THE CANADIAN ENTOMOLOGIST. 39 



at dusk in New Hampshire, which seemed to present a parallel to the 

 archippus flocks, though of course on a very small scale. 



R. Thaxter, Newtonville, Mass. 



Dear Sir, — 



Last summer I discovered, unfortunately too late, that a large Cossus 

 was working in some large and very old Oak trees near here. I hope 

 next June or July to find out what it is, as I shall construct nets to envelop 

 the tree trunks of several of these so infected Oaks. None of my corre- 

 spondents have been able to give me light on the subject ; they think it 

 possible that this is a new species, and urge close observation, advice 

 which I hope to be able to follow. 



I also purchased five large trees of a coarse variety of Poplar, known 

 here as Cottonwood, that were to be cut down, as they had commenced 

 dying, '•' caused by a grub working in them." I found it to be a Cossus 

 larva, but not as large as that working in the Oaks. Judging from a com- 

 parison of the empty pupae cases found in them, which in these Poplars 

 were very numerous, it is not the one described by Mr. Bailey in last 

 January number as " Cossus centerensis" but seems more like Xystus 

 robiniae. I had three of the trees cut down in order to obtain the pupae ; 

 judge of my surprise and disappointment when my man came in, telling 

 me he could find none but " lots of nasty grubs, of which he had given 

 the near chickens probably a hundred or more," not thinking them valu- 

 able to me. I sent him back with instructions to preserve every larva he 

 could find, and I now have about fifty in every stage of development from 

 the half-inch beet red, the nearly two-inch long pink, to the about two and 

 a half-inch long greenish-white larva. I have some in the wood in their 

 own burrows, and have put the rest in sawdust ; and I have ordered him 

 to cut me pieces of that wood, bore some holes in the ends and put in 

 the other larvae, and cork it in, leaving a few air-holes ; with these I hope 

 to complete my observations in a warm room. I did not know before 

 that these hybernated in the larval state, much less did I think they would 

 be found of different moults. A. H. Mundt, Fairbury, Ills. 



mrgration of butterflies. 

 Dear Sir, — 



I have received the following notes on migration of certain butterflies 



from Prof. J. E. Willet, of Macon, Ga., dated 19th Jan'y, 1880. 



W. H. Edwards, Coalburgh, W. Va. 



