401 



larger roots, a wash should be applied. This is prepared by dissolving 

 10 lb. copper sulphate in 6 gals, water. Another 6 gals, water is 

 poured on to 20 lb. lime, and when this has cooled, the two are 

 combined, and to the mixture is added | lb. sodium arsenate or 

 li lb. lead arsenate. 



Kankitsu gaichu Rubii-Romushi. [The Ruby Wax-scale, an Insect 

 injurious to Citrus.] — Shizuoka Agric. Expt. Sta., 28th February 

 1918, 17 pp., 2 plates. [Received 7th August 1918.] 



Ceroplastes rubens, Mask., is a formidable pest of citrus plants in 

 Japan, as also are Chionaspis citri, Comst., and Icerya purchasi, Mask. 

 It was first recorded in 1885 in the Prefecture of Nagasaki and was 

 afterwards imported into the Prefecture of Shizuoka in 1907 on 

 citrus seedlings, and is now infesting several districts. This scale 

 has only one brood. The over-wintered female begins to oviposit 

 at the end of Jxme and continues to do so until the end of July. The 

 male appears at the beginning or the middle of September, when 

 pairing takes place, only the female surviving the winter. The average 

 number of eggs laid is 978. In starvation experiments, 74 per cent, 

 of the insects survived for over two months. This scale is not only 

 harmful in itself, but often gives rise to a sooty fungus on the trees. 



As regards preventive measures, fumigation in winter with hydro- 

 cyanic gas, using 200 grammes of potassium cyanide for over 45 

 minutes, is most effective ; kerosene or resin emulsions are not satis- 

 factory at this time. In summer, however, resin emulsion, if applied 

 at least tmce, first in the middle of July and secondly at the beginning 

 or the middle of August, may be very effective. When new infestations 

 are discovered, the scales should be crushed and the infested portions 

 of the plants removed at the first opportunity. When citrus seedlings 

 are purchased, they should carefully be examined and fumigated. 



Ojima (G). Meichu Rankiseiho Hogoyo no Ekichu Hogoki. [An 



Apparatus for the Preservation of Hymenopterous Egg-Parasites 

 of the Rice-plant Borer.] — Bi/ochugai Zashi [Journal of Plant 

 Protection], Tokyo, v, no. 3, March 1918, pp. 10-11, 2 figs. 



The apparatus here described consists of an inverted cone, about 

 1 foot high and 3 inches in diameter at the top. When in use, the 

 pointed end is buried in the soil. The cone is made of zinc and is 

 closed at the top with a hinged lid, which is provided with a handle. 

 Between the lid and the edge of the cone is a narrow slit on one side 

 to permit the exit of the parasites. Inside the cone and 1^ inches 

 from the top is a small trough containing petroleum, which prevents 

 the exit of the caterpillars of the host that may have escaped 

 parasitism. About 1| inches from the bottom of the cone is a wire 

 septum on which the egg-clusters lie. 



These cones are distributed throughout the rice fields and parasitised 

 egg-clusters are put into them, each containing about 400 individuals. 

 Any borers that hatch from them are caught in the petroleum, while 

 the parasites escape through the slit already mentioned, and infest 

 other egg- clusters in the field. 



(C496) c 



