10 



11.^ 



206 THYSANOPTERA AND ORTHOPTERA. 



Anaphothrips str'iatus, p. 210. 

 \ a. With one conspicuous spine at each posterior angle of the pro- 

 thorax. No other prominent prothoracic spines. . Scirto- 

 thrips ruthveni, p. 208. 

 b. With prominent spines at all four angles of prothorax. (9). 



f a. General color nearly black. Ctenothrips hridwelli, p. 210. 



9. <{ b. General color ^^ellow, usually tinged ^^dth orange or pale brown. 



Genus Euthrips (10). 



a. General color light brown. Body comparatively broad. 

 Wings very short, appearing to be wanting. Sluggish habits. 



Euthrips fuscus, p. 210, 



b. General color yellow, tinged with orange on thorax. Body 

 more slender. Wings nearly always present and of full length. 

 Active. Euthrips tritici, p. 208. 



a. Maxillary palpi two-segmented. Wings with a conspicuous 

 white area at base. Sluggish habits. Baliothrips hasalis, p. 212. 



b. Maxillary palpi three-segmented. Wings without conspic- 

 uous white area at base. Very active insects. Genus Thrips 

 (12). 



a. General color yellow. Four to six widely separated spines on 

 fore vein in distal half of fore-mng. Thrips tahaci, p. 21 1 . 



12. { b. General color brown to black. Usually only three mdely sepa- 

 rated spines on fore vein in distal half of fore-wing. 



Thrips physopus, p. 212. 



Suborder Tuhulifera. 



Family Phloeothripidae. 



{ a. Body slender. Head at least one and one-half times as long 



j as broad. Genus Phyllothrips (14). 



13. ', b. Body stout. Head less than one and one-half times as long as 

 [ broad. (15). 

 f a. Last three segments of antenna yellow. Spines prominent on 



prothorax. Phyllothrips citricornis, p. 214. 



b. Last three segments of antenna brown. Spines inconspicuous 

 on prothorax. Phyllothrips aspersus, p. 214. 



f a. Antennae seven-segmented. Allothrips megacephalus, p. 214. 



15. \ b. Antennae eight-segmented (last two segments may be immov- 



[ ably joined). . (16). 



[ a. Seventh segment of antenna separated from eighth by a mere 



groove, not a movable joint. Neothrips corticis, p. 214. 



b. Joint between seventh and eighth segments of antenna movable. 



[ . (17). 



14 



16 



