THE YOUNG NATURALIST. 



293 



BRITISH BUTTERFLIES. 



By J. E. Robson ; with figures from life by 

 S. L. Moslev. 



(Assisted by Contributors to the V. N.) 



NAPI, Linn. PI. 4 , Fig. 2. 

 G reen-vc ined Wh ite . 



" Napi, feeds on Turnip, Brassica napus" ' 

 — A. L. ; but the turnip is Barssica rapa, Linn., ! 

 B. napus being the rape or coleseed. 



Imago. — (Plate 4. Fig. 2. Male, female, 

 and underside.) Greenish-white, with the 

 veins, tip, and costa blackish. Male, a black 

 spot, beyond the center, near the hind margin : 

 of the fore wing ; another on the costa of the 

 hind wing. Female generally more suffused 

 with black or dark grey ; spots as in the male, 

 another near the anal angle ; a third may j 

 generally be traced near the tip, but it is ! 

 sometimes wanting, and sometimes obscured 

 by the markings of the tip. Underside, j 

 veins very distinct, tip of fore wing yellowish. 

 Hind wing, yellow veins broadly margined 

 with greyish green, 



Larva. — Green, paler below, spirn :Ies in 

 a yellow ring. Not gregarious. 



Pupa- — Green, with very small black ! 

 spots. Is not found on walls and palings like ! 

 the two succeeding species. 



Food Plants- — Various cruciferae, but 

 appears to prefer species of cress, to 1 7 >nts of 

 the cabbage tribe. Hedge Garlic (E. a <-.i 

 alliaria), Watercress (Nasturtium ojfi.inaL), 

 Wintercress (Barbarea prcecox), Flix.veeJ 

 (Sisymbrium soplu'a J, London Rocket (Sisym- 

 brium irioj, and others are named. We have • 

 no personal acquaintance with the larva, corn- 1 

 mon as the butterfly is. 



Times of Appearance.— The imago j 



emerge; about the end of April, or in May. I 

 The second brood is on the wing towards the 

 end of [uly. 



Habitat- — Of general distribution through- 

 out Britain, but not feeding so much on 



garden plants, it does not frequent the 

 suburbs of towns so commonly as the two 

 next. It occurs generally over Europe, and 

 in the North and West of Africa. 



Variation- — Napi varies much in the 

 intensity of the black markings on the upper 

 side, and the green on the underside. Many 

 specimens, particularly of the female, are 

 more or less suffused with dark scales. An 

 Alpine form, Bryonia, Och., (PI. 4, Fig. 2a,) is 

 so much so that the other markings are 

 almost hidden. Specimens closely approach- 

 ing this variety have been taken in Britain. 

 Mr. Buckler states that larva? fed on water- 

 cress produce very dark grey varieties. 

 Napa:, Esp., is a variety of the second brood, 

 with the hind wings paler on the underside 

 than in the normal form. This was thought 

 to be distinct by Stephens, who also recog- 

 nized a third species, Sabellicoe, Pet., which 

 W2 i supposed to be distinct, as the hind wings 

 were shorter and more rounded, and to be 

 identical with the Bryonia of YVallner. The 

 figure given by Stephens is not nearly so 

 much obscured by dark scales as are Alpine 

 Bryonies. 



Parasites —The species is rarely reared, 

 and larvae are s arcely ever found at large, we 

 have therefore not heard of any parasites 

 being bred from it, though it is hot likely in 

 be freer from their attack than others of the 

 genus. 



REPUTED BRITISH 

 BUTTERFLIES. 



2. PARNASSIUS APOLLO, Linn. 



The introduction of this insect to the 

 British fauna rests on very little better foun- 

 dation than that of the last species, Papilio 

 Podalirius. The extreme anxiety of Ento- 

 mologists to swell our somewhat meagre !i-t 

 of Butterfiie render t- 1 them ready to place 

 credence in the occurrence! of any specie.-s 



