220 THE COLOURATION OF INSECTS 



larvae, ringed alternately with orange and slate grey, 

 with black spines and crimson head, could be found in 

 numbers when full fed wandering over the grass land in 

 search of suitable places for pupation. Judging by the 

 situations in which the pupae were found, the larva chooses 

 as conspicuous a site as possible, such as a tall grass stem 

 fully exposed and unsheltered, quite out in the open. 

 Numbers of these full fed larvae and of the equally con- 

 spicuous pupae were collected, and out of seventy, 77 per 

 cent, were destroyed by parasitic Diptera (Tachinidae) 

 and Hymenoptera {Chalcididae, Braconidae). 



Lastly, in the case of M. The very peculiar and highly 

 specialized legless caterpillars of the Apodidae are often 

 brilliantly coloured, and furnished with intensely sharp 

 strong spines set in clusters, often said to be " poisonous," 

 so irritating are their qualities. The Baganda have a 

 great dread of these stinging caterpillars, which they 

 brought me with the utmost caution. I was very seldom 

 able to rear them, for they seemed to be extraordinarily 

 susceptible to some disease which very rapidly killed 

 them. Possibly it was of the same nature as the 

 " pebrine " which Pasteur investigated in silkworms.^ 



A very interesting special case of aposematic colouring 

 is the development of " Terrifying " marks, and just as 

 with the cases previously described, the colouration is 

 associated with a special attitude, whose purpose is to 

 make the specialized areas of colouring suggest some- 

 thing that frightens or discourages the enemy. In many 

 cases the attitude is far more important than the colouring. 

 I would refer the reader to Poulton's book,^ and wish here 

 merely to describe an example from my own experience. 

 The large and handsome moths of the family Saturnidae 

 very often, like our " Emperor moth " of the heather 



* Comparative statistics of the number of caterpillars, procrj'ptic and 

 aposematic, destroyed by p and M would bo exceedingly valuable. 

 ' The Colours oj A^iimals, p. 258 et seq. 



