22 BULLETIN 173, TJ. S. DEPARTMENT OF AGRICULTURE. 



SYSTEMATIC POSITION. 



The pear thrips belongs to that suborder of the Thysanoptera 

 called Terebrantia, which differs from the other suborder, the 

 Tubulifera, in the possession by the female of a sawlike ovipositor; 

 also, the terminal segments of the abdomen are conical and the wings 

 are not equal in structure, the fore pair being the stronger. The mem- 

 brane of the wings, also, has microscopic hairs. This species is placed 

 in the family Thripida? and is separated from the .ZEolothripidse 

 in that the antenna? usually have from 6 to 8 segments, the wings 

 usually are narrow and pointed at the tips, and the ovipositor is 

 downcurved. It is placed in the genus Tasnio thrips of this family 

 because the body is free from reticulation and the abdomen not closely 

 pubescent; the head nearly or quite as long as wide, with a pair of 

 long bristles between the anterior and posterior ocelli; the cheeks 

 swollen, curving abruptly to the strongly protruding eyes; the 

 antennae eight-segmented, with the last two segments (the style) 

 shorter than the sixth; the maxillary palpi three-segmented, the 

 prothorax very slightly, if at all, shorter than the head, with two 

 long bristles at each posterior angle; the fore tibiae unarmed; the 

 bristles on the veins of the forewings not equidistant, and the last 

 abdominal segment of the female conical and without a pair of short, 

 stout bristles on the dorsal surface. 



Until recently this species was placed in the genus Euthrips Tar- 

 gioni-Tozzetti, which most American authors had used in the sense 

 of Physothrips and Odontothrips, TaBiiio thrips and Frankliniella. 

 Hood 1 has recently shown that the name Euthrips Targioni-Tozzetti 

 (1881) was first used in a subgeneric sense as a substitute for the name 

 Thrips, which had been used for a subgenus of Thrips Linne (1758), 

 and that it is consequently a synonym of that genus. The pear 

 thrips he places in the genus Tseniothrips Amyot and Serville, the 

 orange thrips in Scirtothrips Shull, and, partly following Karny, 2 

 the various other species formerly assigned to Euthrips in the genera 

 Physothrips, Odontothrips, and Frankliniella. 



ANATOMY. 3 



OVIPOSITOR. 



The ovipositor is attached to the ventral side of the eighth and 

 ninth abdominal segments and is composed of four distinct plates, 

 the under pair attached to the eighth segment and the upper or 

 posterior pair to the ninth abdominal segment. The ovipositor in 



1 Hood, J. Douglas. On the proper generic names for certain Thysanoptera of economic importance. 

 In Proc. Ent. Soc. Wash., v. 14, no. 1, p. 34-44, 1914. 



2 Karny, H. Revision der von Serville aufgestellten Thysanoptera Genera. In Zoologische Annalen, 

 Bd. 4, Heft 4, p. 322-344, 1912. 



3 For a description of the mouthparts see discussion under "Manner of feeding and type of mouth- 

 parts," p. 11-13. 



