|Walker, Gregory - U OF CALIF, RIVERSIDE|
Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 1996
Publication Date: N/A
Interpretive Summary: A survey was made of the waxy particles produced by 6 species of adult whiteflies and of the waxes on the surface of their cuticle. These results were compared to those of the plant damaging silverleaf whitefly, Bemisia argentifolii, its close relative the sweetpotato whitefly, Bemisia tabaci, and the common greenhouse whitefly, Trialeurodes vaporariorum, about which we have previously published. All species produced waxy particles with which they covered themselves as well as their surroundings. The particles were composed of aldehydes and alcohols of 30 to 34 carbons and the major component was either 30, 32 or 34 carbons on a given species. The cuticular surface lipids were largely saturated wax esters on all species. The chain length of the major wax esters differed between species but was in the range of 38 to 50 carbons in all species. When the composition of the wax particles and of the wax esters wax considered, all species could be differentiated from each other except for B. argentifolii vs. B. tabaci, the most closely related species. The differences in chemistry between species may be the cue by which certain species-specific parasites and predators recognize their prey. Thus, the external lipids may represent the interface between predator and prey. Further work is directed to determine the potential role of these lipids in the acceptability of artificial diets for rearing insects.
Technical Abstract: The external lipids produced by adult whiteflies consisted of 'wax' particles adhering to body hairs and of surface lipids, largely wax esters. The 'wax' particles of each species were composed of a mixture of long-chain aldehydes and long-chain alcohols of the same carbon numbers, the major chain lengths being C30, C32, or C34. C34 was the dominant chain length in Aleurothrixus floccosus, Dialeurodes citri, Dialeurodes citrifolii and Parabemisia myricae, C30 in Aleuroplatus coronata and C32 in Aleurotithius timberlakei. The major wax esters in the cuticular surface lipids were C40 and C42 in A. timberlakei, C42 in A. coronta, C42 and C44 in A. floccosus, D. citri and D. citrifolii, C44 in P. myricae and Aleyrodes singularis, and C46 in Aleurodicus dugesii. Other chain lengths occurred in lower proportions. Hydrocarbons, largely n-alkanes, were minor components of the surface lipids.