COMMON BUTTERFLIES OF THE PLAINS OF INDIA. 29 



Pupce are not, tir« a rulo, attacked by parusitiu insects tliougli 

 Jchneitmon wjisps of the larner kinds :ind Tuchinid flies come to 

 maturity within tliem, the hirval sttioo huvino- been passed in the 

 ])receding caterpillar stage. This innnunity of the pupa may be 

 ascribed partly to the possession of stridulating organs which produce 

 !i hissino- souud and frighten enemies, partly it is undoubtedly due to 

 the integument being fairly hard and tough ; also to protective shape 

 and colouring : though these two factors probably count for very little 

 against purely insect agression. The organs which produce sounds 

 are situated on the abdominal segments <^ to 11 which are capable of 

 beino- rubbed against each other along the margins by a side to side 

 motion of the body. All chrysalides that are formed in the open, t.e., 

 that are not hidden in any way from view, are subject to colour 

 variation according to surrounding circumstances, the pattern often 

 being determined by the shape of neighbouring objects as regards the 

 distribution of the colours. Those, that are formed in crevices, holes, 

 under stones and clods of earth or that have specially prepared leaf- 

 cells to protect them, are not subject to this variation being, pre- 

 sumably, otherwise sufficiently safeguarded. The fresh pupal skin as 

 well as the larval skin must be extremely sensitive to the effects of 

 light, as the colours of surrounding objects invariably produce results 

 on one and the other which are none the less surprising in that 

 they are necessarily confined within fairly narrow limits. 



Many lycajnid larvae are attended by ants of different species 

 for the sake of a sweet juice secreted by them. The ants take 

 great care of them, occasionally building temporary sheds over them 

 for protection and, in the case of certain species, rarely quitting 

 them. Other species attend the caterpillars only from time to time ; 

 or perhaps it would be more correct to say that certain species of 

 caterpillars are attended by ants only from time to time : for the 

 attraction seems to be stronger in some larvci) than in others. The 

 sweet juice is excreted by a gland situated in the centre of the back, on 

 segment 11, which is rather like a mouth in shape. The ants stroke the 

 hinder part of the body of the caterpillars gently with their antennae 

 which has the effect of making the gland exude jwdrop of liquid which 

 is lapped up greedily. On segment 12, just above the spiracle on either 

 side, there is generally a circular opening from which can be everted 

 a white cylinder of a certain length, set round the top with minute 



