THE MYRMECOPHILOUS BEETLE 
GENUS ECHINOCOLEUS 
IN THE SOUTHWESTERN UNITED STATES 
(LEIODIDAE; CATOPINAE)* 
By Stewart B. Peck 
Department of Biology, Carleton University, 
Ottawa, Ontario K1S 5B6, Canada 
The genus Echinocoleus and the species E. setiger were described 
by Horn (1885) from two specimens from an unspecified locality 
in Arizona. Jeannel (1936) placed the genus in the subfamily 
Nemadinae and the tribe Nemadini based on a statement by Hatch 
(1933, p. 191) who had not seen specimens. Jeannel also placed 
the species Dissochaetus arizonensis Hatch in the genus Echin- 
ocoleus, which he would not have done had he seen specimens of 
either. Peck (1973) after seeing the types of both genera, placed 
Echinocoleus in the tribe Ptomaphagini and subtribe Ptomapha- 
gina of the subfamily Catopinae, and reviewed what little was 
known of the genus. 
Recently, Dr. D. E. Foster (Entomology Section, Agricultural 
Sciences, Texas Tech University, Lubbock, Texas) collected a series 
of Echinocoleus from nests of Pogonomyrme x harvester ants in 
west Texas. These specimens prompted me to study this interesting 
myrmecophilous beetle genus as part of a projected series reviewing 
the systematics and evolutionary biology of the Catopinae of North 
America. 
The methods, terminology, and format of this paper follow 
those of my previous studies (Peck 1973, 1976). Dried and pinned 
specimens were relaxed for 24 hours by soaking in a small dish of 
distilled water with two drops of liquid detergent, and were then 
dissected under 70% alcohol. Drawings were made of structures 
on temporary slide mounts or embedded in glycerine jelly. 
Genus Echinocoleus 
Echinocoleus Horn, 1885, p. 136. Type species E. setiger by monotypy, type seen, 
in MCZ. 
* Manuscript received by the editor May 20, 1976 
51 
