574 



general biology, relation to cinnate, spread, and food-plants. Its 

 enemies include a midge {Diplosis sp.), a Chalcid. a Coccinellid 

 {Scymnus sp.) and the Lycaenid, Spal^jis epius. In some cases 

 P. crotcnis undoubtedly causes slight injury to cacao, but its presence 

 should be encouraged in cacao plantations in view of the protection 

 it affords against Helopeliis and to a lesser degree against Acrocercops 

 cramereJla. This supplement concludes with notes on the physiology 

 of the sucking of this scale. 



Shiraki (T.). Paddy Borer, Schoenobius incertellus, Wlk. — Agric. 

 Expt. Sta. Government of Fwmosa, Taihoku, 1917, 256 pp., 1 map, 

 22 pi. 



This elaborate and detailed monograph deals exhaustively with 

 ScJwenobius incertellus, Wlk., the Pyralid moth boring in rice, which, 

 owing to the great difference between the sexes, has been redescribed 

 on more than one occasion, S. bipunctifer, Hmps., being the female, 

 and other synonyms being S. punctellus, Z., and S. minutellus, Z. 



The insect has a wdde range throughout India, Ceylon, China, Japan 

 and the islands of the Malay Archipelago, occurring widely in lowland 

 districts on cultivated rice, while it is absent from the highland areas 

 and apparently does not attack wild plants, except in Burma, where 

 it feeds on wheat and grasses. In Ceylon, which appears to be its 

 original home, it is not known to attack rice, and its food-plant there 

 is still unknowii. In Formosa and Japan it is an important pest, 

 being more widely distributed and destructive than in India and the 

 Philippines. 



The moth, which is nocturnal, oviposits between 6 and 10 p.m. 

 during the spring, summer and autumn months, the long, elliptical 

 egg-clusters being laid near the tip of the leaf. The egg hatches in 

 6 or 7 days ; in Japan this period is lengthened from 8 to 10 or 15 

 days. Immense numbers are destroyed by the mechanical action of 

 rain storms, which remove the clusters from the plants, and although 

 these may hatch, the larvae die through being unable to find their host- 

 plant. The eggs are parasitised by three small Hymenoptera, viz. : — 

 TricJwgramma joponicuvi, Ashm., which destroys about 23 per cent., 

 but is unfortunately preyed uj)on by dragon-flies, spiders, and the 

 Staphylinid beetle, Paederus idae ; Phanurus {Ceraphron) beneficiens, 

 Zehnt., which also attacks the eggs of Chilo simjjlex and Diatraea 

 venosata. Walk, (sugar-cane Pyralid) during the winter ; and by 

 Tetrastichus sp. One of the most important insect checks is the 

 predaceous ant, Pheidole noda. Smith. 



The larvae, of which the majority die immediately after hatching, 

 moult four times during a larval period of about three weeks. The 

 newly-hatched larvae bore into the young stems, the lower part of 

 which they reach in from three to five days. After a week they leave 

 the stems, and having made for themselves cylindrical cases from the 

 rolled up leaf tips, they drift in them on the irrigation water in search 

 of a fresh host-plant. This found, the larva enters the basal part of 

 the stem, where it pupates after spinning a protective covering over 

 the spot.' 



These larvae do the greatest amount of injury during the period 

 before the shooting of tho ears. 'They are parasitised by the 



