14 



THE PRACTICAL ENTOMOLOGIST. 



season in the United States, and consequently two 

 crops of cocoons, from which the silk can be pro- 

 duced. The cocoons are elongate and cylindrical, 

 of rather loose texture, and are fixed generally by 

 means of an incomplete prolongation made first by 

 the larva around the branch, above the cocoon itself. 

 In this action, as indeed in its whole structure, the 

 species approaches the American genus Callosamia 

 Packard, which contains two indigenous species, 

 C. promethea, and C. angullfera. The cocoons are 

 much less dense than in our species and seem more 

 practically of use in silk manufacture on this ac- 

 count. The group to which Samia cyntMa Hiib., 

 belongs, is one of the Lepidopterous family Bom- 

 bycidae, and has been recognised by Linnsens under 

 the name " Attaci," characterized briefly as " Alis 

 patulis" from the mode of holding the wings when 

 at rest. To this group belong our genera Telea (poly- 

 phemus, Hiibner), Tropxa (luna Hiib.), Callosamia 

 (promethia Pack, and angulifera Pack.) and finally 

 Hyalophora Duncan, a genus which difi'ers impor- 

 tantly, structurally from Samia, and of which three 

 species are hitherto described, viz : H. cecropia, 

 Dune, H. Columbia (Samia Columbia, Smith) and 

 K Euryale (S. Euryale, Boisd.)— the latter spe- 

 jies a native of California. 



In Hyalophora the large primaries are not falcate, 

 Droperly speaking, as is the case in Samia and in 

 'Callosamia, while the shape of the secondaries is 

 very different, these being more rounded and not 

 produced at anal angle as are the somewhat lozenge- 

 shaped secondaries of Samia. The neuration is 

 also distinct. In Hyalophora the nervules are 

 longer, more curvilinear, especially the fourth sub- 

 costal, which in Samia is straighter, shorter, and 

 indeed somewhat inversely arcuate ; the discal cell 

 is also much larger, and the nervulation generally 

 importantly modified. In Samia, also, the head is 

 more produced and freer from the prothoracic parts; 

 eyes larger; antennal pectinations slighter and ta- 

 pering to the tips of the antennal stem. The gene- 

 ric characters are carried out in all the stages, but it 

 is unnecessary further to insist on these here. In 

 an article on Insect Architecture, Proc. Ent. Soc. 

 Phil., p. 372, for 1863, Mr. Couper says "The in- 

 sects are all they (i. e. " Students") care to make 

 room for ; large sums are expended to procure de- 

 scriptive books at the very time nature's informa- 

 tion is within reach, little thinking that the Chry- 

 salis covering formed by the caterpillar reveals the 

 genus to which it belongs." Nature indeed sug- 

 gests the idea involved in the above remarks, but 

 in a harmonious manner, that Mr. Couper's sen- 

 tences would do well to imitate, while wo never yet 

 have taken insects ready ticketed and determined, 

 so that "descriptive books" could be dispensed 

 with, a " consummation " on some accounts, per- 

 haps, " devoutly to be desired." Mr. Couper goes 

 on to say, in explanation, " For instance, this year 

 a young beginner [query: — why are beginners 

 always "young," or at least said so to be? We 

 know some "old" ones, and more honor to them 

 that they diffidently acknowledge themselves to be 

 only "beginners," which, we take it, when every- 

 thing is said, we all are] rears the caterpillar of At- 



tacus luna, which forms its cocoon, and in due time 

 he procures the imagu. Next year he finds a cater- 

 pillar oi Attacus pulyphemus, which, although a co- 

 gener differs from the former in form and mark- 

 ings. It also spins a like cocoon in size and tex- 

 ture, and in this way our young beginner discovers 

 that he is in possession of two species of a genus." 

 To this we may remark, that if the young beginner 

 has any sharpness, he will quickly discover, from 

 the cocoons themselves alone, that he has two spe- 

 cies belonging to so many different genera, since the 

 differences between the two are quite considerable. 



We find, indeed, that the cocoons of all these 

 large and more typical Bombycidae are quite cha- 

 racteristic in the different genera, and that Hyalo- 

 phora, Samia, Callosamia, Telea and Tropsea, pro- 

 duce cocoons that afford generic peculiarities in 

 form and structure while retaining a common cha- 

 racter peculiar to the "Group" or Sub- Family to 

 which they belong. 



It remains for us herfe but briefly to refer the 

 reader to a notice of the Samia cynthia published 

 in the Smithsonian Reports; to invite public atten- 

 tion afresh to this interesting subject, and to state 

 that all the species we have here alluded to can 

 produce silk in this country, and that they are all 

 worthy of experiments. We read in a newspaper 

 that in the South, during the war now happily ter- 

 minated, a lady spun the silk from the cocoons of 

 what was probably either Hyal. cecropia or Tel. 

 polyphemus, and made certain of the smaller articles 

 of clothing out of it. At a subsequent period we 

 shall revert to this subject and present an epitome 

 of the means employed in Japan to rear the larvae 

 of S. cynthia, and which may suggest something 

 that we can profit by. 



It appears, however, to us, a more patriotic as 

 well as perhaps an easier experiment, to see what can 

 be done with our native insects as silk-producers, 

 while, from our limited observations, we think that 

 Tclca polyphemus and Hyalophora cecropia are the 

 best suited to the purpose. A. R. Grote. 



Notice of an Eg^-parasite apon the American Tent- 

 CaterpiUar, CLISIOCAUFA AMEBICAITA, Harris. 



BY A. S. PACKABD, JR., M. D. 



In August, 1863, I detected on the inner side of 

 a bunch of eggs laid by the above mentioned spe- 

 cies of moth, upon a twig of a young apple-tree, a 

 minute Ichneumon fly, or Platygaster, which with 

 the mass of eggs I put away for future examina- 

 tion. Upon opening the box a few days since for 

 a further examination I find that several more of 

 the parasites have appeared, and that nearly all the 

 eggs are tenanted by these minute flies either in a 

 chrysalis or perfect state, showing how much is 

 done by these invaluable, as they are infinitesi- 

 mal, friends of the farmer, in staying th« undue 

 increase of noxious insects. 



This minute insect is only four one-hundredths 

 of an inch in length. Its head is remarkably broad, 

 being much wider than the rest of the body, and 

 about one-third as long as broad. The eyes are 

 small, remote; the antennae are 14-jointed, long 



