Insect Picture of the Day

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How many licks does it take to get to the gooey center of a cricket? This praying mantis knows!

Happy Halloween!

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So, for the “creepy bugs” run-up to Halloween, I had a creepy picture of an assassin bug nymph ready to go. But then reader Dennis Havens sent in this photo, and I quickly realized three things:

1. What’s better than an assassin bug nymph? An assassin bug!
2. What’s better than an assassin bug? TWO assassin bugs!
3. What’s better than two assassin bugs? Two assassin bugs getting busy!

These assassin bugs, Arilus cristatus, are commonly called “wheel bugs”, which is a silly name for a bug that should obviously have been named the “half-a-sawblade-back bug”. And not just because my name for them is more descriptive and accurate, but also because “half-a-sawblade-back-bug.com” is not being parked by domain-name squatters. Not so for wheelbug and wheelbugs–I’m not even going to put the .com next to those words, let alone link them. Anyway, the point is, these bugs clearly did not do their internet research.

Assassin bugs are fitting for Halloween because they are genuinely scary. They are not intimidated much by people, and will rear up in a threatening stance rather than run away. See their beaks, folded back from their heads? The bite of an assassin bug is commonly reported to be “excruciating”. They inject a dual-purpose venom: if you’re a tiny bug, it is very quickly lethal. If you’re a big vertebrate, it causes an intense burning pain. One person on bugguide.net reported the pain was like having a tooth drilled without anesthetic… for two days.

Still not scary enough for you? Okay, check out this video on National Geographic’s website. It gave me the squirms.

I don’t know the exact sizes of these bugs, but Arilus cristatus ranges from 15mm to 30mm long, with the females being much larger than the males. There are four different species in genus Arilus, but A. cristatus is the only species currently found in the United States.

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Yesterday’s spider concludes the Halloween Spider Week. Halloween is still 3 days away, I have picked 3 really creepy insect pictures for your enjoyment this week.

Today’s picture is a ladybug larva. After the winter cold snap, Sandra Tayler called me to tell me that her side of the valley had not received snow and that they still had bugs in their yard. I grabbed my camera and came over, and we spent some time photographing insects and spiders in their yard.

I’m not really sure what the purpose of metamorphosis really is for ladybugs. The larvae are fully mobile and eat aphids just like the adults.

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Sometimes my camera annoys me, and other times it amazes me. This would be one of the amazing ones. This is the same spider I posted last week, but in a side pose showing off her fur. She is sitting on the window screen of my front door, which is about a 2mm mesh, which puts her body length right at about 4mm.

This jumping spider astonished me by being so distinctly colored and beautiful on such a tiny scale. I caught her in the act of eating a midge, but didn’t manage to get any clear pictures of her (and she dropped the midge, the better to run, when the camera got close).

This barn funnel weaver spider made its nest under a board in my wife’s parents’ garden. Happily, I had my camera when said board was overturned.

I suspect that this one is a juvenile, as the chevron pattern on its back is still rather indistinct. It was also hiding under a board rather than lurking in a web, and while this is typical behavior for males, it lacked the large pedipalps of a male funnel weaver. It could have simply been a female spider that was between webs at the moment, but this is uncommon behavior for that species and gender.

The other reason to suspect that it is juvenile is its size: maybe 7-8mm in body length, most funnel weavers in my in-laws’ garden reach 15-20mm in length in adulthood.

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This garden spider picture was taken by Jarek Kucek and sent in by his coworker, reader Kit Watson. It’s a female Cross Spider, Araneus diadematus, which is another one of the larger orb weavers. They can reach up to 3cm body length. The name Cross Spider comes from the pattern on her abdomen.

You can tell it’s a female by checking the pedipalps. Males have pedipalps with tips so swollen that they look like little boxing gloves; females will catch you staring and say “Ahem. My face is up here.” This particular spider says it with a charming British accent: Kit and Jarek send us this picture from England.

If you look carefully at the larger resolution image, you can see how she clings to her web: the silk is pulled in under tension where each foot makes contact. Yesterday I said that the radial lines are not sticky while the spiraling lines were; I should point out that at the center of the web, none of the silk, radial or spiral, is sticky. You can’t really see it here, but in other webs, you can often see two separate spirals: the outer spiral is made of glue silk, while one at the center is for the spider to lair on and is made of dry silk.

Another detail from the large resolution: there is a dark-colored lump underneath her. It looks like it could be the head of a fly; if this is the case then this spider is quite small for a cross spider, perhaps only a centimeter long. Of course, it could be a horsefly, in which case this diadematus could be pushing 2.5cm after all.

It’s really hard to tell from the photo. I’m going to tell my friend Randy that it’s the head of a chihuahua.

I just swapped a quick e-mail with Kit; she says that, from memory, the spider was perhaps 15mm long, plus or minus 5mm.  (Don’t tell Randy!)

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Halloween Spider Week continues! This Argiope aurantia, or Golden Orb Weaver, lives outside the 2nd story stairwell of a parking garage frequented by reader Andy Roche, who sent in this great photo. Argiope spiders have a very high “creep factor” because they can reach up to 3cm–and remember, that’s not counting legs.

Orb Weavers build the classic spiral spiderwebs, called–you guessed it–orb webs. The radial guy lines are made of dry silk, while the spiraling pieces are made of sticky silk that traps insects. The general theory is that the spider can walk on the dry silk without getting stuck, and this is generally true; the reality is that spiders just understand how silk and webs work, and when they get a leg stuck in their own web they carefully pull it free without thrashing around to get the rest of themselves stuck. The next time they return to the center of their web to rest, they pull the affected leg up to their mouth and carefully chew any residual glue off.

One of the interesting telltales of Argiope webs is the stabilimentum, the fuzzy white sheet at the center of the web, often with zig-zaggy bits above and below. (You can see a very small, single “lightning bolt” zigzag coming down from below the spider’s perch.) Nobody knows why they do this; the best theory is that it provides camouflage against avian predators.

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This funnel-web weaver lives right outside my front door, on the brickwork about a foot away from the door handle. She’s pretty big, nearly 2cm from eyes to spinnerets. One thing I notice about spiders in the wild is that they’re usually hungry, but they’re always thirsty. I happened to be carrying a spritzer bottle, and gave her web a good beading–that’s the reason she’s on a white sparkly background here. First she fled from the sprinkling water, then she came out and drank up the “dew” that had fallen on her web.

Funnel-web weavers get their name from the shape of their web. It’s a wide sheet of dry tangle silk, and the spider lurks at the back in a funnel-shaped tube. It is a true funnel: it is open on the other end, usually exiting somewhere away from the web, preferrably on the other side of some barrier. The spider uses this as her “bolt hole” in case something too big to fight comes prodding at her web.

Funnel-web weaver spiders seem to be rather opportunistic about their webs as well. There are two webs on either side of my front door (for a total of four) and at any given moment only two of them are ever occupied. A few weeks ago a male spider came calling; he boldly stepped right into this spider’s web. I came out the next night to find him lurking in the funnel waiting for prey, while the web’s former occupant had moved into the web above. After he moved on, she came down and moved back into her old web.

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One afternoon about a month ago I was at home when the doorbell rang twice followed by urgent knocking. I opened it to see my neighbor’s young son breathless on the porch. “Mom says come quick, there’s a spider you gotta take a picture of!”

This is what responsible parenting is all about. If you have a weird neighbor that photographs insects for a website, don’t just squash bugs when you see them. Call the weird neighbor over instead!

Mark and Tamina Halladay live at the end of my street, just a few meters from the protected wetlands surrounding Utah Lake. Ecogeodemographically speaking, this means they get a better class of insect that I often do: There’s a hundred meters and half a dozen houses between my yard and the wetlands.

This is not the spider I was sent to photograph; they had a 3cm lycosa rabida on their porch complete with young spiderlings on her back, but I could not coax her out of her hiding hole to get a clear photo. While there, however, Tamina mentioned that Mark had cleaned out the garage because he thought they had black widows. Knowing that black widows were uncommon in our neighborhood (but not at all impossible for our county), I offered to take a look. What I got for my trouble was a picture of this gorgeous steatoda triangulosa in her web tending a couple of egg sacs. She’s fully grown at about 5mm long.

Since these spiders put ecological pressure on black widows, I gave the Halladays a quick primer on how awesome steatodae are. I saw them at church last Sunday and was happy to hear that the spiders are no longer in danger of being wiped out by Mark on account of them no longer being in danger of being black widows.

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Halloween Spider Week continues! Phidippus Audax, the “daring jumping spider”, is possibly my favorite of all spiders. Their awareness and expressiveness make them lots of fun to interact with. This gal is enjoying the brief warm of afternoon sun on the sliding door to my deck.

Again, gender is determined by examining the pedipalps, the short fuzzy appendages just below her eyes. What you do is this: you examine them very carefully, and if the spider says “Hey. My face is up here” then you know she’s a girl.

The brilliant green below her eyes are her chelicerae–you can only see the top half of them. Down where you can’t see them (because her pedipalps are in the way) are her fangs, which in phidippi are quite fearsome and plainly visible to the unaided eye. The chelicerae are covered with tiny iridescent scales, much like a butterfly wing. When threatened or courting (and as we’ve already seen, with jumping spiders this is often the same thing), they raise and spread their forelegs to make themselves appear larger, and they draw aside their pedipalps to fully expose chelicerae to make themselves look more fierce. I recall reading that the color of the chelicerae is important to the mating display. My memory may be faulty on this, but I seem to recall that males have blue chelicerae while females have green ones; I think this is limited to the phidippus genus.

Oh, and she’s about 10mm long. She’s in her penultimate instar, which is why she’s black and orange. (Fitting for Halloween, no?) She’ll probably overwinter in this stage and go through her final molt in Spring, emerging a pure black with clean white markings.