Insect Picture of the Day

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I had no idea what I was looking at. “Hey hon, can you grab my camera?” I knew I had to get a picture of this strange little mantis-like bug before it disappeared back into the hole it had come out of. The hole was tiny, the size of a small screw hole. That would be because it was a small screw hole.

My wife, camera in hand, knew why I wanted the camera. “Some kind of bug in the house?” It’s just one of those things, now; I photograph bugs. Sure, she thinks it’s kind of weird, but it’s nice that she’s willing to support me in my weird hobbies.

I sent the picture to David, knowing it wasn’t great, but was at least okay. I figured, in the worst case, it could be used as a back-up for Winter, which seems to grow longer every year, and in the best case he’d think it was great. He wrote back pretty quickly:

“Nice Assassin Bug photo!”

They’re living in the walls! I know I joke a lot about spiders just biding their time, waiting for the day that they’ll band together and eat me, but now they’ve hired help! Should I hire a bodyguard of some kind? Maybe a Praying Mantis?

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One of the advantages of my 2nd-story office is that really interesting bugs crawl on the screen just inches from my computer.

Of course, the downside is that I have to photograph them through the screen. Can’t win them all, I guess.

I don’t actually know if this is a leaf-footed bug or not. I actually think it might be an assassin bug instead. Take a careful look down the middle of its belly. See that thin black line that ends down around its belly button? That’s it’s beak! It stabs that into things. The question is, does it stab it into fruit… or other bugs?

Also, bugs don’t have belly buttons. That’s silly.

Aughh. I wrote this post but didn’t click “publish”. Just got home and saw that we’ve been without InsectPOD all day, AGAIN.

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James R. Newman perfectly captures the saw-toothed wheel on the back of this wheel bug,which is one of the largest species of assassin bug. He has this to say:

I was out in the back yard, playing with the new camera (you know:
“Shiny!”) when I caught a hint of movement on the dog’s old water bowl.  It
was this assassin bug, which had apparently decided that if it moved slowly
enough, I wouldn’t notice.  It didn’t move any faster as I got closer, but
the antennae did move a bit more, like it was trying to figure out what the
large circle in front of it was.

Great shot, James! Thanks!

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Jesse Moore went back out looking for those bugs later, and found this assassin bug. He has this to say:

This time, I have some good shots of what I am fairly sure is a Bee Assassin Bug (Apiomerus crassipes).  I was definantly hunting in the time I observed it.  Unfortunately, it did not catch anything though.

He also tracked down yesterday’s bug and identified it as  a wheel bug nymph. (”Wheel bug” is a common name for one of the largest species of assassin bugs.)

Jesse included this awesome phrase in one of his emails: “if you decide not to use these I would appreciate some critique on how I can improve.”

Yes, I have some advice: Keep doing what you’re doing. It’s working.

Thanks, Jesse!

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Jesse Moore writes: Last is a strange one. I was picking some cherries and happened to notice one of these crawling up the branch. Then I started to notice more and more of them, probably 4 or 5 in one little area. I have no clue as to what it is. The picture of one on a cherry gives a good idea of scale.

Jesse’s email is letter perfect, and he does not use the phrase “what in the freaking heck is that thing???” I just want to point out a bit of bug identification etiquette here: when you have a bug this weird, that phrase is actually completely acceptable.

I mean, look at the butt on this thing:

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Jesse continues: They have that pointy-looking beak that makes me think it is some kind of assassin bug or maybe a sap-sucking bug. None of them seemed to be interested in eating the tree but rather seemed to be hunting so I am favoring the hunting assassin bug idea.

I am favoring this idea, too. But with an extra dash of “ewww, that thing is freaky.”

Don’t freak out or anything, guys, but Jesse has more pictures of these critters tomorrow.

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A few nights ago I noticed something trundling across the carpet into the downstairs bathroom. I grabbed my camera and a flashlight and snapped this shot of an assassin bug nymph. I’m not really sure if it needed to go potty or if it was just up to get a glass of water.

If you haven’t seen these nymphs before on the site, they’re actually jet black: the white coating is lint and dirt that they glue to themselves with spittle to form camouflage. When they molt into their final adult form, they’ll discard the camouflage as well and be a beautiful, shiny blue-black.

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Here’s another great picture from Scott Roche. This one is of a “wheel bug” or assassin bug. The fluted rills on the sides of its abdomen are pretty characteristic for this type of bug. The namesake feature of this bug is hard to make out in this photo because of the angle: between its shoulders is a ridge that sticks up in a rounded “wheel” shape.

I still can’t tell for sure if these critters are venomous or not, but they will bite, and quite painfully, if provoked. At least, that’s the theory. Several readers have written in to say that they handle these bugs all the time without incident. Maybe these bugs just find some people less biteworthy?

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Here’s another view of the assassin bug nymph I posted last month. It is a titch under 1cm long.

I still don’t know what the exact function of the lint covering is, but after researching unusual bug defenses I suspect that it is tactile camouflage, designed to render the nymph invisible to ants and other insects who would attack immediately upon touching its exposed carapace with their antennae. Ants palpating the nymph with their antennae would conclude that it is nothing more than a ball of lint and leave it alone.

It may also be that this camouflage is aggressive in nature, allowing the nymph to peacefully lurk in ant-infested areas. This could possibly be to allow them to prey upon ants but is equally likely to allow them to prey upon species found near ants, such as aphids. (Well, maybe not aphids–they’re a bit on the small side for assassin bug fare.)

One final option suggests itself, and the more I think about it the more likely I think it may be: I find these nymphs in my house and garage in areas heavily infested with Steatoda triangulosa, but I don’t find dead nymphs in the spider webs. It could very well be that this camouflage also works with spiders. Upon falling into a web, if the nymph holds still, the Steatoda might misidentify it as a bit of fallen debris and eject it from its web.

Then again, given their highly predatory nature, perhaps they then eat the spider. I haven’t observed any of this, so it’s all just armchair entomology and I’m probably very wrong. But in the three months I’ve been running this site, I have learned that this behavior is by no means too complex or complicated to be possible in the world of bugs!

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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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Oh noes! It is a killer ball of lint! …well, actually, that’s not far from the truth. You are looking into the face of an assassin bug nymph, and it has indeed covered itself in lint.

Assassin bugs, Family Reduviidae, are a fairly diverse group of insects, varying considerably in shape and coloration. The adults out here are a gorgeous shade of black: a pure, glossy black that is so black it shimmers blue and looks wet. The nymphs, as you can see, are… well, actually you can’t see their coloration, at least not easily. The nymphs gather up lint and dust, spit on it, and stick it all over their body for camouflage. I assume that this is defensive camouflage rather than offensive, but that’s just my assumption. They are fairly slow moving, while the adults are quite nimble. I don’t know if the camouflage helps them sneak up on prey, but it could well enable them to ambush prey: a passing insect might touch it with its antennae and assume that it was just a lump of dust.

Oh, and it’s about 4-5mm wide in this photo. The nymphs tend to be 5-8mm long.