18 NORTH AMERICAN THYSANOPTEEA. 



b. Postocular spines very short and not conspicuous, 

 c. Color brown, with conspicuous red pigment blotches; mouth cone pointed 

 and reaching beyond posterior margin of prosternum; segments 

 1 and 2 of antennse brown, unicolorous with body. 



(72) Trichothrips dens Moulton. 

 b\ Postocular spines prominent. 

 c. Postocular spines acute; color of body black; mouth cone blunt, short, 

 reaching but slightly past middle of prosternum; segments 1 and 2 

 of antennse black, segment 2 shading to lighter. 



(73) Trichothrips brevicuralis ShuU. 

 c'. Postocular spines prominent and nobbed at ends. 

 d. Color of body brownish yellow, shaded with brownish black, with maroon- 

 colored hypodermal pigmentation; mouth cone considerably sur- 

 passing base of prosternum; segments 1 and 2 of antennae paler 



than body color (74) Trichothrips angusticeps Hood . 



d''. Color of body brown to deep brown, with maroon-colored pigmentation; 

 mouth cone not surpassing base of prosternum; segments 1 and 2 



unicolorous with body (75) Trichothrips ruber new species. 



a'. Fore tarsi not armed; body length about 1.8 mm.; antennse about twice as long 

 as head . 

 b. Wings fully developed; tibiae, tarsi, and intermediate segments of antennse 

 bright lemon-yellow; prothorax two-thirds as long as head; tube 



fully as long as head (76) Trichothrips longitubus Hood. 



y. Wings short; antennal segments 1 to 3 yellowish-brown, segments 4 to 8 

 black; prothorax about as long as head; tube slightly shorter than 



head (77) Trichothrips buffx Hood . 



2. Prominent spines on body acute; most forms yellow-brown (except T. ilex which 

 may be almost black); antennae about twice as long as head; all 

 rather large individuals, about 1.7 mm. or more in length, and with 

 wings usually fully developed (except T. smithii, which is without 

 wings and very small, about 1 mm. in length). 



a. Individuals small and without ocelli or wings (78) Trichothrips smithi Hood. 



a^. Individuals large; wings usually fully developed (they may be rudimentary 

 in T. americanus.) 

 b. Each fore tarsus armed with a small tooth, 

 c. Small stout spines on head borne upon small warts; tube fully as long as head. 



(79) Trichothrips beachi Hinds. 



c''. Spines on head not borne on small warts; tube shorter than head. 



d. Antennse one and three-fourths times as long as head ; tube two-thirds as 



long as head; total length about 2 mm.; fore tarsus with a short, 



stout tooth; wings clear white, except a slightly clouded band at 



one-third the wing's length (80) Trichothrips ambitus Hinds. 



d^. Antennse twice as long as head; tube three-fourths as long as head; total 

 body length about 1.7 mm.; fore tarsi with a very small tooth; 



wings clear white (81) Trichothrips femoralis Moulton. 



d'^. Antennse slightly more than twice as long as head; tube slightly shorter 

 than head; total body length about 1.7 mm.; fore tarsi with a small 

 acute tooth; wings light gray-brown, spotted with darker. 



(82) Trichothrips americanus Hood. 

 V. All tarsi armed each with a small tooth, 

 c. Color very dark brown, almost black; all tarsi, tips of fore tibiae, and seg- 

 ments 3 and 4 of antennse shading to yellow; sides of head slightly 

 arched (83) Trichothrips ilex Moulton. 



