|Gerling, Dan - TEL AVIV UNIV.|
Submitted to: National Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: October 29, 2003
Publication Date: November 1, 2003
Citation: Gelman, D.B., Gerling, D. 2003. Tcaiii is not required for photorhabdus luminescens toxin complex a's toxicity against adult silverleaf whiteflies (bemisia tabaci strain b). National Entomological Society of America Annual Meeting. Technical Abstract: Previous life history studies of Encarsia species were conducted on multivoltine host species. The present work deals with the developmental adaptations of Encarsia scapeata, which develops on a univoltine whitefly host, Trialeurodes lauri on Arbutus andrachne trees inhabiting the Mediterranean hills of central and northern Israel. The tree has one flush of leaves each year during April and May and the whiteflies respond by emerging during that time, laying eggs and within ca. 3 weeks, developing to the 4th instar. The whiteflies pass the next 10-11 months of the year as 4th instar nymphs (in diapause), rather than as pharate adults. Parasitoid emergence occurs at two separate times. Some female emergence occurs in the fall (group 1) whereas most females and all males emerge in the spring (group 2). The mated females of group 2 lay female-producing eggs in the new whitefly generation during May. A few of these will emerge in the fall and give rise to group 1 females which are virgins and will lay male-producing eggs in parasitized hosts. Most female parasitoids develop to adults only from January through April, probably after inducing premature development of their hosts. These parasitoid females will constitute group 2 and will emerge in the spring together with the males that develop from the eggs laid by group1 females. Thus, there is considerable developmental synchrony between the parasitoid and its host requiring a complex series of interactions between the two insects.