24 THE YOUNG NATURALIST. [February 



i 4th- i 6th, in 1887, my other dates are intermediate. Mr. Porritt bred 

 his from Scotch larvae on July 24th and following days, ("Entomologist's 

 Monthly Magazine," Vol. XXII., pp. 103-105), and Mr. South bred a 

 specimen (also from a Scotch larva) on July 21st, ("Entomologist," 

 Vol. XXIII., p. 281). 



Larva — Mr. Barrett thus writes of the young larva : — " The larva 

 of Bertrami, which feeds, (exclusively, I think) on Achillea millefolium 

 and ptarmica, attacks the top of a young shoot, eating out the heart 

 and feeding downwards for a short distance into the tender young 

 stem, then leaves it to attack another young shoot in the same manner. 

 This larva is, in fact, rather an external, than an internal feeder," 

 ("Entomologist's Monthly Magazine," Vol. XVIII., p. 177). The larva 

 of this species has been described by Mr. Porritt from specimens 

 taken feeding" in yarrow by Mr. HinchclhTe of Tillicoultry, on June 

 25th, 1885." Those received were "in three stages of growth, though 

 most were in the middle stage, or apparently about half grown. They 

 were of the usual form of larvae of this genus, though perhaps a little 

 more slender than some species ; body cylindrical, stoutest in the 

 middle, tapering towards the extremites, head small and polished, con- 

 siderably narrower than the second segment, segmental divisions, well 

 defined, the skin rather glossy. When about a quarter of an inch 

 long the ground colour is pale greyish-olive, but this is almost hidden 

 by dark purplish-brown dorsal and sub-dorsal stripes, which give the 

 larva a very dark appearance ; head very pale straw colour, marked 

 with smoky-brown, the ocelli black, and the mandibles reddish-brown; 

 frontal plate and anterior legs polished black. 



" In the next stage, that is, when about three-eighths of an inch long 

 it has become considerably lighter in colour; the ground is glaucous- 

 green, the dorsal and sub-dorsal stripes purple, but more interrupted, 

 and not so wide as in the earlier stage, head of the same straw-colour, 

 but not so clouded with darker though the ocelli are still black, and 

 the mandibles reddish-brown, the frontal plate is gradually becoming 

 pale like the head, the black being confined to the front in some speci- 

 mens, in others to a black edging, more or less broken all round. 

 Ground of the ventral area and the prolegs uniformly glaucous-green, 

 the anterior legs now ringed with black only. 



" In the adult stage, about half to five-eighths of an inch, the larva 

 has a still paler appearance. Ground colour, bright pea-green ; head 

 *The northern locality probably had something to do with the late date. 



