Some turfgrasses form symbiotic relationships with Neotyphodium fungi. These fungi produce alkaloids found throughout the foliage of the plant that can adversely affect many turfgrass pests. However, the black cutworm, Agrotis ipsilon, is a foliage feeder that is relatively unaffected by the alkaloids. Some Lepidoptera are able to alter or sequester noxious plant compounds, in some cases producing defensive compounds. Recent research has demonstrated that A. ipsilon, fed endophyte-infected perennial ryegrass, shows decreased susceptibility to the entomopathogenic nematode Steinernema carpocapsae. We examined possible mechanisms of decreased susceptibility to this nematode. We found that those larvae fed endophyte-infected perennial ryegrass had increased rates of encapsulation and LT50 when fed endophyte-infected perennial ryegrass. Tissue and frass alkaloid content were examined to determine alkaloid fate. The distribution of alkaloids within the insect and discharged with the frass were analyzed using an HPLC, and results will be discussed.
Species 1: Lepidoptera Noctuidae Agrotis ipsilon (black cutworm)
Keywords: perennial ryegrass, entomopathogenic nematode
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