58 BRITISH GALLS 
resulting from the presence of the larvae of this well-known 
insect. 
In all the galls so far alluded to in this chapter the burrow 
remains open, and provides an easy exit for the imago ; such 
is the rule with lepidopterous galls. There is an exception to 
the rule which I may be pardoned for alluding to, though it 
concerns an African moth, because of its interest. Oecocecis 
guyonella (Tineidae) deposits its eggs in Limoniastmm guyoni- 
anum , a plant that is the favourite food of camels on the 
deserts to the south of Algeria. This plant is frequently 
covered with sand. The gall completely encapsules the 
larva, a feature usually seen in dipterous galls. I am not 
aware of a similar record. This observation was recorded 
by Gudnee many years ago.* The advantage of the sealed 
cavity is obvious. 
Economic Notes 
There are no very troublesome pests amongst lepidopter¬ 
ous gall-causers. Rhyacionia resinella is the chief British 
example. By destroying the terminal bud of young Scotch 
Pines it retards the growth of the tree, and where it occurs 
in abundance, as it does in a few localities in Scotland, it is 
becoming a serious pest. The only way to keep it in check 
is to cut off and burn the galls during the second year. 
The larvae of Dioryctia splendidella and Laspyvesia cosmo- 
phorana may affect seriously the Scotch Pine when present 
in numbers. In these, as in the case of R. resinella, the 
mouth of the burrow is marked by a lump of resinous 
exudation. In all there is usually slight hypertrophy of the 
twig at the attacked part, which feature only, justifies their 
inclusion in this chapter. 
* Ann. Sac. Ent. France (4}, x., 1S70. 
