101 



ON THE LIFE HISTOEY OF ANTHOCAEIS 



CAEDAMINES. 



By Dr. T. A. Chapman. 



The "Orange Tip Butterfly" (Anthocaris Cardaminps) is supposed to be 

 " common everywhere." Any interest there may be in these observations is not 

 therefore due to the rarity of their subject. The egg of this butterfly and the 

 newly-hatched larva are not however familiar objects to most entomologists, and 

 have not, I believe, been described in any English work, and therefore possess 

 sufficient freshness to justify my laying these notes on them before the Club. 



The subject is also appropriate to this meeting, as at this season it is usually 

 possible to find the butterfly, the eggs and the young larva. This year, however, 

 the season is so late that this hope will be disappointed, as, though the butterfly 

 was on the wing three weeks since, it has since disappeared ; and I shall not be 

 lucky enough to be able to show you the eggs, as the main flight of the insect is 

 probably not yet out. Last year the spring was also late, and eggs were not laid 

 before June, and were to be found as late as June 30th. Usually the middle of 

 May is the date of oviposition. 



Last year white butterflies were very scarce, and it so happened within the 

 range of my observation, that any white butterfly seen proved to be a female 

 Cardamines ; Pieris Rapa usually so abundant, was so scarce that I was unable to 

 obtain eggs of it for comparison with those of Cardamines. Early in June I 

 observed the female of Cardamines settling on the flowers of Alliaria Officinalis, 

 the common Jack by the Hedge or Garlic mustard, and noted that whilst sipping 

 the honey from the flowers she also deposited an egg on the flower stalk. At the 

 date when this occurs there is usually about an inch of the stem occupied by the 

 seed pods already formed, and the pedicel selected for the egg is usually that of a 

 flower nearly over, so that it might equally be called a young pod. Only one egg 

 is laid in one head ; if a second be found it is probably the result of a visit by 

 another butterfly. The Alliaria grows in little colonies in the hedge banks, and 

 usually each colony afforded one head containing an egg, and no more— though 

 there were exceptions, some colonies being uninhabited, and others with several 

 eggs. A large patch of Alliaria did not afford a second egg more frequently than 

 a small one. 



The Alliaria is undoubtedly the food plant of A. Cardamines in this district. 

 I found eggs also on charlock and on turnip, and the larva is said to feed on 

 various other Cruciferse, but all these in this district may be regarded as 

 exceptional. 



The egg is very like that of Rapce, but is larger and darker, both are of the 

 inverted vase shape usual in the Pierida. The height of the egg in Cardamines is 

 1.10 mm., the greatest diameter 0.52 mm ; of Raps the height is 0.90 mm, and 

 the diameter 0.41. In Cardamines the longitudinal ribs are 13 in number, several 

 joining towards the top, so that the rosette at top has 10 or 11 rays. Rapae has 



