Brillia Kieffer, 1913

Namayandeh, Armin, Hudson, Patrick L., Bogan, Daniel L. & Hudson, John P., 2024, Chironomidae (Diptera: Insecta) of Alaska, USA, with descriptions of new species and a checklist, Zootaxa 5511 (1), pp. 1-95 : 54

Brillia Kieffer, 1913

Prior to our work, the only records of adult Brillia in Alaska were that of Brillia retifinis Saether, 1969 collected by Sommerman & Simmet (1965) using a car-top trap along Highways 1, 3, and 4 in the Southcoastal and Central bioregions ( Oliver & Roussel 1983). Our collections of Brillia in Alaska consist of pupae and larvae. Oliver& Roussel (1983) described the pupal and larval stages of only four of the five Nearctic species of Brillia . The fifth species, Brillia laculata Oliver and Roussel, 1983 , is known only from adults that were collected in Oregon, Washington, and Wyoming. If we assume B. laculata doesn’t occur in Alaska, we have recorded two additional species new to the state, Brillia flavifrons (Johannsen, 1905) and Brillia parva Johannsen, 1934 . Our collections of B. flavifrons include a pupa from the East Alsek River, Glacier Bay NP, and a larva from a first-order stream near Lena Point in Juneau. We also collected a B. parva larva in the Lena Point stream. Our collections of Brillia retifinis include pupae from the Lena Point stream and larvae from a Margaret Creek tributary on Revillagigdo Island and Kruzof Island, also in Southeastern bioregion. Unidentified Brillia larvae have been reported from Baranof Island, Denali NP, a tributary of the Stuyahok River and the Bristol Bay region. Some larvae of this genus mine wood (i.e., xylophagous), which can wear off the fifth and sixth lateral teeth used to distinguish B. retifinis and B. parva . Therefore, we also used other morphological characters to distinguish these species. Oliver & Roussel (1983) indicated that B. parva and B. retifinis are eastern and western Nearctic species, respectively. However, B. parva has been reported as far west as California ( Ashe & O’Connor, 2012). Around sunset, adults of Brillia species can be found close to the surface of flowing waters ( Oliver and Roussel 1983). Swarming, although rarely observed, is believed to be common among most adult Brillia ( Oliver & Roussel 1983) .