258 



PLUTELLA Schrk. 

 Plutella omissa sp. n. 



Head, face, and antenna, white; palpi slightly tinged «vith brownish at the sides. 



Fore-wings, white, with a yellowish tiuge, most uoticeable along the fold, sometimes 

 with a very few scattered brownish scales; the dorsal and apical margins and the 

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



Eind-ivings, very pale grayish, iridescent, with a rosy hue ; cilia paler. 



Exp. al., 13'"f". 



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



Type, <? 9, Mus. WIsm. 



{To he continued.) 



GENERAL NOTES. 

 NOTES ON THE COCHINEAL INSECT. 



In October, 1886, we received from Mr. A. F. Carothers, luka Ranch, 

 near Cotulla, La Salle Coimty, 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 caterpillar, which 

 worked in precisely the same way as Bakruma cocciMvora 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 fortunately able to rear the adult, 

 which proved to be beyond question identical \ii\M. Daliruma 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., Willistoj 



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

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

 Antennas 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 on 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 in color; the pair on the second mod- 



