Relative humidity impacts development and activity against Aedes aegypti adults by granular formulations of Metarhizium humberi microsclerotia
The impact of ambient relative humidity (RH) on conidial production of Metarhizium humberi IP 46 microsclerotia (MS) formulated in pellets or granules was investigated, and a promising granular formulation was tested against Aedes aegypti adults to confirm its efficacy. Microcrystalline cellulose (M...
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Published in | Applied microbiology and biotechnology Vol. 105; no. 7; pp. 2725 - 2736 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.04.2021
Springer Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The impact of ambient relative humidity (RH) on conidial production of
Metarhizium humberi
IP 46 microsclerotia (MS) formulated in pellets or granules was investigated, and a promising granular formulation was tested against
Aedes aegypti
adults to confirm its efficacy. Microcrystalline cellulose (MC) and diatomaceous earth (DE) or a combination of vermiculite (VE), DE and silicon dioxide (SD) were tested as carriers in granular formulations containing MS. A range of 93–96.5% RH was critical for fungal development, and at least 96.5–98.5% RH was required for high conidial production on pellets or granules. Conidial production was clearly higher on pellets and granules prepared with VE than MC as the main carrier. VE granules containing MS were highly active against
A. aegypti
adults. Most mosquitoes were killed within 6 days after treatment regardless of the exposure time of adults to the formulation (1 min–24 h) or ambient humidity (75 or >98%). Production of conidia on dead adults varied between 7.3 × 10
6
and 2.2 × 10
7
conidia/individual, when exposed to MS granules for 12 h and 1 min, respectively. Granular formulations containing VE as the main carrier and MS as the active ingredient of
M. humberi
have strong potential for use against
A. aegypti
.
Key points
• High conidial production on granular microsclerotial formulations at >96.5% RH
• Vermiculite is more appropriate as a carrier than microcrystalline cellulose
• Granules with IP 46 microsclerotia are highly active against Aedes aegypti adults
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0175-7598 1432-0614 |
DOI: | 10.1007/s00253-021-11157-6 |