Characterization of Waxy Material of the Giant Whitefly, Aleurodicus Dugesii, Using Scanning Electron Microscopy (SEM) and Capillary Gas Chromatography-Mass Spectrometry (CGC-MS)

Extract

The giant whitefly is a pest, particularly of Hibiscus and sometimes avocados, in southern California. The insect is unique in that the nymphal stages produce copious quantities of waxy material differing in structure and chemical composition. Adults produce a waxy material (waxy particles) which covers them and surrounding surfaces, and the female also produces a waxy material with which she forms a circular trail of wax strands on the abaxial leaf surface.

Waxy particles produced by male and female adults consisted of long-chain aldehydes and alcohols, largely 32 carbons in chain length. As waxy ribbons extruded from anterior abdominal wax plates, they are periodically broken off by the tibia and the resulting particles coat adults, nymphs and surrounding surfaces. The female has a second set of wax plates posteriorly on her abdomen which produce waxy strands. As her abdomen drags along the abaxial leaf surface during oviposition these strands break off forming a waxy trail camouflaging the eggs.

The nymphs produce several types of waxy material. Two types are produced at the same time from 10 pores on the dorsal surface; waxy material is extruded as a filament on which a second waxy material curls off as extrusion occurs.