Contortionists

Well, as promised, I’m thoroughly impressed!  Four of you correctly (and independently) guessed that the face in my last post belonged to a walkingstick nymph.  I suppose Matt gets the prize for identifying it to species: Diapheromera femorata, the northern walkingstick.  Do I get points for guessing that Troy Bartlett would be one of the people who knew?

I have wanted to see northern walkingstick eggs ever since I read about them in Frank E. Lutz’s 1948 Field Book of Insects.  He describes how the females drop their hard, seedlike eggs at random from the treetops, and how one autumn in Pennsylvania there were so many eggs falling that it sounded like rain.  The eggs have neat little lids (opercula) that pop off when the nymphs hatch.  This winter, someone posted on BugGuide a photo of some eggs laid by an adult he had caught in October, and I asked if he would be willing to send me some.  He was happy to, and I kept them in the fridge along with the wood-boring beetle parasitoids and the cocoon of a luna moth that Noah Charney (for whom I was house-sitting at the time) had raised from an egg.  (I took the luna out of the fridge in April, and it kindly waited to emerge until the day after Noah got home.)

The eggs got a little moldy after I removed them from the fridge, and I didn’t have much hope for them, but I tend not to throw things out until several months after all hope is lost. The other night I took a look in the jar, and a single nymph had hatched.

A northern walkingstick hatchling, with its feet still in the egg. The operculum is in the upper right.

I find it astounding that this 7.5-mm insect has just come out of that 2.5-mm egg.  I am similarly amazed that this green lacewing (Chrysopidae; Chrysoperla rufilabris, I believe) was able to fit inside its 3-mm cocoon:

Obviously these long, skinny insects are curled into tight balls as they develop, unfurling when they emerge.  But they must also be extremely compressed, filling with air as soon as they’re free.  These stink bug (Pentatomidae) hatchlings I found yesterday are a lot bigger than their eggs, and their body shape doesn’t leave much room for curling up to occupy less space.

I saw no shed skins on this leaf, so I believe the nymphs are still in their first instar and have not grown substantially from whatever feeding they have done.  I wonder how long stink bug nymphs hang around their eggs like this–anybody know?