84 



THE PRACTICAL ENTOMOLOGIST. 



cane of the Blackberry, is the work of the Diastrophux 

 nebulosu.i of Osten Sacken. (You will find descriptiotia 

 both of the p;all and of thu insect in the Proceedings, Ac, 

 II. p. 36.) This insect is a four-winged' fly, belonging to 

 the Cynips family in the Order llymenoptera; and the 

 genus Diastrophus is confined to the Blackberry, as Rho- 

 dites is to the Rose, and Cynips to the Oak — all these 

 genera belonging to the same family. Formerly ento- 

 mologists used to refer at hap-hazard any gall that they 

 knew nothing about to Cynips ; and I believe I was the 

 first to clearly point out, that Cynips is confined to the 

 Oak, and that, as a general rule, each genus of Gall- 

 making insects is confined to a particular genus of plants. 

 Of course, your horticultural friends are mistaken in 

 supposing, that this Blackberry gall contains the larva of 

 the Curculio. You will breed from it a Guest-fly that 

 sponges upon the poor, honest makers of the gall, for 

 board and lodging, and resembles them very closely, 

 though it belongs to a very distinct genus of the same 

 family; and also several true Parasites that prey on the 

 bodies of the Gall-making larvte. But in all probability 

 you will not breed from it a single Snout-beetle of any 

 kind. 



If you had sent along the "nest" out of which you 

 took the wingless moth, I could have told you with toler- 

 able certainty to what species the moth belonged. At 

 present I cannot; for there are several species of these 

 wingless gentry that are hard to distinguish. It cer- 

 tainly cannot be the female of Hibernia tiliaria, as you 

 conjecture, for that species transforms underground, 

 like the Canker-worm moth, and makes no " nest" or 

 cocoon on the infested tree. The specimen sent cannot 

 be distinguished from the wingless female of the Canker- 

 worm moth ; but neither does that species make any 

 "nest" on the tree. Perhaps a Canker-worm moth had 

 accidentally crawled into a "nest" made by some other 

 insect. 



Dr. Houghton, Penn. — All the specimens of Bark-lice 

 that you sent belong to tiie Native American species 

 {Coccus Harrisii). I have searclied carefully every twig 

 that you have sent, and cannot find a single individual 

 on them belonging to the Imported Species {Aspidioius 

 conchiformis). Consequently, although, as you say, you 

 have 20,000 trees afflicted in this manner, you ought not 

 to be greatly alarmed. I never knew a tree killed by 

 this Native Bark-louse, while in this single State there 

 have been millions of trees killed by the Exotic Bark- 

 louse. Even if you do nothing at all towards counter- 

 working this pest, I am persuaded that in process of time 

 it will be more or less completely subdued by the Lady- 

 birds and other insects that make war on it. Repeatedly 

 in the woods I have seen clumps of crab-trees infested as 

 badly as your trees seem to l>e ; and two or three years 

 afterwards not a scale could be found on them. Our 

 Bock Island nurseryman, Mr. Kinney, has also had this 

 Bpecies on a few of his apple-trees for seven or eight years, 

 and he does not think that they have done him any very 

 material injury, although he left them entirely to their 

 own devices. Not that I would recommend you to follow 

 neighbor Kinney's example ; neither would I recom- 

 mend you to fold your arms and do nothing, if some Irish- 

 man were coming at you with his shillelagh. Still, it is 

 some comfort to know that, even if the worst comes to 

 the worst, life is not endangered ; and that tlio enemy is 

 armed, not with bowie-knife and revolver, but only with 

 a club. 



The eggs were quite plump and healthy under the 

 scales in all the specimens sent, except in No. 4, {" Bark- 

 louse on dead bark,") where of a dozen scales examined, 

 only three contained plump, healthy eggs, the remain- 

 ing nine, which were probably old scales of A. D. 1865, 

 containing nothing but the shrivelled remains of eggs. 

 As the lot No. 2 (" Specimens taken from the body of a 

 tree that was thoroughly painted last summer with a 

 wash made by dissolving i lb. of concentrated lye in 1 

 gallon of water") contained perfectly healthy eggs, one 

 of two things must necessarily follow ; either 1st, that you 

 did not have every single limb and twig of this tree 

 painted with the lye. and thus that numerous bark-lice 

 escaped death, and afterwards crawled on to the parts 

 which had been painted, and then made last autumn the 

 ecales which you now send ; or 2nd that, if you had the 

 entire tree painted, twigs and all, even lye as unusually 

 Btrong as that which you used, will not kill bark-lice 

 when applied in the summer. I rather incline to the 



former supposition, though I know nothing personally of 

 the efl'ects of lye upon bark-lice. All accounts, however, 

 seem to agree, that lye, when applied in summer, checks 

 up the bark-louse. 



In applying kerosene to destroy any kind of bark-lice, 

 my jilan hiis always been first to prune very heavily all 

 the limbs to which I am about to apply it, so as to leave 

 nothing but wood of say J inch in diameter. I do this 

 partly for convenience' sake, and partly because a limb 

 badly infested by bark-lice needs pruning as much as a 

 transplanted tree does, because it is similarly weakened 

 and impoverished by the loss of the proper supplies of 

 sap. Although limbs thus pruned put forth new sprouts 

 during the summer, yet it is always easy to distinguish 

 them from unpruned limbs, and tiius to follow out the 

 results of your operatious, without any danger of mis- 

 takes. 



As to specimen No. 3, (" Bark thought to be injured by 

 the lye applied to it,") in any case you would be a far 

 better judge of this matter than I am; and having no- 

 thing but a partially dried specimen to form an opinion 

 upon, I am doubly bound to hold niy tongue. 

 ■ I can add nothing of any value to what I have already 

 said on this subject, further thau to caution those who 

 may be experimenting on the best and most successful 

 mode of destroying bark-lice, not to be deceived by a y&ry 

 puzzling phenomenon: Both with our Native speciesand 

 Avith the Imported species, old dead and dry scales, 

 which were formed li or 2^ years ago. and which had 

 the eggs underneath them completely killed by kerosene 

 or other such preparation 1 or 2 years ago, still adhere to 

 the bark after the lapse of 1 or 2 years, and are externally 

 undistinguishable from scales formed last autumn and 

 containing healthy and plump eggs. They do not, how- 

 ever, adhere so tightly to the bark as do the recent scales, 

 and when they are raised with the point of a knife, a 

 lens of very moder.ate power shows at once that they 

 contain no plump, fresh eggs, but only a shrivelled mass 

 of old dead and dry eggs. 



Edward Orton, Ohio. — The Plant-louse that infested 

 the White Pine in your yard last summer was most pro- 

 bably the Lacknus strobi of Fitch, which, as that writer 

 tells us, gives the bark of the infested trees "a peculiar 

 black appearance," and is largely attended by ants. 

 Their elongate-oval, shining black eggs, about 0.40 inch 

 long, attached in regular rows of from ;> to 20, but usually, 

 as you observe, in rows of 8, to the thread-like leaves of 

 the pine, have, I believe, hitherto escaped observation. 

 The specimens sent are precious, because, as I have al- 

 ready remarked in my Paper on the Plant-lice, there are 

 certain species of Plant-liee which appear never to lay 

 any eggs at all. I have myself described the eggs of a 

 giant species of Laehnus, L. caryce, Harris, which occurs 

 not only on the Hickory, but on the Oak and Basswood. 

 (Proceedings, &c., 1. p. 303.) If you wish to rid your tree 

 of these lice, I should recommend you to catch a dozen or 

 two Lady-birds and place them gently on the infested 

 twigs about the time that the eggs of the Plant-lice are 

 hatching out. 



John Murphy, Georgia. — The cocoons full of eggs which 

 you send are those of the female of the common Bag- 

 Worm, Basket-worm, or Drop- worm, (Thyridopieryx ephe- 

 vierceformis,) respecting which see Mr. Kathvon's article 

 in the Puactical Entomologist, II. pp. 53 — i. The 

 cocoon without any eggs in it is that of a male of the 

 same species. In this species, as in our Northern Vaporer 

 Moth, { On/y/o leucostigma.) \.\i& female is wingless and 

 never leaves her cocoon, the male, which has full-sized 

 wings and can fly well, searching her out, and consum- 

 mating the marriage lites at her own house. The only 

 difference in the economy of these two insects is, that the 

 female Bag-worm lays her eggs inside her cocoon, and 

 the female Vaporer Moth plasters them to the outxide of 

 her cocoon with a kind of^ varnish. Hence, as you will 

 at once perceive, this species of insect cannot sjiread as 

 rapidly through an orchard as those which have winged 

 females, capable of flying to the other end of the county 

 to search out a suitable tree on which to lay their eggs. 

 For here it is only the larva of the female that is loco- 

 motive, and slie, of course, has nothing but her legs to 

 trust to, or perhaps an oeeasicmal squall of wind, for 

 gaining another tree. The fact of your early apple-trees 

 not being attacked, is probably due to their being located 

 in a difl'erent part of your orchard. Possibly, however — for 



