Adults and nymphs, with piercing-sucking mouthparts
feed on soybean plant sap
inject saliva and phytotoxic enzymes into leaves
excrete excess liquid as honeydew onto leaves
Yield loss in soybeans occurs from
plant sap removal, wilted leaves, stunted plants
extensive sooty mold growing on honeydew-soaked leaves, which reduces photosynthesis
incomplete pod filling caused by sap removal
No economic threshold has been developed for soybeans
Pest Status and Importance
Pest Status and Importance
A minor soybean pest in most states
Large populations may cause plants to wilt, especially during hot, dry weather
Yield losses documented in Florida and Georgia, but not in Midwestern soybean fields
Interesting Fact: The silverleaf whitefly is a complex of at least 24 species which are morphologically indistinguishable!
Source: Annual Review of Entomology. 2011. 56:1-19.
Whiteflies can develop very large colonies. Here adults and pupae of thebanded-winged whitefly are seen on velvetleaf.
Facts
Facts
Common names: whitefly, silverleaf whitefly, sweetpotato whitefly
Latin name: Bemisia tabaci, family Aleyrodidae
Description
Adult: yellowish body with snow-white wings and red eyes; length is 0.03 inch (0.8 mm)
Nymph: first instar is called a crawler; there are 4 instars, the last stage being 0.6 mm in length
Egg: microscopic in size and laid in clusters on the underside of leaves
Adult silverleaf whiteflies on soybean
Whitefly nymphs
Origin and distribution
Silverleaf whitefly has a global distribution, but originally occurred in the Middle East-Asia Minor region
A global invasion occurred in the late 1980s, primarily via trade in ornamental plants
First reported in soybeans in Florida during 1988
Life History
Life History
Females lay 50-400 eggs on the underside of leaves
First-stage nymphs (crawlers) move away from the hatching site, settle down to feed, and become immobile (stop crawling)
There are 4 nymphal stages
Development occurs between 57 F and 97 F
Generation time is 22 days (range 18-50 days)
Silverleaf whiteflies have been recorded from over 500 plant species including many vegetables, ornamentals and cotton
Multiple generations occur per year
Silverleaf whitefly nymphs are small and difficult to see on the underside of a soybean leaflet.
IPM Practices
Integrated Pest Management Practices
Recommendation: spraying solely for whiteflies is probably not economically profitable; consider an insecticide if soybean aphids or two-spotted spider mites are also present and extended hot, dry weather is forecast
Insecticides: products containing bifenthrin may provide the best control of whiteflies in soybeans
Plant resistance: no known resistant soybeans
Biological control: some predators will prey on whitefly nymphs and pupae, but beneficial insects cannot be expected to quickly suppress large populations
An insidious flower bug feeding on whitefly pupae
Photos and Text
Marlin E. Rice, Pioneer
Reviewed by Herb Eichenseer, Pioneer