144 



As regards remedial measures, the removal and burning of injured 

 twigs, the envelopment of the fruit in stout paper bags in June and 

 July and again in August, spraying with Paris green or sodium arsenate, 

 picking infested fruits and clean cultivation, are recommended. 



Harukawa (T.). I no Habachi no Kenkyu (Yoho). [A Study of 

 the Eush Saw-fly (Preliminary Report).] — Byochugai Zasshi 

 [Jourfial of Plant Protection], Tohjo, vii, no. 1, 5th January 1920, 

 pp. 4-15. 



A sawfly infesting rushes [Juncus effusiis), which are used for 

 making mats, ls known to occur in several prefectures in Japan. 

 The insect concerned is believed by Rohwer to be a species of 

 TomostetJivs. 



Judging by breeding experiments, the insect has two generations ; 

 overwintering mature larvae appeared as adults in May and 

 laid eggs which hatched at the end of the month ; the resulting 

 larvae pupated in a cocoon in the earth in the middle of July 

 and emerged at the end of September ; the eggs of this generation 

 hatched at the middle of October and constructed cocoons at the 

 end of November. Observations in the field agree with this result 

 to a great extent, though in nature a few adults are met with at 

 the beginning of July. In breeding cages the females laid 7-57 

 eggs, and lived 4-6 days, and the males 4-10 days. As soon 

 as the adult female emerges, it lays eggs either after or before mating 

 and in either case the egg is fertile. The eggs are inserted singly 

 into the tissue of the rush leaf, and the presence of the young larvae 

 may be detected by a white patch at the infested spot. After 9-15 

 days wathin the leaf-tissue the larva comes to the surface and attacks 

 the leaf externally, the damage it does being easily recognised at a 

 distance by the white colour of the plant. The larva of the June 

 -July generation remains by day at the base, and at night migrates 

 to the tip of the leaf ; in larvae of the October generation this habit is 

 reversed. The larva may be destroyed with poison sprays or with 

 kerosene emulsion and insect powder, and the adults may be easily 

 captured with a net. The destruction of the cocoons in the soil is 

 of importance. Rotation of crops is also recommended. 



Okada (T.). Kankitsu no Shingaichu Mikan no Kuromukugemushi 

 ni tsuite. [On a New Black Thrips attacking Citrus.] — Byochugai 

 Zasshi [Journal of Plant Protection], Tokyo, vii, no. 1. 5th January 

 1920, pp. 23-25, 1 plate. 



This thrips is of recent occurrence as a citrus pest in the Shidzuoka 

 Prefecture, and the infestation is believed to have come from Eurya 

 japonica grown near the orange groves. When first discovered, the 

 navel orange was attacked, but afterwards other varieties of orange 

 as well as tea, mulberry and other trees became infested. The 

 attacked orange fruits not only lose their value for sale, but are 

 unsuitable for preserving. Repeated spraying with kerosene emulsion 

 or pine resin mixture has proved to be efficacious against this pest. 



