LASIOCAMPA QUERCUS. 57 



2. Brownish, with a pale transverse band crossing the fore- and hindwings=:ab. 

 brunnea-virgata, n. ab. 



3. Brownish with the outer area of hindwings paler to margin=ab. brunnea- 

 semimarginata, n. ab. 



4. Brownish, with the outer area of both fore- and hindwings paler to margins 

 ab. brunnea-marginata, n. ab. 



The following are the chief described forms of this species 

 with, as far as possible, the original description of each form. 

 Some of these are highly specialised local races, and the details 

 of their life-histories have considerable bearing on the nature of 

 species and so have been described, as far as possible, in full. 



a. ab. tenuata, Fuchs, " Stett. Ent. Zeit.," xli., pp. 120 — 123 (1880) ; Kirbyj 

 "Cat.," p. 828 (1892); Auriv., "Iris," vii., p. 150 (1894); Staud., "Cat," 

 ed. 3, p. 121 (1901). — The yellow transverse band is narrower in both sexes, 

 especially on the hindwings, in which, towards the anal angle of the $ , it appears 

 almost as if broken. The transverse band does not fade into the dark brown ground 

 colour of the margin but is sharply divided therefrom ; the marginal colour being 

 as dark as that of the basal area. In these general characters both sexes agree. 

 The forewings of <? 28mm. from base to tip (i.e., of about normal size), the 

 colour somewhat darker than usual, of a deep chestnut-brown, whilst near the 

 base on the costal margin is a small, but conspicuous, yellow spot (a character 

 shown by no local <?s). The yellow transverse band is broader on the forewings 

 than on the hindwings and is sharply defined exteriorly. Although a male taken 

 locally has a similar appearance, and has a transverse band on the forewings 

 still narrower than that of var. tenuata, yet it differs from the latter in having 

 the brown marginal area outside the centre of the transverse band lighter than 

 in this form,* and not of" the uniform dark chestnut-brown characteristic of the 

 ab. tenuata. The differences in the hindwings are still more important, for the 

 yellow band is farther from the margin, is less bent, very narrow, and at the hinder 

 angle so constricted that it appears broken, whilst the broad marginal band which 

 is distinctly separated from the yellow band is just as dark brown as the basal 

 area. In this respect, ab. tenuata is exactly the opposite of var. sicula. . . 

 The underside of var. tenuata differs from that of typical L. quercus in that the 

 latter has the yellow band increased in width, only the apex remaining brown, 

 whilst on the hindwings the yellow stretches to the fringes : in ab. tenuata. the 

 margin of the hindwings is a broadly brown band but the brown is somewhat 

 lighter than that of the upperside, and the broad transverse yellow band is, 

 therefore, not so sharply separated. The ? var. tenuata, whose forewings measure35mm., 

 is dark, with distinct narrow yellow bands on all the wings, sharply divided from 

 the brown ground colour ; the forewings have yellow nervures especially in the 

 basal area ; the hindwings are uniform dark yellow-brown to the fringes (which 

 are yellow), the ground colour only interrupted by the sharply-defined, yellow, 

 transverse band (Fuchs). 



This aberration was the result of an experiment in which Fuchs 

 gave the larvae pine for food, and, under artificial conditions, 

 induced them to feed up in the winter, the examples here described 

 emerging in early spring {anted, p. 48). Comparing the ab. tenuata 

 with the other varieties of L. querc&s, Fuchs states that the ab. 

 tenuata is nearest to the $ ab. catalaunica, which is, however, not 

 so dark as the $ ; from the ab. catalaunica 2 > the ab. tenuata 2 

 differs in having a distinct transverse band on the hindwings which 

 is hardly visible in ab. catalaunica. In the latter, there is, associated 

 with the dark yellowish-brown basal area, a somewhat paler marginal 

 band, the colour of which is only a little lighter where it crosses the 

 transverse band. Staudinger refers, with a query, var. dalmatina, 

 Gerh. {Bed. Ent. Zeit., 1882, p. 128), to this form, diagnosing it 

 himself as : " Alis omnibus anguste flavo-fasciatis." 



* The descriptions are very suggestive that the typical male of the district 

 =the wider banded ab. roboris, F. J. A. D., and that the narrow-banded ab. 

 tenuata, is somewhat near ab. spartii, Hb. 



