|Freeman, Thomas - ND STATE UNIV, FARGO|
Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 8, 2003
Publication Date: September 22, 2003
Citation: NELSON, D.R., FREEMAN, T.P., BUCKNER, J.S., HOELMER, K.A., JACKSON, C.G., HAGLER, J.R. CHARACTERIZATION OF THE CUTICULAR SURFACE WAX PORES AND THE WAXY PARTICLES OF THE DUSTYWING, SEMIDALIS FLINTI. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. 2003. v. 136(2)B. p. 343-356. Interpretive Summary: Dustywings (Neuroptera: Coniopterygidae) are minute (1-3 mm) predators of small arthropods such as aphids, scale insects, whiteflies and mites. They are active on non-crop plants (shrubs and trees) in areas surrounding agricultural areas and in urban areas, where whiteflies spend time between crop seasons. The common name derives from their covering of a whitish, powdery material. Because of their small size and dusty appearance, they are often mistaken for whiteflies. Whiteflies also produce a white, powdery material from pores on their body. Adult whiteflies produce such copious amounts of waxy particles that they become scattered over their surroundings, partially camouflaging their eggs and nymphs and producing a grayish appearance on the surfaces of heavily infested leaves. Thus, both whiteflies and dustywings appear white due to a coating of waxy particles. The adult dustywing, Semidalis flinti Meinander, begins producing waxy particles after eclosion as do whiteflies. The waxy material, which forms the particles, is extruded from individual pores, mainly found on the abdomen. The pores have a rosette-like appearance and each pore extrudes dual waxy ribbons. As each ribbon extends a short distance out of the pore it begins to curl back on itself until the end makes contact with the ribbon. The curled end then breaks free from the extruding ribbon to form circular waxy particles, resembling a wheel rim without spokes, with fluted edges and approximately 2.75 µm diameter. The major chemical components of the particles are free fatty acids, almost exclusively the 24-carbon fatty acid, tetracosanoic acid. Hydrocarbons and fatty alcohols are minor components. The chemical composition of the dustywing waxy particles contrasts with that of whitefly waxy particles which are a mixture of a long-chain aldehyde and a long-chain alcohol. The role of these chemicals in predator-prey interactions remains to be determined.
Technical Abstract: The adult dustywing, Semidalis flinti Meinander (Neuroptera: Coniopterygidae), begins producing circular-shaped waxy particles after eclosion. The waxy material, which forms the particles, is extruded from individual pores found in clusters on the abdomen. Pores also are present in two rows of 3 pores on the frontalis and 2 pores on the first segment of each antennae. The pores have a rosette-like appearance and each pore extrudes dual waxy ribbons. As each ribbon extends a short distance out of the pore it begins to curl back on itself until the end makes contact with the ribbon. The curled end then breaks free from the extruding ribbon to form the circular waxy particles with fluted edges approximately 2.75 µm diameter. The adults use the particles to cover all parts of their body except for their eyes and appear to lightly coat their antennae. The lipid portion of the particles consists largely of free fatty acids, almost exclusively the 24-carbon fatty acid, tetracosanoic acid. Minor lipid classes are hydrocarbons, fatty alcohols and unidentified material.