The Bug Geek

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Category Archives: Insects

Photo Friday: Faves of 2012

Green Lynx Spider, Peucetia viridans [Explored]Bolitotherus cornutus (Forked fungus beetle) 1Phidippus sp. 2Baby corn snake!Phidippus regiusAnisomorpha buprestoides (Southern Two-Striped Walkingstick, Devil Rider, or Musk Mare)
Brown Anole, Anolis sagreiStriped Bark Scorpion, Centuroides hentziMole cricket, Scapteriscus borelliiSnipe fly, Rhagio hirtus (female)Spider sex - Eris militaris Wasp Mantidfly (Climaciella brunnea)
Stratiomys badia (soldier fly, Stratiomyidae)Variable Fan-Foot (Zanclognatha laevigata) # 8340Spring Peeper, Pseudacris crucifer

Faves of 2012, a set on Flickr.

Over at Compound Eye, Alex Wild is curating submissions of nature and science themed “best of 2012” photo sets. If you have some photos you’re proud of and would like to share, why not leave a link in the comments?

While I didn’t spend nearly as much time taking photos this year as I would have like, I still managed to get a bunch of shots I’m really happy with. Here’s my submission: some of my faves from 2012. ūüôā

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Poop, not parasites

So a very cool bug photo has been circulating on the web: I’ve seen it on Tumblr, Facebook, Pinterest and Twitter. It’s a pretty darn great photo:

Photo of a Cereal Leaf Beetle Larva, by Giles San Martin, used under a Creative Commons License.

Photo of a Cereal Leaf Beetle Larva, by Giles San Martin, used under a Creative Commons License.

Let’s zoom in on that a little, shall we?

Closeup

Well, my goodness. That’s really something, isn’t it? Here’s the accompanying story circulating on the web:

This is a juvenile form of the Cereal leaf beetle (Oulema melanopus) after being parasitized by Tetrastichus julis, a parasitoid wasp which lays its eggs inside the larva of the beetle. They eggs hatch within the larvae and begin to feed while it is still alive, before they burst out and kill it.These parasites are often used as a biological control, as the Cereal leaf beetle is considered a pest and regularly feeds on crops.

Well, now, that is REALLY something isn’t it? Parasites are so freaking cool.

The problem is, the pairing of this particular image with this particular caption has lead to some confusion. 

While the species identities are correct, and the stated relationship between the two is correct, the caption seems to imply that the skin of the poor beetle larva is stretched shiny-tight and close to bursting from a insanely huge parasite load (indeed, this is how the interwebz has been interpreting it).

This interpretation is only a little bit correct.

The beetle IS parasitized Рby one parasite. Just one. 

The rest of that squirmy-looking mass on the back of the beetle is a perfectly normal thing (well, if you’re a leaf beetle anyways): it’s¬†a fecal shield. Yes,¬†fecal shield. As in, “poop”.

Many, many Chrysomelids (leaf beetles) create fecal shields, depositing their feces on their backs. It’s so prevalent, in fact, that the study of fecal shields warrants its own term, apparently. From the section in Caroline Chaboo’s book chapter¬†on Chrysomelid defences entitled, “Fececology” (ha!):

The [Chrysomelid] subfamily Cassidinae has ~3,000 species whose larvae carry a mobile shield made of dried feces, attached to paired processes at their hind end, and held over the body like an umbrella. This shield may be held flat on the dorsum or elevated to hit an attacker. In two other leaf beetle subgroups, the subfamily Criocerinae (~1,400 species) and in some members of the subfamily Galerucinae (~14,000 species) the fecal material is simply piled directly onto the back of the animals, with some falling off as the animal moves around but regularly replenished to maintain coverage of the exposed dorsal surface (Fig. 2b, c). In Chrysomelinae leaf beetles (~4,000 species), the mothers take time to build a fecal case entirely around every single egg.

Compare the photo above with this one showing the fecal shield of a Criocerine Chrysomelid, Lilioceris lilii:

Photo by Luis Sanchez, used under a Creative Commons License.

Photo by Luis Sanchez, used under a Creative Commons License.

Also goey, revolting, and arguably very unsanitary – but normal.

Here’s a different spin on the same theme, this time in a tortoise beetle larva (Cassidinae):

_MG_9225

Photo by Kurt Komoda, on Flickr: http://www.flickr.com/photos/komoda/ Used under a Creative Commons License.

Less slimy, and mobile – but normal. (And still poop).

Fecal shields provide camouflage, prevent desiccation (drying out), and, ironically, can deter predators and parasitoids. Some parasitoids, however, can exploit the fecal sheild and may actually be attracted to the plant volatiles (smelly plant chemicals) in the feces. This could be what happens in the relationship shown in the photo, since the T. julis is a well-established predator of the cereal leaf beetle and, obviously, that goey shield is not much of a deterrent.

So, just to clarify what you’re seeing in the original ZOMGPARASITES photo: in addition to piles of poop, the one visible parasitoid larva is the pale, segmented critter in the front near the beetle larva‚Äôs head. Now, its placement is a little odd, because T. julis is normally an endoparasitoid, meaning that the mother wasp lays her egg(s) directly inside the body of the host (the beetle larva). In this case, though, it looks like the parasitoid larva is¬†floating in the fecal shield, so I‚Äôm not sure what that‚Äôs all about. Lousy aim, perhaps? Even if it was a motherly misfire,¬†I have it on good authority (hat tip to Richard Comont) that the photographer reared out the parasitoid and it did indeed grow up to be T. julis.

So. Long story short:

This is a normal fecal shield, people. Not an imminent explosion.

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ResearchBlogging.org

Chaboo, Caroline (2011). Defensive Behaviors in Leaf Beetles: From the Unusual to the Weird in Chemical Biology of the Tropics, J.M. Vivanco and T. Weir (eds.), 59-69 DOI: 10.1007/978-3-642-19080-3_4

Evans, E., Karren, J., & Israelsen, C. (2006). Interactions Over Time Between Cereal Leaf Beetle (Coleoptera: Chrysomelidae) and Larval Parasitoid Tetrastichus julis (Hymenoptera: Eulophidae) in Utah Journal of Economic Entomology, 99 (6), 1967-1973 DOI: 10.1603/0022-0493-99.6.1967

Schaffner, U., & M√ľller, C. (2001). Exploitation of the Fecal Shield of the Lily Leaf Beetle, Lilioceris lilii (Coleoptera: Chrysomelidae), by the Specialist Parasitoid Lemophagus pulcher (Hymenoptera: Ichneumonidae) Journal of Insect Behavior, 14 (6), 739-757 DOI: 10.1023/A:1013085316606

Photo Friday – A horned beauty

I’m still not entirely sure how this little fellow caught my eye – he was resting on the rough bark of a maple tree, blending almost perfectly.

Maybe he sneezed, or something.

Either way, he’s probably one of my favorite finds of the summer, partially because it’s a “new-to-me” species, and partially because…well, just LOOK at him:

Bolitotherus cornutus (Forked fungus beetle) 1

Male Forked Fungus Beetle, Bolitotherus cornutus

Is that not one of the most adorable little faces you’ve ever seen? The little upturned “nose”! But the fancy adornments on the thorax of this male forked fungus beetle (Bolitotherus cornutus) are what makes him stand out from the crowd:

Bolitotherus cornutus (Forked fungus beetle) 4

These Darkling beetles (family Tenebrionidae) like to hang out on shelf fungi on maple and poplar trees, and are mostly active at night. Only the males sport these fuzzy-tufted “horns”. I have scoured the literature and can’t find a single conclusive answer for their purpose. I suspect they’re partially for fighting with or expressing superiority over other males, but the hairs suggest some kind of sensory function. I really don’t know, and would love it if anyone could shed some light on these structures.

Bolitotherus cornutus (Forked fungus beetle) 3

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An another note, I just wanted to tell you that I’m on the Entomology conference circuit for the next two weeks! I’ll be attending and speaking at the Entomological Society of Canada and the Entomological Society of America meetings. If any of you are coming, I’d love to know! Send me a tweet at @GeekInQuestion ūüôā (Also, once these talks are finished, I’m going to FINALLY get around to updating you all on my research a bit – it’s been a productive couple of months!)

Photo Friday: Wolf spider parasite

I’m busy preparing my talk for the Entomological Society of Canada conference*, which is coming up in just a few short weeks! I plan to give a presentation about the cool/gross beetle parasites I found in some of my Arctic study sites.

Since I’m once again (still?) parasite-obsessed but don’t want to bore you with more photos of worms coming out of beetle’s butts, here’s another cool parasite (well, parasitoid, technically) from the Yukon territory, photographed while driving up the Dempster Highway this summer.

Parasitic wasp emerging from the egg sac of a wolf spider

Wolf spiders are incredibly abundant predators on the tundra – you can see them scatter underfoot with every step. Females are even easier to spot, since they are often toting their pale-coloured egg sacs at the end of their abdomens.

Many of the spiders’ eggs will never hatch, however: somewhere along the line, a teeny-tiny parasitic wasp laid HER eggs beneath the carefully spun silk.¬† The baby wasps hatch and then feed on the spider’s offspring, and the end result is what you see up there: little wasps emerging from the poor mama spider’s egg sac.
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* Speaking of the ESC meeting, if you are attending and haven’t yet submitted your images to the Photo Contest, GET ON IT! It promises to be a great competition, with extra-cool judges like John Acorn !! Go submit now!

ESO Bug Eye Photo Contest!

The results of the Entomological Society of Ontario Bug Eye photo contest were announced last night!  We were treated to a slide show of the 130ish entries; there was some spectacular work!

Also this:

I took 2nd place in the “Ontario Insect” category for

Mine foot is tasty (omnomnom) - a green Katydid

2nd in “Photo by an Ontario Resident” category for

Anisomorpha buprestoides (Southern Two-Striped Walkingstick, Devil Rider, or Musk Mare)

and 1st in the “Open Category” for

Green Lynx Spider, Peucetia viridans [Explored]

It was a good night! <—massive understatement. I’ll be one of the judges for next year’s contest ūüėÄ

I don’t think I mentioned this either: one of my photos was one of seven selected in the Entomological Society of Canada photo contest to be on the cover of the journal, The Canadian Entomologist, for 2013!

Stratiomys badia (soldier fly, Stratiomyidae)

Other than simply being ridonculously thrilled over these results, I think what I’m most pleased about is that all four of these photos use different techniques (natural setting/outdoors and studio), lighting (ambient light and flash), use of backgrounds (white box, coloured, black) and subjects (spider, phasmid, fly, katydid).¬† I’m happy to be producing decent AND diverse images! ūüôā

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