332 PROTECTION AGAINST INSECTS. 



Pupation in a cocoon either above or in the ground. Pupa 

 with rows of spines on their backs. The caterpillars attack 

 the buds or shoots, the fruits and seeds, or the needles or 

 leaves of broadleaved or coniferous trees. The characteristic 

 rolling up of leaves is only practised on broadleaved species. 

 Many insects injurious to forests are included in this family. 



1. Halias chlorana, L. (Green Willow Leaf-Roller), 

 a. Description. 



Moth with wing expansion of 20 mm. ; fore-wings and 

 thorax light green, the former with a whitish anterior border; 

 head, hind-wings and abdomen white, the latter sprinkled with 

 greenish-grey scales. 



Caterpillar 15 mm. long, with 16 legs, of a dirty flesh-colour, 

 with a dark dorsal stripe, and a few bristles. Pupa light 

 brown, with rounded head and smooth hinder extremity. 



b. Life-history, etc. 



The eggs are laid in April and May on the terminal buds of 

 young willows, especially on Salix viminalis, L. The solitary 

 caterpillar hinders the development of these buds in May, 

 spinning up the terminal leaves into a bundle which is bent 

 towards one side of the shoot in which it lives ; it feeds from 

 May till July, not only on the leaves, but on the tender young 

 shoots of the osiers. The lengthening of the osiers is thus 

 rendered almost impossible, and a straggling production of 

 side-shoots results. In July the larvae pupate on leaves or 

 shoots, in white boat-shaped cocoons. The rnoth appears 14 

 days after pupation. Neither Hess nor J-udeich are clear 

 about the subsequent life-history, but as osiers are cut down 

 in December, there is probably a second generation, eggs being 

 laid in July, pupation in September and the pupae hibernating 

 near the ground. 



c. Protective Rules. 



Cut off the shoots containing the caterpillars, in May and 

 June and again in August. Each bundle contains only one 

 larva, which should be killed. 



