TWO NOTORIOUS INSECT PESTS. G89 



39. As a rule, the larvae when mature, quit the leaves on which 

 they have been feeding and pupate in the leaves of the undergrowth 

 below, or, in the absence of suitable undergrowth, in the dead leaves 

 lying on the ground and in the soil. Of course pupa may be occa- 

 sionally found on the leaves of the tree attacked and on dead leaves on 

 the ground, even where there is a thick undergrowth of shrubs below the 

 attacked trees, but such cases appear to be exceptions to the rule. 

 When pupation takes place on the leaves of the attacked trees, the larvae 

 usually leave the higher branches and pupate on the leaves of the lower 

 branches, but occasionally the larva remains in the shelter, near which it 

 has been feeding and pupates there. Fig. XII shows a larval shelter in 

 which pupation occurred. 



40. When the leaves on which the larva feeds are close to the 

 ground, and there is no undergrowth, an unusually large proportion of 

 larvae pupate on the leaves of the attacked plants, and this is still more 

 marked when there are no dead leaves on the ground below. This 

 accounts for the interesting case recorded by Mr. L. S. Osmaston* 

 in which the larvae, which had been attacking young teak transplants 

 in a nursery, pupated in large numbers in the rolled up ends or edges of 

 the teak leaves. The plants were only 6 inches high, there was no 

 undergrowth of herbs, and there were no dead leaves on the ground. 



41. It will then be noticed that pupation may take place on the 

 leaves, either dead or green, of many different plants and consequently the 

 shelter, which the larva makes to hold the cocoon in which it pupates, 

 exhibits great variety in shape and mode of construction. In dead 

 leaves, depressions and hollows caused by the drying of the leaves usually 

 exist which, with a little manipulation on the part of the larva, form 

 suitable shelters, while on green leaves such cavities are scarce. Again, 

 green leaves have to be treated differently according to their texture,, 

 coriaceous leaves cannot be folded so easily as soft flexible leaves, and 

 so on. 



42. When pupation takes place on leaves, the pupal shelter may be 

 made in any of the following ways : — 



(1) The tip of the leaf is pulled down and the leaf folded trans- 

 versely to its length — pupation taking place inside the fold, . 

 Fig. XXIV illustrates this. 



* Vide Indian Forester, Vol. XXVI, p. 516. 

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