Bug o’the Week – Bugs at the End of Summer

Bug o’the Week

Bugs at the End of Summer

Howdy, BugFans,

The general rule of thumb is that if you want to find insects, look at flowers.  Even though summer is fading, there are still flowers in bloom.  Some Liatris/blazing stars linger, along with brown-eyed Susan, wild sunflowers, asters and goldenrod (more than a century ago, Asa Gray said that the 12 pages about goldenrods in his Manual of the Botany of the Northern United States, from New England to Wisconsin and South to Ohio and Pennsylvania Inclusive (aka Gray’s Manual) were the most uninteresting in the Manual).  Late summer and early fall are dominated by flies, bees and wasps, and by grasshoppers, katydids, and crickets.

Most adult insects die by the first frosts, leaving behind the next generation in the form of eggs or pupae (occasionally as nymphs or larvae), so the clock is starting to tick pretty loudly.  As BugFan Mary stated dispassionately many years ago, they’re dead and they don’t know it yet.  Meanwhile, their activities are centered on eating and on producing the next generation.

AMBUSH BUG (pictured above) – One of the BugLady’s favorite insects is the ambush bug (she’s always had a soft spot in her heart for predators).  Ambush bugs tuck themselves down into the middle of a flower and wait for pollinators.  They grasp their prey with their strong front legs, inject a meat tenderizer, and slurp out the softened innards.  They’re paired up these days (the BugLady has a picture of a stack of three), and she has several pictures where the female is multitasking – eating an insect while mating.

BUMBLE BEE – A bumble bee forages for nectar and pollen for the brood well into September, but the brood will not survive the winter.  Only the newly-fertilized queens will see the spring and establish a new colony.  Moral of the story – plant Liatris/Blazing star.

PUNCTURED TIGER BEETLES (aka Sidewalk or Backroad Tiger Beetles) are named for the rows of pits on their very-slightly-iridescent elytra (hard wing coverings).  They’re common across the continent in dry, sandy, bare spots, and as one of their names suggests, they’re sometimes seen on sidewalks.  Like their (much) larger namesakes, Tiger beetles chase their prey https://bugguide.net/node/view/1106590/bgimage.  For more info http://www.naturenorth.com/Tiger%20Beetle/The%20Tiger%20Beetles%20of%20Manitoba.pdf.  

Some Punctured tiger beetles are “plain” https://bugguide.net/node/view/1343674/bgimage, and some are “fancy” https://bugguide.net/node/view/223895, and some are green https://bugguide.net/node/view/2025474/bgimage.  

FAMILIAR BLUETS signal the end of the damselfly season.  Big, robust, and startlingly-blue, they’re one of the BugLady’s favorite bluets.  

EASTERN COMMA – There are two generations/broods/”flights” of Commas (and Question Marks – the “anglewings”) each year.  The second generation overwinters as adults, tucked up into a sheltered spot (a hibernaculum).  They sometimes emerge during a January thaw, but they quickly resume their winter’s sleep.  They fly briefly in spring – one of our early butterflies – and produce the summer brood.

FALL FIELD CRICKET – Poking her ovipositor into the soil and planting the next generation.  Her eggs will hatch in spring, and her omnivorous offspring will eat leaves, fruits, grain, and other invertebrates. 

The BugLady loves their simple songs http://songsofinsects.com/crickets/spring-and-fall-field-crickets and is happy when a cricket finds its way indoors in fall.  Males form a resonating chamber by setting their wings at a certain angle; then they rub their wings together to produce sound (one wing has a scraper edge and the other has teeth).  There are mathematical formulae for calculating the ambient air temperature based on cricket chirps that give you the temperature in the microclimate on the ground where the cricket is chirping (add the number of chirps by a single field cricket in 15 seconds to 40). 

CANADA DARNER – Common Green Darners are robust dragonflies that fill the late summer skies with dramatic feeding and migratory swarms.  There are other darners, though, primarily the non-migratory mosaic darners (like the Canada, Green-striped, Lance-tipped, and Shadow Darners) whose abdomens have blue and black, “tile-like” patterns.  Identify them by the shape of the colored stripe on the thorax and by the shape of the male’s claspers (lest you think it’s too easy, females come in a number of color morphs – this is a green-form female Canada Darner).  

MONARCH BUTTERFLIES were alarmingly scarce this summer – the short-lived Gen 3 and Gen 4, whose job it is to build the population in the run-up up to the migratory Gen 5, simply weren’t there.  But, on one of the BugLady’s recent stints on the hawk tower, she saw 289 Monarchs heading south during a six-hour watch.  Moral – Plant goldenrod (and native milkweeds).

GOLDENROD CRAB SPIDER – Like ambush bugs, crab spiders live on a diet of pollinators.  They don’t build trap nets and wait for their prey to come to them, they pursue it.  Sometimes they lurk on the underside of the flower, but their camouflage makes hiding unnecessary.  This female looks like she’s sitting at the dinner table.

RED-LEGGED GRASSHOPPERS are very common in sunny grasslands at this time of year from coast to coast.  They eat lots of different kinds of plants (including some agricultural crops, which does not endear them to farmers), but they prefer plants in the Legume/pea family and the Composite/aster family.  As the air temperature increases – and when predators are around – they eat more carbs.  Grasshoppers are food for spiders, many birds, and other wildlife.  Moral of the story – plant wild sunflowers.

PAINTER LADY – You don’t get to be the most widespread butterfly in the world (found everywhere except Antarctica and South America) by being a picky eater.  It migrates north in spring – sometimes in large numbers and sometimes in small.

THIN-LEGGED WOLF SPIDER – This Thin-legged wolf spider formed an egg sac (with about 50 eggs inside), attached it to her spinnerets and is going about her business.  When the eggs hatch, her young will climb up on her abdomen and ride around piggyback for a few weeks before dismounting and going about their lives. 

GREAT BLACK WASP and GREAT GOLDEN DIGGER WASP – Two impressive (1 ¼” long) wasps grace the flower tops at the end of summer.  Both are good pollinators, both are solitary species that eat pollen and nectar, and both dig tunnels and provision chambers with paralyzed insects for their eventual offspring.  Great Black Wasps https://uwm.edu/field-station/great-black-wasp/ select crickets and grasshoppers for their young’s’ pantry, and so do Great Golden digger wasps https://uwm.edu/field-station/great-golden-digger-wasp-family-sphecidae/.  Neither is aggressive.  

The moral of the story?  Plant lemon horsemint.

Kate Redmond, The BugLady

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

Bug o’the Week – Early Summer Scenes

Bug o’the Week

Early Summer Scenes

Howdy, BugFans,

Well, the sun has solsticed, and it’s all downhill from here.  Our pre-Christian, Germanic ancestors, who were more intimately attuned to the rhythms of the sun, correctly celebrated the winter solstice, aka Yule (which may have come from the Norse word houl, which referred to the sun as the wheel that changed the seasons).  They recognized that the winter solstice marked a turning point that would lead to longer, warmer days.

In the BugLady’s neck of the woods, the insect world is dominated these days by mining, sweat, and bumble bees and by lots of flies, including a big hatch of mosquitoes that timed their appearance to coincide with the Riveredge Butterfly and Dragonfly count (causing the BugLady to move along the trail rather smartly).  Here’s what she’s been seeing in the run-up to summer.

STILT BUG ON FERN: This started out as a fern fiddlehead picture – the BugLady did not see the stilt bug when she took the picture, it was one of those happy surprises that photographers get when they put an image up on the monitor.  Most stilt bugs/thread bugs are plant-eaters that supplement their diet of plant juices with the odd, small invertebrate.  Some are more “meat-oriented,” and one species is used to control Tobacco hornworms.

CRAB SPIDER: A friend of the BugLady’s recently asked where all of the beautiful, plump crab spiders are.  They’re here, but they have some growing to do.

KATYDID NYMPH: And another friend, from Southern climes, asked if the BugLady was seeing katydids yet.  Same answer.

TIGER BEETLE: The BugLady loves seeing the flashy, green Six-spotted tiger beetles.  Usually they perch on a bare path, wait until you get too close, fly ahead of you about a foot above the ground, land, and repeat the process when you get too close again.  Until this year, the BugLady had never seen one off the ground, but she’s photographed three in the past month.  Get to know Wisconsin’s tiger beetles at https://wisconsinbutterflies.org/tigerbeetle.

MILLIPEDE ON RUST: Millipedes are decomposers/detritivores, feeding on dung, plant juices, and pieces of dead plant materials like decaying leaves, breaking them down for organisms even smaller than they are.  Some like fungi. 

If you’ve seen the invasive shrubs Glossy and Common buckthorn, you’ve probably seen stems and petioles with a bright orange blob on it.  The blob is a rust – a fungus – called Crown rust (Puccinia coronata).  Buckthorn is one of its hosts, and the alternate hosts are a variety of grasses, including agricultural crops like oats and rye.  If you see grass leaves with thin orange streaks on them, you’re probably seeing a variety of crown rust.  Crown rust has a complicated life cycle (http://www.minnesotaseasons.com/Fungi/Crown_Rust.html ), but the bottom line here is that the rust on buckthorn releases its spores in a soupy, sweet liquid that attracts insects, and the insects carry the spores to rust patches on other buckthorns and fertilize them.  The rust probably doesn’t get much bang for its buck when its spores are eaten by a short-legged pedestrian like a millipede.

BALTIMORE CHECKERSPOT CATERPILLER: The astonishing Baltimore Checkerspot https://bugguide.net/node/view/1771510/bgimage and https://bugguide.net/node/view/1636206/bgimage, and its caterpillar, is one of the BugLady’s favorites.  This caterpillar hatched last summer and munched on its host plant (historically white turtlehead, but in the past 50 years, they’ve adopted Lance-leaved/English plantain, and those are the only two plants a female will oviposit on).  It overwintered as a caterpillar, woke up hungry this spring, and looked around, – no turtlehead in sight yet – so it’s been eating a variety of plants, especially white ash.  Both turtlehead and plantain leaves contain poisonous glycosides (turtlehead has more), allowing the caterpillar and butterfly to get away with their gaudy colors.  And remember – the butterfly (and the oriole) get their names not because they were discovered in that city, but because 17th century English nobleman Lord Baltimore, a familiar figure to the colonists, dressed his servants in orange and black livery. Get to know Wisconsin’s butterflies at https://wisconsinbutterflies.org/butterfly.

MONARCHS: Most of the Monarchs that return to Wisconsin are probably Gen 2 – the second generation north of their wintering ground in Mexico.  There ensues two short-lived generations – Gen 3 and 4 – whose only job is to increase the population, and these two clearly got the memo.  Gen 5, produced in August, is the generation that is signaled by both waning day length and the lowering angle of the sun to migrate instead of reproducing (though there always seem to be a few that didn’t get that memo). 

BEE ON LEATHERWOOD: At a quick glance, you might think that this is a bumble bee, but bumble bees have hairy butts.  The BugLady thought this was a carpenter bee (which have shiny butts), but now she thinks it’s one of the larger mining bees in the genus Andrena.  Leatherwood is a spring-blooming shrub in woodlands – those fuzzy bud scales protect the bud from chilly spring nights.  It gets its name from the fact that its branches can’t be torn off the shrub, and from its strong bark fibers, which were woven into baskets, bowstrings, ropes, and the cords that lashed together canoe frames.  Settlers used its branches when they took their children to the woodshed.  All human use of it is problematic, because its caustic bark raises some serious blisters.

ROBBER FLY: Another bumble bee look-alike.  Bumble bees eat nectar and collect pollen to feed their larvae; robber flies are carnivores.  Laphria thoracia (no common name) can be found on woodland edges from the Mason-Dixon Line north into the Maritime Provinces and west through the Western Great Lakes.  Adult Laphria thoracia eat bees and adult beetles (this one has a clover weevil, but the BugLady recently photographed one with an assassin bug), and their larvae feed on beetle larvae in decaying wood.  Get to know Wisconsin’s robber flies at https://wisconsinbutterflies.org/robberfly  

GOLD-BACKED SNIPE FLY: June is the only month to enjoy these dramatically-colored flies that perch low in the vegetation in moist areas. 

SWAMP MILKWEED BEETLE: The BugLady loves finding these “ladybugs-on-steroids.”  They’re often tucked down into the axils of the milkweed leaves, and when they see company coming, they either duck down deeper into the crevice or they default to the typical escape behavior of an alarmed leaf beetle – they tuck in their legs and fall off the plant.  Their bright (aposematic/warning) colors tell potential predators that they are toxic, due to the milkweed sap they ingest, but damsel bugs, stink bugs, and flower/hover/syrphid fly larvae prey on them nonetheless.  For the full (and fascinating) Swamp milkweed leaf beetle story, see https://uwm.edu/field-station/swamp-milkweed-leaf-beetle/.  

ICHNEUMON WASP: Every year, large and colorful Therion (probably) Ichneumon wasps drift through the vegetation in perpetual motion, legs dangling, taunting the BugLady https://bugguide.net/node/view/739675/bgimage.  They often occur in wetlands, and the BugLady swats mosquitoes and deer flies as she waits for them to show their faces.  Which this one did.

Experienced BugFans are saying, “But, but, but – where are the dragonflies?”  Tune in next week.

Go outside – look for bugs.

Kate Redmond, The BugLady

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

Bug o’the Week – Striped Fishing Spider

Bug o’the Week

Striped Fishing Spider

When the BugLady was on Riveredge’s excellent floating pier in the Milwaukee River last spring, she looked over and saw two, spectacular Striped fishing spiders on rocks above the waterline.

Fishing spiders are in the Nursery web spider family Pisauridae and in the genus Dolomedes, (the fishing spiders), so called because even though most of their diet is made up of aquatic invertebrates, these large spiders are hefty enough to catch tadpoles and small fish (as one website said, “They’re big enough to saddle up and ride”).  Because they’re found near water, they’re often called “dock spiders.”

They are marvelously adapted to locomote across – and under – the water.  These are pretty hairy spiders, and their “hydrophobic” (water-repellant) hairs allow them to dive under the surface film (to pursue or to escape) and to swim without really getting wet, and the air bubbles trapped in those hairs provide them with enough oxygen to stay under for about 30 minutes.  They can not only stand https://bugguide.net/node/view/311363/bgimage, “row,” and run across the water, they can glide across its surface using their raised front legs as a sail.    

Different spider families have unique eye arrangements – here are the eight eyes of a typical nursery web spider https://bugguide.net/node/view/1151143/bgimage.  Weber, in Spiders of the North Woods, says that their eyes glow green at night in the light of a flashlight. 

They catch their prey by ambushing and/or chasing it, not by making trap webs, but they do produce silk.  Fishing spiders spin silken lines to keep from being carried downstream, and females lay a trail of pheromone laced web across the water’s surface for males to follow.  They use silk to construct egg sacs, which they carry in their jaws, and later suspend it in a nursery web (wolf spiders also carry an egg sac around, too, but at the rear, attached to their spinnerets).  And, of course, newly-emerged spiderlings disperse by parachuting away from their siblings https://uwm.edu/field-station/spider-flight-rerun/.   

STRIPED FISHING SPIDERS (Dolomedes scriptus) (scriptus means “written”) are also called Writing fishing spiders because the markings on their abdomen look like a broad letter ”W” https://bugguide.net/node/view/122617/bgimage.  They are found around wetlands in southern Canada, much of the eastern US, and a few Great Plains states, and they prefer fast-flowing streams and rivers. 

Some have a white stripe around the sides of their cephalothorax and abdomen, and some don’t https://bugguide.net/node/view/1219135/bgimage.  There are several other species of large fishing spiders in the area that Striped fishing spiders can be mistaken for and, as always, BugFan Mike reminds us that the most accurate way to ID spiders is by aiming a hand lens at its naughty-bits (he may have used more technical terminology).  Males are smaller and have a slimmer abdomen than females https://bugguide.net/node/view/1225089/bgimage.  The books say that this species grows to a 2 ½” leg-span, but the BugLady is pretty sure that the two females she saw exceeded that.  

Their normal prey is mostly insects that they find on or in the water.  Striped fishing spiders typically sit on the shore or on floating leaves with their three front pairs of legs extended onto the water.  They can sense the ripples caused by insects that are swimming on the surface film (like water striders), or are trapped on it (like moths that dipped too close), or are swimming below it, and they rush out to apprehend them.  They also eat dragonflies, various fly and mosquito larvae that come to the surface to breathe, and other fishing spiders.  The BugLady found an article about a Striped fishing spider that was seen eating a small crayfish.  By the time it was discovered, the spider had anchored the crayfish with silk and had eaten most of its abdomen.  Researchers speculated that the spider had grabbed the crayfish from behind, avoiding its pincers as it injected its cocktail of toxins (their bites are not a problem for people unless you happen to be sensitive to them).  

Great predators though they are, they are also prey.  Striped fishing spiders are eaten by fish, frogs, birds, and even large dragonfly naiads.  And there’s a spider wasp (wasp family Pompilidae) that specializes in the Dolomedes spiders!  Anoplius depressipes https://bugguide.net/node/view/84121/bgimage, which at first glance resembles some solitary wasps in the family Sphecidae, collects fishing spiders and caches them in nest cells for her young to eat when they hatch.  Let the Missouri Department of Conservation “Discover Nature” Field Guide  tell it: “In the early 1900s, entomologists — including Missourian Phil Rau — noted an unusual sight: a wasp flying very low over a stream, dragging a spider across the surface film like a wind skier. It remained a mystery species among insect geeks until entomologist and nature writer Howard Ensign Evans identified it as Anoplius depressipes, one of the so-called blue-black spider wasps. It turns out this species hunts fishing spiders (Dolomedes spp.) and possesses specialized flattened front feet that are fringed with hairs, which allow it to walk on water, just like its prey. When transporting a spider, this species grasps the spider with its middle or hind legs, faces forward, then extends its forelegs and uses them like water skis while it propels itself and its prey across the top of the water, beating its wings, like an air boat in the Everglades https://bugguide.net/node/view/2039627/bgimage. This spider wasp sometimes dives down into water to chase its prey, since water spiders often swim underwater when frightened. Not surprisingly, it nests in burrows in stream banks.”

Curious thing – bugguide.net’s collection of pictures of any one species may contain three pictures or 300-plus.  There were only 13 shots of Anoplius depressipes, but seven of them had captured the wasp on water with prey https://bugguide.net/node/view/262134/bgimage!

Much has been written about female spiders dining on their inamoratos (it’s called sexual cannibalism); it’s not inevitable, but it does provide a nutritional boost for egg-making.  Male fishing spiders woo cautiously, and because she is already tuned in to the vibrations that insects make on the surface film, his signals must be different (his rhythm is slower than that of a trapped and frantic insect).  If she misreads his signals, or he misreads hers, or she’s just plain hungry, or if she gets the message, sizes him up, and he is found wanting, it doesn’t bode well for him. 

She may lay as many as 1,000 eggs, spinning a two-layered, waterproof sac around them.  She guards her offspring by carrying them with her jaws for a week or so until she senses that they’re hatching inside the sac https://bugguide.net/node/view/1572784/bgimage https://bugguide.net/node/view/277075/bgimage (she doesn’t eat for the duration – her mouth is already full).  She installs the sac in a three-dimensional jumble of silk in some leaves or twigs https://bugguide.net/node/view/1304813/bgimage and hangs around for another week or so https://bugguide.net/node/view/886889/bgimage to protect her spiderlings https://bugguide.net/node/view/886890/bgimagehttps://bugguide.net/node/view/1025906/bgimage.  The partially-grown spiderlings will overwinter in a sheltered spot.

Kate Redmond, The BugLady

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

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