THE CANADIAN ENTOMOLOGIST. 137 



ON NORTH AMERICAN PHLŒOTHRIPID.E (THYSANOP- 

 TERA), WITH DESCRIPTIONS OF TWO NEW SPECIES. 



BY J. DOUGLAS HOOD, U. S. BIOLOGICAL SURVEY. 



Trichothrips a?iomocerus, sp. nov. — (Plate VI, figs. 1-4.) 



Female. — Forma brachyptera. Length about 1.5 mm. Colour clear 

 brownish yellow, with conspicuous hypodermal pigmentation in head, 

 thorax and abdomen, which is orange by reflected light and maroon- 

 brown - by transmitted light ; tube heavily chitinized and darker at 

 middle ; segments 7 and 8 of antennae blackish brown. 



Head distinctly wider than long, blunt anteriorly, frons not at all 

 produced between antennae, dorsal and latera? surfaces with very minute 

 spines ; vertex flat, evenly declivous ; genag subparallel, rounded ; 

 postocular bristles pointed, moderately long. Eyes greatly reduced, only 

 one facet visible on lateral profile. Ocelli wanting. Antennae slightly 

 more than twice as long as head, the last two segments compactly united, 

 the separating suture scarcely visible ; segment 3 subconical ; 4-6 oval, 

 pedicellate ; 7+8 lanceolate, pedicellate ; segments i and 2 exactly 

 concolorous with body ; 3-6 successively very slightly darker ; 7 + 8 

 rather abruptly dark blackish brown ; sense cones moderate in length, 

 slender; formula: 3, i-i j 4, 1-2; 5, i-i"^; 6, i-i-i; 7, o-i j 8 with 

 one at middle of dorsum. Mouth-cone not quite attaining base of pro- 

 sternum ; labium broadly rounded ; labrum pointed, scarcely surpassing 

 labium. 



Prothorax large, massive, notum weakly chitinized ; it is distinctly 

 longer than head (about equal in length to width of head), and across the 

 coxae is just twice as wide as long; bristles long, pointed; anterior 

 marginals wanting. Pterothorax greatly reduced, narrower and shorter 

 than prothorax. Legs stout, concolorous with body ; fore femora short, 

 thick ; fore tarsus armed with a strong, acute tooth. 



Abdomen large, heavy, about Qne and one-fourth times as wide as 

 pterothorax ; all bristles pointed. Tube thickly chitinized, slightly shorter 

 than head, about two and one-half times as wide at base as at apex ; 

 terminal bristles short, about half as long as tube. 



Measurements: Length, 1.53 mm.; head, length .18 mm., width 

 20 mm.; prothorax, length .205 mm., width (inclusive of coxae) .40 mm.; 

 pterothorax, width .37 mm.; abdomen, width .47 mm.; tube, length 

 .17 mm., width at base .101 mm., at apex .041 mm. Antennœ : Segment 



Mav. 1912 



