Foreign exploration for natural enemies of the Colorado potato beetle in Central and South America

Abstract

Abstract To expand the area searched for natural enemies of the Colorado potato beetle, Leptinotarsa decemlineata (Say) we collected throughout Honduras, Guatemala, and El Salvador and also made collecting trips to Colombia, Bolivia, and Ecuador. In South America the only Leptinotarsa beetles encountered were L. undecimlineata (Say) collected in Colombia, where few natural enemies were found. In Central America, L. undecimlineata Stal was again the only Leptinotarsa collected, and this species was found commonly on several wild Solanum species. Among natural enemies collected from L. undecimlineata were several species of tachinid parasitoids (Myiopharus spp.), the egg parasitoid Edovum puttleri Grissell, and several hyperparasitic species (Exoristobia sp., Perilampus sp., and Conura n. sp.). Only one pathogen, the microsporidium Endoreticulatus fidelis (Hostounsky and Weiser) was found. Predators included a number of generalists, primarily of the egg, and early larval stages. The ectoparasitic mite, Chrysomelobia spp., was also observed under the elytra of infested beetles. Although many of the natural enemies had been discovered previously, options for importation biological control of L. decemlineata could be improved by a better understanding of the taxonomy of existing groups, determination of the specificity of the beetle’s hyperparasitoids and predators, and further study of the impact of ectoparasitic mites and natural enemies attacking the pupal stage. Finally, the spatial and temporal occurrence of Leptinotarsa on their host plants suggest meta-population effects that could serve as selective forces influencing the densities and diversity of beetle natural enemies.