Factors affecting the ecology of a large population of Pacific cicada killers (Sphecius convallis) occupying
a field of mine tailings in Ruby, AZ, were examined. Burrows were quite dense in certain areas around
the periphery of the mine tailings, but were dispersed randomly within these areas. Approximately 1600
females (based on burrow counts) and 2500 males (based on mark-recapture) were recorded, yielding a
total population estimate of 5000–6000 adults. Female wasps were able to dig much more rapidly in the
mine tailings than their congeners S. speciosus in soils from PA, suggesting that the habitat suitability was
a large factor in this robust population. Provisioning rate was comparatively slow, however, suggesting
that cicada abundance in that year was not a contributor to the high population density. The presence of
a sap-producing tree may have eased the energetic and thermoregulatory demands of the wasps. Although
excavations revealed that the number of burrows and cells could easily maintain the population size, the
lack of cicadas probably resulted instead in a population crash the following season.
Nesting ecology of the Pacific cicada killer, Sphecius convallis Patton (Hymenoptera, Crabronidae), in the Sonoran Desert
Coehlo, J. R., J. M. Hastings, and C. W. Holliday (2020 Dec 29). "Nesting ecology of the Pacific cicada killer, Sphecius convallis Patton (Hymenoptera, Crabronidae), in the Sonoran Desert." Journal of Hymenoptera Research 80: 177–191.