NOTES ON SILK-PRODUCJNG BOMBYCES. 129 



unsuccessful owing to various causes, others have not sent the 

 results of their experiments. 



With respect to ni}' own experiments, the species which I had 

 in the open air, A. yama-ma'i, A. pernyi, and roylei-iiernyi, were 

 entirely destroyed by the sparrows as above stated, the netting 

 I have over some trees being now entirely rotten. Besides this, 

 having been in Paris during the month of August, I liad to 

 discontinue the rearings in the house at the end of July ; these 

 had gone on in a very satisfactory manner, till most of the larvae 

 were sent to various correspondents. 



Anthercea yama-ma'i, Guerin-Meneville (Japanese oak silk- 

 worm). — This valuable species, which forms a beautiful cocoon, 

 yellow or green, similar in shape to that of Bombyx mori, was, 

 during a certain number of years, cultivated in several European 

 countries. The greatest hopes were entertained respecting 

 the ultimate success and acclimatization of this Japanese silk- 

 worm, which was going to transform our oak leaves into silk. 

 But gradually all these hopes vanished as two great difficulties 

 stood in the way to success : the eggs generally hatched before 

 the breaking out of the oak buds, and the moths, for the most 

 part, refused to pair in captivity. So every year the rearings 

 went on a decreasing instead of an increasing scale, till at last 

 the species disappeared almost entirely. In Spain, however, the 

 rearers of this species had been remarkably successful, and the 

 worms were bred for several years in immense quantities in tlie 

 oak forests on the estates of the Marquis de Riscal, in the 

 province of Caceres, Estremadura. At the Paris International 

 Exhibition, in 1878, large quantities of A. yama-ma'i cocoons 

 were exhibited. Unfortunately, one year, in the month of May, 

 a night frost destroyed the young oak leaves on which the 

 thousands of worms were feeding, and starvation was their 

 fate. After this unexpected disaster, the rearings were entirely 

 abandoned. 



In the meantime, while the A. yama-ma'i was gradually disap- 

 pearing, a formidable rival had made its appearance ; that was 

 Anthercea pernyi (the Chinese oak silkworm), introduced into 

 France, like A. yama-ma'i, by Guerin-Meneville. 



From that time the Chinese A. vernyi was reared in prefer- 

 ence to the Japanese A. yama-mai, the latter being abandoned 

 almost entirely ; and what was the cause of this ? The cocoons 



ENTOM. MAY, 1887. S 



