Premium
The nymphal‐adult molt of the silverleaf whitefly ( Bemisia argentifolii ): Timing, regulation, and progress
Author(s) -
Gelman Dale B.,
Blackburn Michael B.,
Hu Jing S.,
Gerling Dan
Publication year - 2002
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.10051
Subject(s) - instar , biology , greenhouse whitefly , trialeurodes , whitefly , metamorphosis , nymph , homoptera , botany , larva , pest analysis
The developmental progress of silverleaf whitefly ( Bemisia argentifolii) 3rd instars and 4th instar/pharate adults was monitored using a tracking system that had been designed to identify synchronous individuals in another species of whitefly, the greenhouse whitefly, Trialeurodes vaporariorum . When reared on greenbean under conditions of LD 16:8 and a temperature of 26 ± 2°C, the body depth of 3rd instar SLWFs increased from approximately 0.04 mm (Stage 2) to 0.175–0.2 mm (Stage 7–8) and the body depth of the 4th instar increased from approximately 0.1 mm (Stage 1) to 0.25–0.30 mm (Stage 4–5). The durations of the 3rd instar and the 4th instar/pharate adult were approximately 3 and 7 days, respectively. Examination of coronal sections of 4th instars revealed that adult eye and wing development are initiated during Stage 6, the stage in which an external examination showed that the eye has begun to undergo pigment diffusion. Ecdysteroid titers peaked at approximately 400 fg/µg protein during stages 4 through 6A of the 4th instar, i.e., just prior to and upon the initiation of the pharate adult stage. Although adult development is initiated later in the SLWF than in the GHWF (adult eye and wing development begin in Stages 4 and 5, respectively, in GHWFs), the same rapidity of metamorphosis is observed in both species. Within approximately 24 h, the simple bi‐layered wing bud developed into a deeply folded wing of nearly adult proportions and within an additional 12–24 h, the nymphal eye and wing bud had been replaced by the well‐differentiated eye and wing of the adult whitefly. Our study is the first to describe the regulation, timing, and progress of the nymphal‐adult molt and of the structural changes that accompany nymphal‐adult metamorphosis in the SLWF. Arch. Insect Biochem. Physiol. 51:67–79, 2002. Published 2002 Wiley‐Liss, Inc.