Xylophagous chironomidae from oregon streams

Abstract

Wood‐mining Chironomidae in Oregon were studied using sound wood submerged for 5–6 years as standard substrates. The dominant species were the orthocladiine midges Orthocladius lignicola Kieffer and Chaetocladius ligni Cranston and Oliver. Larvae were much more abundant in alder than in conifer wood. Using a combination of multiple washings and rearing, the population density of xylophagous midges in alder posts was estimated as 618 ± 173/m² of wood surface. This was over 25% of the total wood‐associated invertebrates at the site, indicating that a significant component of the fauna is missed if the subsurface Chironomidae are not collected.