Bug of the Week – River Damsels revisited

Howdy, BugFans,

The BugLady is still on hiatus but plans to get back in the saddle soon.  She spent a magic day at the river recently, where the bushes were sparkling with Ebony Jewelwings.  This is a slightly modified version of an episode from 2011 – some new words, all new pictures.

The stars of today’s show are two, big (close to 2”), beautiful, unmistakable members of the Broad-winged damselfly family Calopterygidae.  Once again, the BugLady would like to recommend Damselflies of the North Woods by Bob DuBois (watch for the 2nd edition, coming soon, if the creek don’t rise), Dragonflies and Damselflies of the East, by Dennis Paulson, the Beginner’s Guide to Dragonflies, by Nikula, Sones, Stokes and Stokes, and the on-line Wisconsin Odonata Survey (http://wiatri.net/inventory/odonata/).  There are eight species of Broad-winged damselflies in the US, and the Odonata Survey site lists four of those for Wisconsin – River and Ebony Jewelwings, and American and Smoky Rubyspots (but the Smoky Rubyspot has been recorded from only two counties in the extreme southern part of the state).

Broad-winged damselflies get their name from the base of their wings, which taper gradually instead of looking “stalked,” as in other damselflies.  When they sit, they hold their wings together vertically over the top of their abdomen.  They come in metallic colors, with the male showier than the female (the female is no slouch, though).

Like dragonflies and other damselflies, Rubyspots and Jewelwings are tied to the water – in this case, running water.  Other Odonates may hunt far from streams and ponds, but the Broad-winged damselflies tend to be homebodies.  They are perchers – sitting on plants or rocks and sallying forth to hunt or to defend their territories.  Rubyspots seldom gain more than a foot or two in altitude, but the BugLady has seen jewelwings seven or eight feet off the ground.  Like all Odonates, they are carnivores, both as naiads in their aquatic nurseries and as airborne adults, eating whatever small, soft-bodied invertebrates they can catch.  They are eaten by a host of bugs, bats and birds, as well as by some fish, frogs and turtles.

Ebony Jewelwings and American Rubyspots lay their eggs in the stems of submerged plants or in decaying wood in waters with a moderate current. The books say that the males guard their ladies during egg-laying but are not in contact with them (but keep reading).  Their naiads, which are well camouflaged and not agile, move little and are found on vegetation under water.  Broad-winged damselflies overwinter as naiads, and full grown naiads are about an inch long by the time they are ready to emerge as adults the next summer.

EBONY JEWELWINGS (Calopteryx maculata) (“beautiful wing with a spot”) prefer streams in woods east of the Rockies, and they are said to be the most common damselfly in North America (they certainly are among the most striking).  Their main flight season is in June and July but a few hang around into September.  Several sources testified about their approachability and the BugLady laughed a lot – they can be pretty jumpy.  The flight of Ebony Jewelwings is often described as “butterfly-like,” and they remain on the wing until late in the afternoon.

Male Ebony Jewelwings (a.k.a. Black-winged damselflies) have a stunning Kelly-green, metallic head, thorax and abdomen (unless you see them from a certain angle, and then they are a shiny royal blue), spectacular coloration that effectively camouflages them in the sun-dappled wetland edges that they inhabit. The females’ greens and blacks are more muted and they have a white dot at the tip of each wing.

Donald Stokes, in his wonderful Observing Insect Lives, reports that males are territorial.  When an Ebony Jewelwing spots an intruding male, he will attempt to chase it away.  The two males bounce off each other until one wears out and gives up (males are territorial around patches of floating aquatic vegetation, and patches of the river may sparkle with them).  Plan B involves a behavior called “wing-spreading,” in which he psyches out his rivals by spreading his wings and raising his abdomen (raising the abdomen displays a bright, white spot under its tip which the BugLady has never seen).  An approaching female rates a “cross-display,” in which the abdomen is raised, the hind wings spread, and the front wings folded.

According to Stokes, if a female is unimpressed, he flies around in front of her, faces her, and performs the irresistible “rapid-wing-flutter.”  Both males and females have commitment issues.  DuBois rates her as “blatantly promiscuous,” mating with four or five different males a day for two weeks or so and depositing nearly 2000 eggs!  Stokes says that while the male is guarding her egg-laying efforts, he is making cross-displays to nearby females (though he won’t pursue them until she is finished and out of sight).

The AMERICAN RUBYSPOT (Hetaerina americana) likes larger streams and rivers; its range includes all of the lower 48 states (it’s uncommon in the Pacific Northwest) plus the eastern half of Canada around the east edge of Hudson Bay.  The American Rubyspot is a summer damselfly that notably likes a crowd (one observer caught 75 in a single net), and it has been observed feeding in groups (swarm-feeding) on clouds of emerging mayflies.  The reason for its name is obvious if you see a male in bright sunlight, but in shade their posture is characteristically “hunched over,” and they are not as conspicuous.  The BugLady often sees them as red dots on rocks or on floating plants in the river.  The proximal third of the male’s wing is ruby/blood red (according to Paulson, the spot starts small and grows in size for about two weeks).  The (more variable) female’s wing often has a red wash at the base, and its overall color is often amber.

Males defend territories that change daily, chasing rival males in ever-widening circles until one poops out and flies off and the other claims/reclaims the spot.  Females are also somewhat territorial, but neither gender has display behaviors like the Ebony Jewelwing.  Receptive females fly into a territory, hover, and are grabbed/clasped by the male.  As they fly in tandem to a perch to exchange bodily fluids, rival males may charge them and separate them. Duke University professor Clifford Johnson described how, still clasped, they may land on a floating mat of vegetation.  The male walks backwards toward the water with the female backing up behind him until the female is fully submerged (several sources noted that she is partly to completely submerged while laying eggs, but she will enter the deep end on her own, too).  She may stay under water briefly or for almost an hour (in fact, though other researchers have seen them, Johnson said he never saw a female re-emerge and wondered where/if they did).  The male guards her from all comers – con-specific or not.

Ironically, those crimson wing spots that make us gasp render males potentially more visible to predators as they cruise low over the river’s surface.  And, it turns out, they are also a “hunting handicap” that make males more visible to their own flying prey.  In one study, males (and females with red spots painted onto their wings) gained weight more slowly than the better-camouflaged “natural” females.  The things we do for love.

Find a river and enjoy the show.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Crayfish Revisited

Greetings, BugFans,

 

Still in the process of moving, and it’s May, so another re-run.  The BugLady dusted off another decade-old episode (yes, BugFan Laurel – 10 years!!!) and added new pictures and information.  And yes, as always, the BugLady is using a rather inclusive definition of the word “bug.”

Crayfish are classified in the Phylum Arthropoda (“jointed legs”), in the Class Crustacea (referring to their hard, outer coverings), and in the Order Decapoda (“ten legs”).  More than 300 species of these “mini-lobsters” blanket North America; the Rocky Mountains and western Great Plains have historically been fairly crayfish-lite, and the Southeast is most species-rich.  A Wisconsin DNR publication dated 2012 lists eight species in the state at that time – Northern Clearwater, Rusty, and Virile crayfish (the three most common species), and Devil, Calico, White River, Red swamp, and Prairie crayfish.

 

Crayfish inhabit shallow waters, running and still, though some live in damp-lands away from standing water, and some will even settle at the base of a hillside where run-off from above provides their moisture.  Most species are intolerant of pollution.  Species that live in drier conditions or whose aquatic homes dry up in late summer build “chimneys” in an attempt at climate-control.  In search of water to keep their gills moistened, these relative landlubbers excavate vertical tunnels in the earth, constructing at the mouth of the tunnel a cylindrical pile of mud pellets – a chimney. There they live, in damp and solitary splendor (except for a bit of co-habiting during the breeding season).  The Bug Lady’s youngest child once wrote in a poem that “crayfish build chimneys so their voices will echo when they sing.”

According to Wikipedia, “The study of crayfish is called astacology.

 

A carapace covers the cephalothorax (fused head and thorax), and the “snout” that protrudes from the front of the carapace is called the “rostrum.”  Antennae and stalked eyes decorate the cephalothorax, and five pairs of walking legs are found on its underside (the front set has been modified into a pair of impressive claws that they use to crush or rip their food).  Gills and a balance organ, into which the crayfish incorporates grains of sand as sensors, are located inside it.

The abdomen consists of six segments terminating in a flipper-like “telson” (tail).  Below the first five segments are pairs of small appendages called swimmerets.  The swimmerets move to create water currents that wash over the gills and assist in respiration, and they also function in reproduction.  Crayfish go forward by creeping and move backward pretty fast by tucking/folding their jointed abdomen under them several times, and they can walk sideways.  If a limb is lost, a crayfish can regenerate it.

 

See https://www.biologycorner.com/worksheets/anatomy_crayfish_virtual.html for an up-close look at the external anatomy of a crayfish.

 

Crayfish (crawfish, crawdads, mudbugs) are omnivores and often scavengers, feeding on dead plants, live plants, snails (mainly those species with thinner shells), aquatic insects, small fish and carrion (when she was in a much earlier instar, the Bug Lady was given some raw bacon with which to angle for crayfish, and both she and the crayfish thought it was mighty tasty).  Crayfish are eaten by raccoons, otters, screech owls, lots of fish (and, apparently, Ring-billed Gulls), and by humans, who should cook them well in order to avoid a lung fluke that some crayfish are intermediate hosts of in the eastern part of their range.

 

Reese Voshell, Jr, in his excellent book A Guide to Common Freshwater Invertebrates of North America, tells us that crayfish are an important domino in aquatic ecosystems. Their actions may determine the density of the aquatic plants, which determines the health and composition of the accompanying animal community.

 

Invasive crayfish?  Two of Wisconsin’s species are.

 

The aggressive Rusty crayfish (Orconectes rusticus), is an invasive “native” (native, that is, to the Ohio River Basin) that was first found in Wisconsin in 1960 and has since achieved pest status here.  Rusty crayfish were probably introduced by bait fishermen and/or aquarium owners discarding unwanted animals into ponds and waterways, but they are also sold to schools by biological supply companies, and when the kids go home for the summer…..  They are aggressive toward native crayfish, toward the fish that would normally eat them, and toward the toes of wading humans.  They eat twice as much as native crayfish, and they impact fish populations by eating fish eggs, small fish, insects eaten by fish, and aquatic vegetation needed by fish for cover and for spawning areas.  And they reproduce avidly.  Pretty much a clean sweep, damage-wise.

 

Here’s their present range: https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=214; for an interesting tale of crayfish eradication, see https://news.wisc.edu/in-whole-lake-experiment-have-invasive-crayfish-met-their-match/.  Rusty crayfish control?  You can help: https://onwisconsin.uwalumni.com/on_campus/tasty-invaders/.

 

Since this original crayfish episode was written 10 years ago, a second alien crayfish has appeared in Wisconsin, the Red swamp crayfish (Procambarus clarkii).  Back in the summer of 2009, residents of a subdivision northwest of Milwaukee started finding bright red crayfish in their lawns (and running them over with lawnmowers).  When the DNR investigated, they found a population of Red swamp crayfish in a local pond and began an all-out effort to eliminate them https://bayviewcompass.com/aggressive-red-swamp-crayfish-invades-wisconsin/.  This species is farmed extensively in the south and shipped live to people who want to have a real Cajun crawfish boil, and it’s also sold as a classroom animal – whatever the origin, someone released the extras.

 

Red swamp crayfish are called an “ecologically plastic species,” another way of saying that they’re very adaptable.  They tolerate drought and can hike considerable distances looking for water.  Like the Rusty crayfish, they out-compete and out-reproduce the native species, and they are notably hard on amphibians.  Red swamp crayfish can transmit to native crayfish a fungal disease called “crayfish plague,” which damages the muscles.  On their home turf around the Gulf Coast, this crayfish is famous for weakening earthen berms and undermining stream banks with its tunnels.

 

Here’s the present range of the Red swamp crayfish: https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=217.  They’ve also immigrated to more than 25 European and Asian countries.

 

Yay – dandelions are blooming!!!  http://uwm.edu/field-station/wildflower-watch-dawdling-among-dandelions/.

 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Bumble Bee redux

Greetings, BugFans,

The BugLady has been out enjoying the spring warbler migration, and as she searches the branches for birds, she’s also loving the soundtrack – the echo of Wood Thrushes and the buzz of early bumblebees.  She wrote this episode ten years ago, and then in 2014, she “Celebrated Bumblebees” http://uwm.edu/field-station/celebrating-bumblebees/.  Here’s an updated version of the 2008 episode – some new words, all new pictures:

The impressively-sized bumblebees that visit spring’s early flowers are the queens, newly emerged from their underground winter shelters.  Bumblebees do not store food over the winter, a la honeybees, and only the fertilized queen survives until spring because she is better nourished than the workers.  There are 46 species of bumblebees (family Apidae) north of the Rio Grande, and they emerge at different times of the spring and early summer.

Their bodies are plump, and their wings are too small for their bulk (bumblebee flight was long thought to be mathematically impossible https://www.livescience.com/33075-how-bees-fly.html), and they are clumsy fliers.  They have a fuzzy thorax and a hairy abdomen, and a yellow and black color scheme (Mother Nature’s warning colors).  Their antennae are short, and their mouths are shaped for biting as well as sucking.  Yes, they will sting to defend hearth and home, and their hidden nests surprise pedestrians, outdoor workers, and livestock.

Bumblebees emerge early to claim the limited available nest sites, but their extra hairy bodies are well insulated against the chill of April.  In the dandy Field Guide to Insects of North America, Eaton and Kaufman refer to bumblebees as an essentially “warm-blooded bee.” This housing crunch also causes the queen to camouflage her nest by piling dried vegetation outside its entrance when she leaves.  Even so, an interloper queen may discover a nest site and evict a resident queen.

After the queen locates a cavity – underground in a deserted rodent burrow or in the walls of an old building or even in outdoor furniture – she makes a nest of moss and grass, and lays eggs (400 to 1,000) in a disorganized array of wax cells.  She sits on them for four or five days to keep them warm (maternal solicitude is uncommon in invertebrates).  When the larvae hatch, they feed on a mixture of pollen and nectar.  Some species provide a cache of pollen for the larvae to nibble on, and others regurgitate nectar and pollen into individual larval cells.  Four to five weeks after the eggs were laid, the newly-minted adults (sterile female workers) emerge from their cocoons to gather pollen and nectar and care for the queen and her future broods.  Fertile males and females are produced in late summer.

Kaufman and Eaton say that bumblebees “buzz pollinate” some blossoms – they set up a vibration that causes pollen to be rain down on them.  Though they feed protein-rich pollen to their offspring, adult bumblebees mainly eat high-energy nectar, collected from a variety of flowers (they are generalist feeders).  Different species of bumblebees have tongues of different lengths, and this governs their flower choices.  They’re also “muscly” pollinators, able to force their way into flowers that other bees can’t.

[Quick aside – The BugLady gave a program about native orchids a few years ago.  Some species of orchids are pollinated by “naïve bumblebees.”  Naïve?  Many orchids have alluring arrangements of flower parts but little or no nectar to reward those who visit.  Bumblebees may be fooled once or twice, but sooner or later they catch on and eschew the orchids.  The orchids, therefore, are pollinated by bumblebees who haven’t caught on yet.]

Not all bees are social – in fact, most are not.  Bumblebees are our only native social bees (like most of our ancestors, honeybees came over on the boat).

 

The BugLady, who enjoys etymology as well as entomology, is pleased to report that “bumble” is derived from a Middle English word (bumblen or bomblen) meaning “to boom.”

Kate Redmond, The BugLady

Nota Bene – The BugLady pulled off her first deer tick of 2018 last week.  http://uwm.edu/field-station/deer-ticks-revisited/

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Bugs in the News – the Videos

Howdy, BugFans,

In past years, the BugLady has taken off during the month of May or June to refresh her sadly depleted “BOTW Future” file with new images of emerging insects, and she plans to do that.  BUT – she’s also in the process of moving out of a house that she’s lived in for 40 years (rule of thumb – if you haven’t seen it/thought about it/used it for 10 years or so, you probably don’t need it).  St. Vinnies’ is thrilled.  The BugLady is thrilled that she’ll go forward with about 1/3 of her present worldly possessions.

So – BOTW will be sporadic for the next month or so.  In the meantime, here are some Bugs in the News links that BugFans have sent in.

As the BugLady’s Mother used to say, “apropos of nothing”…….. – enjoy https://player.vimeo.com/video/251621697

Confession time.  The BugLady’s family got its first Golden Retriever in 1952, and she submits that there is nothing (sorry, kids) cuter than a Golden pup.  However – these guys run a close second (sorry, kids).https://www.youtube.com/watch?v=M0E3OoBi_4o.

After some short ad content, ants, doing what ants do – https://video.nationalgeographic.com/video/news/one-strange-rock/180402-ants-clean-new-york-city-eat-food-scraps-one-strange-rock-deleted-scene-vin-spd?utm_source=NatGeocom&utm_medium=Email&utm_content=WatchThis_20180413&utm_campaign=Ngdotcom&utm_rd=2030610309

Monarch butterfly migration seen through a different lens (and with subtitles) (but first, a 30 second ad) – https://video.nationalgeographic.com/video/news/170306-mexico-monarch-butterfly-sanctuary-vin.

Common Green Darners have been spotted in southeastern Wisconsin in the past week!  These are part of the state’s migratory population, the offspring of the dragonflies that departed last fall (http://uwm.edu/field-station/common-green-darner-rest-story-family-aeshnidae/).  BugFan Freda even saw a pair flying in tandem.  See a 14 second video of a pair ovipositing here: https://www.youtube.com/watch?v=QmXwg0OpNHE.  And remember, if you see a swarm of dragonflies (doesn’t have to be in Biblical numbers), report them to the Dragonfly Woman at https://thedragonflywoman.com/dsp/report/.

Spring.  The BugLady photographed porch bugs last night for the first time since last fall, a few moths, an ichneumon, a brown lacewing, a box elder bug, and some midges.

Go Outside!  Day or Night!  Look at Bugs!!!!

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Speed-dating the Spiders II – Ghost Spiders

Greetings, BugFans,

 

This is the second of an occasional series begun last week with house spiders, and (belatedly) titled “Speed-dating the Spiders” (sorry, BugFan Mary).  Once again, the BugLady would like to thank BugFan Mike, who looks at the BugLady’s out-of-focus spider pictures and identifies them (to the extent that they can be), and tells her about them.  Remember the old saying “Your guess is as good as mine?”  Well, in the case of spiders, BugFan Mike’s guess is a highly educated one that is way better than the BugLady’s.

Ghost spiders, family Anyphaenidae, get their name from their generally pale appearance and the fact that they are (mostly) nocturnal.  There are about 500 species of ghost spiders globally, with only a single species in northwestern Europe, and 37 in North America (10 of those in Wisconsin).  Look for them on living or dead vegetation or on rock piles, or under loose bark in winter.  Today’s spiders are in the genus Anyphaena, and you have to get up-close-and-personal to ID them to species.

 

They range from smallish (a half-inch) to very small.  Some species (the grassland dwellers) have long legs, and others (the leaf litter dwellers) have short legs.  Their legs are tipped with distinctive clusters of hairs on the bottom of each “foot” (“claw tufts”); these increase traction and allow them to be good climbers.  Most spiders have eight eyes, and a ghost spider’s are arranged like a smiley face (https://bugguide.net/node/view/307226/bgimage).

 

Like crab spiders and jumping spiders and some others, ghost spiders are active hunters that don’t build a trap net.  They do spin silk “retreats” in sheltered spots, and their egg sacs are made of silk https://bugguide.net/node/view/608037/bgimage.  Males vibrate their abdomens really fast during courtship (the European ghost spider is called the “buzzing spider” because of the small noise made by the male’s abdomen as it vibrates against vegetation). Mom sticks around and guards the egg sac until the spiderlings hatch https://bugguide.net/node/view/575133/bgimage.

 

They prey on small insects and are considered to be good controls of agricultural/orchard pests, and some species even add insect eggs to their menu.  This is a very active spider that doesn’t indulge in a lot of “down time,” and it needs energy to sustain it while hunting.  What’s a spider to do?  It turns out that some species of ghost spiders are among the spiders known to feed on nectar from flowers or from extra-floral nectaries (http://uwm.edu/field-station/ants-in-my-plants/).  Some spiders eat sap, honeydew from aphids, pollen, spores, or even fruit (they bite the fruit, inject a tenderizer and wait a bit, just like they do when they catch an insect).  This habit mostly exists in warmer climes and does not totally replace meat-eating.

 

Ghost spiders figured in a study of the occurrence of spiders in urban areas.  Researchers Meinke, Holmquist, Wimp and Frank looked at the invertebrates that live in urban trees.  It was known that populations of plant-eating insects increase with the temperature, but the effect of warmer weather on their predators was not known.  The researchers observed that ghost spiders don’t like it hot.  Or dry.  Seasonal rises in temperature, exacerbated by the urban heat island phenomenon, are hard on them, and they may escape by ballooning, leaving the trees to the leaf-eaters, and recolonizing when temperatures cooled.  The authors suggest that global climate change could eradicate heat-sensitive organisms from cities and bring about boom populations of tiny grazers.

 

They’re baaacccckkkkk – Raise your hand if the outside of your house is decorated with box elder bugs.  For more information, see: http://uwm.edu/field-station/box-elder-bug-revisited/

 

 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Common House Spider

Howdy, BugFans,

 

“House spider” is, of course, a name that’s applied to lots of different species in lots of different countries.  Because they hang around human habitation, Common/American house spiders (Parasteatoda tepidariorum, akaAchaearanea tepidariorum) are one of our most familiar spiders, and Wikipedia says that “Statistically, they are the most often encountered spider by humans in North America.”  They are – vocabulary word of the day – asynanthropic species (from “syn” (together) and “anthropic” (man)), a species that lives near people and benefits from that association.  They are on the BugLady’s Porch Bug list.

Common house spiders (CHSs) are in the Class Arachnida and in the family Theridiidae, the “cobweb” or “comb-footed spiders” (comb-footed because of the spines on the lower part of the final pair of legs, spines that help them draw/comb silk from the spinnerets).  They are related to the notorious Black and Brown widow spiders, but despite that, CHSs are shy, don’t take offense easily, and will run away/drop to the ground when alarmed.  Their bites are painful but are not considered dangerous unless you’re allergic (or unless you are a grasshopper-sized-or-smaller invertebrate).

 

CHSs probably originated in South America, but they’re now recorded across most of the Lower Forty-eight, into southern Canada, and around the world, apparently hitchhiking in shipments of plants.  The front pair of legs is extra-long; females, at about ¼ inch, are larger than males and are variably-colored (https://bugguide.net/node/view/853226/bgimage and https://bugguide.net/node/view/1507434/bgimage) and the dark red-orange males have smaller abdomens (https://bugguide.net/node/view/960840/bgimage).  According to BugFan Mike, a newcomer in town, an Asian look-alike named Parasteatoda tabulata whose abdomen is relatively smaller than the CHS’s (pea-sized vs chickpea-sized), may be more common in Wisconsin now than the CHS.

 

The three-dimensional webs are described as “random” and “tangled.”  The spider constructs a densely-woven nook near the center of the web, in which it awaits its prey.  Prey may get caught in the body of the web or stick to the extra-gluey “guy lines” that anchor it.  Like a good fisherperson with a finger on the line, the CHS monitors the vibrations of the web, and if it feels a struggling insect, rushes out to paralyze and secure it.  Apparently, it is able to shoot web at a thrashing insect from afar in order to get it under control before getting close.

Unlike species that spin daily, the CHS tries to maintain its web by discarding used food items, but it will also abandon a web spun in an unproductive area (they favor spots that are open to air currents).  Females tolerate other females that make adjoining webs (though a neighboring female may get eaten if she strays too close).  This can result in some pretty big masses of cobwebs, like the one in the water treatment plant in Baltimore that covered tens of thousands of square feet and probably held a spider population of more than ten million, more than half of which were CHSs https://www.huffingtonpost.com/2014/11/03/four-acre-spider-web_n_6095724.html.  In the picture of the dark and the light spider, the light-colored individual has recently shed and her color isn’t set yet (thanks, BugFan Mike).

Contrary to the practices of many spiders, in which the males’ post-courtship survival depends on getting out of Dodge, fast, male CHSs often share webs with females.  After mating, females start making distinctive, tan, papery egg sacs containing 100 to 400 eggs each, and (uncommon among spiders) she may make as many as 15 of them!  She puts non-viable eggs in the sacs, too – these her young will eat during the four days between hatching and leaving the egg sac.  The spiderlings stay together for a few days, adding to their mother’s web, and then, after about 10 days, they disperse aerially, by ballooning.  They are extremely vulnerable during this stage (the second instar) because they are very small and can only prey on critters that are even smaller, and even though they can go without eating for three weeks, mortality is about 98%.  Females mature in about 40 days, and can live more than a year; males mature in about 30 days.

They feed on insects – mostly flies and mosquitoes – but they’ll take prey up to the size of a grasshopper, and will also eat a few species of spiders.  There were several accounts of CHSs taking very small lizards that had been attracted to their webs by snagged flies.  One of today’s pictures shows a CHS that has captured a daddy long-legs.  Their eyesight is poor, no more than three or four inches.  They hunt at night and take shelter during the day.

One day, a decade ago, when the BugLady was prowling around a building looking for bugs to photograph, she came upon an interesting tableaux (and photographed it badly).  A solitary wasp had flown close to the corner of a window that held a CHS web. The BugLady can’t recall whether the wasp had targeted one of the spiders, was already carrying one of the spiders or was just confused by the window.  At any rate, it encountered a strand of web, a female responded, and then the second female (while the male looked on), and pretty soon they had everything wrapped up.

To spider days.

 

The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Leaf Miners

Greetings, BugFans,

 

There’s never a leaf nor a blade too mean to be some happy creature’s palace.”  J. R. Lowell

 

First of all, with apologies to botanists everywhere, here’s a quick and dirty review of the anatomy of a leaf.  It’s a thin, green organ that consists of the working guts sandwiched between top and bottom layers of epidermis that keep the innards in place and prevent them from dehydrating.  The area between the epidermal layers is the mesophyll (“middle leaf”), which is made up of a “spongy” and a “palisade” layer of living “filler” or ground cells called parenchyma (the parenchyma that contains the chloroplasts that carry out photosynthesis is called chlorenchyma).  This tissue is served by veins that move food and water into and out of the leaf and provide a certain amount of rigidity (and may restrict a leaf miner to a small portion of the leaf).  There’s a nifty diagram at PBS Learning media (who knew?):  https://wpt.pbslearningmedia.org/resource/480848277-plants-animals/leaf-anatomy-plants-and-animals/#.WsjrbS7wbIU.

 

What is a leaf mine?  It’s a translucent trail left by a tiny larva as it feeds in the parenchyma of a leaf.  Mines may be linear in shape, or serpentine, trumpet, blotch, or tentiform (a slightly three-dimensional blotch).  The larvae grow as they feed, and so does the circumference of their mine.  Artist/blogger Anita Sanchez calls mines “botanical doodling.”

 

And what are leaf miners?  Sibyl Hausman, in her article “Leaf-Mining Insects” (The Scientific Monthly, July 1941), says “These tiny creatures are small worms, the larval stages of insects which are able to obtain plenty of food and a suitable lodging by living entirely between the surface cells of the leaves.  Certain members of the Lepidoptera, Coleoptera, Hymenoptera, and Diptera spend their larval life within the leaf tissues, feeding on either the palisade or spongy parenchyma cells where chlorophyll is located, well protected and concealed by the thin, colorless cells of the upper and lower epidermis…..  The forms of these mines or tunnels and the leaves of the plants in which they occur are both characteristic of a given species.”  Researchers Connor and Taverner refer to leaf mining as “consuming live foliage while simultaneously dwelling inside it.”

 

Being a leaf miner is just a hair’s breadth away from being a borer (which excavates deeper into plant tissue) and a gall-maker, and insect families that contain one often have the others.  Leaf miners generally do their work in more mature leaves; if they started chewing on young, actively-growing leaves, the plant would produce extra tissue and envelope them, creating a gall.  Leaf miners can tolerate lots of the chemical defenses that leaves throw at other grazers, like toxins and sticky, milky juices (though they sometimes drown in excess latex).  Of the approximately one million species of insects known today, about 10,000 are leaf miners, and most families of plants entertain miners, even conifers, and aquatic plants.

 

What goes in, must come out – according to Sibyl Hausman, “Often the mines are obscured by the accumulation of dark particles of waste material, known as frass, but some species keep their mine clean by distributing the frass in separate pockets.” https://bugguide.net/node/view/862705/bgpage.

 

What do the miners look like?  Needham, Frost, and Tothill, in Leaf Mining Insects (1928) describe them, “The principal needs of the miner in accordance with which all its peculiarities of form have been evolved, are for thin, flat, forward-reaching mouthparts, and for holding apparatus for keeping them up against the mesophyll for their work.  Hence the mouth turns forward and the head takes on the shape of a flat wedge.  Walking legs tend to disappear and a variety of stay apparatus tends to be developed – spacing humps, and tubercles and bristles and setulae … The larva may develop chewing mouthparts capable of devouring cells bodily, or it may develop cell-shearing apparatus and sap-feeding habits.”

 

[NB. The four orders that produce leaf miners are all flying insects (so they can find their host plants) with complete metamorphosis, and despite the radically different appearance of the adults of those orders, their leaf-mining larvae, shaped by the demands of their environment, are quite similar.]

 

Eggs are often laid in or on the underside of the host plant.  “The larvae of some of them on hatching from the egg may come out on the surface of the leaf, but in all the more specialized miners they pass directly into the leaf through the epidermis that the egg covers, and do not appear outside (Needham, et al).”  Some larvae spend only a short time in the mines, some live their larval stage there and pupate elsewhere, and others pupate there, too, poking through the leaf’s epidermis to emerge as an adult.

 

In describing the emergence of an oak leaf gall-maker, Needham says, “the pupa has a sharp, hornlike process on its head with which, when ready for the final transformation, it can penetrate the walls.  When part way out of the leaf the pupal shell (chrysalis) breaks open on the back, and from it emerges a resplendent little moth, clad in scales of gold and ermine and jet, a veritable atom of Lepidopterous loveliness.  There is hardly anything in nature more beautiful than are some of the moths that have leaf-mining larvae.” (It’s a wonderful book:  https://www.biodiversitylibrary.org/item/28922#page/8/mode/1up).

 

Just how safe is this pantry/hideaway?  Not as safe as you’d think.  Egg predation is rare (anything that fits between the top and bottom surfaces of a leaf has a pretty tiny egg), but despite the fact that they’re undercover, the larvae are preyed upon by a varied bunch of parasitoids whose mothers manage to locate them.  They’re also eaten by predatory insects, a few bird species, and accidentally, by general leaf-eaters who get a bit of protein as a bonus.  Premature leaf drop also takes its toll.

 

And apparently, they’re not protected from cosmic events like asteroids, either.  Mines persist in leaves after the leaves fall, and they can even be seen in fossil leaves and used by paleo-entomologists to study the miners’ lifestyles, gauge populations, and even clarify taxonomy.  The BugLady found a paper out of Penn State about how the dinosaur-killing asteroid that hit the Yucatan Peninsula in the late Cretaceous period also killed off the leaf-mining insects in the western US (and elsewhere, since three-quarters of all of the plant and animal species on earth became extinct in that one event) (it’s called the Cretaceous–Paleogene (K–Pg) extinction event – see the lovely video at https://www.britannica.com/science/K-T-extinction).  According to a study done in southeastern Montana, the leaf miner fauna bounced back in that area after only a million years, populated by newly-minted, post-Cretaceous species.

 

Except when the mines appear on leafy vegetables like spinach, or in large outbreaks, mines are a fleeting, cosmetic issue.  The tissue around the mine does dry out, but mostly, the plant is not injured.  Chemical control is tough since the larva is inside the leaf.

 

Pictured here are mines of the

Needham, et al, tell us that “The feeding operations of many leaf-mining larvae may be observed with a good lens, holding their leaf up to the light and watching them work by looking through the transparent epidermis,” which, of course, violates the Prime Directive since you have to pick the leaf to do it (unless you’re far sprier than the BugLady and can climb underneath).

 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Frothy Forage Helpful Tips

Woo-hoo! An awesome day of celebrating great drinks and the great outdoors awaits! Thanks for joining the fun. Here’s some helpful tips to make your Frothy experience fantastic.

  •  All parking for event attendees is at Fireman’s Park in Newburg (508 Main Street, Newburg, WI 53090) a short drive down the road from Riveredge, as we need to keep the limited parking at the Riveredge lot clear for our breweries and volunteers
  • Shuttle buses will be running from Fireman’s Park to Riveredge throughout the event. The shuttle will start running at 11:30 AM. Please be aware that if you arrive earlier to the parking lot, you will need to wait until the shuttles start running. The drive takes only a few minutes, so if a shuttle is not there when you are, it will be coming very shortly! We will have attendants at the park if there are any questions.
  • Everyone drinking MUST be 21 or older and MUST bring a photo ID. We can not allow anyone to get a sampling wristband without an ID, so please make sure you bring it with you on to the shuttle bus to avoid having to take the shuttle back to the parking lot.
  • We have a new registration system this year, so we’re still working to determine the best check-in system so you can get to the Frothy fun as fast as possible. Expect an email closer to the event with full details- we may send tickets by email or ask you to print or show your receipt if possible, but no matter the system, you’ll also be able to check in by name. Needless to say, as long as you have registered, you will be able to get into the fun! 
  •  Plan on bringing cash for raffles, snacks (pretzel necklaces and popcorn!), Frothy t-shirts, and food trucks (some of the food trucks may take cars). We unfortunately do not have an ATM on site.
  • The free sampling, including access to the Beer Trek through the trails, goes from 12 to 3 PM. From 3 to 4 PM, we will have a cash bar, and the food trucks and live music to keep the party going!
  • The event goes on rain or shine, so refunds are not available. Mother Nature has trained us well, though, so if rain is an issue, we will move some stations inside as well as having a big tent in the yard so we can still have fun outside!
  • It’s better with friends: If you haven’t already, we’d be super grateful if you could share the Frothy with your friends and family who might be interested in joining! We’re a small nonprofit putting on a big beer festival, so all the help in getting the word out for this great day of fun and fundraising is hugely appreciated.
  •  Please drink responsibly. If you do not have a designated driver, you are responsible for making sure you are in a state to drive home safely. Water stations will be available around the event and we will have a table with free soda for all attendees. Be sure to take advantage of the food trucks who will be selling some delicious eats.

Other Questions? How can we help?
Please let us know any other questions you have! We’re happy to help! We can be reached by phone at 262-375-2715 or by email at riveredge@riveredge.us!

We can’t wait for an amazing day!

River Valley Ride 2018 Helpful Tips

We’re so glad you’ll be joining us for another incredible year of the River Valley Ride on Sunday, June 24! Here are some important updates to keep in mind before the big day!

  • Parking: A reminder that all parking and the start of all routes take place at Fireman’s Park in Newburg (508 Main St, Newburg, WI 53090), right down the road from Riveredge. All routes do end at Riveredge for the picnic and afterparty, so you will need to pedal the 1.4 miles back to the park after you’re done celebrating OR new this yeara shuttle will be available for one person per party to return to Fireman’s Park and bring the car back to the loading zone in the parking lot.
  • Riders will need to pick up a ride packet that includes your t-shirt, ride map, and perhaps most importantly, your wristband that will get you the lunch included with your registration. Packets are now available for early pick-up! Stop in Riveredge’s nature center (4458 County Rd Y, Saukville, WI) weekdays from 8 AM to 4:30 or Saturday’s from 9 to 5 PM. Of course, you can also pick yours up the morning of the ride (starting at 6:30 AM- unfortunately we can not open registration earlier than that, so if you’re itching to go super early, please plan on picking up the packet ahead of time.)
  • When checking in and picking up your ride packet all you’ll need to give is your name- no need to bring any tickets or receipt. 
  • Recommended start times vary on which route length you are choosing to ride. Recommended start times are as follows: 

 

 

 

 

 

 

 

 

 

 

  •  Route Maps: there’ll be a copy of the route map in your ride packet, but if you’d like an earlier peek, click here for a PDF copy. We’ve also got the routes available digitally on Map My Ride, for those hi-tech riders. Check out the bike ride page on our website, and underneath each route description, find a link to the appropriate Map My Ride. Please note: routes do occasionally need to be changed slightly to detour around unexpected construction or the like. Stay tuned for any final updates closer to the race.
  • Member Thank You: As a special thank you to our wonderful members, we’ve got some great gifts for you. If you’re a Riveredge member, please stop by the membership booth at the after party for some special thank you’s.
  • It’s better with friends: If you haven’t already, we’d be super grateful if you could share the ride with your friends and family who might be interested in joining! We’re a small nonprofit putting on a big ride, so all the help in getting the word out for this great day of fun (and one of Riveredge’s biggest fundraisers of the year!) is hugely appreciated.
  • Safety Reminders: Your safety is our biggest concern! It is very important to remember that the River Valley Bike Ride is not a race and the routes/roads are not closed. That means you’ll be sharing the roads with vehicles, so rules of the road must be observed and single file riding is required. We’ll have intersections marked for you, but most will not be guarded. Major intersections will be manned by route monitors, so please observe traffic monitors’ directions. Emergency repair and pre-ride bike safety checks are offered at the start and at all the rest stops. Helmets are required. Thanks for helping us make this a safe and enjoyable ride for everyone!
  • Have a blast: The motto of the River Valley Ride is “Enjoying The Journey And The Destination”. The routes are designed to show off the best the area has to offer, so slow down, enjoy the view, and cherish time with an awesome community of riders. After all, it’s a ride, not a race!

Other Questions? How can we help?
Please let us know any other questions you have! We’re happy to help! We can be reached by phone at 262-375-2715 or by email at riveredge@riveredge.us!

We can’t wait for an amazing day!