195 



Shakutori-mushi no Higai-Kiji no Zemmetsu shitaru kekkwa. [Out- 

 break of Looper Caterpillars due to Extinction of the Pheasant. ] — 

 Ryokai Jiho [Shooting News], Tokyo, ii, no. 1, 28th January 

 1920, pp. 33-34. 



The pheasant is a bird generally considered to be very injurious to 

 crops in Japan. In the Kodama District, Saitama Prefecture, how- 

 ever, where formerly pheasants were numerous but have now entirely 

 disappeared, looper caterpillars have occurred in abundance in 

 mulberry plantations and have done considerable damage. 



KiTAJiMA (Y.). Fusanranga oyobi Shosusanranga ni Kwansuru 

 Kenkyu. [Studies in Sterility and reduced Oviposition in Silk- 

 worms.] — Sangyo Shimpo [Jo^rrnal of the Silk Industry], Tokyo, 

 xxviii, no. 32l7lst December 1919, pp. 1165-1176,6 figs. ; no. 323, 

 1st February 1920, pp. 112-119. 



Absolutely sterile moths occur very rarely among silkworms, and 

 the author only found 5 such individuals out of 2389 moths. Such 

 examples usually occur among hybrids between the Japanese and 

 European races. They contain as many eggs as normal ones, but their 

 genital system is usually deformed, the principal cause being mostly 

 due to mechanical injuries in the pupal stage. Another type of 

 sterile moth is one that does not oviposit after pairing on the day 

 of emergence ; but such an individual may do so if pairing is repeated 

 with a sound male on the following day. Individuals of this type are 

 common in hybrids and less so in the native races. A third type 

 is one that produces but few eggs, and examples of this occur in both 

 native and European races. Many individuals of this type lay 

 unfertihsed eggs, and the phenomenon is therefore probably due 

 mainly to sterility in the male. 



Sillvworm diseases seem to have no relation at all to abnormal 

 oviposition. Methods of rearing may have some influence, since 

 abnormalities are not uncommon amongst individuals fed on soft 

 mulberry leaves. The compelling of silkworms into spinning cocoons 

 of a definite shape which may deform the abdomen of the pupa may 

 also be a factor in causing sterility. 



KiTAjiMA (Y.). Sanran ni Kwansuru Kenkyu. [Studies on the 

 Silkworm Egg.] — Dainihon Sanshikivaiho. [Rejjort of the Japan 

 Sericultiiral Society], Tokyo, xxix, no. 337, 1st Februarv 1920, 

 pp. 98-103. 



In investigations on the relation between the condition of sillcworm 

 eggs and the situation of the pupa, 55 out of 222 moths from erect 

 pupae, 56 of 447 from obliquely situated pupae, and 19 out of 197 

 from horizontal pupae laid their eggs badly, i.e., the eggs are placed 

 obhquely; erect or in a heap. From this result pupae in erect positions 

 seem to give rise to bad oviposition. The same phenomenon is 

 observable in moths that emerge from pupae the abdominal end of 

 which is compressed or deformed. When the deformation is very 

 marked the eggs are also usually fewer in number. This is especially 

 the case in moths of the summer brood. No relation seems to exist 

 between the weight of pupae and bad oviposition. The author has 



