212 
Psyche 
[September 
Zone during 1967. Our collections of D. nevermanni in the Canal 
Zone have extended the distribution of this beetle several hundred 
miles. This would imply a continuous distribution of the genus 
Diploeciton from Costa Rica to Brazil. 
ETHOLOGY 
On 11 February 1967 we found a raid column of N. pilosus 
crossing a damp stream bed at 3:00 PM. Upon our return at 7:03 
PM these same ants were engaged in an emigration. Brood was seen 
being carried, the column was 2-4 ants wide and 90% of the traffic 
was moving in one direction. Myrmecophiles were continuously 
abundant in the column and between 7 103 - 1 1 145 PM, when the 
observations were terminated, a male and a female D. nevermanni 
were taken from the column. The queen passed our stationary 
observation post at 9:24 PM but guests were collected until 10 
minutes before observations ended. The specimens of Diploeciton 
were taken running in the center of the column and were difficult 
to distinguish from the ants except for their color and long hind 
legs. The myrmecoid abdomen was held at approximately 45 0 from 
the perpendicular while the beetles were running. 
A large sample of ants, still carrying brood, was taken with bottle 
aspirators at 1 1 145 PM. This sample was later found to contain 
4 additional males and 1 female of Diploeciton. 
On 12 February all Diploeciton were placed in laboratory nests 
with about 2000 N. pilosus workers and were observed for a minimum 
of one hour each day until 1 March when the contents of the nests 
were preserved. 
The staphylinids spent nearly all their time in the laboratory 
nests grooming worker ants their size or smaller. They were never 
seen grooming any of the major workers present. Grooming consisted 
of licking the head and thorax of the workers. Although the staphyl- 
inids groomed workers from a number of positions, Diploeciton had 
their own unique grooming position that was assumed most frequently 
(Fig. 1). In this behavior the staphylinids are remarkably similar 
to the staphylinids Probeyeria pulex (Sanderson) and to a lesser 
extent Ecitophya bicolor Reichensperger (Akre and Rettenmeyer, 
1966). While Probeyeria and Ecitophya straddled their host across 
the longitudinal axis of the body, Diploeciton assume a position 
parallel to, but slightly to one side and on top of, the ant. To posi- 
tion itself, a beetle grasps with its mandibles the scape of an antenna 
of an ant close to its base. It then positions its body parallel to 
the body of the ant and uses the first and third legs on the lower 
