1979] 
O’Neill — Behavior of Philanthus psyche 
25 
number of territories a marked male was seen to occupy was nine. 
Fifty-two territories were recorded for males returning after the day 
on which they were marked. Of these, forty-six (88%) were in the 
area of grass in which they were originally marked (area in Figure 
!)• ° nl y S1X (12%) were recorded outside this area with only one 
being more than 5 m away. These six were found during periodic 
checks of nearby areas (within 50 m) where there were known to be 
territories and it is possible that others were missed because of the 
area to be covered. 
Intraspecific and Interspecific Interactions 
Much of the male’s time while on the perch is occupied by 
interaction with intruding insects, particularly conspecifics. An 
intruder is defined as an insect that Hies into or through a territory 
(or immediately adjacent to it). A male’s response towards an 
intruder may fall into one of two functional categories: aggression 
towards a conspecific male or investigation of a potential mate. 
Barash (1977) designates aggression as an interaction between 
individuals with the result that one must relinquish access to some 
resource important to its fitness. It is difficult in this species to 
distinguish between these two functional responses. However, ob¬ 
servations support the fact that at least one type of male-male 
interaction (the swirling flight) represents aggression, suggesting 
that P. psyche exhibits true territorial behavior. The swirling flight 
consists of two (or rarely three) males repeatedly circling one 
another in loops with a radius of 5 to 15 cm, at a speed making them 
difficult to follow. These flights usually last from less than 1 to 
approximately 10 seconds. The term was used by Alcock (1975a) to 
refer to a similar behavior in males of P. multimaculatus. Swirling 
flights take place between males holding adjacent territories or 
between territorial and non-territorial males, the latter probably 
trying to usurp the former’s area. Since they take place repeatedly 
between the same two males over a short period of time, it is 
unlikely that this behavior could be continued mutual investigation 
of a potential mate. Swirling flights do not resemble any observed 
male-female interaction, and are usually terminated by the intruder 
leaving the immediate area. However, on three occasions at least, it 
was observed that the continual harassment by the intruder resulted 
in its usurping possession of the resident’s territory. I assume that 
