Soil treatment of Metarhizium brunneum F52 granule containing microsclerotia: Effective in reducing egg hatch of Aedes aegypti

Authors: Weiler, Lina; Behle, Robert; Johnson, Eric; Rooney, Alejandro - Alex; Strickman, Daniel

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/20/2019
Publication Date: 11/20/2019
Citation: Weiler, L., Behle, R.W., Johnson, E.T., Rooney, A.P., Strickman, D.A. 2019. Soil treatment of Metarhizium brunneum F52 granule containing microsclerotia: Effective in reducing egg hatch of Aedes aegypti. Meeting Abstract. [abstract].

Interpretive Summary:

Technical Abstract: Application of a granular formulation of Metarhizium brunneum F52 containing microsclerotia (MbMSc granules) in soil with eggs of Aedes agypti effectively reduced adult emergence. When MbMSc granules were applied in moist potting soil with mosquito eggs, rates of 1, 5 and 25 mg of MbMSc granules significantly reduced adult emergence with only 81 ± 2.1%, 47 ± 1.9%, and 34 ± 2.1% emergence, respectively (EC50 = 7 mg). Application of MbMSc triggered premature eclosion of eggs (EC50 = 12 mg) with percentages as high as 31 ± 2.9% and 67 ± 4.3% of the eggs treated with 5 and 25 mg MbMSc granules, respectively, after 14 days on moist filter paper. Premature eclosion of eggs started at 3 days subsequent to MbMSc granule application and survival of larvae was significantly reduced for granule treated eggs (74 ± 2.2%, 39 ± 2.0% and 23 ± 4.9% larvae survived for 1, 5 and 25 mg granule treatments, respectively, EC50 = 4.9 mg). Eggs treated with increasing concentrations of fungal conidia enhanced premature eclosion of eggs with an EC50 = 1.6 × 10**6 conidia/mL. Our results demonstrate that MbMSc granules are a promising candidate for control of A. aegypti and that fermentative production of Mb F52 microsclerotia as the active propagule has the potential for use for mosquito control.