Survey on the natural enemies of the white grubs (Coleoptera: Scarabaeidae) in Eastern Antioquia

Abstract

The population of the white grubs has increased lately in Antioquia, Colombia. The insect has been reported cutting roots and stems of beans, corn, grasses, potatoes, vegetables, fruits, and forest crops. In order to identify the natural enemies of the insect, a collection of larvae was made in some towns of the eastern part of the department. Each larva was placed in a plastic container with soil from the same place of collection. The natural biological control caused 44% of the mortality of white grubs. The most common regulator factor was the disease caused by Bacilluspopilliae, which was the best enemy and was found in all the sites sampled. Rhabditid and Mermithid nematodes as well as the entomogenous fungi Metarhizium anisopliae and Beauveria bassianu were detected causing parasitic action. Insect para­sitoids were found in less amount; two of them exerting an ectoparasitic action (Hymenoptera: Tiphiidae and Scoliidae), and others as endo­parasite (Diptera: Tachinidae).