Tuesday, August 12, 2008

Spined Soldier Beetle vs. Caterpillar

This past weekend I was out in the field with some amazing naturalists, helping lead field trips for the Appalachian Butterfly Conference in Shawnee State Forest. (Jim McCormac's blog covers this event nicely, and, if you didn't join us this time, maybe you can next time. Don't believe his false accusations of butterfly bait snarfing; they are simply not true :) Cheryl Harner is a much more likely candidate for that. ;) )

I encountered some amazing sites at ABC, so I will cover some of those in the next week. Many of these things are found in Indianapolis and Indiana, as well. Today I wanted to share with you a super cool bug, the Spined Soldier Bug. It gets its name from the spines sticking out on either side of its thorax. This thing can tackle insects many times its size.

At Sandy Springs I discovered a bunch of caterpillars clustered at the end of a small Sumac tree. They were munching away and we were all admiring their beautiful red and yellow color. These are Sumac Caterpillars, otherwise known as Spotted Datanas, Datana perspicua.

One of the participants in our hike noticed a caterpillar that just didn't look so good. That is when we discovered this guy, the Spined Soldier Bug, Podisus...

Below is a closeup of the killer. This particular bug is a young one otherwise known as a nymph. Nymphs of bugs will look similar to the adult, but will usually have some size and color differences. The Spined Soldier Bug is grouped in with stink bugs and can also prey on monarch caterpillars. Most stink bugs feed strictly on plants. Spined Soldier Bugs are distant relatives to the Wheel Bug, both belonging to the Sub-order Hemiptera. (This link is for all the super-geeks like myself who love to know what qualifies an insect to be a "true bug". Fascinating to me, probably boring to most of you fine folks. :) Anyway, on with the gruesome details....

It always amazes me how these predacious bugs operate. They will sneak up on some slow moving soft-bodied insect, like a caterpillar. They will then jab their proboscis, the mouthpart, also called a stylet, into the prey. Whammo! The prey is soon paralyzed and sits there helplessly as its insides are turned into a giant bug milkshake by the enzymes the Spined Soldier Bug has pumped into it. The stylet is divided, so one side delivers enzymes, the other is used like a straw. The SSB will then slurp up its treat and leave behind the caterpillar's outer skin.

Bugguide has such great photos and here you can see a better view of the stylet.

My friend, John Howard, took a great picture of the carnage. I cropped it so you could have a closer view.

The caterpillars turn, at least the ones that make it, into this fascinating moth called a Datana. There are many species of Datana that look similar. All look somewhat like a crushed cigarette butt, so that is our nickname for them-Cigarette Butt Moths. Look at the picture below and judge for yourself. They would be camouflaged quite nicely at any outdoor smoking area.

Tomorrow I promise some eye candy, some beautiful orchids!StumbleUpon

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