56 Psyche [April 



well-developed. Mesonotum convex, somewhat cordate, owing to 

 a posterior cleft or indentation. Parapsidal furrows incomplete, 

 indistinct during life. Scutellum oval, without longitudinal 

 furrows. Tegulse with a pair of bristles. Abdomen elongate- 

 ovate, about as long as the thorax, laterally keeled or compressed. 

 Ovipositor scarcely visible when at rest. Color, black, highly 

 polished, tarsi, except for dusky terminal joints, testaceous. 

 Antennae dark, but translucent, hence appearing yellowish when 

 mounted; clothed with whitish hairs. Eyes very dark russet-red, 

 almost black; ovipositor yellow, transparent. Wings with a dis- 

 tinct median cloud, and a marginal thickening or pigmentation ex- 

 tending from the end of the post-marginal vein to a point on the 

 posterior margin opposite the stigmal vein. Wing-cilia very 

 long, dark-colored. 



Male: Smaller (on the average) than the female, abdomen 

 slenderer more abruptly tapering. Antennae 7-jointed, as in 

 female, but differing as follows: scape broader, pedicel shorter 

 than the funicle, club much less marked. Joints of the flagellum 

 with whorls of bristles. Terminal joint with a rod-like, bristle- 

 tipped prolongation, about two-thirds as long as the joint. Color, 

 as in female. 



This species is very readily distinguished from T. russelli by 

 its uniformly black color and clouded wings. The rod-like ap- 

 pendage of the male is very curious and distinctive, though it may 

 pass for an ordinary bristle if not closely examined under a com- 

 pound microscope. I presume that it is characteristic of the genus, 

 though I have no means of knowing this, the male of T. russelli 

 being as yet undescribed. 



Habits of the Hosts. 



Specimens of the thrips were sent for determination to Dr' 

 J. D. Hood of the Biological Survey, who kindly identified them 

 as belonging to two species, Megalothrips spinosus Hood and 

 Cryptothrips rectangularis Hood, both members of the family 

 Phloeothripidse. Unfortunately, the larvae of the two forms were 

 not distinguished during the course of my observations, and it is 

 impossible to ascertain at present whether their relations to the 

 parasite are different, but it seems probable that either is attacked 

 without discrimination. 



