THE LANCASTER FARMER. 



163 



cabbage, and various species of grass, were 

 vegetable substances upon which it was found 

 feeding, and upon some of tliem so numerous 

 that it had entirely defoliated the parts of the 

 trees, shrubs and plants it infested. Usually 

 this larva has been brougnt to us in single and 

 isolated numbers, but during the season Just 

 closed it was frequently brought to us in tens. 

 Indeed, very early in the spring (1S84) Mr. H. 

 Zahm gathered, on one occasion, between 

 twenty-five and thirty of their coccoons, found 

 about the base of a hop vine, which he de- 

 stroyed, supposing them to be an enemy of 

 the hop vine, although he had not noticed any 

 larvae on the hop vines the previous season. 

 He brought us two of these coccoons in the 

 beginning of the month of April, (he not 

 knowing what they were,) and on opening 

 them they revealed the larva of Empretia 

 stimula, living and almost as fresh in colora- 

 tion as it usually is found before it spins itself 

 up. The anterior and posterior fleshy ht/rns 

 were backward and forward compressed upon 

 the back, and partially divested of their 

 spiney barbs. On seeing the larva in its full 

 state of development, it is difficult to under- 

 stand how it can manage to compress itself 

 within such a small, symetrical, spherical 

 coccoon. Intimately related to the possibility 

 of this insect ever becoming a serious infesta- 

 tion, is the redeeming/oct, that it is itself the 

 subject of parasitic infestation, and perhaps 

 this may be the cause of this irregular and in- 

 frequent presence. 



We confined seven of these larvic in a glass 

 jar with a wide mouth and a wire-net cover. 

 Only one of them seemed to relish the food we 

 gave them (pear leaves) and that one soon 

 spun itself up in a nicely shaped cocoon. The 

 other six ate sparingly, and finally abandoned 

 the food entirely, affixing themselves to the 

 sides of the jar, never removing from the 

 spot first selected, although on various occa- 

 sions we introduced fresh leaves. Supposing 

 them, of course, to be dead, on the first of 

 September we essayed to remove them. Al- 

 though they adhered to the glass by the 

 whole ventral surface, yet we found their 

 bodies shrunken and empty, aad the anterior 

 and posterior spiney horns almost meeting on 

 the centre of back. Beneath them respec- 

 tively on the bottom of the jar, we found six 

 specimens of a brown (evidently Dipterous) 

 pupa, 15 millcmetres in length, and from four 

 to five in diameter ; tapering from the middle 

 towards the ends, but more abruptly towards 

 the one end than the other; but no fly has yet 

 (October 15) evolved, and probably they all 

 have died of drouth. These larvaj were very 

 probably "tachinized" before we received 

 them, and the evolution of the parasites de- 

 feated by their unfriendly surroundmgs. Not 

 suspecting their presence, we did not happen 

 to see the larvse of the parasites, but suppose 

 they approximate those of Tachinct. We are, 

 at least, practically impressed with the fact< 

 that Empretia sti7nula is infested by a parasite 

 that totally destroys it. 



According to our observations this insect is 

 gradually, but slowly increasing in numbers 

 every season. Forty years ago we only found 

 an occasional specimen or two, during the en- 

 tire summer season—indeed, we have no dis- 

 tinct recollection of ever having found a speci- 

 men at all until we made Lancaster city our 



residence in 184S. Lamicodes scapha, an allied 

 species, we occasionally found at Marietta, 

 Pa., but we have never found it in Lancaster. 

 The family to which these insects belong 

 (CoNCHir.opoi)iD<K) exhibits some of the 

 most unique and grotestpie larvie forms that 

 are found in the entire order Lei'IUOI'TEKA— 

 some of them so completely disguised, that a 

 novice would never su.spect that they were in- 

 sects al all. 



The larva of the species which is the sub- 

 ject of these remarks possesses a peculiar 

 ([uality that causes people to avoid it who 

 have ever come in contact with it, with the 

 naked hand. The slender spines with which 

 the fleshy horns are covered produce an ex- 

 ceedingly burning, and sometimes painful 

 sensation, if they happen to only touch the 

 back of the hand, or any portion of the body 

 where the skin is delicate or thin. Very few 

 of those who have met them for the first time 

 but what have had the peculiar burning in- 

 flamation, resulting from incautious contact 

 with them. The spines are very sharp and 

 barbed, and are said to be hollow, and when 

 the minute point penetrates the skin an infini- 

 tessimal drop of an acrid liquid is injected, 

 which produces a sensation similar to nettle- 

 rash intensified. 



The body of the full grown larva is about 

 three-quarters of an inch long, three-eighths 

 of an inch broad, obliquely truncated at both 

 ends, with a pair of long fleshy horns, slender- 

 ly spined, and a smaller pair beneath them, at 

 the anterior end, above the head ; a similar 

 posterior pair; and a small anal pair beneath 

 them. That portion of the body which is be- 

 tween the anterior and posterior horns, is a 

 line, bright green, bordered with white, and 

 has an oval reddish-brown dorsal patch, bor- 

 dered with white, and again bordered with a 

 narrow black line. This dorsal patch has 

 suggested the common name of "saddle-back." 

 The horns and the anterior portion of the 

 body are a reddish-brown, with a yellow spot 

 between the anterior pair, while the posterior 

 pair rises from a yellow patch. After the last 

 moult the horns diminish sufficiently in size 

 to enable the larva to compress them within 

 the coccoon. We have never been fortunate 

 enough to see the pupa. 



The moth is short and thick, less than half 

 an inch long ; the body and fore-wings are a 

 uniform dark fenuginous color, with two 

 white spots (in the female, and four in the 

 male,) near the base of the wings. The hind 

 wings are a pale reddish-brown. Rather a 

 plain insect, considering its gaudy larva. 

 Tachina Flies. 

 i,Tachiiiidx.) 



Without intending to depreciate the good 

 offices of the " Ichneumon Flies"— a very 

 large and effective family of Hijmemrpteroug 

 parasites— we desire to call the attention of 

 the reader to the existence of the Dipterous 

 fmiily Tachinid.k ; which, if not so numer- 

 ous as the former, yet, puts in as much ef- 

 fective work, in proportion to its number.'. 

 When we say inmihers, wq allude mure pa;- 

 ticularly to genera and species; as to indi- 

 viduals of the same species, occasioiis have 

 occurred when they were present in thou- 

 sands. Tachina is the typical genus of the 

 family, and perhaps ptr se, the most nu- 

 merous in species. The larvas of many of the 



Lepidoptera are infested by these parasites, 

 and it is a consolation to know this, when we 

 reflect that this whole order in its larva state 

 preys upon vegetation or its fruits, with 

 scarcely a single exception. All these flies 

 bear a general resemblance, in size and color- 

 ation, to the common house-fly. (Musca do- 

 ntestica.) The white parts are more silvery ; 

 the dark parts blacker, and they are all more 

 bristled. The posterior margins of the ab- 

 dominal segments and especially the caudal 

 segments are often conspicuously bristled. 

 The head, the thorax and the base of the 

 antenna', are also more or less bristled. They 

 are also more active and swift in their flight 

 than the domestic fly— and they need to bo, 

 to succeed in depositing their eggs upon other 

 insects. Tachina aletia', Prof. Ililey describes 

 as being parasitic on the "Cotton-worm." 

 Although it has not yet succeeded in destroy- 

 ing all the cotton-worms, from the very na- 

 ture of the case, it must have, not only de- 

 stroyed immense numbers of these pests, but 

 it has prevented the development of, by far, a 

 greater number. Tachina anysoptcryx, ac- 

 cording to Ur. T. W. Harris, is parasitic 

 upon the body of the "Canker-worm," the 

 trees upon which this pest is feeding some- 

 times fairly swarming with these flies. This 

 is surely more hopeful than the attempt to 

 plow the army-worms under, as had been sug- 

 gested or tried in the State of New York. 



Tachina bifaciatu, according to Riley's Fifth 

 Report on the Noxious Insects of Missouri, is 

 parasitic on the body of a Maple-worm(2)rj/o- 

 canipa rubicunda). Another species, namely, 

 T. bicim-td, is said to be parasitic on the lai-va 

 of the same moth. Tachina archippivoroi in- 

 fests the beautiful large "Archippus butter- 

 fly." True, the larva feeds on the Asclepixxs, 

 or " Wild Cotton," a plant which as yet has 

 no special value, but it illustrates no less the 

 functions of insect parasites. Ur. Harris also 

 mentions Tachina nivida, but it is not clear on 

 what it is parasitic — perhaps also the Army- 

 worm. Exoi-ista militaris. Prof. Riley, in 

 Vol. I. of the American Entomologist, de- 

 scribes as parasitic on the Army-worm, and 

 that he has witnessed their presence in large 

 numbers. Kiley designates this species, in 

 common language, as the "Red-tailed Ta- 

 china." Here we are reminded that on one 

 occasion we confined about a dozen specimens 

 of the "Army-worm " in a box, with moist 

 earth, and a gauze lid. From these we bred 

 but three moths. One or two of the worms 

 died without entering the ground, and from 

 six or seven of them evolved that number of 

 gray flies— hairy, but without the " red tail." 



Exorista cecropia'., Prof. Riley bred from the 

 large and beautiful "American Silk-worm," 

 or "Cecropia Moth," and Exorista liuMnic,, 

 from the " Army-worm ;" and E. Jlavicauda, 

 or " Yellow-tailed Tachina," from the same ; 

 also a variety, named E. ostensackeyiii. Dr. 

 LeBaron bred Exorista phijcitm from the larva 

 of Phycita, or the " Leaf-crumpler. " Exorista 

 unonyma, was bred by Riley from the larva of 

 the Attacus jyohnjhemas, and other of the large 

 American Silk-worm moths. Lydella dory- 

 plwrce was bred by Riley from the larva of the 

 ■•Colorado Potato Beetle;" and it unques- 

 tionably has done much in restraining the 

 duplication of that destructive insect, about 

 which wc do not hear as much as we formerly 



