228 IOWA ACADEMY OF SCIENCES. 



NOTE ON A NEW SPECIES OF PHLCEOTHRiPS, WITH DESCRIPTION. 



HERBERT OSBORN. 



In connection with the paper by Miss Beach on the Thri- 

 pidso it seems desirable to describe a species which has for a 

 long time been in our collections, but has not received a techni- 

 cal description. 



Pbloeothrips rerbasci, n. ep. Black, polished; head quadrate with a 

 prominent post-ocular bristle; prothorax widened behind; first joint of 

 anterior tarsi armed on inner side with a curved tooth. 



FemUe: Head quadrate, very slightly constricted behind, a prominent 

 bristle behind the eye: antenrte light yellowish with dusky base and tip, 

 joints 1 and 2 black, 3-6 yellow, 7-8 dusky, ending with two bristles: pro- 

 thorax widening behind, with prominent angles, three lateral bristles; 

 meso and meta-thorax subquadrate. Legs black except anterior tibue and 

 all tarsi which are yellow, the tarsi somewhat clouded with dusky. 

 Anterior tarsi with a short curved tooth on inner side of first joint at mid- 

 dle. Wings hyaline except base of anterior pair, which is fuliginous; 

 anterior pair with no fringe at base: anal vein entire; median vein distinct 

 at base, but becoming obsolete; three long spines in a row on the inner 

 side of the median vein near base; posterior wings at base with two long, 

 slender bristles near together on hind margin; abdomen at apex with six 

 long and seven short bristles; tube reticulate. 



Male smaller than female and having two slender spines on a slight 

 elevation at side of the anterior margin of the first segment of the 

 abdomen. 



Length of male 1.50-1.60 mm., female 1.80-1.90 mm. 



This species stands near to nigra, Osb. , but differs decidedly 

 from that species in the more quadrate head, prominent poste- 

 rior angles of the prothorax, as also in the presence of two 

 prominent bristles just behind the eyes and the different num- 

 ber and character of bristles at apex of tube. 



It occurs almost invariably in mullein, hibernating in the 

 stools, and may be found in early spring at the base of the 

 fresh leaves, especially among the dense interior leaves. The 

 whitish, cylindrical eggs are deposited during April, and 

 larvte develop on the mullein leaves. The larvte differ decid- 

 edly from the larvte of nigra, in being yellow or orange instead 

 of deep red. 



Adults, bred forms of which matured June 20th to 26th, are 

 found in mullein blossoms in midsummer (July), and probably 

 produce a second brood. Adults have been taken in Septem- 

 ber in the seed pods, and in November at the base of dead 

 mullein stalks. 



This is the species referred to in my article on "The Food 

 Habits of the Thripida3 " (Insect Life, Vol. I, p. 141) as Phlwo- 

 thrips sp., the species being cited in evidence of an herbivorous 

 di t for the Th7'ipidce. 



