The Scottish Naturalist. J 17 



BALANINUS BJtASSIOE Fab. 



This is the commonest species found in the galls of N. galli- 

 cola. It is also found, but very rarely, in those of N.pedunculi. 

 I was not able to observe the manner of oviposition, or the 

 eggs, but have found the larvae when they could not have been 

 more than a day or two out of them. They were then per- 

 fectly white, and the fuscous colour of the head was not so 

 conspicuous as it was when they were of a more mature age. 



When full-fed the larva is about 1^ lines in length ; the 

 head is narrower than the body, and is of a fuscous colour, with 

 the mandibles, which are well developed, of a darker hue. It 

 has neither legs nor claspers, but the segments, especially the 

 anterior, are very prominent, and by their aid they manage to 

 progress at a smart pace when ejected from their nidus ; the 

 colour of the body is of a shining pale-yellow. In form it is 

 somewhat cylindrical, stout and flat-looking, with the segments 

 decreasing a little in width towards the anus • a few hairs are 

 scattered over the body. 



The weevils devour the contents of the galls like the saw-fly 

 larvae, and have a peculiar energetic way of jerking the head 

 in feeding or walking. Usually only one larva is found in a 

 gall, but occasionally two, three, and in one instance four, were 

 found living harmoniously together. After they have become 

 full-fed, they eat a round hole in the side of the gall, and drop 

 to the ground, to pass into the pupa state. In the breeding jar 

 they moved restlessly about for two or three days before bury- 

 ing themselves in the earth, and a number which happened to 

 be ejected from the galls before being full fed, completely 

 riddled some willow leaves which were in the jar. Mr. M tiller 

 records'" the interesting fact, that they drop to the ground by 

 means of a silken thread, but this does not appear to be always 

 the case. 



The galls which have been tenanted by the weevils may be 

 easily recognised by the round hole in the side — the saw-fly 

 larva escapes by a hole at one end — and by the smallness of 

 the pellets of frass. 



Six or seven clays after having entered the earth, they cast 

 oft' the larval skin and enter the third stage of tlieir existence. 



* Ent. Mo. Mag., vol. ix. p. 192, and vi.' p. 137. 



