WHITE-PINE LEAF-LOUSE. 89 



the pro-thorax. Scutellum large, sub-quadrate. Last segment of the abdomen abrupt- 

 ly narrowed and terminating in a straight awl-shaped style, as long as the abdomen. 

 Wings two, large, lying flat upon the abdomen, and one over-lapping the other in repose, 

 extending more than half their length beyond the tip of the abdomen; two veins, a sub- 

 costal vein, parallel with the costa, and extending upwards of two-thirds the length of 

 the wing, and emitting a branch near the base which runs somewhat parallel with the 

 posterior margin, and extends more than half the length of the wing. Behind the wings 

 are two poisers, somewhat like those of Dipterous insects, but furnished at their extrem- 

 ity with a slender hook-like appendage. 



Middle and posterior legs approximate, situated far back and remote from the ante- 

 rior pair. Tibiae and tarsi bristly. Tarsi one-jointed but with two slight contractions 

 which indicate three normal joints consolidated into one. The tarsi terminate in a 

 bristle-like claw; and in addition to this are four flexible finger-like processes or digituli, 

 slightly enlarged at their tips. 



We have thus far said nothing of the times of hatching of these 

 insects, nor of their peculiar distribution upon the foHage, upon 

 the understanding of which their practical treatment will depend. 



Unlike the Bark louse of the apple tree, this species produces 

 two broods in a year, and the periods of their hatching are not 

 sharply defined, both of which circumstances will enhance the 

 difficulty of reaching them etfectively with destructive applications. 



One brood, like the single brood of the Apple-species, passes 

 the winter in the egg state, safely protected under the maternal 

 scale. These eggs, unlike the white eggs, of the M. concAiformis, 

 but similar to those of the Harris's Bark louse of the apple-tree, 

 and some other species, are of a blood-red color. Their number 

 averages considerably less than those of the M. conchiformis. 

 These latter, when in good condition, range all the way from 

 forty to sixty and sometimes more, whilst those of the Pine spe- 

 cies* so far as I have observed, do not exceed half the number. 

 Of a considerable number of scales which I have this day exam- 

 ined '(Nov. 15th), the number of eggs under each varied from 

 twerfty to thirty, a good average being twenty five. 



I did not commence my observations early enough to deter- 

 mine the precise time in the Spring when this winter clutch of 

 eggs hatch, but it must be quite earl}"-, since by the fourth of July 

 they have completed their development and have begun to lay 

 their eggs for the second brood, and by the middle of July the 

 work of deposition is completed. It is proper to remark here 

 that the past Summer has been excessively hot and dry, and pro- 

 bably the dates here given may range somewhat earlier than in 

 ordinary years. We know that the eggs of the Apple-tree Bark- 

 A— 12 



