THE LARVAL HAP.ITS OF DIORYCTRIA ARIETELLA. 41 



Drepana lacertinaria , L. Both imago and larva beaten freely 

 from birch at Kippen and Forres. 



D.falcula, L. Very typical imagines from birch on Strensall 

 Common, Yorkshire, and Chopwell Woods, Dm-ham ; fine whitish 

 forms beaten from birch both as larvae and the perfect insect at 

 Kippen, Stirling, and Forres. 



Zoological Dept., 

 Armstrong College, 

 Newcastle-on-Tyne. 



THE LARVAL HABITS OF DIORYCTRIA ABIETELLA. 



By Robert Adkin, F.E.S. 



In view of Major Smart's remarks on this species (antea, 

 p. 21\ it may not be out of place to relate my own experiences, 

 which, although by no means extensive, may help to tbrow some 

 light on a much-debated subject. On May 15th, 188G, a friend 

 and-I were collecting pine-shoots for Retinea \a,vy<G at Oxshott, 

 Surrey, when my friend met with what appeared to be the dead 

 shoot of the previous year's growth ; the buds that should have 

 made their present year's shoots were brown and dry, and 

 surrounded by a good deal of resinous exudation — no doubt pro- 

 duced by a Retiuea larva that had fed there in the year before. 

 But, as it evidently contained a larva of some sort, it was taken, 

 and eventually produced a fine D. abietella. The tree was a small 

 Piniis sylvestris not more than some four feet high, and the 

 shoot was the leading one. Again, on March 18th and May 15th, 

 1891, I received a number of shoots of Pinus sylvestris from 

 Forres containing larvae of Retinea resinella in their conspicuous 

 resinous nodules ; the pine -shoots, all of which were of a 

 previous year's growth, were stuck in damp sand in a large 

 flower-pot and covered with fine net. On June 14th I noticed 

 some fresh reddish-coloured frass protruding from a hole in the 

 side of one of the shoots, and further examination proved that 

 several of them were similarly affected. The resinella had all 

 long since pupated, and the majority of the moths had emerged ; 

 it was therefore clear that I had here some other species feeding, 

 not in or about the nodule, but in the hard, dry twig some 

 distance below it. A few days later one of these larvae was seen 

 to be spinning a cocoon just between the top of one of the 

 resinous nodules and the bark of the twig, apparently having 

 found its way up through the old workings of the resinella 

 larvae, and between July 17th and 26th six fine D. abietella 

 emerged from similar positions. Although in both the cases 

 mentioned resinous excrescences were present, I am quite clear, 

 from observations made and noted at the time, that the aJjietella 



ENTOM. FEBRUARY, 1919. E 



