Abstract
The seasonal flight periodicities of six small caddisflies were studied from April, 1995, to November, 1996, at a large riffle of the Brazos River in north-central Texas. Light trap samples for adults suggested a synchronized univoltine cycle for Protoptila alexanderi, asynchronous univoltine cycles for Hydroptila icona and Orthotrichia cristata, bivoltine cycles for Ithytrichia clavata and Ochrotrichia tarsalis, and a multivoltine cycle for Hydroptila angusta; the last species accounted for 82% of the total hydroptilid adult abundance. Larval collections of P. alexanderi, H. angusta and I. clavata confirmed their presence in the benthic community. Seven site records and one drainage record of Neotrichia vibrans were documented, increasing the total number of caddisfly species found at this site by Moulton et al. (1993) to 30.