October, 'OS] journal op economic entomology 307 



so that the sexual forms have always been deposited upon the walls 

 of the breeding cages.^ 



NATURAL ENEMIES 



The most active natural enemies of the woolly aphis in Colorado 

 have been predaceous insects. We have reared no parasite from it, 

 but, Aug. 21, 1908, Mr. L. C. Bragg brought into my office a female 

 ApJielinus mali- busily ovipositing in apterous females of this louse. 

 Among the Coceinellids, Eippodamia convergens is by far the most 

 abundant destroyer of this louse both upon the eastern and western 

 slopes of the mountains. Mr. E. P. Taylor also took H. sinuata, Coc- 

 cinella 9-noiata, C. monticola and C. transversalis feeding on this 

 louse in the orchards about Grand Junction, and we have noted H. 

 transversalis, C. 9-notata, C. monticola, C. frigida, and C. 5-notata 

 {transversalis and transversoguttata) feeding upon it in eastern 

 Colorado. 



]\Ir. Taylor also reared two syrphus flies at Grand Junction on this 

 louse, namely, Catdbornha pyrastri Linn, and Eupeodes volucris 0. S. 



Lace-wing flies (Plate 5, figs. 15 and 16) are also very destructive 

 to Scliizoneura lanigera in Colorado, and especially upon the western 

 slope in the Grand Valley, where Mr. Taylor concluded that they did 

 more than all else to subdue the unusually severe outbreak of this 

 louse in that valley during the early summer of 1907. The Capsid, 

 Campfohrochus nebulosus LThl, we have found a common feeder upon 

 this and some other plant lice in Colorado. 



Alate Female— Plate 5, fig. 10. 



General color nearly black to naked eye, but the abdomen is really a dark 

 yellowish or rusty brown. Leg, eyes and antennae are black or blackish, prox- 

 imal ends of femora and tibiae may be yellowish, nerves of wings black, the 

 subcostal being very heavy, and the stigma dusky brown to the naked eye, 

 but really a dark green. Third cubital vein sub-obsolete half way to the fork. 

 Cauda and cornicles nearly obsolete. 



The yellowish brown color of the abdomen is due mainly to the female 

 embrj-os showing through, the two sexes being present in about equal num- 

 bers, usually four or five of each, but the numbers may vary from three to six. 

 Sixteen winged females dissected gave a total of 66 females and 48 males. 

 Joints three to six of the antennae are strongly annulate, as shown in Plate 6. 



' Since writing the above, I have succeeded in obtaining numerous examples of light 

 orange yellow sexual females and the smaller duslty brown males, and a few j-ellow eggs 

 upon leaves and barli of twigs that had been inclosed six weeks before in small cheese 

 cloth sacks in the orchard. The first egg was obtained Sept. 18, at Ft. Collins, Colorado. 



2 Determined for me by Dr. L. O. Howard. 



