THE ENTOMOLOGIST. 335 



doings in the fifth vohime of the 'Massachusetts Agricultural 

 Uepository and Journal.' A very similar caterpillar, and 

 ]:)()ssil)ly the same, for it is also an American, mines the solid 

 wood of the red oak, but its ravages do not seem so exten- 

 sive, and certainly are not so well iisceilained, as those of the 

 two species I have mentioned by name. It ought here to be 

 observed that the two species, Cossus and Robinioe, although 

 described as being so similar, have really very distinctive 

 characters: in Cossus the sexes are nearly alike; in Robinia?. 

 they are very different, and the male is so nuich smaller than 

 the female that it has been supposed to be a distinct species: 

 it has, moreover, a large yellow-ochre-coloured spot near the 

 hind margin of the hind wings. I will, however, leave Xy- 

 leutes Robinias to our American cousins, who have studied 

 its habits so successfully, and confine my attention to its 

 English relative. 



I have already spoken of the predilection of Cossus for 

 willow, but it by no means confines its attentions to this tree; 

 elm, oak, birch and alder are among those trees which, next 

 to willow, it has selected for its operations. Mr. Corbin 

 describes its ravages in the New Forest to be principally 

 committed amongst the oaks : he writes to me in these 

 words : — " The trees in some parts of Ringvvood, particularly 

 oaks, are entirely perforated by the destructive larvae of this 

 odoriferous species, and yet I have never seen the perfect 

 insect. While pupa-digging during the past winter, on the 

 estate of the Earl of Normanton, 1 tore off a piece of loose 

 bark, and in it were no less than eleven larviB of this three- 

 year wood-feeder, all about three-quarters of an inch in 

 length. In 1860 I succeeded in getting three larvae to turn 

 to pupa3, but, by some misfortune or other, not a perfect 

 insect appeared." The larva, like that of Robinia), certainly 

 remains three, and possibly four, years in that state ; and 

 when anyone has witnessed its extraordinary power of de- 

 stroying timber in a single day, as I have done when I have 

 had it shut up in a deal box, and will calculate the sura-total 

 of this destruction continued for three years (I am not good 

 at such calculations myself), he may form some idea of its 

 doings. 



To begin the lifohistory of this noxious moth at the 

 beginning, we must watch the act of oviposition. The I'emale 



