Anais da Sociedade Entomológica do Brasil
On-line version ISSN 1981-5328
REIS JR, Ronaldo; SOUZA, Og De and VILELA, Evaldo F.. Predators impairing the natural biological control of parasitoids. An. Soc. Entomol. Bras. [online]. 2000, vol.29, n.3, pp. 507-514. ISSN 1981-5328. http://dx.doi.org/10.1590/S0301-80592000000300013.
A well known case of ineffective natural biological control: the puzzling coexistence of the coffee leaf miner, Leucoptera coffeellum (Guérin-Mèneville), and its natural enemies was analyzed. Despite being a suitable prey to eight parasitoid species and three wasp species, all occurring simultaneously, the coffee leaf miner too often presents populations far above the damaging level for the coffee plantation. It is demonstrated that predatory wasps and parasitoids interact negatively, possibly because predatory wasps kill parasitized miner's larvae. In doing so, predatory wasps indirectly kill parasitoids, thereby impairing the efficacy of the natural biological control. It is warned that biological control programs should be based on knowledge of food web interactions, rather than simply on strategies involving introduction of exotic natural enemies.
Keywords : Insecta; Interguild interaction; Leucoptera coffeellum; coffee.