THE AMERICAN ENTOMOLOGIST. 



29 



TFooly slugr>lil£e irorni on Apple — 11. A. Green, 



Afio, A'. </.— The slug-like worm found on a young 

 apple tree, and wliich is covered above witli thickly 

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

 hairs generally meeting and lorining a sort of ridge 

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

 llabbit Moth (Za<7oa 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 

 uitli curly wool which is marked more or less with 

 rusty black. The generic name which comes from the 

 trreek, signifies of, or belonging to, a rabbit, and was 

 given by Dr. Harris on account of 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, wlio stated that he bad met 

 with it iu very considerable numbers on one of his apple- 

 trees. 



And now Mr. Green, you deserve a good scoldingl 

 As often as we have remonstrated against sending 

 insects folded loose in a letter, you persist iu com- 

 mitting the same offense. Here is a choice and rare 

 larva, which we should have been much pleased to 

 have reared, and you send it all the way from Kew 

 Jersey to St. Louis, folded loose in 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 

 squeezed in the mail bags that life was past recovei'y. 

 And when we ponder, Sir, over the torture and linger- 

 in.;,' 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 suffer the highest penalty of 

 the law. Tlic 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 Water-Bug.— ir. V. SmUh, Broolhja, X. }'.— 

 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 Ilunatrafusca of Keauvois. An almost 

 exactly Identical species occurs in Europe, which is 

 known as Satiatra linearis. This insect belongs to the 

 same Kepa Family of the Half- winged Bugs [Heteroptera) 

 as the Gigantic Belostoma, of which we gave a figure 

 on page 249 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 

 (ront 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. 



Goldenrod Galls— (;. W. C, Alton, iZZ.-The round, 

 pithy galls which you find on the stems of the Goldenrod 

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

 formed by a two-winged fly Tnjptta (Acinia) solidaginis. 

 Fitch. The ' 'busby bunch of leaves' ' at the extremity of 

 iliesame plant is, as you rightly suppose, agall; butitis 

 made by a Gall-gnat {Cecidomyia solidaginis, La'W),and 

 not by the same Gall-fly which produces the round gall. 



Oak>leaf Gall— ^. E. Broadnox, Picl-ens' Sta., 

 Miss. — You send us a spherical but somewhat depressed 

 gall on the leaf of the Black Jack Oak ( Quercus nigra), 

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

 running together into an liregular mass; its under sur- 

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

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

 and often divided by slender trninvrs into ft-om 12 to 20 

 four-five-or sLx-sided conii.nrtnh m-. lik,. the back of 

 a tortoise. This gall was ilr.nii.r.l in isijl under the 

 name of the Oak-pill Gall iv- ;"'/-/; l.y the Senior 

 Editor. The specimens you sent coutaiued the larva ot 

 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 unknown gall- 

 making Gall-fly. Subsequently, however, he became 

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

 {Cynips), but a Gall-gnat {Cecidomyia), and that the 

 very same gall had been briefly described, but not >. 



named, by Osten Sacken in the year 1802 as the pro- i 



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 olher such cases 

 have since been discovered. The true gall-making 

 larva of this Oak -pill Gall, which larva, as ah-eady 

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

 orange-colored, with a very small pointed head and a 

 clove-shaped "breast-bone;" (see our figure 86 a, A'ol. 

 I, No. 6;) 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 not 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. iincforia), and Red Oak {Q. rubra), upon whicli 

 trees in certain seasons it swarms so prodigiously, that 

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

 and some leaves are studded 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 

 Qufrcus as the Red and Black Oaks, and because there 

 is no known Oak-gall tlfat 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. Botanically, these two 

 groups of Oaks differ 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-leaf Gall of Osten Sacken, also produced by 

 a Gall-gnat, which scarcely differs from yours except 

 in 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 Red and Black Oaks— namely, the Spanish 

 Oak{Q./a?M<a). 



