576 Mr Brindley, Further notes on the 



Further notes on the procession of Gnethocampa pinivora. By 

 H. H. Beindley, M.A., St John's College. 



[Bead 6 June 1910.] 

 [Plates XIII, XIV.] 



In October 1906 I described to the Philosophical Society 

 some observations made at Arcachon in the previous April on 

 the processional habit of the larvae of the Eupterotid moth 

 Gnethocampa pinivora (Proc. Gamb. Phil. Soc, 1907, XIV. Pt. I. 

 p. 97). In this paper I referred to the work already published 

 on the subject from the pioneer observations of Reaumur in 1736 

 to the account of the life history of the moth given by Fabre 

 in 1898 (Souvenirs Entomologiques, Serie VI.), which is our chief 

 source of information. It is unfortunate that this work, so 

 delightful for its literary beauty, often fails the reader in 

 exactness and statistical detail. The moth lives entirely among 

 the pines of the Landes (where the tree is chiefly Pinus pinaster) 

 and other districts of southern France. The eggs are deposited 

 in cylindrical clusters on the young leaves of the pine, hatching 

 occurs in September and the offspring of one parent construct 

 a silk nest in the branches. Feeding and enlargement of the nest 

 take place during the winter months, and on warm days in late 

 March and early April excursions are made in procession from the 

 nest tree over the sand. Burrowing for pupation concludes the 

 last procession. The images appear in August and live only 

 a short time, how long exactly is still uncertain, but Fabre's 

 account indicates that the eggs are laid a few days after the adult 

 stage is reached. The procession is in single file and each larva 

 secretes a thread which Fabre holds to be the guide for return to 

 the nest tree. 



The accounts of Reaumur, Ratzeburg (1840), and Fabre and 

 my own observations in 1906 left certain points about the 

 procession in doubt, and last year Mr T. G. Edwards of Emmanuel 

 College, at my suggestion, went to Arcachon and examined many 

 processions between March 18th and 31st. His observations are 

 recorded in the Proceedings, 1910, xv. Pt. v. p. 483. I visited 

 Arcachon again from March 29th to April 5th of the present year, 

 but was unfortunate in the weather, for it was unusually cold for 

 the region in April, two days presenting the exceptional event of 

 snow squalls, which kept the larvae in their nests. On no day 

 could I discover any processions in the woods, though, except 

 on the coldest days, larvae were to be found on the march in the 

 Allee de Turenne, which is a sheltered road of villas in gardens 



