Collecting Larvae.—Practically every stream or lake has some aquatic insect larvae which may be collected by various methods, some simple and others requiring specialized and complicated apparatus. For general collecting, the following suggestions may be of value:
1. Look under logs and stones. Search out crevices in them; some insects hide away and demand of the collector a keen and careful search.
2. Tear apart bunches of leaves, roots, and other debris that may have piled up in front of a rock or log, or that may have accumulated at the end of a root or branch dangling in the water.
3. Pick out bunches of aquatic plants and search through them carefully.
4. Sift mud, sand, or gravel taken from the bottom of a lake or stream. Remember that some insects build cases in which they hide when disturbed. It takes a practiced eye to see a motionless case. After an insect has dried out a little, it partially emerges from the case and drags it along in search of water; moving in this way, it is easy to see.
HOW TO HANDLE UNMOUNTED SPECIMENS
Soon after insects are killed they dry out, become very brittle, and are damaged easily. Small, fragile insects especially are susceptible to breakage and, when dry, break up readily into fragments. Hard-shelled insects, such as beetles, may appear to be sufficiently durable to withstand handling when dry, but even these insects have fragile legs, antennae, and other parts which snap off readily when handled dry. Newly killed material should be either mounted or put in temporary storage before it has dried out. If collected material dries out before it can be mounted or stored, it should be relaxed by special techniques so that the specimens can again be handled without danger of breakage.
Temporary Cases
If it is not convenient to mount the specimens when they are taken from the killing bottle, the moths and butterflies should be put in papers and other insects in cellucotton.
Papers are simply rectangular strips of paper of convenient size folded as in [fig. 9]. A moth or butterfly, with its wings folded, is placed in a paper, the edges of which are then crimped over to lock it shut.