Control of garden weevil ( Phlyctinus callosus) larvae and pupae with a parasitic nematode and a fungal pathogen

Abstract

The entomophilic nematode {IHeterorhabditis bacteriophora} and the entomogenous fungus {IBeauveria bassiana} were evaluated for the control of the curculionid {IPhlyctinus callosus}, using larvae and pupae collected from asparagus in New Zealand. Topical treatment with 10-15 nematodes/larva gave 90-100% mortality after 62 h, while soil treatment with 5 X 104, 10 X 104 and 250 X 104 nematodes/pot resulted in 55, 70 and 80% mortality after 28 days, resp., compared with 28% for an untreated control. Immersion of larvae and pupae in a suspension of 4.6 X 106 conidial spores of {IB. bassiana} gave 85% mortality after 72 h, while exposure to rice grains infected with {IB. bassiana} gave 75% mortality of larvae after 48 h. When larvae and pupae were confined to pots treated with 4 X 1010 conidia/12.5 ml, mortality of larvae was 0 and 35% after 48 h and 35 days, resp., while that of pupae was 70 and 100%