Influence of intraguild predation among generalist insect predators on the suppression of an herbivore population

摘要: We evaluated the influence of intraguild predation among generalist insect predators on suppression an herbivore, aphid Aphis gossypii, to test appropriateness simple three trophic level model proposed by Hairston, Smith, and Slobodkin (1960). manipulated components predator community, including hemipteran larvae predatory green lacewing Chrysoperla carnea, in field enclosure/exclosure experiments address four questions: (1) Do feed C. carnea? (2) Does (IGP) represent a substantial source mortality for (3) species act independent, additive manner, or do significant interactions occur? (4) Can experimental addition some result increased densities aphids through cascade effect? Direct observations demonstrated that several consume carnea other carnivorous arthropods. Severely reduced survivorship presence showed IGP was major mortality. Decreased survival primarily rather than competition. created between influences lacewings either Zelus renardii Nabis population suppression. Despite fact web too complex delineate distinct levels within arthropod links were sufficiently strong produce cascades from higher-order carnivores herbivore dynamics: Z. generated sufficient larval one experiment release populations regulation predators. conclude this system is wide-spread has potentially important dynamics key herbivore.