A REVIEW OF THE DISTRIBUTION AND BIOLOGY 
OF THE SMALL CARRION BEETLE 
PRIONOCHAETA OP AC A OF NORTH AMERICA 
(COLEOPTERA; LEIODIDAE; CATOPINAE)* 
By Stewart B. Peck 
Department of Biology, Carleton University, 
Ottawa Ontario K1S 5B6 Canada 
With the continued interest shown by ecologists in studies of 
carrion insects it is now appropriate to present a summary of the 
known distribution and biology of Prionochaeta opaca , one of the 
most frequently encountered species of the Catopinae, the small 
carrion beetles. This paper is number 17 in a continuing series on 
the systematics, biology, and evolution of the catopine beetles of 
the Americas. 
Prionochaeta opaca is the only North American member of the 
otherwise large Eurasian tribe Cholevini ( sensu Jeannel, 1936; 
Szymczakowski, 1964). The genus Prionochaeta was erected by 
Horn (1880) to contain the North American species described as 
Catops opacus by Say (1825). Since then, three other species of 
Prionochaeta have been described from Asia: also in the opaca 
group is P. sibirica Reitter from southeastern Siberia; and in the 
harmandi group is P. harmandi Portevin from Japan, and P. 
roubali Hlisnikowski from Szechwan, China. 
Diagnostic Description. From most other small beetles com- 
monly occurring at carrion or other decomposing matter, the 
Catopinae can be distinguished by their antennae, having a five 
segmented club with segment 8 smaller than segments 7 and 9. P. 
opaca is easily separated from all other American catopines by the 
following combination of characters: It is the largest catopine in 
eastern North America (ranging from 4 to 5.5 mm in length in a 
normally reflexed condition). The pronotum and elytra have 
neither striae nor a coarsely granular surface, but are covered with 
abundant setae with prominent basal sockets. Males have ex- 
panded front tarsal segments but the first tarsal segment of the 
middle leg of males is not enlarged or swollen (a character of the 
tribe Catopini). The elytra appear to have a pale blue-grey pru- 
* Manuscript received by the editor December 22, 1977 
299 
