Submitted to: Journal of Insect Physiology
Publication Type: Abstract Only
Publication Acceptance Date: November 20, 2004
Publication Date: November 20, 2004
Citation: Gelman, D.B., Blackburn, M.B. 2004. Identification of the molting hormone of the sweeet potato (bemisia tabaci) and greenhouse (trialeurodes vaporariorum) whitefly.. Journal of Insect Physiology. Vol.51 (2005) p.47-53
In order to identify the whitefly molting hormone, whole body extracts of mature 4th instar and newly formed pharate adult Bemisia tabaci (Strain B) and Trialeurodes vaporariorum were prepared and subjected to reverse phase HPLC. Ecdysteroid content of fractions was determined by enzymeimmunoassay. The only detectable ecdysteroids that were present in significant amounts in whitefly extracts were ecdysone and 20-hydroxyecdysone. The concentration of 20-hydroxyecdysone in B. tabaci and T. vaporariorum extracts, respectively, was 40 and 15 times greater than the concentration of ecdysone. The identity of the two ecdysteroids was confirmed by normal phase HPLC. When ecdysteroid content of RPHPLC fractions was assayed by RIA, small amounts of polar ecdysteroids were also detected indicating that these ecdysteroids have a very low affinity for the antiserum used in the EIA. Although ecdysteroid administered by feeding did not stimulate whiteflies to molt, based on our results, it is exceedingly likely that 20-hydroxyecdysone is the whitefly molting hormone.