In our neck of the woods... Junk Bugs

Trish and I were sitting on our deck recently, and we noticed a little ball of fuzz that seemed to be walking across the glass tabletop. The fuzzball was less than a centimeter long. Fascinated by this strange sight, we looked closer and saw that it actually had legs, and a head with two large, wicked-looking mandibles. The first photo is the best one I could get with my phone. You can see legs and the mandibles.

We decided it had to be some kind of insect. Perplexed, we did some research. It turns out this is the larva of a green lacewing. These are often called debris-carrying lacewing larvae. AKA junk bug or trash bug. Yes, it's a real thing. These insect larvae disguise themselves by attaching junk to their backs. You can't make this stuff up.

The larvae of some green lacewings have numerous bristles on their backs, allowing them to pick up pieces of junk and attach them to their back, as camouflage. They attach plant fibers, lichens, miscellaneous debris, and their favorite—the dead bodies of their victims.

Green lacewing larvae (and adults) are predators, preying on aphids and other tiny soft-bodied insects. Hence the wicked-looking mandibles. They grab insects with those mandibles and suck the juices from their bodies. Then, instead of leaving the dry husks of their victims behind, the larvae plop them onto their back, adding new junk to their clever disguise.

The second photo is a debris-carrying lacewing larva sporting the remains of its many victims.

So, is there any proof that this trash-carrying habit actually helps hide the lacewing larvae? After all, maybe these little trash-mongers simply consider the heap on their back to be fashionable. Actually, there is proof. I'll explain a few details. You may know that ants are often the guardians of aphids. Ants and aphids have a fascinating symbiotic relationship, in which aphids provide ants with honeydew (a yummy food rich in sugar). The ants actually "milk" the aphids by stroking their backs, causing them to secrete honeydew, which the ants happily slurp. In return, the ants protect the aphids by attacking any aphid-loving predators (such as lacewing larvae) that come near the aphids.

Well, biologists, being forever curious, removed the trash from the backs of lacewing larvae. When these trash-free larva attempted to enter an aphid colony, the ants quickly identified them and attacked. However, when the lacewing larvae were allowed to keep their trash piles on their backs (consisting mainly of aphid carcasses), they easily snuck by the ants undetected and gorged themselves on tasty aphids.

So, if you ever see a tiny walking pile of junk, take a closer look, and compliment the lacewing larvae on its clever, stylish disguise.

Photo Credits:
- Lacewing larva on glass table - Stan C. Smith
- Lacewing larva on white background - DepositPhotos