144 THE ENTOMOLOGIST S RECORD. 



}ii('n>n!iis)] only two more imagines emerged (continued from Ent. 

 Record, vol. ix., No. 12, p. 319), on November 17th and 19th, making 46 

 in all. The rest died. A few larvae of the first fertile pairing of the 2nd 

 generation (a) Avere full-fed early in November, and most had pupated 

 by November 17th ; those remaining were fed on privet, and went 

 down early in December. From these pupae 2 imagines, both $ s (3rd 

 generation, a), appeared before December 28th, and, having been over- 

 looked, were then so rubbed as to be unfit to set. On December 29th, 

 another $ emerged, and between January 1st and 27th, 1898, 14 

 came out — (11 ^ , 3 $ ). The imagines are small, pale brownish- 

 white or greyish-brown in colour, with some ancestral markings more 

 or less defined, but only 4 can be referred to a distinct form {T. hiun- 

 (lularia). Four were paired, and one $ deposited 2, the other 6 ova. 

 These, except 1, were fertile, and hatched in January, but the larvre 

 refused to feed on either fir, pine or privet, and died within a few days. 

 The 2nd fertile pairing of the 2nd generation (a), produced a fair batch 

 of ova on October 21st-22nd, which hatched on November 13th-14th. 

 The larvjB were given spruce fir, Scotch pine, privet, and a few half 

 dead leaves of sallow. Some nibbled the privet for a few days, but by 

 November 23rd only one larva was alive, which seemed to hybernate 

 in its first stage, but died towards the end of January, 1898. 



The hybrids, 2nd generation (/^), S and ? (^ T. histortata + ? 

 T. biundularia) [Ent. Fwcord, loc. cit.'] kept emerging during 

 November and December, 1897, till January 19th, 1898—34 imagines 

 in all (23 <? s, 11 $ s). These are paler than the parents, varying from 

 pale brownish to brownish-grey, some approaching the 2nd brood of 

 r. histortata in appearance ; others, the t? s of T. bmndnlaria : some 

 few might be classed with the latter, but most have very mixed 

 characters. Six of these were paired in November, and small batches 

 of ova were laid by each of the 5 s within a few days. About half 

 hatched during the second week of January, and though supplied with 

 fir, pine and privet, refused to eat, and died shortly afterwards. The 

 rest hatched a few weeks later, with a similar result. 



It may be noted, that in the third generation the hybrids seem to 

 be losing their power of reproduction, scarcely any ova being laid. 

 The 2nd generation {(3) would probably have produced a third 

 generation, had not the ova hatched during the winter, and at a time 

 when there was no supply of the usual food-plants. 



During the spring of 1897, I paired two typical ab. dclainerensis 

 (York). Ova were obtained in somewhat diminished numbers 

 (probably due to interbreeding). These hatched, and the larvae fed up 

 a»id pupated in due course. The first imago appeared on February 5th, 

 1898 (pupre brought into warm room), and was a typical York biiaidu- 

 laria. In all 18 have emerged, less than half the pupie, the rest dying. 

 Four of these, besides the first, are typical York T. hiundularia, and 

 4 others, though of the delamerensis type, are paler than the parents. 

 There is, therefore, reversion to the grand-parents. It will be remem- 

 bered that the original stock was a wild York ab. delawcreiisis $ , and 

 a (? parent unknown, and that the ova produced the typical York 

 binndidaria, and the ab. delaiiu-rmsu in equal proportions in 1897. 



I also paired, in 1897, two typical York T. biundularia. The 

 pairing produced, in 1898, IG imagines, all taking after the parents, 

 though the original stock was a wild typical York biundularia ? and 



