A Review of the Genus Cricotopus in Ohio, With a Key to Adults of Species of the Northeastern United States (Diptera, Chironomidae)

Abstract

In the northeastern states, 21 species of Cricotopus are recognized: C. sylvestris, uncommon in Ohio but abundant in California, the larvae feeding on rice plants, Spirogyra, Myrioph yllum and other vegetation; C. trifasciatus ( — remus), with larvae mining in and skeletonizing leaves of Potamogeton, Polygonum, Nuphar, Nymphaea and Nelumbo; C. bkinctus, living as larvae in masses of Spirogyra, capable of withstanding low oxygen levels and showing remarkable resistance to pollution by industrial wastes; C. tricinctus ( = lebetis), more or less questionably distinct from C. trifasciatus; C. triannulatus { — exilis), a northern Holarctic species associated with swift streams or shallow areas of lakes subject to wave action; C. politus, a clean-water species of lakes and streams; C. varipes and C. slossonae, closely related species showing a positive response to crude oil contamination; C. absurdus, with Neotropical affinities and apparently rare in the northern Nearctic; C. fugax, not recorded since it was described; C. flavibasis, closely related to C. sylvestris; C. infuscatus {=aratus, ceris), with larvae showing considerable resistance to heavy-metal pollution; C. vierriensis, easily confused with C. bicinctus, with larvae able to withstand high salt concentrations; C. trifascia ( = ithacanensis), having larvae present in small numbers in streams; C. flavipes, relatively rare, the larvae making linear mines in submerged leaves of Potamogeton; C. elegans, rarely reported, with larvae riddling the floating leaves of Potamogeton; C. junus, with larvae inhabiting hard-bottom creeks; and C. nostocicola, with larvae feeding on Nostoc and attaching the algal colonies to rocks and other objects. New species are C. diversus, with similar to C. junus except for leg coloration and to the European C. festivellus except for details of abdominal coloration; C. baptistenis, known only from southern Canada but at the latitude of Michigan; and C. olivetus, probably most closely related to C. fugax and the European C. annulator.