12 NORTH AMEETCAN THYSANOPTEEA. 



e. Antennae with second segment drawn out into an acite process on outer 

 angle; fore femora usually broad and with small tooth ai 



end on outside (14) Chirothrips Haliday. 



e^. Antenna? with second segment normally symmetrical' fore femora 

 smaller and without tooth. 

 /. Ocelli and wings wanting; hairs upon the end of the abdomen short 



and as a rule very weak (15) Aptinothrips Ilaliday. 



/''. Ocelli and wings present; hairs upon the end of the abdomen moder- 

 ately long and proportionately stout. 

 g. With a long spine at the middle of each side of prothorax; spines on 



body and wings very strong (16) Scolothrips Hinds. 



g^. Without a spine at the middle of each side of prothorax. 



h. Ovipostor long and extending considerably beyond tip of abdo- 

 men (17) Scirtothrips Shull. 



h^. Ovipostor not unusually long and not extending beyond tip of 

 abdomen (18) -Ett^AnpsTargioni-Tozzetti. 



3. Antennae with apparently nine segments. 



a. Head only slightly wider than long; wings not regularly set with spines; spines 



weak and not conspicuous (19) Anaphothrips Uzel. 



a^. Head fully one and one-half times as wide as long; wings set regularly with 



spines (20) Pseudothrips Hinds. 



4. Antennae with clearly nine segments, sometimes apparently ten. 



(21) Heterothrips Hood. 

 C. Family Phlceothripid^. 



1. Head about as long as wide and either shorter or only a little longer than the pro- 

 thorax. 

 a. Antennae with seven segments. 



b. Antennae one and one-half times as long as head; head rounded in front and 

 about as wide as long; basal segments of antennae subap. 



proximate (22) Allothrips Hood. 



y. Antennae two and one-half times as long as head; head rectangular; basal 

 segments of antennae widely separated and placed on the 

 prominent anterior angles of the head. 



(23) Rhaptothrips Crawford. 



a^. Antennae with eight segments and one and one-half to twice as long as head. 



b. Width of abdomen of females not nearly eqiial to one-half its length; wings 



constricted in the middle. 



c. Mouth-cone not longer than its breadth at base; labrum narrowed toward 



the tip but not sharply pointed; fore femora but slightly 



thickened; fore femora of males without large curved tooth 



on inner side (24) Anthothrips Uzel. 



(/. Mouth-cone reaching nearly to hind edge of presternum; labrum blunt; fore 

 femora of females thickened, of males greatly enlarged and 

 with a large curved tooth on inner side. 



(25) Aleurodothrips Franklin. 

 y. Width of abdomen of females equal to about one-half its length. 



c. Head narrowed in front (26) Eurythrips Hinds. 



(/. Head not narrowed in front. 



d. Third antennal segment very short and narrow (27) Lissothrips Hood. 



d' . Third antennal segment normal. 



e. Segment 8 of antenna shorter than segment 7 (28) Trichothrips Uzel. 



ef. Segment 8 of antenna very slender and noticeably longer than segment 7. 



(29) Plectothrips Hood. 



