THE AMERICAN ENTOMOLOGIST. 



41 



all right, but the larvce were so weak that they 

 were unable to feed. On the other hand, indi- 

 viduals who had obtained eggs out of the same 

 lot found no difficulty in getting their larvfe to 

 eat, and for a time to thrive well. So it should 

 seem that, as I hinted before, the temperature 

 at which the eggs are kept may have a good 

 deal to do with the health of the future cater- 

 pillar. 



Most of us who have been in the habit of rais- 

 ing caterpillars have doubtless met with similar 

 instances wliere they have refused to eat. Eveu 

 this year I have seen such in the case of a brood 

 of the Royal Horned-Caterpillar that refused to 

 cat a particle, and of course all died. But even 

 here it is possible that the eggs may have been 

 kept too cool or too hot; and it must be borne in 

 mind that, although I attribute the failure of 

 my Yama-mai to the unfavorable weather, I 

 have by uo means forgotten that disease may 

 have been superinduced by the maltreatment of 

 the eggs. Illustrative of this point are two re- 

 markable cases involving one exception to the 

 general failure of the Yama-mai crop to which 

 1 have already alluded. 



A friend of mine, in Brooklyn, wishing to 

 make sure that his eggs should not hatch out 

 prematurely, placed them in an ice-house where 

 the temperature was about 40"; and the conse- 

 quence was that not a single caterpillar ajjpeared. 

 Yet a quantity of B. mori eggs, placed in the 

 same situation, hatched out, thus showing that 

 Yama-mai eggs cannot be exposed with impu- 

 nity to a degree of cold that may be harmless to 

 species duly acclimated. 



On the other hand, a correspondent in Massa- , 

 chusetts, being also desirous of shielding his I 

 eggs from harm, placed them in a glass in his \ 

 bed-room. The servant, however, objected to 

 this " littering up," aud look down the glass to 

 wash it out, throwing the whole of the eggs 

 into very hot water. My friend was just in time 

 to rescue two eggs, both of which hatched out; 

 the caterpillars gi-ew and flourished, and in due 

 time formed beautiful cocoons; and, strange to 

 say, this is the only instance, with an exception 

 to be noticed presently, in which any of ray cor- 

 respondents have this year been successful in 

 rearing Yama-mai. An extract from his letter 

 may be of interest: 



" The eggs hatched out May 21st, and on the 

 14th of July I had one cocoon fully formed, and 

 on the 21st the other. One of the larva3 was 

 much larger than the other, aud had five silvery 

 spots on each side, while the other had only two ; 

 so I think I have a male and female. The worms 

 were kept in a room facing the south, with 



doors and windows open, night and day. 

 ! Highest temperature 98'^ ; lowest o5", Fahr.'"* 

 j The other successful instance occurred with 

 the young ladies of the Academy of the Sacred 

 j Heart, at Manhattanville, New York, who have 

 j had the good sense to introduce the study of en- 

 I tomology, and I believe the other natural sci- 

 ! ences, into their admirably conducted school. 



One would infer from these facts that, as the 

 I time for hatching out approaches, the egg should 

 be exposed, not to direct sunshine, but to a good 

 degree of heat; aud this treatment would seem 

 to be the more necessary if, as is generally sup- 

 posed, the caterpillar is fully formed in the egg 

 shortly after laying, and one can also see why 

 any great or sudden change to a low tempera- 

 ture is injurious to the egg. 



A word now as to the food-plant and manner 

 of feeding. 



1 have little doubt that Yama-mai will feed 

 on any kind of oak, and it is stated in Dr. Wal- 

 lace's report that they will feed on apple tree. 

 Nay more, that some larvaj which refused " ever 

 green and other fancy oaks," did well on apple. 

 More experiments are required in this direc- 

 tion, for it is quite possible that a change of cli- 

 1 mate may necessitate a change of food. 



One thing struck me during the feeding of 

 my larvEB, and that was that they seemed to be 

 very lazy, inert fellows, preferring to feed on a 

 half-dead leaf to taking the trouble to crawl to 

 a fresh one near at hand. I believe that this 

 eating of half-dry food is injurious, and gener- 

 ally removed the caterpillar, dry leaf and all, to 

 pastures new. But it must not be forgotten that 

 , in Dr. Wallace's report it is asserted, that moist 

 I succulent leaves do not appear to agree so well 

 \ with the caterpillar as well grown, fully devel- 

 oped leaves, even if they should be a little dry. 

 More experience is required here. 



It Is perhaps not worth while to go more fully 

 into details in this paper, when the experiments 

 of another season may be productive of very 

 ditlerent results ; but I may say that, notwith- 

 standing these almost complete failures, I have 

 no doubt that both Yama-mai and Pernyi will 

 in due time be acclimated in this country, and 

 form auother source of wealth for our energetic 

 and enterprising people. If a number of indi- 

 viduals could succeed in raising a few cocoons 

 each, we may, by making a collection from 

 each, succeed in bringing together a number of 

 males and females sufficient to secure a few lots 



* A subsequent letter from this correspondent informs me 

 that his moths hare come out male and ftmale, and that tliu 

 lanic \rere ted on Red Oak (Q. rubra) . Food changed twice 

 a week, liranches sprinkled daily ; and that they were kept 

 at an open wmdow facing the southeast, with a curtain 

 placed so that the e.^rly morningsun only, could fall on them. 



