TORTRIX RESINELLA. 



339 



Other species of pine, such as the Weymouth pine and Pinus 

 ponderosa, Dougl., are liable to attack. The insect is less 

 common than the preceding. 



c. Remedial Measures. 



The injured buds, which can 



be recognised by their small 



size and dark colour, should be 



cut off towards the end of April. 



5. Tortrix (Retinia) resinella, L. 

 a. Description. 



Moth with a wing-expanse of 

 16 to 18 mm. ; fore-wings slaty- 

 grey with numerous shining 

 leaden - grey transverse lines 

 forked on the fore-margin ; 

 hind - wings grey - brown ; the 

 fringes pale. Body slaty-grey. 



Caterpillar 11 mm. or more 

 in length, with 16 legs, orange- 

 brown, with brownish-red head 

 and thoracic shield. 



b. Life-history. 



The eggs are laid in May and 

 June, just under the whorl of 

 buds of the recently - grown 

 shoots of young pines, usually 

 on the lateral shoots. The 

 caterpillar bores into the pith 

 and thus causes the growth of 



a hollow gall-like resinous mass, as large as a pea, in which it 

 passes the winter. In the spring it continues feeding, causing 

 the gall to increase to the size of a cherry or of a small 

 walnut, and form a swelling on the underside of the shoot 

 which encircles two-thirds of it. On section the gall is seen 

 to be divided into two compartments by a strong vertical 

 partition. In the larger one the larva lives and pupates (in 



z2 



Fig. 174. Eesiu-gall of T. rest- 

 nella, L., on a pine shoot. 

 (Natural size.") 



