First Record ofIthytrichia(Trichoptera: Hydroptilidae) in Alberta, Canada

Abstract

The caddisfly genus Ithytrichia Eaton (Trichoptera: Hydroptilidae) is a relatively small Holarctic and Oriental genus (Wiggins 1996) with three known species in North America (Harris and Contreras-Ramos 1989, Morton 1905, Ross 1944). The most widespread of these three species, I. clavata Morton, has been recorded in most Canadian provinces (British Columbia: Ross 1944, Sas kat chewan: Phillips et al., 2008, Manitoba: Moulton et al., 1999, Ontario: Barton and Hynes 1978, Quebec: Moulton et al., 1999, Nova Scotia: Peterson and van Eeck haute 1990), but has not previously been documented in Alberta. I. clavata is considered a transcontinental species (Ross 1944) and it has long been suspected that this species would eventually be collected in Alberta (Clif ford 1991). A single Ithytrichia larva was collected and identified as part of benthic mac roinvertebrate surveys conducted by the Alberta Biodiversity Monitoring Institute (ABMI). The specimen was identified in a composite sample collected from the Bear River (near 115° 38' 17 W / 58° 17' 55 N) in north central Alberta on 23 July 2008. Benthic macroinvertebrate samples were collected using a 500 μm D-frame kicknet in the fastest flowing water within 100 m of each of six transects at the study site. Samples were preserved in 10% buffered formalin and sent to the ABMI Sample Processing Center at the Royal Alberta Museum in Edmonton, Alberta, Canada (ABMI 2008). The composite sample was sub-sampled with a Marchant box using a fixed count of 350 organisms, and sorted into coarse taxonomic groups. Sorted specimens were sent to a qualified taxonomic expert for identification to the lowest taxonomic level possible (ABMI 2007). Identi fica tions are based on Merritt & Cummins (2008) and Wiggins (1996). Voucher speci mens are retained at the Royal Alberta Museum in Edmonton, Alberta, Canada. The Bear River is a small turbid river (draining ~2500 km2) that originates in the Buffalo Head Hills region of the boreal highlands, and flows through dry and central mixed wood forest subregions before emptying into the Wabasca River. The 2.5 km-long study site, located on a lowland fourth order reach, consisted of continuous slow-moving runs over silt and sand/silt substrates; riffles and welldefined pools were absent. Water depth ranged from 1.5 m to 0.15 m but the overall mean depth was ~0.8 m. Aquatic vegetation was limited to the shallow margins with arum-leaved arrowhead (Sagittaria cuneata) being the predomi466 ENTOMOLOGICAL NEWS