A Surprising Find
A couple of weeks ago we went to the Oregon Department of Agriculture's Insect Collection. We needed some images of different insect orders for a new series of videos we've been working on. Jim LaBonte, the head entomologist in the collection, had told us that we could bring some fresh specimens to play with under their new Scanning Electron Microscope (SEM). Cool! We'd never actually gotten to use an SEM before so we jumped at the chance. After digging in the mulch at our local Starbucks for some springtails (**insect collecting tip-if it hasn't rained in a couple of months, you can always find insects and other soil arthropods in and around businesses that regularly water and maintain their plants.) - we brought them to the lab in Salem, OR.
Entomologist Josh Vlach using the SEM.
They have a compact SEM and it's literally smaller than a desktop computer. Here's a little breakdown on how these machines work:
A beam of electrons move over the outside of the specimen. The electrons on the surface of the specimen are dislodged by the beam. Detectors on the inside of the SEM monitor how these electrons scatter and as the beam moves from one end of the specimen to the other, the image is projected onto a computer monitor.
What you get is an incredibly detailed, 3-D view of your specimen. Right down to tiny sensory pits in the surface of the exoskeletal microstructure. Very cool!
Entomologist Josh Vlach put our specimens into the chamber and we all watched anxiously for the image to appear on the screen. What we found was even cooler than using an SEM. We had a springtail AND a mystery animal. Here's a picture of all of us bugdorks talking about what it could be.
Bugdorking out over what we found in our sample at the ODA lab.
It looked vaguely like a collembolan, but had strange fleshy protuberances on its abdomen and while it looked like a two-pronged furcula extended from the abdomen...it just wasn't right. The antennae were thickened at the ends and it was larger than expected. After much discussion, zooming in and textbook referencing we all came to the conclusion that we had a dipluran and a springtail!
Springtails are primitive hexapods that live in moss and soil. They are wingless and tiny – the size of a pin head or smaller. These animals have a very special organ on the end of their abdomens called a furcula. It acts as a two-pronged lever to launch them through the air if they encounter a potential predator (hence the name “springtail”). When resting, it is held against the abdomen with a structure called a tenaculum. There are more than 6,000 species of springtails worldwide.
Diplurans are small wingless entognathus hexapods that are related to insects. (Entognathus meas that their mouthparts are located inside the head cavity as opposed to an insect like a grasshopper, where you can plainly see all of the mouthparts below the head.) There are about 800 species of diplura worldwide. Diplurans are predators of springtails, mites and other tiny soil arthropods. In addition, they eat algae, fungi, detritus and mold. They're hardly ever seen because many of them live under the ground. This was the first dipluran that we, The Bug Chicks, had ever seen in real life.
To learn more about the ODA Plant Division, Insect Pest Prevention and Management, click here.