Mortality of the prickly pear cactus weevil Metamasisus spinolae with the application of Heterorhabditis bacteriophora JAAN-19

Abstract

We tested the nematode Heterorhabditis bacteriophora (Poinar) JAAN-19 as a biocontrol agent of Metamasius spinolae. A concentration of 1000 Jl/ weevil in vitro achieved 90% mortality in the females and males after 6 days. These results demonstrated the strong searching and infective capacity of the nematode, which resulted 97% mortality within 6-8 days. The lethal dose (LD50) was calculated at 138 Jl/weevil, and the LD90 was 463 Jl/weevil 6-8 days later. These findings strongly suggest that H. bacteriophora JAAN-19 can be used to control M. spinolae.