Host Plant-Selection by Helicoverpa-Armigera (Hubner) (Lepidoptera, Noctuidae) - Role of Certain Plant Attributes

The role of some plant properties in host plant selection by adults of the polyphagous H. armigera were investigated. Those factors found to positively influence host plant selection included presence of flowers, plant height and application of soil fertiliser. The presence of flowers greatly increased a plant's attractiveness to oviposition. Non-hosts, on which larvae did not survive, were readily oviposited on when offered in flower along with known hosts not in flower. The attractiveness of flowers may provide a mechanism for the expansion of host range. However, no effect of crude plant extracts (including various flowers) on oviposition could be detected. The role of chemical attractants is discussed. Tall plants attracted heavy oviposition and it is suggested that moths use silhouette as a cue to locating plants. There was no effect of plant water status on oviposition.