321 



Takagi (S.). Kansho no Gaichu, Imohamushi, ni kwansuru Kenkyu. 



[Investigation on the Leaf Beetle attacking the Sweet Potato.] — 

 Byokingaichu-Iho. [Report of Plant Disease and Injurious Insect 

 Research]. Imperial Agricultural Bureau, Tohjo, no. 7, 30th March 

 4920, pp.' 1-7, 1 plate. 

 The Chrysomelid beetle, Chrijsochus sp. {C. chinensis, Baly ?), that 

 attacks the sweet potato has hitherto only occurred in the Miye, 

 Tokushima and Tochiki Prefectures. The adults appear from the end 

 of June to the middle of July, and the eggs hatch about a week after 

 deposition. The larvae pupate from the middle of September to the 

 beginning of June of the next year. The pupal stage usually lasts 

 about two weeks. The egg is usually laid singly just beneath the 

 earth. The beetles are less active at early morning and night, and 

 shelter at the roots of the sweet potato or among wheat. They are 

 active by day and feed on the leaves and stalks. The larvae are very 

 active and bore into the sweet potato tuber and devour the flesh. 

 When mature they pupate in earthen cocoons. Infested sweet potatoes 

 are of a dark green colour along the puncture and the tunnel is filled 

 with excrement. The skin is also superficially attacked. Such tubers 

 are bitter to the taste and smell. By deep ploughing hatching of the 

 eggs may be prevented to some extent. While the larvae are still in 

 the tubers, the latter may be examined for them and the insects killed. 

 The adults may also be captured by putting hay or straw on the fields. 

 Rotation of crops, clean cultivation, trapping the insects etc., are 

 also recommended. 



Harukawa (T.). Nashihimeshinkui (Momoshinorimushi) ni Kwansuru 

 Kenkyu. [Investigation on the Small Pear Borer (Peach Moth).] 

 — Bijokingaicliu-IJio. {Report of Plant Disease and Injurious Insect 

 Research], Imperial Agricultural Bureau, Tokyo, No. 7, March 

 30th 1920, pp. 9-74, 2 plates. 

 This report on Cydia molesta, Busck, forms a supplement to a former 

 one [R.A.E., A, vii, 108]. As regards the life-history many new 

 experiments were made, but it was found to be essentially the same 

 as already described. Regarding remedial measures, capture of the 

 moths may be eftected by making the store-houses dark and collecting 

 the emerging individuals at the windows. Removal of infested peach 

 shoots should be effected in early spring, and newly infested ones 

 only should be cut off ; these can be detected by the withering of the 

 single top leaf of the shoot. Conspicuously withered shoots as a rule 

 do not contain the borer. In cleaning the orchard, rubbish on the 

 ground as well as loose and rough bark of the fruit trees should be 

 carefully removed. Each fruit should be covered with paper. Kero- 

 sene emulsion with insect powder should be sprayed three times, 

 from the middle of July to the end of August. 



Ishiyama (Z.). Rakkwasei no Gaichu, Tobiiro-Zomushi ni kwansuru 

 Chosa. [Investigations on the Weevil, Scepticus insularis, 

 Roelofs, attacking the Peanut]. — Chibaken Naimuhu [Home Divi- 

 sion, Chiba Prefectural Government], April 1920, 8 pp., 1 plate, 

 1 map. 

 The weevil, Scepticus insidaris, Roelofs, that attacks peanuts is 

 spreading to such an extent in the Prefecture of Chiba that at present 

 (632) Wfc.P1850/163. 1,500. 8.20. B. &F.,Ltd. Gp.ll. A 



