PIERIS. By J. RoBKK. 59 



P. napi I.., altliouL;-li (]i^tiilnile<l over the wliole of Xoiih America, is iiuicli I'arei' tlieie tliaii in flie impi. 

 Palaeai-ctic Region. The summer form uajti (hffers from the spring form oleracea ll((iris Ijy more ahini(hint o/mirra. 

 dark markings, especially on the under surface, whilst in the Palaearctie Region on the contrary the spring 

 form has more mai kings; 'ah. virginiensis /-.'//r. (lUI)) is distinguished from ulcrarni in that the forewing has virginimsis. 

 an indistinct dark apical spot on the upper surface and on the imder surface of the hindwing there is very 

 fine but broad dark scaling along the veins, but specimens also occur in which the whole of the hindwing 

 beneath is darkened except for ilie fine white veins; such specimens have also broad grey streaks at the 

 veins at the apex of the forewmg beneath; ab. pallida Srmhl. is puier white above and lieneath. only the pallida. 

 ? has a small black spot on the upperside of the foivwing. - The alpine and northern form bryoniae drhs., hiyoniac. 

 which occurs in Alaska as well as in some i>ar1s of the Palaearctie Region, has in the ? yellowish ground- 

 colour on the upper surface and rather broad dai'k margins to the veins. This foi'm is considerably lighter 

 than the Palaearctie form of the same name. — acadia F.ihr. is a large form, which comes between palliila acadia. 

 and /ii//iiii!iii in colouring and pattern. — frigida Snnld., from Labiador. is a whiter form and hulda l-jlir. fn'i^ida. 

 (19 b), from Alaska, is similar to friijiiln, but much smaller. - castoria Haik. (^ resedae Uih.). from ( lali- Imlda. 

 fornia, is a form without nuich marking. — Larva brownish green, lighter at tlie sides, with small white '"■*'"<"■'"■ 

 tubercles, black dots and a yellow lateral stripe, aljove which the l)lack, red-yello.w edged spiracles are placed, 

 head grey-green: -Jit — 30 mm. long, on the same plants as idpne. Pu\n\ greenish yellow, wilh black spots 

 and dots and yellowish margin to the wing-cases. Egg pear-shajjcd. likewise laid singly. 



P. protodice J!i/r. (19c), distributed from (lanada to Guatemala, lias white ground-colour, a large /"■"wAVr. 

 median sjiot divided with white and in the o'' slighter, in the ? stronger pattern of mai'ginal and submai'ginal 

 spots on the forewing. The up]ier surface of the hindwing in the cf is almost without markings, in the ? with 

 submarginal dentate markings as well as black marginal spots. The under surface has nuich paler markings 

 in both sexes. — In the winter form, vernalis I'.'i/ir.. the cf i.s smaller and less mai'keil than the cf oi' pnita- vmialis. 

 '//Vr, the ? on the contrary scarcely different from that o( prolodin-. — Larva in Ihe earliei' stages unicohjrous 

 orange-yellow, head ])lack, in the later stages the head light straw-colour, posterior half light purple, a gold- 

 yellow spot on each side, the whole head sprinkled with Idack-brown, eyes purple, broadly edged with black. 

 Body alternately glossy gold-yellow and dark greenish piu'itle, sometimes with unitorm, in other cases with 

 unecpially bi'oad black band. The yellow colouring of the sides of the back and of the stigmatal band runs 

 into the purple of the infrastigmatal band. Beneath dull hght green with reddish tinge. On the whole body 

 larger and smaller black spots, each of which bears a short black hair, also numerous small hairy tubercles 

 (from specimens jireserved in glycerine). Pupa light bluish green, slightly suffused with yellowish on tlie 

 abdominal segments, a dull, broad yellowish lateral stripe on the abdomen, suprastigmatal ridges margined 

 with yellow. Head with small, dispersed blackish spots, wing-cases with faint dark brown marks, veins marked 

 with small, se])arated, distinct black spots, a black spot on the basal protuberance, segments of the antennae 

 mostly marked in the same wa}'. The spiracles are the same coloui- as the body. Lar\'a on Brassica oleracea, 

 Lepidium virginicum and other (Irucifers. 



P. OCCidentalis llrak. (19c), frum the mountain(.ms regions of the west of the L'nited Stales, has Ihe occidcntalis. 

 dark markings more extended and less interrupted than piafuf/irr and the under surface, especially of the 

 hindwing, is strongly marked with green. — orridnihi/is is regardeil by Scuhder as the third generation of 

 jirolfiJice (onl\' occuring in the west?). Thus it would seem that the early .stages do not differ .from those of 

 protiidicr. 



P. sisymbrii />'/'•. (19c). from the L'nited States, is smaller than (h-i-ii/n/fo/is. the lilack marginal mai'k- sisymlirii. 

 ings are more s!iar])ly defined and divided by the veins, which ai'C light here, but sharply dark in the rest 

 of the wings. The undei-side of the hindwing has black-green markings, broken up iji a peculiar manner. 

 The ? is ([uite similar to the cf. — Egg long, narrow, conical, ground-surface and vertex flattened and 

 depressed, with longitudinal ridges, the interspaces hollowed out and crossed by numerous stripes; colouring 

 at fii-st light yellow, shortly befoi'C emergence red. Full-grown larva about 22 nnn. long, cylindrical, moder- 

 ately narrowed anteriorly and posteriorly, light yellow, with black stripes crosswise, each segment sometimes 

 with a fold and in this case on the l)ack small yellow jirotuberances of irregular size, each terminating in 

 a small fine hair: on all the segments behind the 2. and inclusi\e of the 1:2. are 2 stripes. The larva \aries 

 very much. Time of development from the egg to the jiupa in April — May :53 days, in May — .tune '■>() 

 days. Pupa cylindrical, narrow at the head, hollowed out at the sides, a short thick projection between the 

 eyes, mesothorax projecting, rounded, slightly keeled in consequence of a depi-ession as deej) as the meso- 

 thorax is high, which however is not uniformly rounded but rather angular, on each side of the dorsum and 

 the anterior abdominal segments are small, angular, incons|)icuous elevations, the anterior ones the most 

 distinct; colouring dark brown, the whole upperside except the wing-cases irregularly coxered with small 

 protuberances (the ]iupa is figured by Ei.)w\i;iis, Buttertlies of Xortli .\merica, hanginic ti-ee). 



P. beckeri Iu/t. (19c). from the United States, is similar to the AVc/;/o -species. L'pper and under ^crAvn. 

 surface white, on the upperside of the forewing a large black median spot, divided with white, and smaller 



