LASIOCAMPA QUERCUS. 89 



egg, whilst that of L. var. callunae (anted, p. 74) suggests an 

 opalescent piece of the shell of a robin's egg. They are also 

 similar in the raised points which are found at the angles of the 

 reticulation with which the eggs are covered. The reticulation, in 

 both eggs, is more distinct over the ends of the eggs than over 

 the central parts. The eggs of both are laid loosely. The eggs 

 suggest a wider separation than we had previously considered possible 

 between the more isolated forms of the two races. The main differ- 

 ences noted were as follows : 



1. L. quercus— Blackish-grey, the black micropylar area cut oft sharply from the 

 surrounding white area ; plumper and rounder, especially on upper surface, where 

 there is no depression, only a smooth shining portion marking the position of 

 the usually sunken area ; micropylar area black, formed of closely-set cells, the 

 black area cut off sharply from ground colour. 



2. L. -callunae — Pale creamy-brown, the black micropylar area surrounded 

 by a ring of large, pale brown polygonal cells, which, in turn, are surrounded by the 

 creamy ground colour; the egg flattened at top and bottom (long sides), and with a 

 distinct depression on upper surface ; the micropylar area composed of distinctly 

 open (clearly defined) cells, and not cut off sharply from ground colour. 



Comparison of ova of Lasiocampa quercus (English) and L. 

 var. MERIDI0NALI3 (French). — In critically comparing an English 

 egg of L. quercus with a French one, we are much astonished 

 at their close resemblance, as they at first appeared very differ- 

 ent owing to the fact that, whereas the ground colour of the 

 egg of the French insect is tinted with reddish and the mark- 

 ings tend to a more ochreous - brown colour, that of the English 

 quercus has the ground colour clearer white and the markings of 

 a more fuscous hue. Still the difference appears a very superficial 

 one when closely compared, and the modification, marked as it 

 appears when the eggs are examined separately, is a very slight one. 

 Even the micropylar areas are identical in structure, although different 

 in colour, the same minute depressed micropylar point, and the same 

 want of denned coloration around the area. The depression on 

 the long side, too, is very much less marked in both than in the eggs 

 examined of either var. callunae or var. viburni. [We have already 

 described eggs of British L. quercus- as being without a depression; this 

 is true of some, but a depression has since been observed in others.] 



Habits of larva. — The larva hybernates at least one winter in 

 all its various forms, but, as var. callunae, usually in a later stadium 

 than does the southern quercus. In spite of this, the latter commences 

 to feed up more rapidly in spring, overtakes and passes the callunae 

 larva, and, pupating in June and early July, the imago appears 

 the same year, whilst the larvae of the latter, feeding on until 

 July and August, pupate then, but do not disclose their 

 imagines (except very occasionally) until the succeeding May 

 and June. In southern Europe, the metamorphoses take place 

 within a year, but, in the high mountains of central Europe, and 

 in high latitudes, the callunae habit of two years is normal. On the 

 south coast of England, e.g., at Plymouth, the larvae cannot be said 

 to hybernate at all ; they may be found throughout the winter on 

 sunny days feeding in hedges, but they are still very small, and do not 

 increase much in size until the spring is far advanced, and, never, in 

 this district, have been known to pupate in the autumn of the year in 

 which they hatch (Reading). We have also already noted (anted, 



