FACTORS AFFECTING EGG HATCH, DEVELOPMENT AND SURVIVAL OF BEMISIA ARGENTIFOLII (HOMOPTERA: ALEYRODIDAE) REARED ON AND ARTIFICIAL FEEDING SYSTEM

Authors: BLACKMER, JACQUELYN; LEE, LINDA; HENNEBERRY, THOMAS

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2002
Publication Date: 4/1/2002
Citation: N/A

Interpretive Summary: Improvements in the way silverleaf whitefly is managed have led to reduced populations in the southwest U.S. However, its potential for developing new biotypes, as well as its apparently increasing role in virus transmission makes it a persistent threat. Characteristics such as biotype formation and vector efficiency are partially explained by it's host range. .Consequently, a better understanding of the host acceptance process and subsequent development of this pest could lead to new control strategies. We used an artificial feeding system to determine how various factors influenced egg hatch, crawler establishment, and development of silverleaf whitefly. Egg age influenced hatch rates, and to a lesser extent survival and development of nymphs reared on the artificial diet. Five- to six-day- old eggs had higher hatch rates, and nymphs survived longer and developed faster than nymphs from younger or older eggs. There were negative associations between the number of eggs placed on the membranes and both hatch rate and establishment of crawlers. Eggs oviposited on and then subsequently removed from plants held under long day conditions or high light intensity, had higher hatch rates than eggs oviposited under short day conditions or low light intensity. Long day conditions during oviposition also significantly enhanced survival of nymphs through Day 20 and developmental rate for Day 6 counts. Light intensity did not significantly affect development or survival of whitefly nymphs.

Technical Abstract: Improvements in the way Bemisia argentifolii is managed have led to reduced populations in the southwest United States. However, its potential for developing new biotypes, as well as its apparently increasing role in virus transmission makes it a persistent threat. Characteristics such as biotype formation and vector competency are partially explained by the host range of B. argentifolii. Consequently, a better understanding of the in the host acceptance process and subsequent development of this pest could lead to novel control strategies. We used an artificial feeding system that consists of a polycarbonate chamber, equipped with a Teflon membrane, and filled with a sterilized artificial diet, to determine how various factors influenced egg hatch, crawler establishment, and development of B. argentifolii. Egg age significantly influenced hatch rates, and to a lesser extent survival and development of nymphs reared on the artificial diet. Five- to six-day-old eggs had higher hatch rates, and nymphs survived longer and developed faster than nymphs from younger or older eggs. There were negative associations between the number of eggs placed on the membranes and both hatch rate and establishment of crawlers. Eggs oviposited on and then subsequently removed from plants held under long day conditions or high light intensity, had higher hatch rates than eggs oviposited under short day conditions or low light intensity. Long day conditions during oviposition also significantly enhanced survival of nymphs through Day 20 and developmental rate for Day 6 counts. Light intensity, at least for the range tested here, did not significantly affect development or survival of whitefly nymphs.