TERRITORIAL BEHAVIOR IN MALES OF 
PHILANTHUS PSYCHE (HYMENOPTERA, SPHECIDAE)* 
By Kevin M. O’Neill 
Department of Zoology and Entomology 
Colorado State University 
Fort Collins, Colorado 80523 
Introduction 
The comparative ethology of the family Sphecidae has been the 
subject of intensive study over the last thirty years, although the 
behavior of these wasps was observed and recorded by Fabre as 
early as the mid-1800’s. The majority of work has been done on 
females, probably because of the conspicuousness of their activities 
and their complex, species-specific behavior patterns. In the past 
few years, an increasing amount of work has concentrated on the 
behavior of male sphecids, revealing complex and sometimes puz¬ 
zling behavior patterns. Lin’s paper (1963) on male territoriality in 
Sphecius speciosus was one of the first attempts at a rigorous study 
of male behavior. The conspicuousness of female activity is often 
matched by the inconspicuousness of the males, particularly when 
they do not frequent the nesting area subsequent to emergence. 
Even when males are easily observed, in the nesting area or 
elsewhere, matings are rarely observed. Male sphecids, except in a 
few species, do not participate in the nesting activities of the 
females. 
Alcock et al. (1978) classify the mating strategies of male acu¬ 
leate Hymenoptera as taking the form of either searching for 
females (e.g., the “sun dance” of Nyssonine sand wasps, Evans 1966) 
or waiting for (e.g., territoriality) females at particular localities 
where they are most likely to be found. The distribution of receptive 
females in time and space has been a major influence on the 
evolution of male mating strategies. A recent review of territorial 
behavior in male sphecids (Alcock 1975a) shows that in all known 
cases this behavior is associated with securing females for copula¬ 
tion. I define territoriality here as “a fixed area from which intruders 
are excluded by some combination of advertisement, threat or 
* Manuscript received by the editor March 27, 1979. 
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