The effect of introducing the aphid-pathogenic fungus Erynia neoaphidis into populations of cereal aphids |
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Authors: | N. WILDING SUSAN K. MARDELL PATRICIA J. BROBYN S. D. WRATTEN JANET LOMAS |
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Affiliation: | AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UK;**Department of Biology, Building 44, The University, Southampton S09 5NH, UK;*Ministry of Agriculture, Fisheries and Food, Harpenden Laboratory, Hatching Green, Harpenden, Herts AL5 2BD, UK |
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Abstract: | The aphid-pathogenic fungus Erynia neoaphidis, as dried fungus-infected aphids, was applied to caged plots of winter wheat infested with cereal aphids at two sites, one in Hertfordshire and the other in Hampshire, in 1983. In each trial, the fungus became established in the aphid populations in the treated plots even though conditions were drier than average and therefore sub-optimal for fungus spread. Treatment applied in the third week of June increased the proportion of infected aphids more than that applied two weeks later at one site, and the early application was the only treatment to have an obvious effect at the other. In spite of the observed effect of treatments on the proportion of infected aphids, the fungus failed to reduce the numbers of aphids relative to those in untreated plots, chiefly because in these plots many aphids were killed by fungi of the same species as that introduced and other related species from natural sources. Artificial introduction of E. neoaphidis acts too slowly and unpredictably to be likely to form a practical alternative to conventional insecticides for cereal aphid control. |
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Keywords: | Cereal aphids biological control entomopathogenic fungus Erynia neoaphidis |
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