Comparison of aerial conidia and blastospores from two entomopathogenic fungi against Diaphorina citri (Hemiptera: Liviidae) under laboratory and greenhouse conditions

Authors: MORALES-REYES, CELSO - THE ANTONIO NARRO AGRARIAN AUTONOMOUS UNIVERSITY; MASCARIN, GABRIEL - EMBRAPA; JACKSON, MARK; HALL, DAVID; SANCHEZ-PENA, SERGIO - THE ANTONIO NARRO AGRARIAN AUTONOMOUS UNIVERSITY; ARTHURS, STEVEN - UNIVERSITY OF FLORIDA

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2018
Publication Date: 6/20/2018
Citation: Morales-Reyes, C., Mascarin, G., Jackson, M.A., Hall, D.G., Sanchez-Pena, S., Arthurs, S.P. 2018. Comparison of aerial conidia and blastospores from two entomopathogenic fungi against Diaphorina citri (Hemiptera: Liviidae) under laboratory and greenhouse conditions. Biocontrol Science and Technology. https://doi.org/10.1080/09583157.2018.1487028.
DOI: https://doi.org/10.1080/09583157.2018.1487028

Interpretive Summary: We compared efficacy of different formulations of two fungal pathogens for controlling Asian citrus psyllid. Some formulations were superior to others under the conditions of the laboratory and greenhouse. Larger scale field-testing will be required to determine how successful these might be under different environmental scenarios.

Technical Abstract: This study compared the insecticidal activity of liquid culture produced blastospores and solid substrate-produced aerial conidia of Beauveria bassiana GHA and Isaria fumosorosea ARSEF3581 strains against Diaphorina citri adults. Insects exposed to 107 propagules/ml in a spray residue contact leaf bioassay died within 6 days at 25°C, with no significant differences between fungal treatments. At higher concentrations (108 propagules/ml), Isaria fumosorosea conidia killed psyllids faster compared to its blastospore formulation, i.e. 4 versus 5 days, respectively. In greenhouse tests, the same treatments applied to infested citrus plants (2 × 106 spores/ml) all significantly reduced the number of nymphs compared with the untreated controls over 3 weeks; however, only Isaria fumosorosea blastospores significantly reduced the number of F1 adult psyllids when compared with controls. Similar results were observed in the follow-up greenhouse test, where Isaria fumosorosea blastospores were the most effective treatment overall, reducing Diaphorina citri populations by about 60% after 21 days; by contrast, imidacloprid killed almost 100% of psyllids within a week in both tests. Fewer psyllids exhibited mycosis in the greenhouse (i.e. almost equal to 20 versus greater than or equal to 87% in the laboratory). This is the first report comparing both conidial and blastospore formulations of Beauveria bassiana and Isaria fumosorosea for the control of a psyllid pest. Field testing is required to determine how successful different spore formulations might be under various environmental conditions.