Paracricotopus millrockensis, 



a New Species of Orthocladiinae 



(Diptera: Chironomidae) 



from the Southeastern United States 



Broughton A. Caldwell 



2382 Rockwood Way, 



Stone Mountain, Georgia 30087 



ABSTRACT. — The adult male and female, and immature stages, of 

 Paracricotopus millrockensis n. sp. are described from specimens col- 

 lected in Georgia and North Carolina. This species is also known from 

 South Carolina. The new species is clearly separable from other species 

 of Paracricotopus in the larval, pupal, and adult female stages. The 

 male is very similar to P. niger (Kieff.). The immature stages of P. 

 millrockensis have been found in small streams associated with stone 

 substrates, and the larvae feed mainly on detritus and algae. 



INTRODUCTION 



Saether (1980a) revised and emended the generic diagnoses for all 

 stages and both sexes of Paracricotopus Thienemann and Harnisch. In 

 North America only one species of this genus has been described, Para- 

 cricotopus glaber Saether, from South Carolina. I collected in an urban 

 Georgia stream specimens that, based on Saether's diagnoses, belong to 

 Paracricotopus, but the pupal stage clearly differed in several characters 

 from published descriptions -of known species. This paper describes the 

 new species and presents information concerning several aspects of its 

 ecology and distribution. 



The various life stages were obtained from specimens reared in iso- 

 lation. All specimens were preserved in 70 percent ethanol prior to 

 mounting on microscope slides. Some specimens were dissected, cleared, 

 or fixed, and all were mounted in Euparal or Canada balsam. 



In the following discussions, N= the number of specimens exam- 

 ined, and measurements are usually expressed as the total range. All 

 measurements were made with a calibrated ocular micrometer. Except 

 where otherwise noted, all measurements are given in jum. The numerals 

 in parentheses indicate the number of features used to derive the range 

 given. General terminology follows that of Saether (1980b). 



Paracricotopus millrockensis n. sp. 



Male. — N = 2; one specimen a mature pupa. 



Head. Eyes pubescent, without dorsal elongation. Inner verticals 



Brimleyana No. 1 1:161-168, October 1985 161 



