503 



IsHiKAWA (T.). Ine Nika-Meichu Kujoho to shite Wara-niho 

 Kakiharai ni Kansuru Chosa Kenkyu. [Researches on the Method 

 of Raking Straw-Stacks, as a Control Measure for the Two- 

 brooded Rice Bovev.}-Tokubefsu Hokoku [Special Report], 

 Agric. Expt. Sta., Niigata, 25th July 1918, pp. 48, 2 plates. 



The system of raking the straw-stacks is considered one of the most 

 effective measures for dealing with the serious rice pest, the two- 

 brooded rice-borer (Chilo simplex, Butl), and this report gives a 

 detailed account of its value. It has long been practised amongst 

 farmers of the Kita-Kambara District of the Niigata Prefecture,, and 

 in 1904 it was recognised as very effective by the Prefectural Agri- 

 cultural Experiment Station and is now generally encouraged. To 

 carry it out the rice straw should be stacked as follows : -First the 

 ground should be covered with rice hulls or straw to a depth of five 

 or six inches in circular patches 8 or 9 feet in diameter for protection 

 against wet. Upon this foundation, sheaves are laid round the 

 circumference of the circle with their ; tubble ends directed outwards, 

 the centre being also filled up with other sheaves. This is done to 

 the height of about 5 feet, the whole being held together with ropes 

 and thatched with straw. 



For raking the heap, a special implement is necessary, two kinds 

 of which are described and compared. Before raking the stack, 

 the ground surrounding it should be covered with mats to catch any 

 larvae that drop from it. The work is done by two men, one on each 

 side, who rake the sides of the stack as vigorously as possible, gradually 

 travelling round it and making two complete circuits of it. This 

 method, however, may be almost useless unless it is carried out at 

 the proper season, i.e., when the mature larvae are migrating towards 

 the surface of the stack to pupate, so that the accurate determination 

 of this point is most important. In Niigata, except in special circum- 

 stances, the period in question is from the middle of May to the middle 

 of June, and it has been found from experiments that after 11 a.m. 

 and after 3 p.m. are the best times of the day. The satisfactory 

 results obtained with this method are shown in numerous detailed 

 tables. 



Maki (M.). Boko-cho ni okeru " Kattsau Kua " ni tsukite. [On 



the " Kattsau Kua " of the Pescadores.] — Konchu Sekai [Insect 

 World], Gifu, vol. xx, no. 250, 15th June 1918, pp. 1-8, 1 plate. 



The Capsid bug, Halticus minutus. Rent., which is a noted sweet- 

 potato pest in India, has recently begun to ravage the Pescadores 

 Islands. It chiefly attacks the leaves and stalks of the peanut, sweet- 

 potato, water-melon, cucumber, pumpkin, cabbage, peppermint, 

 Luffa cylindrica, Rhaphanus sativus, Cucumis melo, Brassica campestris, 

 Vigna sinensis, Phaseolus vulgaris, Solammi melongena. Chrysanthemum 

 sinense, Erythrina indica, Ficns retusa, Pachyrhizus angulatus, etc. 

 It appears to have several generations per annum and the adults 

 are present throughout the year. Outbreaks of this pest occur 

 intermittently, the last serious one having been in 1916. Its appearance 

 in large numbers has hitherto been considered to be due to the 

 occurrence of exceptionally wet seasons favourable to its multiphcation. 



