Compatibility of the predatory beetle, Delphastus catalinae, with an entomopathogenic fungus, Cordyceps fumosorosea, for biocontrol of invasive pepper whitefly, Aleurothrixus trachoides in Florida

Authors: AVERY, PASCO - University Of Florida; KUMAR, VIVEK - University Of Florida; FRANCIS, ANTONIO - Florida Department Of Agriculture And Consumer Services; McKenzie, Cindy; OSBORNE, LANCE - University Of Florida

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/30/2020
Publication Date: 9/1/2020
Citation: Avery, P., Kumar, V., Francis, A., McKenzie, C.L., Osborne, L. 2020. Compatibility of the predatory beetle, Delphastus catalinae with an entomopathogenic fungus, Cordyceps fumosorosea, for biocontrol of invasive pepper whitefly, Aleurothrixus trachoides, in Florida. Insects. 11(9):590. https://doi.org/10.3390/insects11090590.
DOI: https://doi.org/10.3390/insects11090590

Interpretive Summary: Solanum or pepper whitefly, Aleurothrixus trachoides Back (Hemiptera: Aleyrodidae), is an emerging pest of neotropical origin that has continued to spread and cause damage in some areas of Florida. Sparse biological information is available to develop effective management practices for this whitefly because it is a relatively recent pest of economic relevance in Florida. However, the integration of fungal entomopathogens with native predatory beetles might provide an environmentally friendly alternative to traditional control approaches using insecticides. The main objectives of this study were to evaluate the efficacy and compatibility of a commercially available fungal entomopathogen for whitefly control for suppressing infestations of Aleurothrixus trachoides on ornamental pepper plants in a synergistic or additive, environmentally safe, and economical means using the lady beetle, Delphastus catalinae alone and in combination with the fungus. Results showed that both these natural biological control agents could offer an effective alternative in the battle against invasive whiteflies such as pepper whitefly in U.S. horticulture production, either as a stand-alone strategy or in an integrated approach. Although these findings are promising, compatibility of the two treatments needs to be evaluated further under greenhouse and semi-field conditions before recommending to commercial growers.

Technical Abstract: Aleurothrixus (formerly known as Aleurotrachelus) trachoides Back (Hemiptera: Aleyrodidae), commonly known as pepper or solanum whitefly, is a new emerging whitefly pest of several horticultural crops in the United States. During the preliminary survey for pepper whitefly infestations in Florida, a whitefly specific predatory beetle Delphastus catalinae Horn (Coleoptera: Coccinellidae) was observed associated with this pest in the natural ecosystem. The current study was undertaken to demonstrate the efficacy of this naturally occurring predator, D. catalinae, and an entomopathogenic fungus, Cordyceps (formerly known as Isaria) fumosorosea (Cfr) (Wize) (Hypocreales: Cordycipitaceae), alone or in combination under controlled laboratory conditions. Whitefly mortality was significantly higher in the beetle alone or in the combination treatment (100%) than Cfr alone treatment (88%). In the combination treatment, Cfr did not impact Delphastus catalinae longevity and daily food intake, indicating a neutral interaction between the two treatments. Results showed that both these natural biological control agents could offer an effective alternative in the battle against invasive whiteflies such as pepper whitefly in U.S. horticulture production, either as a stand-alone strategy or in an integrated approach. Although these findings are promising, compatibility of the two treatments needs to be evaluated further under greenhouse and semi-field conditions before recommending to commercial growers.