a sapling). The vibrating line alerts the resident spider that dinner is on the way.
When they catch an invertebrate (and they’re considered good biological controls of agricultural pests), they use the combs on their back legs to pull out a bunch of sticky web to wrap it in; and after their prey is immobilized, they bite and paralyze it (lots of spiders that build trap webs do it the other way around – bite, then wrap). Most spiders don’t use sticky web for this purpose, but the stickiness allows Theridids to take on prey that’s much bigger than they are. When they’re not subduing prey, the spiders hang head-down in their webs or rest in a woven hiding place.
Unique things that some Theridids do:
In some species, Mom allows her offspring to live in her web briefly, and in some species, she even feeds them predigested food until their first molt, the only spider family that has this level of maternal care.
In some species, males stridulate (make sound via friction), rubbing teeth under the front edge of the abdomen against ridges on the rear of the carapace (the top of the cephalothorax).
Spiders in some genera, including Theridon, are mildly social and will build communal webs.
Some camouflage the webs by sticking bits of plant material to it.
The BugLady saw a long, fresh strand of spider silk, recently, trailing in the air from its attachment on a twig the other day. Perhaps a newly-hatched spiderling drifted in from parts unknown.
The BugLady was working on this week’s episode, about a lovely little spider, but then she took a walk at the north end of the Bog and encountered a mob of springtails. She searched for a collective noun for springtails and found a few on-line discussions about it – “mass aggregation” is the science-y choice, but other suggestions were cluster, swarm, sprinkle (for a small swarm), furcula (in honor of the springtail’s jumping appendage – teachable moment), and sproing.
She was walking along a short, wetland boardwalk and noticed that the surface of a small pool of water looked gritty. Pollen from above? The maples aren’t in bloom yet, the ash trees are dead, and spring ephemerals are weeks away. Not pollen. But, on sticks and wet leaves at the edges of the pool and on the end of the boards there were masses of springtails, and she realized that the specks on the open water were springtails, too (the other folks on the trail gave her an extra-wide “social distance” berth when she said “Excellent” in a loud voice and started snapping pictures, apparently of the ground).
Springtails have appeared in these pages before, most recently in the form of “Semi-aquatic Springtails” https://uwm.edu/field-station/semi-aquatic-springtails/ in 2014 and “Super Springtails” https://uwm.edu/field-station/super-springtails/ in 2016. You can find out about their basic biology (and vocabulary) in either. The short version: Although they have six legs, springtails are not insects (anymore) but are now in their own Class, Collembola (making them peers of Insecta, which is also a Class). They are wingless, but most have a furcula that allows them to leap into the air (every once in a while, as the BugLady watched, an individual would levitate above the crowd); they are decomposers, feeding mostly on rotting vegetable matter; they have taste organs at the tips of their antennae; and they usually live in moist habitats in or under leaf litter, bark, and fungi, but some species are found on/around water. They’ve been here for 400 million years, give or take.
The first question is always “what is it?” because that answer opens the doors to finding out what it does for a living and where it fits in. There is an aquatic springtail called Podura aquaticahttps://bugguide.net/node/view/180064/bgimage that has reddish antennae and legs and a pincer-like furcula. The BugLady really squinted at her pictures and a few of the legs looked marginally purple, but mostly, not. All the furculae she could see were straight.
The commonly-seen springtails here in God’s Country are snow fleas, in the genus Hypogastrura, which gather in Biblical numbers on snow and in tracks in the snow – boot, ski, snowmobile, and mammal https://bugguide.net/node/view/512490 and can be a nuisance in sap buckets, but which aren’t necessarily associated with water. Their pedigree reads: Class Collembola (Springtails and allies), Order Poduromorpha, and Family Hypogastruridae, and there are about 80 members in the genus. Most of the diagnostic features are seen more clearly with a microscope than with a camera.
But, the BugLady did a little midnight digging, and found the genus Hypogastrura in The Aquatic Invertebrates of Texas (“typically found on water’s surface, not truly aquatic”), and in Aquatic Insects of Michigan, which listed one genus member as “semi-aquatic” (found on the water’s surface) and two others as “periaquatic” (associated with the edges of aquatic environments). And one of the latter was Hypogastrura nivicola, the snow flea.
A few more words: “epineuston” and “superaquatic” are terms for organisms that float on top of the water. “Nivicola”means “snow dwelling;” its etymology detouring from Sanskrit, proto-Indo-European and proto-Italian through Greek and Latin before making its way into Old English and Old Irish. And, on the topic of Hypogastrura matura, mentioned in the Michigan book but almost nowhere else (it must have been renamed), a Scandinavian resource referred to them as “urine insects.” The BugLady Googled that one, of course, and found more urology hits than she cared to see.
Snow fleas are seriously tiny, 1 to 2 mm (about 1/16 of an inch). For a picture of snow fleas next to a penny, see https://communityenvironment.unl.edu/snow-fleas. They engage in mass migrations after snowmelt in spring and again in fall, capable (according to Walter H. Lyford in a paper published by the University of Notre Dame) of traveling 30 inches an hour across the damp leaves on the forest floor, and more than 18 feet per day, covering as much as 75 feet before disappearing under the leaves again. Lyford tells us that a colony of snow fleas one foot across can contain one-half to one million individuals, that they grow throughout the fall, and that “mature insects are so heavy that the sound of their bodies landing on dry leaves can be heard distinctly.” Springtail expert Kenneth Christiansen theorizes that these migrations allow them “to find new places to reproduce and to mix the gene pool.”
Their forays on the snow’s surface are searches for bits of fungi, algae and bacteria to eat. Most cold-blooded critters get sluggish in winter, but snow fleas have developed a unique antifreeze, a glycine-rich protein that allows them to stay active at temperatures below freezing. Practical applications for this chemical (beyond the very practical snow flea) include extending the life of transplant organs and producing better ice cream.
Food for thought: according to Oregon State University researcher Dr. Alan Moldenke, “Every time you take a step in a mature Oregon forest, your foot is being supported on the backs of 16,000 invertebrates held up by an average of 120,000 legs.”
The BugLady has been elbow deep in her tax packet, and she’s bummed by the global pandemic (as one author put it, we’ll probably learn a lesson from this affair, but probably not the lesson that needs learning), so she offers this rerun from 2014, which includes an suggestion of what the earth might look like if we vanish from the face of it (the Beat, BugFan Tom, will go on).
Many autumns ago, the BugLady was out in the field catching grasshoppers with BugFan Mary and some school kids, and Mary said, “These grasshoppers are dead; they just don’t know it yet.” And while it is true that the lives of most adult insects end by the first hard frosts, the Grim Reaper may be assisted in those waning days by nematodes.
Fast Forward to a more recent spring, when the BugLady was photographing critters at the Ephemeral Pond and this wee beastie swam past her lens. Nematodes (and the BugLady has her fingers crossed that this is, indeed, a nematode) are not on many people’s radar. In fact, “Nematodes are probably the commonest multicellular organism that you’ve never heard of and have hardly ever seen (Platt, 1994).
So – “WHAT ARE NEMATODES?” They’re not insects or spiders or millipedes or anything with legs. Not earthworms or leeches or anything with segments. They belong to the Phylum Nematoda/Nemata (from the Ancient Greek “nema,” for “thread” and “eides” for “species). They are the Roundworms. Their classification has ever been a work in progress; they have been a Family and then an Order and are now their own Phylum (from which the superficially similar Horsehair worms, of previous BOTW fame, have been evicted). There are many known species of nematodes and many more to discover, and we don’t know the biographies of most of them – even, in some cases, enough to know if they are properly placed in the Phylum. And, of course, they have their own website.
Nematodes are a gigantic topic – people get PhD’s in Nematodes – so this is necessarily the introductory course. Put up your feet – it’s a story that takes some telling.
JUST HOW MANY NEMATODES ARE OUT THERE? Huge numbers of species and well-nigh uncountable numbers of individuals, that’s how many. By some reckonings, four out of every five multicellular animals on the planet are nematodes (that’s individuals, not species). The more-than-30,000 known species may jump to a million by the time the taxonomic dust settles.
Nematodes seem to inspire in people a need for over-the-top imagery. In 1914 Nathan Cobb calculated that “if the nematodes resident in a single acre of soil near San Antonio, Texas, USA, were to proceed in head-to-tail procession to Washington D.C., some 2000 miles away, the first nematode would reach Washington before the rear of the procession left San Antonio!”
According to a website that’s no longer up, “A square meter of mud from an inshore area near the coast of Holland was measured to contain over 4 million nematodes. Good farm soil as well as containing a large number of earthworms can also contain from several hundred million to several billion nematodes per acre. A single decomposing apple on an orchard floor has had 90,000 nematodes counted in it of several species and a single decomposing fig around 50,000 of at least eight species.”
WHERE DO THEY LIVE? Everywhere. It’s no hyperbole to say that nematodes are ubiquitous. They occupy almost every habitat, from the ridiculous (vinegar, under the beer coasters in a German study, in the placentas of sperm whales, and in the right kidneys of minks) to the extreme (from the Poles to deep oceanic trenches to mountain tops to the depths of South African gold mines to hot sulfur springs). They are found in plants, in animals, in water, and in soil. They greatly outnumber the other animals found in their habitats – Wikipedia says that they make up 90% of all life forms on the ocean floor.
A century ago Nathan Cobb wrote: In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites (Yearbook United States Department of Agriculture, 1914).
WHAT DO THEY LOOK LIKE? In appearance (and in lifestyle), there are many (many) variations on the basic theme, but the Ancient Greek imagery still applies – “thread species.” They are second only to (ahem) insects in diversity. They have been described as a “tube within a tube,” a gut surrounded by a cuticle with a cavity called a hemocoel between the two. Most are very small (well, except for the one in the sperm whale, which can exceed eight meters in length), translucent/transparent (any pigment you see comes from their food), and round in cross section (roundworms). Muscles run lengthwise and so do nerves, except for a ring of nerves and ganglia around the pharynx that constitutes the animal’s “brain.” Sensory hairs (setae) permit a sense of touch, and two pits on the head allow for chemoreception. There’s no vascular or respiratory system; nutrients and oxygen get into the cells, and wastes exit the cells, via diffusion. Nematodes move by contracting their longitudinal muscles and whipping back and forth, an action that also moves food through the gut and facilitates excretion.
WHAT DO THEY DO FOR A LIVING? Anything that exists in such astonishing numbers has got to play an important part in its ecosystems. Nematodes occupy every strand of the food web – carnivores, herbivores, omnivores, scavengers and decomposers; they are eaten by many other animals, including their brethren – even by a group of carnivorous (“nematophageous”) fungi (including Oyster mushrooms – Pleurotus). It turns out that the nematodes communicate with each other using chemicals and that the fungal/mycelial strands can detect these signals. They form special noose-like structures and lasso soil nematodes as they wriggle through (see a video at https://microbialmenagerie.com/fungi-carnivore-chemical-eavesdropping/). It’s a complex entrapment that, none-the-less, as many as 80% of its victims escape; it’s theorized that the nematodes that are snagged may have existing sensory problems that don’t alert them in time.
Nematodes are informally grouped as “free living” (40% of species) and parasitic (44% of the remaining species feed on animals and 15% on plants) (though the BugLady found one source that switched the last two numbers and another whose numbers landed in between). The BugLady couldn’t find a satisfactory definition of the criteria for this division, since herbivorous and carnivorous behavior is attributed to both groups. Living outside rather than inside its food source? In scanning the literature, it almost seemed like the pejorative “parasitic” may simply refer to behavior analogous to the lifestyle of a flea, but it often seems to be applied to species that damage our plants and animals and ourselves. In both groups, feeding habits and targets can be highly specialized. Some parasitic species concentrate on vertebrates, including humans and their pets (roundworms, hookworms, whipworms, pinworms, and a variety of other conditions including elephantiasis are chalked up to nematodes), and others are serious pests of lawns, crops and gardens. Free living species, both aquatic and terrestrial, eat algae, fungi, bacteria, plants, tiny animals, and dead organic matter, and some are great recyclers.
Many nematodes, both herbivores and carnivores, feed by inserting a rigid “stylet” into their food source – in some the stylet is hollow and acts as a drinking straw. Others feed by “gulping” a food particle whole through a mouth opening. They may have rasping/crushing “teeth” within the pharynx – or not. You can tell what a nematode eats by looking in its mouth.
Grasshopper-eating nematodes? Yes, there are “insect parasitic nematodes” (IPNs) that feed within insects. Once inside, they release bacteria that kill their host, and then they feed on the bacteria and on their hosts’ decomposing tissue. IPNs are potential biological control agents for turf pests, mainly caterpillars and beetle grubs. For more information see http://entnemdept.ufl.edu/creatures/beneficial/misc/mermis_nigrescens.htm#top (not for the faint of heart).
HOW DO BIG NEMATODES MAKE LITTLE NEMATODES? Usually, males insert a chitonous spicule into the operative female opening (in some species, they simply puncture the female’s cuticle anywhere – “traumatic fertilization”) and “amoeboid sperm” crawl in. Most species lay eggs that produce larvae that look pretty much like Mom and Dad.
AND AQUATIC NEMATODES? Many freshwater nematodes are in the 1 mm size class. About half of the known nematodes are marine (salt water); the rest are found in soil or fresh water. Fresh-water nematodes live in still water and fast, rocky or mucky, and on damp shorelines. Most fresh-water nematodes can produce a mucous strand that fixes them temporarily to their substrate. It’s not uncommon for them to carry and transmit disease-causing protozoans.
ANYTHING ELSE WE SHOULD KNOW ABOUT NEMATODES?
Well, they’ve been around for a long time. It’s hard for something as small and soft as a nematode to fossilize, but fossil nematodes have been found that date back 300 million-plus years, and they may have been around for 500 million years. They’ve been found in amber. A dissenting (outlier) note from the U of Illinois Department of Crop Sciences – “Members of the phylum Nematoda (round worms) have been in existence for an estimated one billion years, making them one of the most ancient and diverse types of animals on earth” (Wang et al. 1999).
Nematode-borne diseases were noted in Chinese writings from 2700 BC.
Agriculture has a love-hate relationship with nematodes. “Good” nematodes prey on plant pests; “bad” nematodes are plant pests and spread diseases, besides.
Many species can get through a drought by completely turning off their metabolism (cryptobiosis), sometimes for as long as a quarter of a century (!), resurrecting themselves when favorable conditions return (they travel during this phase, too, blowing across the landscape with the dust. Otherwise, a really peppy soil nematode might only move the distance of a meter during its lifetime).
Nematodes are considered indicator species for various kinds of pollutants, toxins, and general environmental quality.
The gazillions of soil nematodes “mix” soils like earthworms do.
According to EOL (Encyclopedia of Earth) “Eutely [great Scrabble word] is a phenomenon found in a few organisms, including nematodes, wherein each member of a species has exactly the same number of cells.” In one species, males have 1031 cells and females have 959.
Bugs without Bios celebrates the small-but-mighty insects that, mostly unsung, sneak below our radar daily. Today’s catch have three things in common – their identifications are all “probable;” they’re all carnivores; and on each of the three, the BugLady’s Google search ran out in fewer than ten pages.
CALLEIDA PUNCTATA
This metallic beetle is Calleida punctata (probably – there’s a very similar species that’s more southerly in range and we are north of the overlap zone). No common name. It’s a tiny beetle in a large family, Carabidae – the Ground beetles – that includes some rather substantial species, like the 1 ¼” Fiery Searcher https://bugguide.net/node/view/1546816/bgimage, and https://bugguide.net/node/view/648179/bgimage. There are about 34,000 species of Ground beetles worldwide; about 2,500 in North America. While there are a few herbivores and omnivores in the crowd, and some larvae that are herbivores or parasitoids, most species are predators. Here’s a better shot of one: https://bugguide.net/node/view/1073580/bgimage.
Calleida punctata (Calleida means “beautiful form”) is about 1/3 inch long (for scale, here’s one on a single milkweed flower https://bugguide.net/node/view/1468655/bgimage). It’s found in the northeastern quadrant of North America from Quebec to South Carolina to Kansas to Manitoba (though they were listed in Panama and in a paper about insects found on a college campus in Pakistan, too. Our North American fauna includes 64 non-native carabids, and that door opens both ways).
As their name suggests, ground beetles are often found on the ground, where they’re harder to spot https://bugguide.net/node/view/269341/bgimage, but members of this genus also tend to be more arboreal and are seen on leaves and flowers (OK, they’re sometimes “planticolous,” from the Latin “colous” meaning to inhabit, live in/on, dwell, etc.). The Illinois Wildflowers website associates them with goldenrods. Their prey is small insects, including beetles https://bugguide.net/node/view/1411607/bgimage, and in a paper about the first Minnesota record of the beetle in 2000, author Paul Tinerella noted that the adults are said to eat caterpillars.
BRANDED PINION
First off, the name. Please do not ask the BugLady where these moths in the Owlet family (Noctuidae) and the Cutworm/Dart subfamily (Noctuinae) and the genus Lithophane got the name Pinion moths. Pinion pine? Pinion feathers? Rack and pinion? Don’t know. But – the BugLady has long said that the people who name moths (and tiger beetles) seem to love their work. For proof, check the names of tiger beetles and of underwing moths. Along with common names that describe their colors and patterns and discoverers, there are Nameless, Immigrant, Wanton, Shivering (they shiver before flight on cool days to warm the muscles in their thorax), Singed, Luke-warm, Dowdy, and Anti-pinions.
Adult pinions tend to be drab, with a noticeably “square-shouldered” look, and because of their phenology, many of them are loosely called “winter moths.” Overall, they are northern moths, associated with woodlands and edges. Pinions are active late in fall, but they overwinter as adults and then fly, mate, and lay eggs early in the next spring. Pinion larvae eat the leaves of woody plants; some are generalists and some are host-specific – and some supplement their diet of plants with a caterpillar or two, even those of their own species (and isn’t this a dynamite picture https://www.pbase.com/spjaffe/image/112948427!).
The caterpillar on the tree trunk is (probably) a Branded/Dimorphic Pinion (Lithophanepatefacta) (“Litho” means “stone” and “phane” means “looks like”). It’s found in eastern Canada, south to the Carolinas and west to Wisconsin, and there are some records for British Columbia, Louisiana, and maybe northern Florida. Wagner, in Caterpillars of Eastern North America calls the Branded pinion “perhaps the most widespread and abundant pinion in the Southeast.” Adults come in light or dark forms http://mothphotographersgroup.msstate.edu/species.php?hodges=9886 – northern moths are commonly lighter than the darker, southern forms. Caterpillars come in different colors, too – https://bugguide.net/node/view/1728843/bgimage, and https://bugguide.net/node/view/20327/bgimage, and https://bugguide.net/node/view/1728844/bgimage, and Wagner speculates that the darker, southern morphs of caterpillars may be more cannibalistic than the paler forms. Caterpillars especially like sugar maple, but they also feed on cherry, oak, and hickory. And other caterpillars.
WHIRLIGIG MITE
As seasoned BugFans know, the BugLady is attracted to easily-overlooked critters. When she saw these 1/16th-to-1/8th of an inch mites on her porch rail (near her geraniums) last summer, she wondered if they might be the notorious, plant-eating spider mites, but she thinks they were “whirligig mites” in the genus Anystis. It’s in the huge mite order Trombidiformes (26,000 species worldwide) and in the family Anystidae, the whirligig mites. For better pictures: https://www.marylandbiodiversity.com/viewSpecies.php?species=18548.
As commenter “theridula” says, in helping to ID a mite on the Project Noah website, “Mite identification is not easy and frustration is inevitable.” Amen. Whirligig? These are pretty peppy mites. Theridula continues “you said the mite was “quite fast”, automatically dismissing nearly all spider mites (Tetranychidae) which you should think of as slow cows browsing on plant material. ‘Quite fast’ should make you start thinking predator. After all, you need to be fast to chase down prey.
“Then you come to the nearly triangular body, truncated at the posterior, combined with strong latigrade legs that seem to radiate from a central point. Throw in the fast erratic running behavior and that it was found off of the ground and you have excellent diagnostic characters for the genus Anystis (whirligig mites).” The arrangement of their legs also allows them to pivot “on a dime,” which adds to their whirligig-ness (the BugLady wonders how many could sit on a dime).
OLYMPUS DIGITAL CAMERA
Anystis is a tiny carnivore that preys on small invertebrates, including harmful species of mites (scroll down to the fourth page for a shot of Anystis baccarum and prey https://eservices.ruralni.gov.uk/pdfs/crops/Anystis%20baccarum.pdf), and most of the Anystis hits on the internet have to do with its diet. Various species, especially A. agilis, which eats an average of 39 aphids daily in vineyards and also likes grape leafhoppers, and the cosmopolitan A. baccarum, which preys on pests of orchards and tea plants, are effective biological controls of problem species. It would behoove fruit growers to recognize these helpful little critters so that they don’t throw out the baby with the bathwater. Not a “chewer,” a mite punctures its prey and sucks out the juices.
Anystis baccarum (and, the BugLady assumes, other genus members, but she could not confirm it) reproduces by parthenogenesis. Females produce only females; there are no males in the population. Eggs are laid under tree bark or in the surrounding soil, and newly-hatched mites travel up the trunk looking for food. They take a month to mature and don’t live long as adults.
If you check redbubble, you might (mite) find an Anaystis baccarum greeting card.
When BugFan Kine sent this “what is it” picture, the BugLady’s first reaction was to raise her hand and say “Teacher, teacher! Ask me! Ask me!” She didn’t recall its name, but she knew she had seen a picture of it in Kaufman’s Field Guide to Insects of North America (it’s also in the Audubon Society Field Guide to North American Insects and Spiders). It has the look of a darkling beetle (family Tenebrionidae), but it’s in the (fairly closely-related) family Zopheridae (no common name) and the subfamily Zopherinae – the ironclad beetles. Thanks, Kine!
Not a Wisconsin beetle.
Fascinating Ironclad Beetle Fact#1: They’re called Ironclad beetles because they have a phenomenally strong exoskeleton. So strong that you can’t kill them by stepping on them (in the words of Alejandro Santillana of the University of Texas, “Step on one and it will probably just give a coleopteran shrug and walk away.”). So strong that if you are able to kill one, you can’t mount it on an insect pin without first drilling a hole in it.
There are 19 species in the genus Zopherus, and they’re found from Venezuela to Texas, west to California, including Nevada, Utah, and Colorado. Ten species of Zopherus live in North America. Zopherus means “dusky” or “gloomy” in Greek (today’s beetle is the flashiest) – here are a few other species: https://bugguide.net/node/view/919514/bgpage,
One source says that Texas ironclad beetles look as though a random bunch of black paint droplets fell on them (another source suggests that they’re bird-poop mimics). Nodulosus refers to the lumps/nodes on the beetle’s back, especially on the elytra (wing covers), and this species also has four noticeable tubercles on the rear edge of the elytra.
The job of the elytra, which are the hardened, front pair of flying wings, is to protect the membranous flying wings that are folded beneath them, a beetle invention that allows them to crawl under logs and rocks without shredding those delicate wings. But Mother Nature has played a little trick here – beetles in this genus, indeed, in this family, often lack flying wings, and their elytra are fused together. No flying wings = no flying.
They live in east and central Texas, south into northeastern Mexico. Adults are sometimes seen on the trunks of pecan, oak, and elm trees where, despite/because of their coloration, they blend in pretty well. The larvae are found in dead trees and may eat fungi within the rotting wood, but in his blog arrantsoutdoors, Josh Arrants says that “We are sure it eats lichens, dead wood and plant material, even taking fungi…. We also believe that all stages of (Zopherus nodulosus haldemani) eat lichens on dead, or mostly dead, trees.”
There is very little biographical information about this striking, relatively-common-within-its-range, inch-long beetle! Presumably, eggs are laid in bark crevices, which, says Arrants, provides “a highly probable area for the larvae to be able to find and consume lichens.” Here’s a mating pair https://bugguide.net/node/view/1506208/bgimage.
Fascinating Ironclad Beetle Fact#2: In her article about them in the Texas Co-op Power newsletter, Sheryl Smith-Rodgers calls them “Lazarus bugs.” On several occasions, she fished “dead” beetles from the bottom of water buckets, only to have them revive and walk away. They are even hard to kill with the standard-issue insect killing jars.
Fascinating Ironclad Beetle Fact#3: When alarmed, Ironclad beetles play dead (tonic immobility or death feigning or thanatosis are fancier names), and they can play for longer than most people have the patience to wait for their revival. They curl up their legs and tuck in their antennae to protect them https://bugguide.net/node/view/686069/bgimage.
MIND-BLOWING Ironclad Beetle Fact: Science, of course, is interested in this impenetrable insect. The composition of the layers of its exoskeleton have been parsed, and the potential applications are pretty amazing. It is being “copied” in a design for the suspension system of combat vehicles, with the hope that it can bounce back after an IED or other explosion. Even better, First Place in the 2018 NASA competition to design habitats for Mars (the 3D Printed Habitat Challenge) went to Team Zopherus (https://armoneyandpolitics.com/arkansas-architect-nasa-competition-mars/)!
Phoresy, hypermetamorphosis, parasites, Batesian mimicry, aggregation pheromones (it’s Science Vocabulary Day), and an insect that Entomologist Eric Eaton says resembles “a science experiment gone horribly wrong.” This one has it all.
A number of years ago, BugFan Tod sent the BugLady a “what-is-it” picture of a mantisfly on a door-jamb, and she confesses to feeling a twinge of envy. This fall, BugFan Tom shared this shot, taken by his wife Andrea, and the BugLady got a little greener. She seriously wants to see one of these curious insects.
Mantisflies/mantidflies, family Mantispidae, are in the order Neuroptera (“nerve wings”), a very cool order that includes antlions and lacewings, plus owlflies https://bugguide.net/node/view/6309/bgpage and a few other dynamite groups. Neuroptera has been pared down – the order used to include the dobsonfly bunch and the snakefly bunch, and back in Linnaeus’ time, dragonflies and damselflies, too. Neuropterans’ four, conspicuously-veined, oval-ish wings are about equal in size, and they have conspicuous eyes, long antennae, and biting/chewing mouthparts. They’re clumsy flyers. They are one of a few primitive groups that develops by complete metamorphosis (egg-larva-pupa-adult). While adults may eat nectar and/or their fellow invertebrates, their larvae are mostly carnivores. More about that in a bit.
There are about 400 species in the mantidfly family – 13 in North America – and they’re most diverse just about anywhere south of Wisconsin. They’re not related to praying mantises and they’re not related to flies, either.
Wasp/Brown Mantidflies (Climaciellabrunnea), in the subfamily Mantispinae, are found in open areas and edges from Costa Rica to southern Canada. They’re about an inch long, and Eaton describes them thus: “In the case of C. brunnea, the body form has been further modified to look like a paper wasp. The resemblance is uncanny. The base of the abdomen is constricted into a ‘wasp waist,’ and the wings are rotated such that they fold over the back instead of pitched ‘roof-like’ as in other mantispids. Even more amazing, the leading edge of each wing is darkened, to resemble the longitudinal fold in the wings of vespid wasps. When startled, the Wasp Mantid even splays its wings like an agitated paper wasp.”
Because they’re such good mimics, Wasp Mantisflies are probably overlooked frequently (especially by the BugLady). They come in five color phases, and each matches a Polistes (paper) wasp that’s found within its range. Here are some of the color phases along with the associated wasp:
Batesian mimicry is mimicry wherein an animal that is edible disguises itself as something that is either noxious or harmful, benefitting from its doppelganger’s reputation.
They are generally solitary, but in spring, when a young mantidfly’s fancy turns to love, he releases an aggregation pheromone that attracts females. Mafham and Mafham, in The Encyclopedia of Land Invertebrate Behaviour, tell us that pheromones help the male to distinguish his potential mate from its look-alike wasp; “the male C. brunnea broadcasts an olfactory message that can only be deciphered by the correct recipient. He produces a very strong pheromone that can easily be detected as much as 3m away. This presumably accounts for the aggregations of females sometimes noted around males. During courtship, the male merely raises and lowers his wings, while rowing with his front legs. Copulation lasts as along as 24 hours, during which he attaches a white spermatophore to the female. She carries this around for 24 to 36 hours, during which time it is gradually absorbed into her body.” (Here, according to the captions, is a spermatophore being carried by a male https://bugguide.net/node/view/1692664/bgimage). Males live for just a few days, but females live for a month or more.
She lays her eggs (https://bugguide.net/node/view/216539/bgimage) – as many as 3,000 of them – on low stalks and leaves, and the larvae that hatch undergo a process called hypermetamorphosis. Larvae of most insects don’t change much after hatching; they just eat and grow until they are mature enough to pupate. The larvae of Mantidflies in the subfamily Mantispinae (along with those of a few beetle and fly families) emerge as active, long-legged super-larvae (https://bugguide.net/node/view/1120008/bgimage).
Why? Because they are parasites, and Mom hasn’t provided for them, so it’s up to them to find their own food. In the case of the Wasp Mantidfly, the robust and mobile youngsters drop to the ground and look for passing wolf and other ground-hunting spiders. They are far more common on wolf spiders than, say, on crab spiders that dwell in the flower tops.
When it locates a female spider, a larva climbs aboard and rides along (this hitchhiking is called phoresy) (https://bugguide.net/node/view/1028990/bgimage) and waits for the spider to make her egg case. If its spider is a male, the larva will jump ship when he mates, and there may be a little wear and tear on a spider that doesn’t spin an egg case in a timely manner (https://bugguide.net/node/view/1120009/bgimage). Sources generally agree that the larva’s mouthparts don’t allow it to chew into a finished egg case, so it must slip inside as the case is being spun. Once it’s sealed inside, it eats the contents of the spider’s eggs (https://bugguide.net/node/view/288398/bgimage); once inside, it doesn’t need its long legs to get around anymore, so subsequent larval instars (stages) look more grub-like. Eventually, it pupates inside the egg case (https://bugguide.net/node/view/1132517/bgimage) before emerging as an adult (https://bugguide.net/node/view/675707/bgimage).
Adults feed on nectar and on small insects like flies and moths that visit flowers and that they grab like a mantis does (https://bugguide.net/node/view/962799/bgimage). Sometimes they hang on the undersides of flowers (note to self – a wasp under a flowers may not be a wasp).
The “Bugs in the News” folder is overflowing again. Here’s a tasteful selection of bizarre, scary, and thought-provoking information about the wonderful world of invertebrates. Thanks to those who shared articles.
Bumble bee populations are declining, and, as with other insects, it’s hard for scientists to define the problem when, for most species, there are few baseline population studies. You can help! Census the bumblebees that you see with the help of the Wisconsin Bumble Bee Brigade. Observe them casually or establish a bumble bee route. See http://wiatri.net/inventory/bbb/ for information about participating in this Citizen Science project. The good news is that you don’t have to know what you’re looking at – just send pictures per their instructions and they’ll do the heavy lifting.
It’s never too early to start thinking about tick checks in Wisconsin – the BugLady has seen deer/black-legged ticks (of Lyme disease fame) on warm days in February.
Articles from all parts of the globe continue to sound the alarm about drastically decreasing insect populations. It’s important to grasp the potentially profound fall-out from these population declines. Insects provide important ecological services like pest control and undertaking; they pollinate our food (or the food of our food), and they are important members of an awful lot of food chains and webs (they are bird food, trout food, dragonfly food, etc.) (yeah – preaching to the choir, here). Here are a few articles about:
