Insecticides reduce the effectiveness of natural enemies by killing both the natural enemies and their hosts. Several species of natural enemies of stored products pests have been found to have developed resistance to insecticides as reported in the following references. The number of natural enemies killed by insecticides can be reduced by releasing natural enemies that are resistant to the insecticide that is used. This may allow combinations of natural enemies and insecticides to work better than either alone because natural enemies can kill insecticide resistant hosts and hosts in insecticide-free refuges.
Other pages on biological control are:
Conservation biological control for stored product insects
Natural enemies of Tribolium castaneum
Phthorimaea operculella natural enemies
Prevalence of naturally occurring natural enemies
Trichogramma natural enemies of stored-product insects
References:
Baker, J. 1994. Resistance Mechanism in the Bamberg Strain of Anisopteromalus calandrae (Hymenoptera, Pteromalidae). J. Entomol. Sci. 29: 580-584.
Baker, J. 1994. Sensitivities of Laboratory and Field Strains of the Parasitoid Anisopteromalus calandrae (Hymenoptera, Pteromalidae) and its Host, Sitophilus oryzae (Coleoptera, Curculionidae), to Deltamethrin and Cyfluthrin. J. Entomol. Sci. 29: 100-109.
Baker, J. E. 1995. Stability of malathion resistance in two hymenopterous parasitoids. J. Econ. Entomol. 88: 232-236.
Baker, J. and R. Arbogast. 1995. Malathion Resistance In-Field Strains of the Warehouse Pirate Bug (Heteroptera, Anthocoridae) and a Prey Species Tribolium castaneum (Coleoptera, Tenebrionidae). J. Econ. Entomol. 88: 241-245.
Baker, J. E., R. W. Beeman, J. E. Throne and J. Perez-Mendoza. 1997. Fitness of an insecticide-resistant parasitic wasp Anisopteromalus calandrae. Resistant Pest Management 9: 12-14.
Baker, J., J. Fabrick, and K. Zhu. 1998. Characterization of esterases in malathion-resistant and susceptible strains of the pteromalid parasitoid Anisopteromalus calandrae. Insect Biochem. Mol. Biol. 28:1039-1050.
Baker, J., J. PerezMendoza and R. Beeman. 1997. Inheritance of malathion resistance in the parasitoid Anisopteromalus calandrae (Hymenoptera: Pteromalidae). J. Econ. Entomol. 90: 304-308.
Baker, J., J. Perez-Mendoza, R. Beeman and J. Throne. 1998. Fitness of a malathion-resistant strain of the parasitoid Anisopteromalus calandrae (Hymenoptera : Pteromalidae). J. Econ. Entomol. 91: 50-55.
Baker, J. E. and J. E. Throne. 1995. Evaluation of a Resistant Parasitoid for Biological Control of Weevils in Insecticide-Treated Wheat. J. Econ. Entomol. 88: 1570-1579.
Baker, J. and D. Weaver. 1993. Resistance In-Field Strains of the Parasitoid Anisopteromalus calandrae (Hymenoptera, Pteromalidae) and its Host, Sitophilus oryzae (Coleoptera, Curculionidae), to Malathion, Chlorpyrifos-Methyl, and Pirimiphos-Methyl. Biological Control 3: 233-242.
Baker, J., D. Weaver, J. Throne and J. Zettler. 1995. Resistance to Protectant Insecticides in 2 Field Strains of the Stored-Product Insect Parasitoid Bracon hebetor (Hymenoptera, Braconidae). J. Econ. Entomol. 88: 512-519.
Banks H.J. & Sharp A.K. 1979. Insect control with CO2 in a small stack of bagged grain in a plastic film enclosure. Australian Journal of Experimental Agriculture and Animal Husbandary 19: 102-107. (Anisopteromalus calandrae and Theocolax elegans survived CO2 treatment)
Lorini, I. and Galley, D. J. 1997. Toxicity of insecticides to Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae), a parasitoid of the stored grain pest Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). p. 42-44. In: Haskell, P. T.; McEwen, P. K. (Ed.). New studies in ecotoxicology. Cardiff: The Welsh Pest Management Forum
Perez-Mendoza, J., J. A. Fabrick, K. Y. Zhu and J. E. Baker. 2000. Alterations in esterases are associated with malathion resistance in Habrobracon hebetor (Hymenoptera: Braconidae). J. Econ. Entomol. 93: 31-37.
Zhu, Y., A. Dowdy and J. Baker. 1999. Detection of single-base substitution in an esterase gene and its linkage to malathion resistance in the parasitoid Anisopteromalus calandrae (Hymenoptera : Pteromalidae). Pestic. Sci. 55: 398-404.
Zhu, Y., A. Dowdy and J. Baker. 1999. Differential mRNA expression levels and gene sequences of a putative carboxylesterase-like enzyme from two strains of the parasitoid Anisopteromalus calandrae (Hymenoptera : Pteromalidae). Insect Biochem. Mol. Biol. 29: 417-425.
Zhu, Y., A. Dowdy and J. Baker. 2004. Molecular differentiation of two strains of the parasitoid Anisopteromalus calandrae (Hymenoptera : Pteromalidae) using specific PCR primers. J. Entomol. Sci. 39: 1-10.
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