HOME RANGES OF 
MALE CERCERIS SIMPLEX MACROSTICTA 
(HYMENOPTERA, SPHECIDAE)* 
By John Alcock and George Gamboa 
Department of Zoology, Arizona State University, Tempe 85281 : 
and Department of Zoology, University of Iowa, Iowa City, 52242. 
Although it is well known that many sphecid males visit flowers 
and shrubs and attempt to mate with females found there (e.g. 
Peckham, Kurczewski, & Peckham, 1973), many unanswered ques- 
tions about this general pattern of male behavior remain. For 
example, do flower- visiting males move randomly from area to area 
or do they remain in one location for substantial periods of time? 
If they show an attachment to a particular site, do they defend the 
area or do they share it with other males? 
We addressed these questions for one species by studying males of 
Cerceris simplex macrosticta Viereck and Cockerell at two separate 
sites along State Line Rd., p2 km west of Rodeo, New Mexico. 
Study area 1 consisted of a strip of roadside ditch, 75 m X 2 m, 
covered with a dense stand of flowering milkweeds ( Asclepias sub- 
verticillata) . Two mesquites and a sprawling multiflora rosebush 
were the only large plants at this location. Study site 2, located 
several hundred meters from study site 1, was an area roughly 
25 nr X 10 m in an uncultivated pear orchard overrun with clumps 
of Russian thistle ( Salsola kali) and dotted with scattered flowering 
weeds. From 23-27 July 1974 sixteen males were captured in these 
two areas and marked on the dorsum of the thorax with acrylic paints, 
each individual receiving a distinctive color or color combination. 
One or more censuses were made at the two sites on all days from 
23 July to 8 August with the exception of 2, 4, and 7 August. 
Results 
Home ranges of C. simplex 
Nine of the marked males were seen again at or near the location 
where they had been originally captured and seven of the sixteen 
males were followed for a week or more (Table 1). The failure to 
relocate six marked individuals could be attributed to a variety of 
factors including mortality and the passage of transient males from 
the study areas. 
* Manuscript received, by the editor January 20, 1975. 
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