40 Second Report on Economic Zoology. 



gallery and crawl about upon the leaves for a short time. Usiially 

 in a few hours they commence to spin a cocoon on the leaf. These 

 cocoons are generally spun on the under side of the leaves (Fig. 4, }?^, 

 but may occur on the upper side (Fig. 4, V), the latter only when 

 they settle upon small or curled leaves. Very often the cocoon is 

 spun on the leaf in which the larva has tunnelled, or it may be a 

 fresh leaf. This case is formed of very fine shiny white silk, and is 

 made in well-formed examples as follows : a thick strand extending 

 from one branch vein to another on each side, usually parallel and 

 about 5 mm. apart. The length of these lateral strands depends 

 upon the distance of the ribs apart. I have measured some 30 mm. 

 long. The cocoon is spun between these and attached to them by 

 anotlier strand of silk on each side. The cocoon itself is cylindrical 

 and open at each end. They may also occur with the treads 

 running from the mid-rib to the edge of the leaf (6^). The pupa 

 (Fig. 4, (I) is pale apple green, the front fawn-coloured and also the 

 wing-cases. The third segment of the abdomen has a large apical 

 yellow patch, and the liase of tlie fourth is also yellow, the venter 

 pale green, with the tips of the leg-cases black, also the eyes. It is 

 formed a few days after the larva has commenced to build the nest. 

 It is notched in front, and behind tlie antennal cases stick out as 

 two prominences. The leg-cases and wing-cases are long and pro- 

 minent, and there are black marks noticeable at the apices of all the 

 legs. The pupa is 3 • 5 mm. long. 



The pupal stage lasts from ten to twenty days. The larvre found 

 in April give rise to a brood of moths in June and July. These lay 

 their ego-g again, and we find the larvpe occurring in Julv and 

 beginning of August. They mature and give rise to a third brood in 

 September and October. This latter brood of moths hibernate, but 

 those that occur early in September (some hatched out this year cm 

 the 1st) may lay eggs and produce another generation of larvae whicli 

 mature in the middle of October and join in hil^ernating with the 

 late-hatched previous brood. 



Treatment. 



It is extremely difficult to say what to do in such an attack, but 

 fortunately it is so far limited to a few trees, and these usually 

 pyramids and espaliers, where hand-picking can be carried out. The 

 whole life seems to be spent on the tree in a protected condition, 

 the only time the larvae are free being when they leave the tunnels 

 and commence to spin. They then take no food, and as the}' hatch 



