|Greenberg, Shoil - TX AGRI EXPER STATION|
Submitted to: Sweetpotato Whitefly Progress Review Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 1997
Publication Date: N/A
Interpretive Summary: The silverleaf whitefly Bemisia argentifolii ranks among the most noxious insects attacking agronomic and ornamental crops around the world. Since 1987, annual losses in the USA have exceeded $200 million with an additional annual loss between 3,000 - 6,000 jobs. A tiny parasitic wasp of the genera Eretmocerus is among the most important beneficial insects of whiteflies. However, the practical use of this parasite in augmentative release programs depends on our ability to economically produce it in sufficient numbers. We studied the influence of nymphal instars of B. argentifolii attacked by E. mundus on host-specific mortality and parasitoid survival. These findings will be immediately useful in the development of an efficient rearing system for E. mundus which will make augmentative releases of the parasite for management of additional insecticide use and associated environmental problems.
Technical Abstract: Studies were conducted to assess the influence of nymphal instars of Bemisia argentifolii (Bellows and Perring) attacked by Eretmocerus mundus Mercet on host mortality, parasitoid survival, development time, and progeny longevity. Eretmocerus mundus parasitized all nymphal host instars. The highest percentage of parasitized nymphs was on the second instars (66.4%) and the least on the fourth (red-eyed nymph) instars (8.6%). The second instars exhibited the highest proportion of host mortality and parasitoid survival. The greatest rate of parasitoid emergence (93.8%) was when the second instar host was parasitized, and the lowest emergence (35.7%) was on fourth instars. Parasitoid development was longest when parasitized in the first instars (16.3 days). The longevity of unfed female progeny emerged from host attacked at the second instars was 2.6 days from fourth instars.