THE AMERICAN ENTOMOLOGIST. 



39 



Insect Foes of the Bark-louse. — Pr. Jus. W<ed, 

 Muncatine, la. — The insect wliii'h you foiiiid previns 

 upon Uarris's Bark-louse (Aspiiliotus Ihinixii , Wafsh)', 

 and whieh you think lias eflcctually cleaned your trees 

 of that little pest, is the larva of the Twice-stabbed 

 L.idybird (CTtiloeorus Mmlmiiie, Muls). The middle 

 tiffure below gives a rough sketch of this very useful 

 larva, and the right hand tigiu-e an accurate drawing, 

 considerably maguitied, of tlie beetle into which it 



TFlg. 32.] 



Colors— Black 



Colors — Honoy- 

 yeUow and biuck. 



ych.anges. The left hand figure is the Northern Lady- 

 ^ bird (Epilachna horealis, Thunb.), the lan'a of which 

 closely resembles that of your insect; but, instead of 

 preying upon other insects , as that docs, isvei-y injuri- 

 ous in the Eastern States to tlic fruit an<l foliage of the 

 squasli. This last is the only N. A, Latlybird, so far as 

 is at present known, uliicli is a vegetable feeder, al- 

 though several European Ladyl)irds are known to have 

 this habit. In the \Vcsti'rn States, however, so far as 

 we are aware, the Northei-n Ladyljird has never yet 

 been met with, and perliaps never will be, as it is moi-e 

 particularly a Northern species. In the sirring of the " 

 year 1867, by way of experiment, we placed about a 

 dozen living specimens of the Twice-stabbed Ladybird 

 >/ upon an apple tree badly infested by the Oyster-shell 

 Bark -louse {Aspidiotutt conrlii/ormis j Gmelin) ; and in 

 June, 18G8, we had the pleasure of seeing that they had 

 increased lilty-fold, .and were preying upon tlie newly 

 hatched young Bark-lice in a most savage manner. In 

 November, 181)7, we saw great numbers of this same 

 / Ladybird preying upon the I'ine-leaf Scale-insect {As- 

 V pidiotus pinif'iUcn, Fitch), in the garden of Mr. I'aul 

 Wright, at t5outh Pass, Illinois; so that it appears to 

 make war upon at least three distinct kinds of ISark- 

 louse. Hence ,• wherever it is met with, it should be 

 cherished and protected. "Pitch into your enemies, 

 but stand up for your friends. ' ' 



Oest Works ou Sntomolog-y. — B. M. Eeytwlds, 

 Madison, Wis., and others. — Beginners who desire to ac- 

 quire, withoutmucli trouble, ageneral knowledge of our 

 North American insects, and especially of those which 

 are of economic importance, are recommended to pro- 

 cure Dr. Harris's work on Injurious Insects . (Boston, 

 18(>2, one large octavo; price, with colored plates, $0.) 

 Those who require, in addition, to familiariiie them- 

 selves with the natural history of the insects of the 

 whole world, should getKirby itSpence's Introduction. 

 {London, 1857, one stout duodecimo, no pliites; price 

 about $2.) For any one who desires to lay the rudi- 

 ments of a thorough scientific knowledge of Entomology , 

 the very best work is Westwood's Introduction. (Lon- 

 don, 1838-40, two large octavos, with 13;i blocks of out- 

 line woodcuts, and colored plate.) This last work 

 is, we believe, now out of print, but may be occasion- 

 ally met with at second-hand book-stores. It would be 

 cheap at $10 or $15. After proceeding so tar as this, the 

 student had best take up some speciiu order of insects, 

 instead of frittering away his time on the immense field 

 of all the orders. The Beetles (order Ooleoptera) have 

 always been the favorite order for this purpose ; and the 

 best work upon North American Beetles, to begin with, 

 is LeConte's Introduction. (Smithsonian Institution, 

 Washington, D.' 0. , ISGl; one thin octavo with a few 

 woodcuts, price $ — .) 



Kiarvse iu Pluin-griim. — PMl. RicTceH, Milwauiee, 

 Wis. — The small larv;c found by you in the gum oozing 

 out of the bark of your pliuu trees are most probably 

 those of some two-winged fiy (order Diptera), and have 

 nothing to dp with the Curculio, which is a beetle (or- 

 der CoUoptera). Since, however, you send no speci- 

 mens, we can give you no more definite information. 

 From small , white , thread-like worms, feeding upon 

 the gum and detritus of tlie peach tree, \ve have bred a 

 small two-winged fly, belonging to the genus Myceto- 

 phila, an account of which was given in the Prairie 

 Farmer of June 15th , 1867 . Yours is possibly the same . | 



Insect Foes ol the Hop Vine.^J/r«. H. C. 

 Freeman, Sovth Pass, Ills. — The pale green caterpillar, 

 about oiieinch .and a half long, with biinclics of diverg- 

 ing gi-een prickles on its biick, which sting (hctcnderer 

 parts of the human body like a iictllc. is the larva of 

 the lo-moth {Satumia lo, Fabr.) , a laruc and handsome ,- 

 insect, with a great round eye in tlic middle of the hind 

 wing. You found it, as you say, on the hop vine, but 

 it feeds on a variety of other plants as well, though it 

 never occurs in such numbers as to be materially in- 

 jurious. The smaller caterpillar, about one inch and a 

 quarter long when full grown, with its body variegated 

 with brown and yellow, and with long sprangling 

 prickles of a dark color on its back, which you also 

 found on the hop vine, is the larva of the Semicolon 

 Butterfly ( Vamssa inferrogationis , Fabr.) , a large insect, 

 mostly of a brick-red color, and with a silvery mark in 

 the middle of the lower surface of the hind wiiigshaiicd 

 much like a semicolon (;). In tin- (.irci-k h[iigii;i^i' the 

 modern semicolon (;) is used in tlic phu-c nlniTr luilc of 

 interrogation (?); hence the scUnlilic name ami the 

 English name of this Butterfly both of tliini rdir to the 

 same peculiar mark, which nature h;us iinpriiitcd upon 

 this insect. Unhke the preceding, this larva often oc- 

 curs in great numbers upon the hoji iilaiit. so as to ruin 

 the crop if not attended to; and it likewise occurs not 

 unfrequently on elm and basswood. The roundish-flat 

 l!ug, about one-third of an inch long, and of a yellow- 

 ish color, with some dark markings, which you also 

 found on the hop plant, is the pupa of some species of 

 Soldier-bug (^Irma). Cherish him carefully, for he is 

 your friend, though he has the misfortune to possess 

 the same peculiarly unsavory odor as the Bed-bug and 

 Chinch-bug. 



Insect Foe of tbe Apple-tree Borer.— »/. E. 



Walker, Ilillshoro, Mo.. — The larva bearing a strong 

 general resemblance to the one which we figure in this 

 number of the Amehican Entomologist (fig. 26) , is 

 undoubtedly that of some ground Beetle or other ( Vara- 

 1ms family, order Voleoptera), but the particular species 

 to which it belongs cannot be determined. All the 

 known North American species of this family are canni- 

 bals, and your insect no doubt forms no exception to 

 the general rule . "While worming some apple trees , ' ' 

 as you observe, "I found the enclosed larva, and 

 noticed that the borers in its vicinity were dead and 

 partly eaten, and, as I suppose, by this grub or woi-m. 

 I must say that It is fully able to assert its rights, for it 

 fought nobly upon being captured." Your supposi- 

 tion is, beyond all doubt, a correct one; and Jai-vse of 

 this general character, when found above ground, or 

 ill the earth, which they usuaUy inhabit, should always 

 be carcfidly spared and protected . They form the chief 

 protection of the Agriculturist against those most in- 

 sidious and unmanageable of all his insect foes— the 

 subterranean root-feeding liirvaj— and they also prey 

 upon vegetable-feeding larva;, such as those of the 

 common Curculio, and of the Colorado Potato-bug, 

 which go underground to pass into the pupa state. 

 Like aliiiiist all camiibals, they run with prodigious 

 velocity; whereas vegetable-feeding insects are, as a 

 g(!Ucral rule, dull and shigglsh in their motions. In 

 common with most cannibal larvic, tho.se of the Ground 

 Beetles are far more diflicult to rear to the perfect 

 state than are those larva; that live upon vegetable mat- 

 ter; which .accounts fbr the fact that but very few of 

 the former are known to science iu all their stages. 



Oak Tree Caterpillars— W. W. Darnells, Uni- 

 versity, Madison, IFis.— The caterpillars of a bluish 

 white ground-color, marked longitudinally with yeUow 

 baiuls and tine black lines, with the head and a hump 

 ou the 11th segment either of a light coral or dark flesh 

 color; and which gener.ally carry the hinder portion of 

 the body elevated in the air, are the larvas of Edema 

 alhifro-ns, Packard, a gray moth characterized princi- 

 pally, as its name Implies, by a broad white mark on 

 the outer half of the anterior mar-gin of the front wings 

 You say "these caterpillars have been quite destructive 

 to the leaves of the white and burr oaks on our 

 grounds. ' ' They have long been known to attack the 

 oak . Some that we reared the present season entered 

 the ground and changed to chrysalids during the last 

 days of September, and came out as moths about the 

 middle of April. 



