External lipids of adults of the giant whitefly, Aleurodicus dugesii

The external lipids of male and female adults of the giant whitefly, Aleuro dicus dugesii, were found in three forms; as cuticular lipids, as waxy part icles, and only: on the females, as waxy filaments. Collectively, the exter nal lipids consisted of long-chain aldehydes, long-chain alcohols and wax e sters. Cuticular lipids consisted mainly of a ax esters. The major wax este rs were C44 (tetracosanyl icosanoate and docosanyl docosanoate) and C46 (ma inly triacontanyl hexadecanoate and tetracosanyl docosanoate). Hydrocarbons , largely n-alkanes, were minor components of the cuticular surface lipids. Both sexes produced waxy particles soon after eclosion by breaking off ext ruding strands (or ribbons) from anterior wax plates an their abdomens, thr ee pair on males and two pair on females. These particles coated the adults and their surroundings. The waxy particles produced by the anterior wax pl ates of the adults were a mixture of aldehydes and alcohols, predominantly C30. The: wax esters were not part of the waxy particles despite being the major lipid class on the cuticular surface. In addition, the adult female h as two pair of posterior abdominal wax plates which produce waxy filaments that are broken off during oviposition and form spiral trails on the leaf. These trails appear to function to camouflage the eggs which are laid horiz ontally in the waxy trail. The lipid obtained From the waxy filaments from the posterior abdominal wax plates of the female was largely wax esters. Th e predominant wax eater was C46 (mainly triacontanyl hexadecanoate). (C) 19 99 Elsevier Science Inc. All rights reserved.