234 The Pea Thrijjs (Kakotlirips robiistus) 



Description of second stage larva. 

 Measurements. Total length 1-4-1-8 mm. 

 Width of head across eyes 0-09 mm. 

 Length of ninth abdominal segment 0-08 mm. 

 Length of tenth abdominal segment 0-08 mm. 

 Antennae 12 3 



length (fi) 23 40 50-60 

 width (/x) 32 29 28 



Total length of antennae 0-20-0-24 mm. 



Antennae (Fig. 7 b) six segmented, the third segment divided into five rings and 

 the fourth into six. The fourth segment sUghtly narrower than the third. 



The dark coloured ninth abdominal segment equal in length to the tenth segment. 

 Near the hind margin of the ninth segment, in the position of the two most dorsal 

 spines in the first larva, are two short transparent processes about 0-040 mm. long 

 and rounded at the tip. On the tenth segment in a corresponding position are two 

 stouter processes of about the same length, but gradually narrowing from the base 

 to the apex which is sharp (Fig. 8 h). 



The two stages are easily distinguished by the relative and absolute 

 lengths of the ninth and tenth abdominal segments, and by the stout 

 processes on these segments in the second stage which are only 

 represented by hairs in the first. 



Both stages of the larvae are found in the flowers and on the develop- 

 ing pods, less commonly in the terminal leaf cluster; as the pod grows 

 and the petals fade and fall off they retire for shelter into the calyx, 

 which forms a cup round the base of the pod. If the larvae have been 

 sufficiently numerous to cause the pod to curl, they will be found chiefly 

 on the concave surface. Should the pod crack or be pierced by other 

 insects they may enter and produce on the inner surface the same 

 characteristic 'silvering' of the surface. 



In about six days the second stage larva is full fed. It then descends 

 to the ground and goes beneath the surface to a depth of from three to 

 twelve inches where in some suitable crack or crevice it remains for the 

 rest of the year. There appears to be no attempt at the formation 

 of a cocoon or pupal cavity. 



The earliest date in which larvae in captivity have entered the 

 earth was the 28th June (from eggs found on the 8th June), but larvae 

 from eggs laid in May must descend before this. The total time from 

 the laying of the egg to the descent of larva is about 24 days. 



The larva remains without moving, in the position it has first taken 

 up, throughout the rest of the summer, autumn and winter until the 

 following spring when, sometimes during March, April or early May, 

 it changes into the propupa or first nymph stage. 



