Experience‐based food consumption by larvae of Pieris rapae: addiction to glucosinolates?

摘要: When newly hatched larvae of P rapae were transferred to cowpea foliage, they readily accepted this non-host as food, whereas later instars that had fed on cabbage rejected cowpea. However, when leaf discs treated with aqueous extracts by cabbage-reared larvae. Experiments conducted determine whether reared one host plant would be stimulated feed other hosts. Larvae Brassica juncea,Cleome spinosa, Tropaeolum majus, Sinapis alba, Alliaria petiolate, Barbarea vulgaris and (Brassica oleracea) offered each the plants in choice assays. generally all alternate hosts, but quantitative differences consumption occurred. In most cases, levels discrimination between treatment control showed no significant preference for previously experienced plant. Since test (and their extracts) contain glucosinolates widely different structures, a general addiction was suggested. A single glucosinolate, sinigrin, sufficient elicit feeding The time required individual neonates become addicted cabbage, measured refusal cowpea, varied from 6 30 hours. Bioassays failed show any deterrent activity and, therefore, supported conclusion is responsible fixation P. plants.