Behavioral and electrophysiological responses of the soybean beetle, Anomala rufocuprea Motschulsky (Coleoptera : Scarabaeidae) to methyl anthranilate and its related compounds

Methyl anthranilate and 15 related compounds were evaluated for their attra ctiveness to, and electroantennogram (EAG) activity in the adult soybean be etle, Anomala rufocuprea. When combined with the female sex pheromone, six methyl benzoate derivatives, i.e. methyl anthranilate, methyl m-aminobenzoa te, methyl benzoate, methyl salicylate, methyl o-toluate and methyl o-anisa te, exhibited significantly higher attractiveness than a single application of the sex pheromone alone, with methyl anthranilate exhibiting the highes t activity. EAG responses of the male antennae varied between the compounds in the amplitude range of 0.07-0.28 mV, all of which were much lower than the response to the female sex pheromone. The relationship between EAG ampl itude and chemical structure was not clear, but a positive correlation betw een the EAG responses and volatility was shown (r = 0.903). Methyl anthrani late, the most attractive compound tested, gave an average amplitude level in the EAG: 0.14 mV. For the tested compounds, EAG responses did not correl ate with attractiveness for the adult A. rufocuprea.