Evaluation of Entomopathogenic Fungi Against Chilli Thrips,Scirtothrips dorsalis

Abstract

Commercial strains of entomopathogenic fungi were evaluated for control of chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), an invasive pest of ornamental and vegetable plants in the Caribbean and southeastern United States. In laboratory assays, LC50 values against adult S. dorsalis were 5.1 × 104 CFU/mL for Beauveria bassiana GHA, with higher values 3.1 × 105 for Metarhizium brunneum F52 and 3.8 × 105 for Isaria fumosorosea Apopka 97. Second instars were comparatively less susceptible to all isolates, ostensibly due to moulting, with LC50 values of 1.1 × 108, 7.0 × 105, and 9.9 × 105 CFU/spores per mL for GHA, F52, and Apopka 97 strains, respectively. In greenhouse cages, compared with controls, three applications of mycoinsecticides and other biorational insecticides at 7 to 14 day intervals reduced overall S. dorsalis populations on pepper plants Capsicum annuum cv. California Wonder: spinosad reduced populations by 94–99%, M. brunneum F52 by 84–93%, B. bassiana GHA by 81–94%, I. fumosorosea PFR-97 by 62–66%, and different horticultural oils by 58–85%. The proportion of marketable fruit was significantly increased by M. brunneum F52, B. bassiana GHA, and 2% SuffOil-X treatments. Slightly lower levels of control were observed in nursery tests with ornamental rose shrubs, Rosa sp. Red Double Knock Out®, during hot sunny conditions. Four applications reduced thrips populations over 10 weeks: spinosad by an average of 91%, M. brunneum F52 by an average of 81%, B. bassiana GHA by an average of 62%, SuffOil-X by an average of 50%, and I. fumosorosea PFR-97 by an average of 44%. The data show that mycoinsecticides can be used in management strategies for low to moderate populations of S. dorsalis and provide resistance management tools for the limited number of insecticides that are effective against this pest.

Efficacy of biorational insecticides against chilli thrips, Scirtothrips dorsalis (Thysanoptera: Thripidae), infesting roses under nursery conditions

“…Higher efficacy was reported by Arthurs et al. () who tested three applications of different mycoinsecticides applied against S. dorsalis on sweet pepper ( Capsicum annuum L.). In these latter tests, B. bassiana achieved 81–94% mortality with respect to controls, with M. brunneum providing 84–93%, and Isaria fumosorosea 62–66% control, respectively.…”

“…Arthurs et al. () tested entomopathogenic fungi as stand‐alone treatments against S. dorsalis on roses and obtained similar results. This study also showed that biopesticides can be applied in rotation, but were less effective than spinosad.…”

“…However, few reports are available on the use of entomopathogenic fungi against S. dorsalis (Arthurs et al. ). Azadirachtin, derived from neem seeds, Azadirachta indica (A. Juss), works as an insect growth regulator (ecdysone agonist), disrupting the moulting process.…”

“…Vuill., Metarhizium brunneum Petch and Isaria fumosorosea Wize have been tested against F. occidentalis and other thrips (Maniania et al 2001(Maniania et al , 2003Ludwig and Oetting 2002;Ansari et al 2008;Gao et al 2012b). However, few reports are available on the use of entomopathogenic fungi against S. dorsalis (Arthurs et al 2013). Azadirachtin, derived from neem seeds, Azadirachta indica (A. Juss), works as an insect growth regulator (ecdysone agonist), disrupting the moulting process.…”

Diversity of Entomopathogenic Fungi in Argane Forest Soil and Their Potential to Manage Mediterranean Fruit Fly (Ceratitis capitata)

“…This work may be considered as the first record of the high pathogenicity of species of Fusarium, Epicoccum, Scopulariopsis and Aspergillus niger against C. capitata. Fusarium species were considered as saprophytic fungi [35] and also reported to be pathogenic to Aphis gossypii Glover [30], Scirtothrips dorsalis Hood [40,41], Polyphagotarsonemus latus Banks [40], Aleurodicus dispersus Russel [42] and to other pests [37]. Species of Aspergillus have been found associated with a large number of insects such as larvae of bees (A. niger), Troglophilus neglectus (A. niger, A. ochraceus), and Culex pipiens (A. ochraceus) [38,39,43].…”