3/6 LÉPIDOPTÉROLOGIE COMPARÉE 



some cases it simply flops down like hirtaria but usually it assu- 

 mes the curious attitude described above m the case of zonaria, 

 and feigns death for some considérable time. It often lives a 

 very long time. 



(B) Hybrid harrïsoni = I. zonaria cf x /.. hirtaria Q. 

 Ithysia hybr. harrisoni Œntomologist; July 1910). 



This hybrid, unfortunately, was known under the above M. S. 

 name long before the name was published, and, as 1 was the ûrst 

 to use it in print, although I did not propose it, I hâve to stand 

 as the author and thus the insect becomes /. hybr. harrisoni 

 (Harr.). The food plants of the larvas are exactly the same as 

 those of the reciprocal cross. 



As this larva and that of hybrid denhami are so much alike, it 

 is not intended to give a detailed description of the larva in ail 

 its instars, but simply to draw attention to the différences bet- 

 ween an average larva of harrisoni and a similar one of denhami 

 and to reserve the full independent-description for the last instar. 

 It is worthy of note that it would probably be perfectly feasible, 

 if one was rearing many broods of each, to match any give.i 

 harrisoni larva with one taken from the broods of the other cross. 



ist INSTAR. 



The larva, at first, is much less than the larva of denhami^ as 

 one might expect from the disparity in size between zonaria and 

 hirtaria ova, but, toward the end of the instar, the sizes of har- 

 risoni and denhami larvae are both just about 4,5 mm. 



The only other points of différence are in the stripes, which 

 are slightly clearer in this form and therefore contrast more with 

 the blackish ground. This causes the larva, even to the naked eye, 

 to appear more freckled. 



