414 LÉPIDOPTÉROLOGIE COMPARÉE 



note that, whereas in filzii the tvvo sexes émerge together, in hiinïi 

 the females are decidedly later and one will hâve humi females 

 emerging long after the others are done. 



If one had time and material, in ail probability, it would be 

 discovered that the fertility of both sexes of hiinli was equal to 

 that of pilzii, but, up to the présent, although many attempts hâve 

 been made, no ova from Q hwiii hâve proved fertile. This year 

 I secured fertile ova from the cross Jiunii çj x hirtaria g . 



Hybrids between " Pœcilopsis pomonaria " and " Ithysia zonaria. " 



(A) Pœcilopsis pomonaria cf x Ithysia zonaria Q ^ hybr. helenœ. 

 Pœcilopsis hybr. helenœ (Harrison, Entomol., July 1910). 



This cross, too, is very easy to obtain and yields a large per- 

 centage of fertile eggs, which hatch at the same time as those 

 of hybr. denhami. 



The food plants are of a similar nature to those of that hybrid, 

 for the larvas will not feed on yarrow {Achillea Millefolium) and 

 low plants. The favourite foods are haw^thorn {Cratœgus oxya- 

 cantha), sallow {Salix capreà), osier (Salix viminalis) and rose 

 (Posa canina). It is clear that only rarely wouîd the larvae, 

 resulting form this cross, be able to feed up if the pairing took 

 place in Nature. 



ist INSTAR. 



Length at end : 4,2 mm. 

 Head. The head is black and resembles that of pomonaria. 



Body. The ground colour is black and, owing to the w^eakness 

 of the longitudinal markings, seems to be of the same shade 

 as in pomonaria. The usual white bars and spots on the ist, 2nd, 

 3rd, 4th and 5th abdominal segments are well marked and are 

 very similar to those seen in pomonaria for the spot between the 

 end of the bars and the large white spot on the spiracular line, is 



