Response to Drought Conditions on Caddisfly ( Trichoptera ) Larvae.

Abstract

Aquatic insects are crucial players in maintaining the general health of river ecosystems. These insects help filter out and recycle leaf litter and other detritus from the water, as well as providing an important food source for fish, birds, and other organisms higher up on the food chain. Aquatic insects are also a good indicator of stream health. Because they depend on the stream for sustenance, irregular levels of contamination can decimate the organisms living within the stream. The population reduction found in contaminated streams can be measured and used to determine the level of contamination. Trichoptera, commonly known as the caddisflies, are one order whose larvae are important parts of virtually all freshwater aquatic habitats. The larvae are far more interesting than the adults. They build cases for themselves that are used for protection and aid in respiration. These cases are built of silk that they spin and the cases differ greatly from family to family. My study is designed as a two part study. Because of the exceptionally dry year in Southern California, I studied the effectiveness with which the Trichoptera are able to rebound from such a radical loss of habitat. Part One, done this summer, is designed to be contrasted to a Part Two, which will be conducted when there is more rainfall.This data can then be used to determine the resilience of the species to major hydrological changes such as damming up or redirecting a river, especially in water-deprived Mediterranean climates like Southern California