Dissemination of the entomopathogenic fungi, Lecanicillium longisporum and L. muscarium, by the predatory bug, Orius laevigatus, to provide concurrent control of Myzus persicae, Frankliniella occidentalis and Bemisia tabaci

The simultaneous use of two biocontrol agents for the concurrent control of three pest species was investigated. Leaf disc bioassays were conducted to establish a suitable method (surface dosing) for the dissemination of an entomopathogenic fungus (Lecanicillium longisporum or L. muscarium) by the predatory bug Orius laevigatus. Predatory bugs surface dosed with fungal conidia successfully disseminated conidia onto sweet pepper leaf discs. Most (98%) of the peach-potato aphids (Myzus persicae) that were subsequently maintained on the leaf discs became infected with the pathogen and died within 5 days. However, fungal conidia disseminated by surface dosed predatory bugs did not infect and kill the western flower thrips (Frankliniella occidentalis) or the sweetpotato whitefly (Bemisia tabaci). Plant trials were performed to assess the efficacy of using predatory bugs surface dosed with L. longisporum as an effective means of controlling M. persicae and F. occidentalis populations. The results indicated that the number of aphids and thrips were significantly lower (66% and 95%, respectively) on the plants where surface dosed predatory bugs were used as a control measure compared with plants where the fungal pathogen alone was used and were statistically comparable to the numbers on plants where the predatory bug alone was used. The potential for using this dual approach is discussed in the context of improved biological control of glasshouse pests.