24 



produces n large number of live young during the early summer. 

 The young are yellow in color, exceedingly small and very active. 

 They soon establish themselves all along the underside of the twigs 

 and leaves, where, inserting their long slender beaks into the plant 

 tissues, they imbibe the sap. Late in the summer they leave the 

 terminal growth and return to the trunk and larger branches, seeking 

 shelter as far as possible in crevices of the bark. In this condition 

 they remain over winter. In the spring the females (Fig. 14, a) have 

 as-umed a reddish hue and after copulation with the males, which 

 occurs late in May, they remain immovably attached to the bark. 

 They now bt come almost imbedded in a mass of waxy matter (Fig. 

 13, d, e, and/) which they secrete, and have a peculiar sickening 

 odor when present in large numbers, and when crushed yield a 

 reddish color. At this stage, and to some extent in the late summer 

 and fall, they exude from their bodies a large quantity of honey-dew 

 which falling on the leaves and branches gives these parts a peculiar 

 blackened ai)pearance which is very noticeable where the insects are 

 at all abundant. It also attracts ants and other insects to the trees. 



The adult males (Fig. 14, c) like those of all other bark lice are very 

 unlike the females in appearance, and when fully developed are pro- 

 vided with a single pair of wings and a pair of very long, wax-covered 

 organs which project from the hinder part of the body. 



The injuries inflicted by these insects appear severe only to young 

 trees, large trees, apparently, being much better able to withstand 

 their attacks ; and, as the task of destrojMug them is a difficult one, 

 efforts in this direction will pay only on young or valuable trees, 

 leaving those on large trees to be cared for by natural enemies. 

 Kerosene emulsion has been used to hold them in check on infested 

 trees about the college. During May and June, this, diluted nine 

 times, was found to diminish their numbers but slightly. At the 

 same strength late in the fall no better results were obtained. As 

 injury to the foliage at this season of the year would not impair the 

 vitality of the tree, the strength of the emulsion was increased first 

 to double, then to triple, and finally to four times its ordinary 

 strength, and until this last strength was used, few of the insects 

 succumbed. This proportion, however, appeared very effective, and 

 has been used during late August, September and October without 

 any observed injury to the trees resulting. All the sprayings were 

 made by Mr. M. A. Carpenter of the Botanical Department and were 

 for results rather than for experiment. 



