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United States Department of Agriculture

Agricultural Research Service

Title: Combining Azadirachtin and Paecilomyces Fumosoroseu for Silver Leaf Whitefly Control

Author
item James, Rosalind

Submitted to: Ecological Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2002
Publication Date: February 20, 2003
Citation: JAMES, R.R. COMBINING AZADIRACHTIN AND PAECILOMYCES FUMOSOROSEU FOR SILVER LEAF WHITEFLY CONTROL. ECOLOGICAL ENTOMOLOGY. 2003. 96(1):p.25-30

Interpretive Summary: Both azadirachtin and Paecilomyces fumosoroseus have been used to control the silverleaf whitefly (Homoptera: Aleyrodidae), but with only moderate effectiveness. Azadirachtin is a botanical insecticide derived from the neem tree, and P. fumosoroseus is an entomopathogenic fungus. To test whether these two products might be more effective for whitefly control if used together, different rates of each were combined in laboratory bioassays in a factorial experimental design. Both tank mixes and separated sprays were tested. Up to 90% nymphal mortality was obtained when both compounds were used, which was an increase over that seen when only one product was used, where mortality was never greater than 70%. However, the combined effects were less than additive. Azadirachtin had moderate, inhibitory effects on growth and germination of P. fumosoroseus, which may explain this antagonism.

Technical Abstract: Both azadirachtin and Paecilomyces fumosoroseus have been used to control the silverleaf whitefly (Homoptera: Aleyrodidae), but with only moderate effectiveness. Azadirachtin is a botanical insecticide derived from the neem tree, and P. fumosoroseus is an entomopathogenic fungus. To test whether these two products might be more effective for whitefly control if used together, different rates of each were combined in laboratory bioassays in a factorial experimental design. Both tank mixes and separated sprays were tested. Up to 90% nymphal mortality was obtained when both compounds were used, which was an increase over that seen when only one product was used, where mortality was never greater than 70%. However, the combined effects were less than additive. Azadirachtin had moderate, inhibitory effects on growth and germination of P. fumosoroseus, which may explain this antagonism.

Last Modified: 12/21/2014