The Hilltopping Mating System of Leschenaultia adusta (Loew) (Diptera: Tachinidae)
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Males of the tachinid fly Leschenaultia adusta perch on small trees and shrubs on the highest parts of Usery Peak in central Arizona. Individuals select twig perches on the downwind side of these plants and fly out spontaneously from time to time or in response to another passing insect. Conspecific males elicit chases that on occasion escalate into elaborate, high-speed pursuit flights that go back and forth near the plant for several minutes. Although several males sometimes perch together briefly in the same plant, typically only one individual remains at a site for more than an hour on any given day. These site-faithful males can be considered territorial residents; they constituted about one-quarter of the males marked during the study. More than half of these residents returned to the same perch plant for two or more days. Perch plants varied in their attractiveness to male flies; male preferences were largely consistent across two years of study. Given that females were occasionally observed mating at male-occupied plants, we place the mating system of L. adusta within the hilltopping territorial category in which males compete for landmark perching sites attractive to receptive females. As is true for other hilltopping insects, receptive females of L. adusta appear to be rare and widely distributed.
KEY WORDShilltopping Leschenaultia Tachinidae mating system
We thank Jennifer Johnston for helping us gain access to the study site. This work was done while DJK was supported on a postdoctoral fellowship with Ron Rutowski, whose cooperation is appreciated. This paper is partly based upon work supported by the National Science Foundation under Grant No. 0316120 to R. L. Rutowski. Monty Wood graciously agreed to identify several tachinids found on Usery Peak, including L. adusta.
- Alcock, J. (1979). The behavioural consequences of size variation among males of the territorial wasp Hemipepsis ustulata (Hymenoptera: Pompilidae). Behav. 71: 322–335.Google Scholar
- Alcock, J., and Smith, A. P. (1995). Landmark-defense and scramble competition mating systems in two Australian tachinid flies (Diptera). J. Kans. Entomol. Soc. 68: 85–94.Google Scholar
- Arnaud, P. H., Jr. (1978) A host-parasite catalog of North American Tachinidae (Diptera). USDA Misc. Publ. No. 1319.Google Scholar
- Bess, H. A. (1936). The biology of Leschenaultia exul Townsend, a tachnid parasite of Malacosoma americana Fabricius and Malacosoma disstria Hubner. Ann. Entomol. Soc. Amer. 29: 593–613.Google Scholar
- Hansen, D. E. (2003) Notes on tachinids in copula from hilltops in Carnarvon N.P., Queensland. Tachinid Times 16: 3–5.Google Scholar
- Jackson, C. G., Bryan, D. E., Butler, G. D., and Patana, R. (1970). The development, fecundity, and longevity of Leschenaultia adusta (Diptera: Tachinidae), a tachinid parasite of salt-marsh caterpillars (Lepidoptera: Arctiidae). J. Econ. Entomol. 63: 1396–1397.Google Scholar
- Lederhouse, R. C., Morse, R. A., Ambrose, J. T., Burgett, D. M., Conner, W. E., Edwards, L., Fell, R. D., Rutowski, R., and Turrell, M. (1976). Crepuscular mating aggregations in certain Ormia and Sitophaga. Ann. Entomol. Soc. Amer. 69: 656–658.Google Scholar
- Messina, F. J. (1981). The aggregation behavior of Aplomyiopsis xylota (Diptera, Tachinidae). J. New York Entomol. Soc. 89: 197–201.Google Scholar
- Shields, O. (1967). Hilltopping. J. Res. Lepid. 6: 69–178.Google Scholar
- Wood, D. M. (1987). Tachinidae. In McAlpine, J. F. (ed.), Manual of Nearctic Diptera, Agriculture Canada Monograph 28, Ottawa, pp. 1193–1269.Google Scholar
- Zeigler, J. (2003). Summit conference: hilltopping behaviour of male tachinid flies (Tachinidae) at higher elevations of the European Alps. Tachinid Times 16: 3.Google Scholar