Submitted to: Invertebrate Pathology International Colloquium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/18/2002
Publication Date: 10/15/2002
Citation: Lacey, L.A., Mesquita, A.L. 2002. Interaction of entomopathogenic fungi, insect parasitoids and their hosts. Invertebrate Pathology International Colloquium Proceedings. VIII:31-35. Interpretive Summary: Competition between microorganisms and multicellular animals for insect hosts is pervasive throughout nature. A better understanding of the factors that minimize antagonistic interaction of insect pathogens and other natural enemies could improve their integrated utilization against pest insects. Such studies have taken into account the environmental factors which favor each group of natural enemies in relatively few agricultural situations. Increased research on the interaction of insect pathogenic fungi and insect natural enemies of agricultural pests will enhance their combined use. The use of natural enemies will help to decrease the utilization of conventional insecticides and thereby decrease environmental contamination and ensure a safe food supply.
Technical Abstract: There are numerous examples where parasitoids and entomopathogenic fungi coexist within insect populations. There is also mounting evidence for behavioral and biochemical mechanisms that minimize the negative interactions between fungi and insect parasitoids. The best studied mechanisms that improve pest control when the two groups were combined are: avoidance of oviposition in fungal-infected insect hosts; avoidance of host feeding in infected insects; parasitoid protection of host from fungal infection; transmission of fungal spores by parasitoids; and parasite facilitation of fungal infection. Integration of natural enemies has been proposed in a variety of crops where natural enemies can act in a complementary manner. Environmental conditions that favor parasitic insects or fungi will influence the type of interaction and compatibility or antagonism of these two groups of biological control agents. Parasitoids are better at exploiting uninfected hosts because of their abilities of search, whereas most pathogens must wait for chance encounters and proper environmental conditions. Coexistence and enhanced biological control are favored by complementarity between parasitoid and pathogens in terms of their extrinsic and intrinsic qualities.