REPORT OF THE ENTOMOLOGIST. 321 



is at rest, are closely similar to the dead and sere blotches, so frequent 

 on oak leaves. The same may bo said of other kinds feeding on the 

 leaves of other forest trees. 



While the bodies of those noctuid caterj^illars which feed on herba- 

 rpoiu; plants are smooth, those of the tree-inhabiting Catocala, ILomo- 

 pitra, and FhcGcyma are mottled with brown and ash like the bark of the 

 live, and provided with dorsal humjis and warts, assimilated in form 

 ;ind color to the knots and leaf scales on the twigs and smaller branches. 



Tliere is thus a close harmony in color, style of markings, shape, and 

 :co. of the humps and other excrescences of tree-inhabiting caterpil- 

 lars, and it is duo to this cause that they are protected from the attacks 

 of tlicir enemies. Mr. Poulson has recently called attention to the fact 

 that caterpillars are extremely liable to die from slight injuries, owing to 

 their soft bodies and thin skins. They cannot defend themselves when 

 once discovered. The means of protection are of passive kinds, i. e., 

 such as render the delicately-organized animal practically invisible on 

 the part of its enemies, and these means vary with each kind of cater- 

 pillar. In this way different kinds of larvse can live on different parts 

 of the leaf, the upper or under side, or the edge, on different colored 

 twigs, on those of different sizes, with different kinds of leaf scars, 

 scales, or projections, and thus the tree is divided, so to speak, into so 

 many provinces or sections, within whoso limits a particular kind of 

 worm may live with impunity, but beyond which it goes at the peril of 

 its life. 



CO]^DITION OF THE SPRUCE ON THE COAST OP MAINE. 



In my last report it was stated that as the result of journeys in the 

 different portions of Maine, including Aroostook County and the Moose- 

 Iiead Lake region, as well as a prolonged stay in Cumberland County, 

 that the Spruce-bud Caterpillar, the larva of Toririx fumifei'ana, which, 

 in former years, had been so destructive to the spruce and fir on the 

 ]Maine coast between Portland and Eockland, had become scarce. 



This year I have to report that not even a single specimen either of the 

 caterpillar or moth could bo found on the shores or on some of the isl- 

 ands of Casco Bay. From this fact I conclude that this species has 

 assumed its former iDroportions, being usually so scarce an insect in 

 Maine that, previous to 1878, when it became so alarmingly prevalent, it 

 was never met with by me through several years' collecting and obser- 

 vation in spruce and fir woods, particnlarly during the period com- 

 prised betv.-cen the years 1859 and 1SG7. 



^Moreover, throughout the areas of destruction, the young trees are 

 growing up, and already, in some degree, liave effaced the desolate ap- 

 pearance of the tracts which had been destroyed and from which the 

 dead timber had been cut. Probably in twenty or thirty years from 

 now, if the land is suffered to remain undisturbed, a new evergreen for- 

 est will in many j)laces cover the present denuded districts. 



CONDITION OP THE HACKMATACK IN 1885. 



In last year's report I thus summed up the condition of our larches 

 or hackmatacks in 1884 : 



" On th-c whole, then, while a small proportion of larches have begn 

 killed by this worm, this vigorous tree, though defoliated for tvv'o suc- 

 cessive summers, seems, in the majority of cases, to survive the loss of 

 its leaves, though it threw out much shorter ones the present summer. 

 21 AG— '85 



