258 



PLUTELLA Sclirk. 



Plutella omissa sp. ii. 



Meadj face, and antennce, Tvhite ; palpi slightly tinged with brownish at the sides. 



^ore-wings, white, with a yellowish tinge, most noticeable along the fold, sometimes 

 with a very few scattered brownish scules; the dorsal and ajiical margins and the 

 anal angle are dotted with small groups of brown scales ; cilia white. 



Hind-icings, very pale grayish, iridescent, with a rosy hue ; cilia paler. 



IJxj). ah, 13™'^. 



Habitat, Willow Creek, Oregon, September 9, 1871. Five specimens. . 



Tyjye, $ $, Mus. TFlsm. 



(To 1)6 continued.) 



GENERAL NOTES. 



NOTES ON THE COCHINEAL INSECT. 



In October, 1886, we received from Mr. A. F. Carothers, Iiika Eanch, 

 near Cotiilla, La Salle Conutj, Tex., a large number of specimens of 

 the Cochineal Insect (Coccus cacti), and were much interested to find 

 that they were being destroyed by a predaceous cateri)illar, which 

 worked in precisely the same way as Dakruma coccidivora upon the Cot- 

 tony Maple scale, described by Professor Comstock in the annual re- 

 port of this Department for 1879. The caterpillars ate one Coccid after 

 another, spinning a silken tube as they progressed and remained hid- 

 den inside the tube, which was covered with fragments of the Coccus 

 and of its white secretion. We were fortunatelv able to rear the adult, 

 which x^roved to be beyond question identical -with. Dah'iima coccidivora, 

 this species having previously been found only in the District of Col- 

 umbia. 



Another enemy of the Cochineal Insect was reared from this same 

 lot of specimens. This is a true parasitic fly of the genus Leucopis, 

 species of which have previously been recorded as attacking scale in- 

 sects. Specimens were sent to Dr. Williston who has kindly sent us 

 the following description, as the species proves to be new: 



Leucopis bellula, u. sp., Willisto) 



Length l|-2™"\ Black, thickly grayish white dusted. Front with two slender, 

 gently arcuate, black stripes; the narrow orbital space perceptibly more whitish. 

 AutennoB black, the basal joints shimmering whitish ; arista short. Face in color 

 like the frontal orbits. Mesonotum with two conspicuous chocolate-brown stripes, 

 beginning on the inner side of each humerus and gently converging to the posterior 

 margin. In the middle of the dorsum, before the scutellum, there are two bristles; 

 the usual bristles on the lateral margin, and ou the margin of the scutellum ; none 

 on the front or vertex. Abdomen more whitish than the thorax ; clothed with short 

 black hairs; first segment with the lateral margins and a posterior band, deep 

 brown ; second third and fourth segments each with a slender, sub-interrupted stripe 

 and a pair of rounded spots, all deep brown iu color ; the pair on the second mod- 



