Long-time BugFans know that the BugLady is infatuated with the lovely, sedentary Flower Crab spiders (family Thomisidae) that she , and she recently posted a BOTW about the chunkier Ground crab spiders (also Thomisidae).

Running crab spiders, in a separate family (Philodromidae) have been mentioned briefly throughout the years – here’s their story. 

They are “running” by both name and by inclination – they move along smartly, and Philodromidae comes from the Greek “philodromos,” meaning “lover of the race/course.” There are 92 species of spiders in this widespread family in North America, and they’re usually found on the stems and leaves of plants. Philodromuis and Tibellus are common genera.

These are not flashy spiders – most are small (measuring less than ½” long), flat-bodied, and drab. Many (but not all) are crab-shaped like the Thomisids, but in Philodromids, the second pair of legs is noticeably longer than the first. Eye arrangement is an important tool in spider ID – here’s what it looks like to stare .

Philodromids don’t spin trap webs, but they do generate silk to make egg sacs and to form drag lines that catch them if they catapult off of a leaf in pursuit of prey or if they have to bail in order to avoid capture themselves. They are, of course, carnivores that eat any small invertebrate that they can ambush and subdue, including other spiders, and they are small enough to become prey of larger spiders, themselves.

Most sources said that their venom (should they even be able to puncture your skin) might result in some pain and swelling, but is not considered dangerous. 

Males encounter females as they wander the landscape. She leaves a trail in the form of a pheromone-laden silk dragline; he catches up with her and romance ensues. She conceals her egg sac and guards it (like the female Philodromus guarding eggs that she had stashed in an empty beech nut shell) until her young hatch toward the end of summer, which markedly enhances the spiderlings chances of survival. The almost-mature spiderlings overwinter sheltered in leaf litter and under tree bark and mature the next year. A bitterly cold winter takes a toll on overwintering Philodromids. 

The most common Philodromid genus is PHILODROMUS, flat spiders that look similar to the Thomisid crab spiders. There are 55 species in North America and about 200 more elsewhere. They’re found on vegetation, but also on the ground or on walls. Larry Weber, in Spiders of the North Woods, writes that Philodromus spiders are often found in trees (and sometimes inside the house, high on the wall), and that he has collected immature Philodromus spiders on the snow in early winter.

Philodromus spiders don’t spin a web but they may create a silken shelter.

With their cylindrical abdomens, spiders in the genus TIBELLUS (tib-EL’-us), the Slender crab spiders, are un-crab-like crab spiders. There are seven species in North America and two (or three) in Wisconsin, and some are striped and others are not. Based on the presence on the abdomen of both stripes and of two spots toward the end, the BugLady thinks she’s photographed Tibellus oblongus, the Oblong running spider, which has a  and is also widespread in the northern half of the Old World.

When a male Oblong running spider encounters a female, he taps her rapidly with legs and palps, and if she’s agreeable, she remains motionless. He spins a “bridal veil” that covers her and fixes her to the substrate. When the show is over, he leaves (in a rush) and she releases herself from the veil.

Today’s Science Word – the Oblong running spider is referred to as an “epigeal” organism, which means that it’s found on/above the soil surface and does not tunnel, swim, or fly. Oblong running spiders are often seen stretched out on grass leaves – the first two pairs of legs forward, the third pair hanging on, and the fourth pair extended back. 

Like other spiders, Philodromids have superpowers, and one is their ability to walk on smooth, vertical surfaces without sliding off. How do they do it? Scopulae (scopulas). Alert BugFans will recall that many bees have clumps of hairs – scopa/scopae – on their legs or abdomens that allow them to collect and carry pollen. Same root word – the Latin “scopa” means “broom,” “twig,” or “brush” but scopula is the diminutive form (mini-brush). Scopulae are dense tufts of hairs that are found below the claws and at their tips on the feet of walking or wandering (non-web-spinning) spiders. The ends of those hairs are further fragmented, forming many, microscopic contact points for the spider’s foot. This creates a natural adhesion that is sometimes enhanced by liquid excreted from adhesive pads (alternately, one source suggested that the scopulae respond to a super-thin layer of water that covers most surfaces).

HEADS-UP! CICADAS ARE COMING!! –��

The BugLady

The post Running Crab Spiders appeared first on Field Station.

The BugLady and her camera have been out scouring the uplands and wetlands for insects that will sit still long enough to have their portrait made. Many of today’s bugs have starred in their own BOTWs over the years, and you can find them by Googling “51���� Field Station followed by the name of the insect. Her gut continues to tell her that there simply aren’t as many insects to point her camera at as there were a decade ago. 

What did she find in April and May?

Woodland Lucy (Lucidota atra), aka the Black firefly (atra means black). If a lightning bug doesn’t light, is it still a Lightning bug? Yup. Most lightning bugs flash their species-specific light signals at females by night, but some, like the Woodland Lucy, are day flyers (the BugLady starts seeing them in swamps in May, but she usually doesn’t see a light show by their nocturnal relatives until the very end of June). It would be a waste of energy to try to produce a light that competes with the sun, so diurnal lightning bugs communicate via pheromones (perfumes). But, all fireflies make light at some point in their lives, and always as a larva (and even the adult Woodland Lucy makes a weak light for a brief time after emerging as an adult).   

Who says “lightning bug” and who says “firefly?” Lightning bug is heard most often in the South and Midwest, and firefly belongs to New England and the West (and Southeastern Wisconsin is close to the border of the two). Someone did a study and hypothesized that people who live in wildfire country prefer firefly, and people who live in thunderstorm country say lightning beetle. The BugLady likes the alternate theory – that you call them whatever your Grandmother called them.

Disonycha Beetle – isn’t this a neat beetle! The BugLady photographed another member of the genus years ago when she was photographing visitors to her pussy willow shrub. It’s in the (huge) leaf beetle family Chrysomelidae, many of whose members are pretty specific about the host plants for their larvae. This one is (probably) a member of the confusing Smartweed Disonycha bunch.  

Grouse Locusts are in the family Tetrigidae (the pygmy grasshoppers), and at a half-inch and less when full grown, pygmy they are! The BugLady usually sees them in wetlands, and some are actually known to swim. They feed on tiny diatoms and algae and aquatic vegetation at the water’s edge.

A Centipede works the boardwalk at Spruce Lake Bog in April.

Ground Beetle Larva – Ground beetles (family Carabidae) are a bunch of mainly nocturnal, sometimes-sizeable, mostly predaceous beetles. Some of the big ones have no-nonsense names like Fiery Searcher and Caterpillar Hunter, and although they are called Ground beetles, they may climb trees to find their prey. They’re long-lived, spending a year or two as larvae and then two or three more as adults. No – the BugLady was not inclined to pick this one up.   

The White-Striped Black Moth (Trichodezia albovittata) is a small (1” wingspan) day-flying moth that’s often mistaken for a butterfly. It’s found in wetlands because its caterpillar’s food is Impatiens/Jewelweed/Touch-me-not. Like other members of the moth family Geometridae, it has tympanal organs (ears) at the base of its abdomen so that it can hear the echolocation calls of bats.  Since it’s diurnal, its ears are superfluous, but it can hear ultrasound (which suggests to evolutionary biologists that its day-flying habit is a recent one). 

Chalk-Fronted Corpals are one of our earliest dragonflies – the BugLady recalls seeing recently-emerged corporals by the hundreds over a dirt road on warm, spring days.

Daddy Longlegs (aka Harvestmen) are not true spiders, though they do have eight legs. The best description that the BugLady has read is that lacking a sharp division between their two body parts (cephalothorax and abdomen), they look like Rice Krispies with legs. This one is well-camouflaged on the fertile stalk of a cinnamon fern.

The BugLady may have to have this engraved on her gravestone (oh wait, she’s being scattered) – Daddy Longlegs Do No Bite People! Also, counter to both urban and rural legend, they are NOT the most venomous animal on earth!!! The BugLady does not care what your cousin told you, or the person who claims to be allergic to their bite. They have tiny jaws, and unlike the true spiders, they do not pierce their prey and then pump in chemicals from venom glands (no venom glands) (and they have no stinging apparatus). They just sit there and chew off tiny (tiny) pieces. Got it?

The Beautify Bee Fly (Bombylius pulchellus) truly is (pulchellos means “little beauty”)! This small fly (maybe ¼”) was photographed in a wetland in mid-May. Bee fly larvae are parasitoids of a variety of insect eggs and larvae – this one targets the sweat bees, which are among our earliest pollinators (not to worry – the system is in balance).

Crane Fly – there are a number of families of crane flies, plus some near-relatives, and they are often collectively called daddy longlegs (though they’re not spiders) and mosquito hawks and skeeter-eaters (though they don’t catch or eat mosquitoes). What they do, is when they land on the other side of your window screen at night, but they’re completely harmless. The “crane” in crane fly reflects their long, long legs – they’re somewhat awkward flyers and even more awkward landers. Like the Daddy longlegs, they’re reputedly extremely venomous (and now it’s time to introduce the third member of our “daddy longlegs trio,” the cellar spider. , but, alas, cellar spiders only have very weak venom). 

How do these things get started, anyway?

Soldier Fly – it’s always a little startling to come across a lime-green fly! 

This Virginia Ctenucha Moth Caterpillar was photographed in April, but the BugLady has found them walking around on mild winter days. The cute caterpillar will morph into a  that looks butterfly-ish until it lands on a leaf and immediately crawls underneath. Despite its name, it’s a moth with more northerly affiliations. 

The (great) Minnesota Seasons website lists three defense strategies:

• Aposematism: The metallic blue color of the thorax and abdomen mimics wasps which may be noxious to predators.
• Sound production: A specialized (tymbal), corrugated region on the third section of the thorax (metathorax) produces ultrasonic sounds which interfere with (“jam”) the sonar of moth-eating bats.
• Pyrrolizidine alkaloid sequestration: Caterpillars acquire and retain naturally produced toxic chemicals (pyrrolizidine alkaloids) from the plants they eat.

Red-Spotted Purple Caterpillars are hard to distinguish from those of the very-closely-related Viceroy and White Admiral caterpillars, and their food plants overlap, too. The caterpillars overwinter in a leaf that’s still attached to the tree, rolled up and fastened with silk. 

Red-spotted Purple? The , and the .

Hobomok Skippers (once called the Northern Golden Skipper) are an early butterfly, often decorating the wild geraniums that bloom by the bushel in May. One source says that they are strong flyers that take off quickly when startled. Amen! They are a butterfly of woodland, wetland and grassland edges, where males perch in the sun and fly out to chase intruders.

“Hobomok” is a nod to an early Wampanoag chief.    

Crab Spider on White trillium – as we all know, the BugLady has a thing for crab spiders because of their ability to hide in plain sight.  This one was photographed in early May. 

Go outside – Look for Bugs!

The BugLady

The post Slices of Spring appeared first on Field Station.

Howdy, BugFans, 

A while back, BugFan Matt asked the BugLady if she had ever photographed a small bee on a Grass-of-Parnassus flower. Grass-of-Parnassus (not really a grass) is one of her favorite flowers (despite the fact that it shouts “Fall is coming!” every time she sees it). She photographs it a lot in the closing days of August, and it turned out that she had seen the bee, but she hadn’t realized how special it was. 

As BugFans will recall from those six weeks of mythology in high school English, Mount Parnassus was sacred to Apollo and was home to the Muses in Greek mythology. Allegedly, cattle on Mount Parnassus grazed on the plant, and so it was promoted to honorary grass status.   

Mining bees have been featured on these pages before. They are small and fuzzy and are among our earliest pollinators (the fuzz keeps them warm on chilly spring mornings). Some are catholic in their tastes (polylectic), but many species are linked to a single, small group of related plants (oligolectic), and some zero in on only a single species (monolectic). Many have no common name at all, but like the Parnassus miner bee, their scientific name may include a nod to their affiliated plant. 

They emerge when their host plants emerge, make tunnels a few inches deep in the ground, scoop out, waterproof, and provision chambers within them with pollen and nectar, and then install the next generation, which will overwinter underground and repeat the cycle when their flower reappears. The various species of mining bees and their flowers span the growing season, and late summer mining bee species are most often seen on goldenrod and on members of the carrot family. 

Except the PARNASSIA MINER BEES (Andrena parnassiae), which are found only where Grass-of-Parnassus lives – calcareous fens (another name for the plant is the Fen Grass-of-Parnassus) and other wet, alkaline meadows and wetlands. They’ve been recorded in Wisconsin, Michigan, Vermont, New Jersey, and North Carolina. A journal article from the early 20^th century said that the bee’s flight period went from August 25 to September 26, and that its only known Wisconsin occurrence was on the Lake Michigan bluffs in the Milwaukee suburb of Whitefish Bay, on a plant that was misidentified, due to an error in an early botany reference, as Carolina Grass of Parnassus (which is found in Florida and the Carolinas). 

The hairs on their body act as pollen collectors, too, and they have pollen baskets on their back legs.  Parnassia Miner Bees only glean pollen from Grass-of-Parnassus flowers (and they are important pollinators of it – more about that in a sec), but the flowers are also visited by other bee species, syrphid and other small flies, ichneumon wasps, butterflies, (and the BugLady found a lightning beetle checking it), and by spiders with a taste for pollinators.    

When you (or a bee) look at the flower, what do you see? The green lines on the five petals are nectar guides, beckoning the bee to follow them to the nectar source. But the bee also notices a ring of 15 filaments at the base of the petals (actually five sterile stamens or staminoides, each divided into three prongs), each topped with what looks like a drop of nectar, resembling the (male) stamens of the flower. These are false nectaries that provide no nectar reward but serve to get the bee into the right vicinity – the real nectar lies at the base of the filaments. 

There are also five true stamens, each topped with a pollen-producing anther, and in the green center of the flower, the female flower parts – stigma, style and ovary (collectively called the pistil).

[Nota Bene: the BugLady learned just enough Botany in college to make it through the Botany final, and she’s been forgetting it ever since, so she has to pull up a chart on Wikipedia every time she tries to write about flowers.] 

The BugLady was wondering about the pedigree of Grass-of-Parnassus and she encountered some confusion about that. Several reputable sites reported that it was in the Saxifrage family, but another said that there was only a very distant familial connection. Others put it in the Staff tree family Celestraceae, and still others placed it in its own family Parnassiaceae (though it may be destined to rejoin the Celestraceae).   

Putting it all together: It’s a sweet little flower that has worked out some complex strategies to spread pollen and to avoid self-fertilization. Consider the five true stamens. Rather than maturing all at once, only one lengthens, matures and produces pollen per day, arcing over the top of the pistil. After the first day, its anther turns brown and the filament relaxes against the ring of petals, and another stamen grows and produces pollen.  

The pistil does not grow or become receptive to incoming pollen until after all five stamens have matured, making it impossible for the flower to self-pollinate. Eastman, in The Book of Swamp and Bog, says that the flowers exhibit protandry – that is, the flower, which has both male and female parts, is unisexually sequenced, the male parts completing their development before the female parts start. To put it another way, the flowers have a male phase and then a female phase.

When a bee is tempted by the beads of false nectar and orients itself to harvest some, it straddles an anther, and pollen is picked up by the hairs on its abdomen. When it visits the next flower, pollen is brushed off, hopefully onto a flower whose female parts are ready to receive it (“xenogamy” “stranger marriage” — a flower breeding not with itself but with another).  

Bryan Pfeiffer, naturalist and blogger (“Chasing Nature”) and Grass-of-Parnassus watcher, has written some very nice entries about his experiences with both the flower and the bee – here are two [ and .]

Xenogamy, polylectic, oligolectic, monolectic, staminoides, protandry, stamens and pistils and anthers, oh my – it’s January, time to dust off our brains. There will be a quiz. 

The BugLady

As a bit of lagniappe, .

The post Parnassia Miner Bee – a Bee and its Flower appeared first on Field Station.