20 PROCEEDINGS OF THE ACADEMY OF [Jan., 



very few scattering ones on the other joints. Ocelli three in number,, 

 one just above each compound eye, and one median in position upon 

 the front above the insertion of the antennae. 



Legs dusky brown, tarsi two-jointed, the basal joint very short, 

 tibise with prominent sucker at distal end, the use of which is readily 

 seen by allowing one of the winged lice to walk over a glass slip under 

 a microscope. 



The ivax glands are fewer in number over the head and thorax than 

 in the apterous form; on the anterior margin are two that occupy 

 nearly the whole distance from eye to eye, and there are two similar 

 patches on the hind margin; there is also a long narrow patch upon 

 either side along the hind margin, and in front of either of these is 

 another very small patch. On the mesothorax occur the usual two 

 patches near the median line next to the scutum, and upon the meta- 

 thorax two large patches in line with the two inner rows upon the 

 abdomen. Over the abdomen there are three longitudinal rows upon 

 either side extending over about six segments. The patches are largest 

 in the marginal and the middle rows, and the latter sometimes coalesce 

 on the proximal segments. For arrangement of the glands see Plate X, 

 fig. A. 



Young Louse. — When first hatched the young are pale yellow in 

 color and about one-third millimeter in length. The eyes are dark, 

 the antenna 'three- jointed and about two-sevenths the length of the 

 body, the third joint about one-third longer than joints 1 and 2 

 together, and the first two joints are subequal in length. Each tarsus 

 has two glandular hairs. The young of this species can hardly be 

 distinguished from the young of cooleyi shown at Plate III, fig. E. 

 Chermes pinicorticis Fitch. 



I have found this species abundant upon a few trees of Pinus syl- 

 vestris in City Park, Denver, but have seen it nowhere else in Colorado. 

 The cottony covered apterous females were numerous enough upon the 

 smaller limbs of the trees to give them a distinctly whitened mouldy 

 appearance. An excellent paper upon this species, containing a 

 bibliography by Mr. E. L. Storment, was published in the Appendix 

 to the Twentieth Report of the State Entomologist of Illinois. 



Natural Enemies. — Most of the common plant louse enemies attack 

 genus Chermes, but I have never found one of these lice attacked by 

 internal parasites. Chrysopa species seem to attack them very little, 

 but Syrphus and Coccinellid larva? are great destroyers of these lice 

 when exposed upon the surface of plants, the cottony secretion being 

 apparently no hindrance. I have never found Chermes cooleyi dis- 



