24 



THE AMERICAN ENTOMOLOGIST. 



cessively numerous, for iu all our entomological 

 experieuce, we have never known it to swarm 

 in very great numbers. The obvious reason is, 

 that it is so freely attacked by a small parasitic 

 Ichneumon fly — belonging to a genus (Micro- 

 guster) exceedingly numerous in species— that 

 three out of every four worms that we meet with 

 will generally be fouud to be thus victimized. 

 The eggs of the parasite are deposited within 

 the body of the worm, while it is yet young, and 

 the young maggots hatching from them feed on 

 the fatty parts of their victim. After the last 

 moult of a worm that lias been thus attacked, 

 numerous little heads may be seen gradually 

 pushing through different parts of its body ; and 

 as soon as they have worked themselves so far 

 out that they are held only by the last joint of 

 the body, they commence forming their small 

 snow-white cocoons, which stand ou ends and 

 presenttheappearauce. t^'S- i^l 



of Figure 15. In about 

 a week the fly (Fig. 16, 

 a, magnifled; b, natu- 

 ral size), pushes open Color— White. 

 a little lid which it bad previously cut with its 

 jaws, and soars away to fulfil its mission. It 

 is one of those remarkable [Fig. le.] 

 and not easily explained facts, 

 which often confront the stu- 

 dent of Nature, that, while 

 oue of these Hog-caterpillars 

 in its normal and healthy con- 

 dition may be starved to death Color— Biacic. 

 in two or three daj's, another that is writhing 

 with its body full of parasites will live without 

 food for as many weeks. Indeed we have known 

 one to rest for three weeks without food in a 

 semi-paralyzed condition, and after the parasitic 

 flies had all escaped from their cocoons, it would 

 rouse itself and make a desperate effort to regain 

 strength by nibbling at a leaf which was offered 

 to it. But all worms thus attacked succumb in 

 the end, and we cannot conclude this article to 

 better advantage than by reminding the Grape- 

 grower, that ho should let alone all such as are 

 found to be covered with the white cocoons we 

 have illustrated, and not, as has been often done, 

 destroy them under the false impression that 

 the cocoons are the eggs of the worm. 



To OUR Subscribers m Canada. — Parties in 

 Canada, who wish to subscribe for the Ameri- 

 can Entomologist, can obtain it, postage free, 

 by remitting S2.00 to the Eev. C. J. S. Bethune, 

 Secretary to the Entomological Society of Can- 

 ada, Credit, C. W. 



g. 17- 1 



Color— Whitish. 



ANSWERS TO COURESPOFDENTS, 



Notice. — Such of our correspondents as have already 

 sent, or may hereafter send, small collections of insects 

 to be named, will please to inform us if any of the 

 species sent are from other States than their own. 

 Lists of insects found lu any particular locality are of 

 especial interest, as throwing light upon the geograph- 

 ical distribution of species. But to make them of real 

 value, it is requisite that we know for certain, 

 whether or not all the insects in any particular list come 

 from that particular locality, and if not, from what 

 locality they do come . 



Striped Cucumber Beetle — M. M. Gray, Car- 

 dington, OMo. — We quote your letter in full, as it well 

 describes the larva about which you desire inlormation ; 

 I inclose a specimen 

 of bugwhich we call the 

 Cucumber or Squash 

 bug, and also a small 

 worm or larva which 

 has destroyed many of 

 my melon and cucum- 

 ber vines. My object 

 in part is to learn if 

 this worm or larva is 

 the product of the bug 

 or something dilferent 

 and foreign to it. In 

 the early part of the 

 season the small striped 

 bug commenced work- 

 ing on my vines, and 

 they began to wilt and 

 die. I used sulphur 

 and plaster, quassia, 

 tobacco, etc., to pre- 

 vent or check their rav- 

 ages, but with little ef- 

 fect. Finally I hunted 

 outand killed a good many, and shortly they seemed to 

 disappear, and my vines" began to revive and grow. 

 About three weeks later the vines began to wilt and die 

 worse than before ! But this time there were no bugs to 

 be found. Upon examination of the roots, however, I 

 discovered this little white-worm with a black head, 

 from l-16tli to l-4th of an inch in length , eating into and 

 perforating the root and vine; and as the vines they 

 infested the most were the same that the bugs preyed 

 upon the worst, I conjectured there must be some rela- 

 tion between them. 



The larva referred to which attacks the roots, and of 

 which we present highly magnified figures (Fig. 17, 1, 

 dorsal view, 2 side view), is in reality the young of thCj/ 

 very same Striped Cucumber Beetle (Diabroika mitata/ 

 [Fig. 18.] Fig. 19), which is so injurious to 



the leaves ; for we have ourseh'es 

 bred the beetle from this larva, 

 T and in 1865 Dr. H. Shimer, of 

 Mt. Carroll, 111., first published 

 an account of Its transforma- 

 tions.* After boring into and 

 around the roots for upwards of 

 a month, the larva; enter the surrounding earth, and 

 within a smooth oval cavity soon change to jupse (Fig. 

 18, 1, ventral view; 2, dorsal view), which are trans- 

 [Fig. 19.] formed to beetles about two weeks after- 

 wards. There are two or three broods du- 

 ring the year. By getting rid of the beetles 

 in the early part of the season, you of 

 course prevent the injuries of the larva, 

 and the most effective agents for this pur- 

 ^liid yeiiovv.'''' posc. Or at least those in which we have the 

 most confidence, are Paris green and white hellebore . 

 This insect has been very injurious the present year. 



*Frairie Farmer, Aug. 12, 1865. 



Color— Whitish. 



