|Freeman, Thomas - NORTH DAKOTA STATE UNIV|
Submitted to: National Research and Action Plan for Silver Leaf Whitefly
Publication Type: Abstract Only
Publication Acceptance Date: December 21, 1999
Publication Date: N/A
Technical Abstract: All adult whiteflies groom and cover themselves with waxy particles, except for their eyes. Particles are composed of a mixture of long-chain aldehydes and long-chain alcohols:One even-numbered chain length of aldehyde and alcohol predominate (about 90%), with the chain length of the dominant component being 34 carbons for B. argentifolii, 32 carbons for T. vaporariorum, and 30 carbons for A. dugesii.In order to produce copious amounts of waxy particles, the majority of the abdominal surface is covered with wax plates composed of many microtrichia which extrude the waxy material which is broken off by the tibia to form particles. The number of microtrichia were 0.49/um2 in the silverleaf whitefly, Bemisia argentifolii, 0.47/um2 in the greenhouse whitefly, Trialeurodes vaporariorum, & 0.43/um2 in the giant whitefly, Aleurodicus dugesii. Microtrichia are in shape of a 'T' in which all arms appear to be the same length. Length of an arm was 0.7 u for B. argentifolii, 0.8 u for T. vaporariorum, and 1.0 for A. dugesii. Length and width of waxy particles were: 5.0 by 0.8 u for B. argentifolii, 4.7 by 0.9 u for T. vaporariorum, and 11.1 by 1.3 u for A. dugesii. The particles from B. argentifolii and T. vaporariorum are semicircular and form shapes resembling the letter 'C' or a 'horse collar'. These shapes are effective in enabling the particles to stick to the hairs of the whiteflies. However, the particles from A. dugesii do not curl, they remain as straight fragments on the cuticular surface and do not accumulate to the extent observed for the semicircular particles of the other whiteflies.