38 



REPORT OF THE COM^^SSIONER OF AGRICULTURE. 



No. 41. 



lived many (.lays, and laid their eggs in confinement, but died with- 

 out assuming wings. 



Another species, Laclmus strobi, or the white-pine aphis, is found on 

 white pine, and sometimes gives the bark of the trees a peculiar black 

 appearance. The eggs are oval-elongate, shining black in color, and 

 are attached in regular rows of from five to twenty-, but usually in regu- 

 lar rows of eight, to the thread-like leaves of the white pine in Septem- 

 ber. The females are wingless. 

 Eriosoma lanigera, or the woolly apple-tree blight. These insects ap- 

 propriate for their generic nametwo Greek words, 

 signifying wool and body, the insect being par- 

 tially enveloped in a cottony or wool-like secre- 

 tion, furnished from its own body. The eggs are 

 deposited in crotches or cracks of the branches 

 or bark, often at or near the surface of the 

 ground, or on new shoots springing from the 

 I)arent tree. They are mostly enveloped in a 

 cotton-like substance, the young insects in a fiue 

 down, and are hatched out in the spring. As 

 larva, pupa, or perfect insect they are equally 

 injurious, sucking the sap, and, when numerous, 

 do much injury to the trees. These insects are 

 0.10 to 0.12 in length, and are gregarious, feed- 

 ing in societies, which, when seen from a short distance, resemble small 

 bunches of cotton adhering to the trunk or branches of the tree. The 

 insect, when denuded of its cottony covering, is egg-shaped, and of a 

 dull reddish-brown color, with blackish head and feotj when undisturbed 

 and feeding on the tree, it has a tuft of white down on the hind part of 

 the body, which is very easily detached when roughly handled. These 

 woolly i)lant-lice also produce warts or excresences with their powerful 

 beaks, and, when in great numbers on a young tree, cause the leaves to 

 turn yellow, wither, and fall. The young ones are produced alive all 

 summer, but in the fall the females lay eggs which are able to withstand 

 the cold of winter and hatch out into young lice the following spring. 

 Dr. Verrill states that, in Connecticut, in the middle of October, among 

 the wingless neuters, a large number of males and females appear, hav- 

 ing well-formed and rather large wings, in other respects closely resem- 

 bling the rest, and having but little down on their bodies, very plump, 

 and of a black color, the winged females of w^hich are able to fly from 

 tree to tree to deposit the eggs to be hatched out next spring. When 

 the downy covering of these insects is removed by wind or rain, another 

 supply is readily produced, and they are said to be able to withstand a 

 very considerable degree of cold without perishing. These insects have 

 no honey-tubes, but frequently eject drops of a sticky substance from 

 the extremity of their bodies. In order to destroy these pests, it has been 

 recommended to have the insects well scrubbed off with a stitf brush, 

 and the infested parts of the tree immediately afterward well covered 

 with a varnish of shellac. Painting the injured places with a thick 

 coating of whitewash, w^ell mixed withsoft soap or weak glue water, 

 will also destroy the insects, and has been highly recommended. Urio- 

 soma mail of Europe is said by C. H. Sorsby, F. E. S., in the Quarterly 

 Journal of Microscoj)ical Science, in an article on the coloring-matter of 

 some of the Aphides, to produce a red coloring-matter between cochineal 

 and the ha3moglobin of vertebrate animals. 



Eriosoma (Femphigus) pyri, or the apple-tree root-louse, sometimes 

 does much injury to apple-trees, &a, by forming galls on the roots, like 



