Insect Picture of the Day

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European paper wasps were introduced to eastern North America sometime around 1980. Compared to native species, they breed faster, are more tolerant of extreme climates, are more aggressive, and are significantly less averse to building their nests on man-made structures. As a result, they have easily taken over the ecological niche for social wasps, displacing native species and spreading across the entire continent.

My house currently has 9 major nests (larger than 4″) on it and probably a dozen minor nests (less than 2″). I destroy them as I find them, but the major nests got to be major because they’re too high for me to reach with the wasp killing spray. A neighbor suggested I call an exterminator, and then laughed, suggesting that my house alone might qualify for their group rate.

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Here’s one of the last midges of the season, artfully posed on a poplar tree along a wetland trail near Utah Lake. You’ll need the larger version to see the midge closely; I found the scenery framing this image in soft-focus to be as compelling a part of the image. Here’s a zoomed-in version of the midge itself. Note that this species is a little bit different than the midges I have posted in the past; I’ll try to get a better picture of one later.

This female midge is heartily braving the late September night temperatures here. Last night got down to 0.5°C (33°F). For better survival in temperate climes with wild temperature fluctuations, many insects have evolved criostatic compounds in their blood and organs, enabling them to shut down without dying when temperatures hover near or even dip a little below freezing. They can’t actually survive being frozen solid, but the same criostatic compounds that allow them to survive chilling also act as antifreeze, allowing them to remain unfrozen a few degrees below zero. Since Autumn temperatures occasionally reach freezing but rarely plummet more than a degree or two below, this allows them to survive nights of severe exposure. The midges seek out places to spend the night where they hopefully won’t get eaten, and then go into an overnight hibernation mode. This effectively extends their yearly activity cycle by as much as three months here in Utah, where daytime temperatures still get up to 26°C (80°C), which is perfect for flying, feeding, frolicking, and of course, making more bugs.

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Funnel-web spiders like to string tangle webs in the corners between two walls or other surfaces. Their webs are not sticky, but instead start out as instant cobwebs: the silk frays and shreds even as it is spun into place. The result is a sort of fuzzy velcro, and when a bug wanders into it the spines and hairs on his body get snagged in the loops of silk, slowing it down long enough for the spider to catch it.

This funnel-web spider set up shop in an interesting place: below the vent grate in the shed floor above the root cellar. A perfect place to catch bugs migrating from the bright light and fluctuating temperatures outside to the cool, inviting darkness of the cellar. The translucency of her legs and body are due to the harsh backlighting and to the fact that she’s quite small: not counting the legs she’s probably only 8mm long.

For the spider’s part, she knows that the web won’t catch her prey for her, but only slow it down, so she comes rushing out lightning fast and attacks the tangled bug, usually going immediately for a grab and killing bite. It can be rather unsettling to watch at times, because these spiders really do appear very fast and aggressive. Towards humans, however, they are not much of a threat: they use their speed to flee from prying fingers and eyes. The funnel of their web is actually an escape hatch. If anything comes into the web that’s too big for the spider to handle, she bolts down her funnel and out of her web to safety.

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One of the best parts about studying bugs is the Ewww Factor, and these little guys sure do work that angle. These are walnut grubs, and I have no idea what they turn into (but it’s probably a moth). This type of walnut is a black walnut, and walnuts fend off predators and competition alike by producing midly toxic husks and leaves. This combined with a thick canopy to block out sunlight is why it is often hard to grow grass under walnut trees.

Whatever these grubs are, they seem to be unfazed by the walnut’s poison; if anything they seemed to find it extra tasty. They squirmed and glistened the whole time they were photographed. Which just added to the Ewww Factor. (Awesome.)

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A hundred tons of armored devastation! That is what this critter would be if it, well, if it weighed a hundred tons, I guess. This little critter is actually less than 5mm long.

Playing with a sowbugs is a quintessential component of childhood: when you pick them up they roll into a little ball. They have many nicknames, such as pill bugs, potato bugs, and “roly polies”. They belong to order isopoda, which means “balanced foot”, and family Oniscidea, or wood lice.

A few species of Oniscidea may damage garden plants, but by and large they are content to mulch dead leaves in the soil, and are generally considered beneficial–and that’s not counting the cool roly poly factor.

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This female praying mantis hunts in the ground scrub near Pack Creek in Moab, Utah. This is the same praying mantis that was featured two weeks ago on my Dad’s hand. I’m trying to avoid posting duplicate bugs, and when I started the site I even had the lofty goal of going 365 days without posting the same species twice. Two things have combined to prevent this:

1. It is much harder to get good photographs of insects consistently than I thought it would be, and this does not scale with effort. A one-hour field trip typically yields one decent picture, but a ten-hour field trip often only yields four or five.
2. Some bugs are very camera shy and I have to stalk them patiently for many minutes to get even one decent picture, but other bugs–like this praying mantis–are so obliging that in sixty seconds I have half a dozen great pictures, and it’s hard to choose between them, especially when the alternative is a blurry, statically-posed critter who really didn’t want to be on the website anyway.

Since she posed so artfully here, I decided to let her be the Insect Picture of the Day for a second day. Hope you like her, she was fun to photograph!

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The Labor Day trip to Moab produced dozens of great pictures for this site, but this yellow mud dauber wasp apparently didn’t get the memo that I would be coming by and would appreciate it if she would stop for a moment to pose for photos. This was as close as I could get to her for a picture.

Mud daubers make a cocoon out of mud for their larvae; if you have a garage in mud dauber country you might well have one or two of these mud tubes up high on your rafters. They’re left open at one end so the emerging wasp can get out. Although their size can make them appear intimidating, they’re actually quite shy and nonaggressive. Mud daubers are solitary wasps; they do not build hives or live in social groups like bees and hornets. As a result, they don’t have the aggressive nest-defense instinct. Because they’re aggressive predators, however, mud daubers are extremely beneficial wasps to have around.

This wasp was circling a stand of sunflowers with about six other wasps, all of different species, and it was pretty clear from their flight pattern that they were all sure there was one last spider in there somewhere. Solitary wasps don’t even stick around to tend their larvae after they lay their eggs in their nests; they will generally kill or paralyze a prey insect or spider and then leave it behind for the emerging larvae when they abandon the nest.

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Here’s another sarcophagidus fly from my parent’s rabbit farm in Moab, Utah. I believe the distended abdomen here indicates a very pregnant female.

Bug antennae grow out of the same spot that mammals grow nostrils, and both organs are used for the sense of smell. Seeing bugs like this, I am glad that my nose isn’t inside out and hanging out in front of my face. (This fly also makes me glad I don’t eat poop, but that’s not an antennae story.)

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This grasshopper was fully concealed behind the grapevine when I first approached, but as I got closer it turned more and more sideways to the stalk. It had anchored its jumping feet to the side branch, and was tensing for a good evasive leap, but I stopped far enough away to let it relax.

I love the antennae on this gr’opper, as well as this pose that says “I am really quite bad at peek-a-boo.”

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This crab spider managed to convey the ambivalence of the tiniest predators nicely: It waits here for prey to wander in front of its hidey hole, but only if it is prey smaller than a millimeter or two!

Crab spiders have long front and second legs for grabbing prey as it wanders past. A common tactic of larger crab spiders is to perch on a flower petal and grab flies and bees that come for the nectar. This juvenile spider is much too small for that just yet: barely 2mm across! For now it must be content with dark crevices, waiting for gnats and mites to pass by.

A distinguishing trait of all spiders is that they all use silk, but as we learn from crab spiders this does not necessarily mean that they make webs. Crab spiders make their egg sacs from silk and may make small cocoons when they molt, but other than that they’re just an eight-legged bug.