1 14 POMONA JOURNAL OF ENTOMOLOGY 



In the main, this species conforms to the characterization of the genus 

 Heterothrips Hood, but in one or two pecuHarities it does not: (1) antennae 

 clearly 10-segmented ; (2) prothorax much less than twice as long as head; 

 (3) rows of minute teeth extending across entire posterior dorsal margins of 

 abdominal segments two to eight. These characters, however, are not neces- 

 sarily of generic value. The general type of the antennae in this genus is 

 unmistakable. 



Chirothrips mexicana n. sp. 



Length, .86 mm. ; general color, medium brown. 



Head (Fig. 51 A) somewhat wider than long, small, spatulate and nar- 

 rowed anteriorly ; cheeks arched, about two-fifths as long as eye ; portion be- 

 tween posterior margin of eyes and occiput z^ery much elevated, arched and 

 reticulated, bearing the ocelli on the abrupt incline from the occiput to the 

 vertex ; front prolonged triangularly between insertion of antennae ; with eight 

 small spines in front of the ocelli, and two very small postocular spines on 

 each side. Eyes moderately large, finely facetted, slightly pilose ; distance 

 between eyes less than half the greatest width of head ; ocelli small, pale, situ- 

 ated far back on elevated portion of head, between posterior angles. Mouth 

 cone moderately long, broadly rounded at tip ; maxillary palpi consisting of 

 three very short segments; labial palpi one-segmented. Antennae (Fig. 51 B) 

 twice as long as head, stout, with only a few small spines ; general color lighter 

 than body — basal segment concolorous with body, and second lemon yellow ; 

 basal segment large, transversely egg-shaped, the point outward, with dark 

 transverse line ; segment II prolonged outwardly into a long acute apophysis 

 with a small sense cone at tip ; III pedunculate, asymmetrically pyriform, with 

 a prominent sense cone on outer anterior angle, as has, also IV ; IV and V 

 roughly rounded, V smaller than IV ; VI elongate, with two small sense cones 

 on distal half; VII and VIII small, moderately slender. 



Prothorax (Fig. 51 A) about two and one-half times as long as head, 

 one and one-ninth times as wide as long, more than twice as wide posteriorly as 

 anteriorly; sides' with a deep indentation above coxae and a short, black chit- 

 inised line curving in from it ; with one prominent spine on posterior angles 

 and a few small inconspicuous ones on dorsal surface ; dorsal surface deeply 

 reticulated. Metathorax wider than prothorax, and pleurae bulging beneath 

 insertion of wings. Pterothorax reticulated. Wings (Fig 51 H) long and 

 narrow, reaching beyond tip of abdomen ; forewings light brown, surface 

 covered with microscopic hairs ; hind wings lighter colored ; fore-wing with 

 one median longitudinal vein, which disappears before the middle of the 

 wing; with five spines on median vein, and five on apical half of wing, ar- 

 ranged as though the two longitudinal veins were present ; anterior margin 

 with row of twenty-six long slender fringe-like spines ; posterior fringe long. 

 Legs (Fig. 51 E, F, G) short, with only a few small sjiines ; fore-femora 

 (Fig. 51 E) enormously thickened, traiiez.oidal, nearly as broad at base as 

 long; fore-tibiae short and thick; fore-tibiae and all tarsi lemon yellow. 



