Longitudinal study of community composition of caddisflies (Trichoptera) in a first order stream: Wildcat Creek, Clemson University experimental forest

ABSTRACT: The River Continuum Concept (RCC) is a testable model for making predictions about community structure and function across lotic systems and through multiple stream orders. This concept focuses on nutrient input and processing as a key factor for community changes (Vannote et al. 1980). While this model has been useful as a general descriptor, several critiques have emphasized a need for further research. This project proposes to examine the Trichoptera community structure and function to determine if selected abiotic and biotic factors are statistically significant and could account for any differences at a much smaller scale: along the length of the first order stream Wildcat Creek within the Clemson Experimental Forest, Pickens County, South Carolina.

In addition, this project proposes to associate and describe currently unknown life history stages of Trichoptera. Caddisflies are a significant and often dominant part of the aquatic insect fauna, represented in surface waters on every continent other than Antarctica. They are an important group not only as food for predators but also as recyclers of organic material in aquatic ecosystems. Despite over 150 years of research concerning North American Trichoptera taxonomy, the larvae, pupae and females of many species remain unknown. Species must be identified based on morphological traits, usually by genitalic characters of the adult males. Twelve species of Trichoptera in 5 families will be examined for association of undescribed life history stages with idenfiable males; for example, Fumonta major (Banks, 1914) is a species of Philopotamidae for which the female and pupa are still unknown. This research will also focus on other unknown larval and pupal forms in the families Philopotamidae, Polycentropodidae, Rhyacophilidae, Hydropsychidae and Leptoceridae including the following species: in Philopotamidae--Wormaldia moesta, Wormaldia thyria, Fumonta major; in Polycentropodidae--Polycentropus blicklei, Polycentropus carlsoni, Polycentropus confusus, Polycentropus maculatus; in Rhyacophilidae--Rhyacophila teddyi; in Hydropsychidae--Cheumatopsyche etrona, Cheumatopsyche pinaca, Cheumatopsyche harwoodi enigma; and in Leptoceridae--Ceraclea protonepha. The identifiable adults of these species have historically been captured at Wildcat Creek during the months of March-November.

The immature forms of Trichoptera and the physico-chemical measurements will be collected weekly from 4 April 2015–4 July 2015. Community structure and function as well as the physico-chemical data will be analysed using a PCA statistical and pairwise analysis. The immature and female forms will be confidently associated with the male of each species by use of DNA barcoding along with morphological characters. DNA barcodes of some species are already in the Barcode of Life Database (BOLD) Global Library; those not yet sequenced will be processed in the Caterino laboratory and deposited into the BOLD database. The morphological traits of yet-unknown life history forms for each species will be compared to comparable forms of others within the genus or across the family and illustrated using AdobeÒ IllustratorÒ CC. This proposed research is a priority in order to protect and conserve what might be dwindling habitat for these life history forms of these apparently rare species.