Interaction of Ceraeochrysa cubana and Chrysoperla externa with the rose-bush aphids Rhodobium porosum and Macrosiphum rosae (Hemiptera: Aphididae)
The aphids Rhodobium porosum and Macrosiphum rosae are rose-bush (Rosa sp.) pests that can occur simultaneously in crops. These insects serve as prey for predators, such as Ceraeochrysa cubana and Chrysoperla externa (Chrysopidae: Neuroptera), which are common species in the Neotropics. Questioning about possible changes in the behavior of these predators due to their concomitant occurrence led to the search for answers that could support the joint use of these species to control these aphid pests. Thus, we assessed the preferences of C. cubana and C. externa for both R. porosum and M. rosae when the two pests are available in the same rose-bush to test the hypothesis that both chrysopids prefer the same species of aphids. Rose-bush leaflets were infected with first-instar nymphs of both aphid species and provided one newly-hatched larva of each predator species. The number of nymphs consumed was recorded every 24 hours during the larval development of predators. Both chrysopids preferred M. rosae, although they consumed a relatively high amount of nymphs of both species, thus supporting our hypothesis. Third-instar larvae consumed a greater number of prey than another instars, which increased as larvae developed. The preference of both predators for one of the aphid species may limit their simultaneous use in the management of these pests since it may result in an increase in the population size of the less preferred species. Although showing a preference for M. rosae, the studied predators have the potential to control both aphid species in commercial rose-bush plantations.