Trialeurodes Cockerell 1902

Dooley Iii, John W., Lambrecht, Susan & Honda, Jeffrey, 2010, Eight new state records of aleyrodine whiteflies found in Clark County, Nevada and three newly described taxa (Hemiptera: Aleyrodidae, Aleyrodinae), Insecta Mundi 2010 (140), pp. 1-36 : 22-23

Genus Trialeurodes Cockerell 1902

Diagnosis. Puparium: Habitus. Normally oval-shaped, mostly pale with a few species dark brown, or having a pale and dark brown form; about 100 species are described. More abundant on the underside of the leaf and less dense on the upper surface. Slide mounted specimen-Lateral margin. Crenulate (crenulations from small to large, uniform or of varying widths), somewhat weak, and sometimes modified at the thoracic tracheal openings and showing some stippling in the thoracic furrow. Dorsum. A submarginal row of variously shaped papillae (cylindrical, bullet, conical apically rounded or acute) well or poorly developed; if well developed, then separated or closely appressed; such papillae may also occur on the dorsal disc. Seven or 8 abdominal segments apparent in median region of abdomen: A 7 in most species reduced with the median length no more than one-third the length of A 6. Vasiform orifice. Cordateshaped, defined, enclosing a posteriorly lobed lingula that is contained within the vasiform orifice. The lingula has 3 paired lobes and one apical lobe that is usually partially, but may be totally covered by the operculum. The operculum, cordate to subcordate, covers at least half the vasiform orifice. Venter. Antennae usually terminate at the T 1 position. Legs armed with spines on inner portion of leg or such spines absent. Thoracic tracheal folds usually present and unmarked. Pores. Submarginal disc pores and porettes present while distribution and location varies and may be associated with papillae. Chaetotaxy. Cephalic, A 8 (not anterior to anterior margin of vasiform orifice), and caudal pairs of submedian setae present; A 1 setae present or absent.

Comments. Physical characteristics of the host plant leaves sometimes cause a high degree of variation in the shape and pattern of the papillae, and cuticle sculpturing of species in this genus. Of the 67 described species in Trialeurodes , five species are known to occur in Nevada along with one newly described species and one unidentified species. Two species are dark, three are pale to yellow in color and one has both the light and dark form.