THE AMERICAN ENTOMOLOGIST. 



39 



TENT-CATERPILLARS AND FALL WEB-WORMS. 



The following appears in the Western Rural 

 of August 20, 18G9, from the peu of a corrcs- 

 pondent: 



The Tent Caterpillar has taken possession of 

 many fine young trees, and spread his web from 

 " pole to pole." for many are stripped of foliage 

 and resemble bare poles. 



The true Tent Caterpillar, or as it is often 

 briefly called, -'The Caterpillar," hatches out in 

 the spring almost before the leaves of our apple 

 trees put fortli. Early in June they spin up, 

 aud the moths, which are of a reddish brown 

 color, make their appearance early in July, 

 shortly after which they deposit their eggs in 

 the well-known rings on the twigs, of whicli 

 we gave a drawing (Fig. 145 c) on page 208 of 

 our first volume. The Fall Web Worm, on the 

 contrary, does not hatch out till August, and 

 although it makes a very similar web-like nest 

 to that constructed by the preceding species, it 

 is yet a much smaller insect and somewhat dif- 

 ferently colored. Towards the end of the sum- 

 mer this worm spins up like the true Tent Cat- 

 erpillar; but instead of the Moth bursting forth 

 from the cocoon the same season, it does not 

 make its appearance till the middle of the fol- 

 lowing season. Moreover this moth, instead 

 ot being reddish brown, is of a pure milk- 

 white color, and it does not lay its eggs in a 

 ring upon the twigs, but deposits them in an 

 irregular mass upon a leaf. Thus it will be 

 seen that one insect hybernates in the egg state, 

 the other in the pupa state : one larva appears 

 iu May, the other in August; one moth is 

 brown, the otiier is wiiite; and one lays its eggs 

 on the twigs, because if it laid them on a leaf 

 they would fall ott' the tree and be lost in tlie 

 winter, whereas the other species lays its eggs 

 on a leaf, because it is instinctively aware tliat 

 those eggs will hatch out long before the leaf 

 falls to the ground. 



No two insects are more frequently con- 

 founded than the true Tent Caterpillar (C'/isio- 

 campa americana, Harris), and the Fall Web 

 Worm {HypUantria textor, Harris) ; so that the 

 correspondent of the Western Rural will find 

 plenty of company iu the mistake that he has 

 made, iu speaking of Tent Caterpillars in Au- 

 gust. Both species are very general feeders, 

 the nests of the Tent Caterpillar being found on 

 the Wild Black Clierry, the Apple, the Crab, 

 the Choke Clierry, the cultivated Cherry, the 

 Plum both wild and tame, the Tliorn, and the 

 .Shad bush, but scarcely ever on the Fear or on 

 the Peach; while those of the Fall Web AVorm 

 occur in the greatest abundance on Hickories, 



especially the Pignut Hickory, and also on Wild 

 Black Clieny, Apple, Crab, Ash, Elm, Willow. 

 Oak, Birch, and Sj^camore or Buttonwood. 



EXPERIMENTS WITH THE .lAPANESE SILK-WORM. 



' .. {Aniherca Yama-mai.) 



BY W. V. ANDUEWS OF NEW YOUK. 



In the year 1868 I made some experiments in 

 rearing the Ailanthus Silk-worm (Samia Cyn- 

 thia), an account of which appeared in the Amer- 

 ican Naturalist, in Iho August number of that 

 year. I was of opinion tlien, and am now, that 

 Cynthia is the moth best adapted to our noi-th- 

 ern climate as a silk-producer. My reasons 

 need not be repeated here, but I may say that, 

 since writing tlie article above adverted to, I 

 have received from Dr. Wallace, of England, a 

 specimen of sewing silk made from the cocoon 

 of tlie Cynthia, and its appearance and quality 

 have strengthened my previous favorable 

 opinion. 



By way, however, of ascertaining the species 

 of silk-worm moth most suitable to the climate 

 of North America, I obtained from Dr. Wal- 

 lace a number of the eggs of the Japanese silk- 

 worm known as Yama-mai, which is said to 

 produce a most beautiful silk, of a greenish 

 color, and the cocoons of which are as easily 

 reeled as are those of the ordinary silk-worm 

 {Bombyx mori) . These eggs were sold to per- 

 sons residing in widely distant localities, while 

 I reserved a considerable nninbor for my own 

 use. 



I propose iu this paper to give the readers of 

 the Entomologist not only an account of my 

 own experiments with this insect, but also a 

 synopsis of the results of the experiments of my 

 correspondents, so far as I have been iible to 

 ascertain them. 



The whole of the eggs I received from Eng- 

 land arrived in New York in the months of 

 March and April. lam inclined to think that this 

 is a bad time to receive them here, and that in 

 future it will be better to receive them in the 

 fall, so that they may be forwarded to their res- 

 pective destinations belbre the severe cold sets 

 in, thus enabling parties living in widely dis- 

 tant latitudes to keep their eggs at a tempera- 

 ture which, without injuring the egg, will re- 

 tard the hatching till such time as vegetation 

 in their respective localities shall be so far ad- 

 vanced as to aflbrd the caterpillars a good sup- 

 ply of food. If the eggs be kept in England till 

 early spring, it is clear that they will be some- 

 what developed by the warmth of the climate, 



