PROCEEDINGS, 1918 29 



l)h. Fr)urtli antennal segment less tlian three times as long as com- 

 bined succeeding segments. 



c. Antennal segment 7 longer than 8 and 9 together. 



Rhipidothrips. 



cc. Terminal four antennal segments closely jointed, shorter or 



slightly longer than the fifth Aeolothrips Haliday. 



KEY TO THE SPECIES 



Genus Stomatothrips Hood 



S. flavus Hood (Proc. Biol. Soc. Wash., Vol. 25, 1912, p. 64). 

 Female — Length 1.4-1.7 mm.; colour brownish-yellow; antennal seg- 

 ments 1-4 pale yellowish white, the remainder of antenna black; tibiae 

 shaded with black. 



Head about one and one-fourth times as wide as long; wings long; 

 fore-wings expanded apically coloured pale brown, with two white cross 

 bands, one of these being a narrow one at basal seventh and the other a 

 slightly wider one at apical seventh ; intermediate brown area somewhat 

 paler at middle. Abdominal segments 1, 2, 3 whitish on posterior 

 margin; segments 9 and 10 tinged with yellow or white. 



Genus Desmothrips Hood 



D. australis Bagnall. Described by Bagnall under the generic name 

 of Orothrips. Hood (Proc. Biol. Soc. Wash., Vol. 28, 1915, p. 57) refers 

 this species to Desmothrips. 



Genus Orothrips Moulton 



O. kelloggii Moulton (U.S.D.A. Bur. Ent. Tech., ser. 12, Pt. 3, 1907). 

 Length 1.8 mm.; colour dark brown, sometimes light brown; prothorax 

 and abdomen shaded with orange. Antennae uniform dark brown except 

 tip of segment 2, which is light brown, and base of 3, which is yellow ; 

 antennal segments 3 and 4 with elongate light coloured membranous 

 sense areas on outer side. 



O. kelloggii yosemitii Moulton (U.S.D.A. Bur. Ent. Tech., ser. 21, 

 1911). Length 1.7 mm.; colour brown to blackish-brown; antennae, 

 segment 2 yellow, dark-brown at base, segment 3 yellow but brown in 

 outer half; sense areas on segments 3 and 4 ovoid. 



Genus Erythrotjirips Moulton 



E. arizona Moulton (U.S.D.A. Bur. Ent. Tech., ser. 21, 1911). 

 Length of body 2.6 mm. ; colour dark brown ; antennae brown uni- 

 colorous with body except basal part of segment 3, which is light brown. 

 Long slender sense areas on segments 3 and 4. Fore-wings clear white 

 with longitudinal bands, dark brown, extending from base, including 

 scale, to tip. 



