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SIMULATION OF PREDATION BY ANTS BASED ON DIRECT OBSERVATIONS OF ATTACKS ON GYPSY MOTH LARVAE

Published online by Cambridge University Press:  31 May 2012

Ronald M. Weseloh
Affiliation:
Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA06504

Abstract

Predation of gypsy moth larvae, Lymantria dispar L. (Lepidoptera: Lymantriidae), by ants was observed by placing caterpillars on the forest floor and waiting for ants to find them or by placing caterpillars very close to foraging ants. Over 80% of contacts with caterpillars were made by Formica spp. The rate of successful capture varied with caterpillar instar, generally becoming lower as larvae became larger. However, neonates were successfully attacked by ants less often than first-instar larvae that had fed. Neonates probably have developed defenses that prevent excessive predation because many fall to the forest floor when dispersing. The distribution of time intervals between encounters of ants with larvae was adequately fit by an exponential distribution having a mean waiting time of 20 min. This distribution was used to construct a simulation model of gypsy moth larval predation by ants. Based on the model results, ant success rate, ant foraging density, and residence time of larvae on the forest floor were important determinants of mortality caused by ants.

Résumé

On a étudié la prédation de larves de la spongieuse Lymantria dispar L. (Lepidoptera : Lymantriidae) par les fourmis en forêt, en disposant des chenilles sur le sol et en attendant qu’elles soient trouvées par les fourmis, ou en les plaçant devant des fourmis en quête de nourriture. Près de 80% des contacts ont été établis par les Formica spp. L’incidence des captures réussies a varié avec le stade des chenilles, la tendance étant à une baisse avec l’augmentation de la taille. Cependant, le succès de capture des larves néonates était moins élevé que celui des larves de premier stade nourries. Les néonates ont probablement des moyens de défense qui limitent la prédation excessive, en rapport avec le risque élevé de chute lors de la dispersion. La distribution des intervalles précédant une rencontre avec une fourmi a pu être décrite par une loi exponentielle avec un temps moyen d’attente de 20 min. On a utilisé cette distribution dans une modèle de simulation de la prédation des larves de spongieuse par les fourmis. D’après les résultats, l’incidence de succès des fourmis, la densité des fourmis en quête de proies, et le temps de résidence des larves sur le sol sont des facteurs déterminants de la mortalité deux aux fourmis.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1989

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References

Batenburg, F.H.D.Van, J.C.Van Lenteren, J.J.M.Van Alphen, , and Bakker, K.. 1983. Searching for and parasitization of larvae of Drosophila melanogaster (Dipt.: Drosophilidae) by Leptopilina heterotoma (Hym.: Eucoilidae): a Monte Carlo simulation model and the real situation. Neth. J. Zool. 33: 306336.Google Scholar
Campbell, R.W., Hubbard, D.L., and Sloan, R.J.. 1975. Patterns of gypsy moth occurrence within a sparse and numerically stable population. Environ. Ent. 4: 535542.Google Scholar
Finnegan, R.J. 1971. An appraisal of indigenous ants as limiting agents of forest pests in Quebec. Can. Ent. 103: 14891493.Google Scholar
Furuta, K. 1983. Behavioral response of the Japanese paper wasp (Polistes jadwigae Dalla Torre; Hymenoptera: Vespidae) to the gypsy moth (Lymantria dispar L.: Lepidoptera: Lymantriidae). Appl. Ent. Zool. 18: 464474.Google Scholar
Leonard, D.E. 1967. Silking behavior of the gypsy moth, Porthetria dispar. Can. Ent. 99: 11451149.Google Scholar
Leonard, D.E. 1970. Feeding rhythm in larvae of the gypsy moth. J. econ. Ent. 63: 14541457.Google Scholar
Mason, C.J., and McManus, M.L.. 1981. Larval dispersal of the gypsy moth. pp. 161202in Doane, C.C., and McManus, M.L. (Eds.), The Gypsy Moth: Research Toward Integrated Pest Management. USDA Forest Serv. Tech. Bull. 1584.Google Scholar
McNeil, J.N., Delisle, J., and Finnegan, R.J.. 1978. Seasonal predatory activity of the introduced red wood ant, Formica lugubris (Hymenoptera: Formicidae), at Valcartier, Quebec, in 1976. Can. Ent. 110: 8590.Google Scholar
Ostle, B. 1963. Statistics in Research. Iowa State Univ. Press, Ames, IA.Google Scholar
Ripley, B.D. 1987. Stochastic Simulation. John Wiley & Sons, New York, NY. 237 pp.Google Scholar
Sabelis, M.W. 1981. Biological Control of Two-spotted Spider Mites using Phytoseiid Predators. Part I. Modelling the Predator–Prey Interaction at the Individual Level. Centre for Agricultural Publishing and Documentation, Wageningen, The Netherlands.Google Scholar
SAS Institute. 1985. SAS Users Guide: Statistics. SAS Institute, Cary, NC.Google Scholar
Smith, H.R., and Lautenschlager, R.A.. 1981. Gypsy moth predators. pp. 96125in Doane, C.C., and McManus, M.L. (Eds.), The Gypsy Moth: Research Toward Integrated Pest Management. USDA Forest Serv. Tech. Bull. 1584.Google Scholar
Waage, J.K. 1983. Aggregation in field parasitoid populations: foraging time allocation by a population of Diadegma (Hymenoptera, Ichneumonidae). Ecol. Ent. 8: 447453.Google Scholar
Weseloh, R.M. 1987. Accuracy of gypsy moth (Lepidoptera: Lymantriidae) population estimates based on larvae counts in artificial resting sites. Ann. ent. Soc. Am. 80: 361366.Google Scholar
Weseloh, R.M. 1988. Effects of microhabitat, time of day, and weather on predation of gypsy moth larvae. Oecologia 77: 250254.Google Scholar