In crickets, injection of the OA agonist chlordimeform causes normally submissive losers of fights to reengage in fighting faster than sham injected animals . Likewise, in honeybees, injection of two OA agonists, XAMI and DCDM, biases the likelihood of aggressive display toward nonnestmates over nestmates . Hoyer et al. found that aggression is almost abolished in mutant males lacking octopamine in Drosophila by using software to eliminate confounding effects . The expression of octopamine receptor was significantly upregulated in PP AG, indicating that the OA receptor positively regulated the aggression and mating behavior of E. sinensis.