THE AMERICAN ENTOMOLOGIST. 



29 



Wooly slug'-Iike nrorni on Apple — IT. A. Green, 

 Atfo, y. J. — The sUijj-likc worm loiind on a young 

 ai)i>le tree, and wliieh is covered above with tliiekly 

 set, long, but evenly shorn liglit-brown hairs, these 

 liuirs generally meeting and lonning a sort of ridge 

 along the bacic and along each side, is the larva of the 

 liabliit Moth (luyoii opercularis, Sm. and Abb.) This 

 moth is cream-colored with thick wooly body and legs, 

 and with the basal portion of its front wings covered 

 with curly wool which is marked more or less with 

 rusty black. The generic name which comes from the 

 (.ii-cek, signifies of, or belonging to, a rabbit, and was 

 given by Dr. Ilari'is on account ol the short, squat 

 form and smooth fur of the larva. The species is not 

 likely to be troublesome, for it has long been considered 

 a rare insect; though we received it last year from a 

 correspondent in the East, who stated that he had met 

 with it in very eonsidi'rablc numbers on one of his apple- 

 trees. 



And now Mr. (Jreen, you deserve a good scolding! 

 As often as we have remonstrated against sending 

 in.sects folded loose iu a letter, you persist in com- 

 mitting the same otVense. Here is a choice and rare 

 larva, which we should have been much pleased to 

 have reared, and 3 on send it all the way from Kew 

 .Jersey to St. Louis, folded loose iu a letter, in the 

 vain hope that it would reach us alive. Well, by some 

 miracle or other it was not entirely squelched by Uncle 

 Sam's canceling stamps, but it had been so effectually 

 s<iueczed in the mail bags that life was past recovery. 

 .Vnd when we ponder. Sir, over the torture and linger- 

 ing death which you caused the poor creature by your 

 careless packing, we feel strongly inclined to report 

 you to the " Society for the Prevention of Cruelty to 

 Animals" and have you sutler the highest penalty of 

 the law. The only way we can think of, for you to 

 exonerate yourself from prosecution for such a heinous 

 crime, is to bribe us to keep •• mum " by sending us 

 another specimen properly packed ! 



/ A AVater-Bug:.— IK. V. Smith, Brooklyn, X. Y.— 

 The brown-colored and very slender Bug, almost three 

 inches long, including the slender bristle-like tail that 

 projects from its hinder extremity, and with long slen- 

 der legs, is the /i'un«<m/«scu of licauvois. An almost 

 ccactly identical species occurs in Europe, which is 

 known as Eanatra linearis. This insect belongs to the 

 same Kepa Family of the Half-winged Bugs {flcteropiera) 

 as the Gigantic Belostoma, of which we gave a figure 

 on page 'ii'.) of our last number. This entire Family 

 inhabits the water, though they are all provided with 

 wings by means of which they are enabled to fly from 

 pond to pond; and they are all of them Cannibals, their 

 front legs being metamorphosed into arms to seize their 

 prey with. Your insect is very common out West in 

 shallow sluggish pieces of water. We have never met 

 with any in running brooks, which, as you say, is the 

 situation in which your specimen was found. 



GoIdenrodGalls— (?. W. C, Alton, 7Z/.— The round, 

 pithy galls which you find on the stems of the Goldenrod 

 (Solidago,) each containing a maggot in the centre, are 

 formed by a two- winged fly Trypda (Acinia) solijoiji/iis. 

 Fitch. The "bushy bunch of leaves'' at the extremity of 

 the same plant is, as you rightly suppose, a gall; but it is 

 made by a Gall-gnat {Cecidumyia. solidaginis, Lccw), and 

 notby the same Gall-fly which produces the round gall. 



Oak-leaf Gall— ^. U. Uroadiwx, Piclcene' Sta., 

 Miss. — You send us a spherical but somewhat depressed 

 gall on the leaf of the Black .Jack Oak {Qvereus nigra), 

 about the size of a small pea, but several of them often 

 running together into an irregular mass; its under sur- 

 face pale green and flattened, with a central nipple, its 

 upper surface darli blood-red or crimson, much rounded, 

 and often divided by slender grooves into from 12 to 20 

 four-five-or si.x-sided compartments, like the back of 

 a tortoise. This gall was described in 18G4 under the 

 name of the Oak-pill Gall ((,/. pilula) by the Senior 

 Editor. The specimens you sent contained the larva of 

 a Gall-fly (Cynips), and the Senior Editor, from the 

 fact of his having actually bred certain Guest Gall-flies 

 from this gall, when he published his description, sup- 

 posed the gall to be the work of some uiduiown gall- 

 making Gall-fly. Subsequently, however, he became 

 aware that the real gall-maker was not a (iall-fly 

 (Cyiiipn), but a Gall-gnat {Oecidomyia), and that the 

 very same gall had been briefly described, but not 

 named, by Osten Sacken in the year 1S6"2 as the pro- 

 duction of a Gall-gnat. Up to this period this was the 

 first published case of a Gall-fly living as a guest in a 

 gall made by a Gall-gnat; but several other such cases 

 ha\e since been discovered. The true gall-making 

 larva of this Oak-pill Gall, which larva, as already 

 stated, produces not a Gall-fly, but a Gall-gnat, is 

 orange-colored, with a very small i)ointed head and a 

 clove-shaped "breast-bone;" (see our figure 8li a. Vol. 

 I, No. G;) on the other hand, the larva of the Gall-fly 

 that inhabits this gall as a guest is whitish, sometimes 

 with a dark stomach, and has a large round whitish 

 head with long robust horny black jaws, which in 

 the living insect may often be seen to open and shut in 

 a vicious manner. The former does tiot develop to its 

 full size till about the time of the fall of the leaf; when 

 it leaves the gall and is supposed to go under ground 

 and come out the next summer in the perfect fly state, 

 ready to deposit its eggs upon the next year's crop of 

 oak-leaves. On the other hand, the larva of the Guest 

 Gall-fly does not leave this gall till it assumes the perfect 

 or winged state. 



Hitherto, this gall has only been met with upon Black 

 Oak (Q. tinetoria), and Red Oak [Q. rubra), upon which 

 trees in certain seasons it swarms so prodigiously, that 

 almost every leaf bears at least half a dozen of them, 

 and some leaves are studiled all over with them. Y'our 

 finding it upon the Black Jack Oak is a new fact, but it 

 is quite in accordance with the general rule, because 

 that Oak belongs to the same great group of the genus 

 Quercus as the Red and Black Oaks, and because there 

 is no known Oalc-gall that occurs indiscriminately upon 

 certain species belonging to the White Oak group and 

 upon certain other species belonging to the group 

 of the Red and Black Oaks. Botauically, these two 

 groups of Oaks ditt'er in this very notable character, 

 that while it requires two years to perfect the acorn of 

 the Red and Black Oak group, the acorn of the White 

 Oak group is perfected from the blossom in a single 

 season . There is a very closely allied gall, the Symmet- 

 rical Oak-leal Gall of Osten Sacken, also produced by 

 a Gall-gnat, wliich scarcely difl'crs from yours except 

 iu the lower surface being as much rounded and of the 

 same crimson color as the upper surface. It is very 

 satisfactory that this gall also occurs on a species be- 

 longing to the lied and Black Oaks — namely, the Sjianish 

 Oak (Q./alcata). 



