TWO NOTORIOUS INSECT PESTS. 683 



(a) and the adjoining spaces (bb), the orange colour then extending over 

 the middle of the dorsal surface as far as the white lines (cc) on either 

 side. The spaces (bb) may be as dark as the upper part of the sides (ee), or 

 they may be considerably paler, and their colour spreads transversely 

 along the junction of two adjacent segments, thus more or less in- 

 terrupting the central line (a). All the colours become pale shortly 

 before pupation, and it is often difficult to determine to what extent the 

 normal colouring has been modified by this approaching change. 



14. I have by no means indicated all the variations of colour which 

 the larva may present, but the most constant and remarkable variations 

 •certainly appear to be with respect to the presence or absence of the 

 orange dorsal line and to the extent of the space occupied by it when 

 it is present ; and I particularly wish to emphasize the fact that there 

 appears to be a complete series of intermediate forms, uniting the two 

 extremes, in which the orange or flesh-coloured line is entirely absent 

 and in which this line occupies the whole of dorsal surface between the 

 white lines (cc), respectively. 



15. The larva is shy and seldom exposes its whole body to view 

 voluntarily. It usually constructs for itself, among the leaves on which 

 it feeds, a shelter in which it lies during the day and in the neighbour- 

 hood of which it feeds at night. Consequently it is somewhat difficult to 

 measure it ; for, if measured when at rest, crouching in its shelter, the 

 measurements are too small, while it moves so quickly if disturbed that 

 it is difficult to measure it when extended to its true length. Measure- 

 ments recorded by me gave the length and mid-diameter in inches of 

 the mature larva as 1*26 and 0*22, respectively. It tapers to both ends. 



16. Pupa. — Stout, colour bright brown to very dark purplish -brown 

 or black, with a few scattered bristles. Tail short, obtuse, furnished at 

 the extremity with a hook, like a minute grapnel with several flukes 

 or claws. Length and mid-diameter in inches 0"74 and 0*21, respect- 

 ively. Fig. VII. represents the pupa. 



17. The above descriptions have been given in considerable detail 

 for the following reasons : — 



(1) The descriptions of the eggs, larvae and pupae at present on 

 record are meagre and of little help in the identification of the insects, 

 while the work of preparing a complete account of the pests will clearly 

 be greatly aided if observers are able to identify the insects in any stage 

 of their existence. 



