233 



pupal stages, while larvae emerging in October passed less than half 

 this time in the two stages ; through November these periods were 

 still further reduced. Pupae collected in June matured in a minimum 

 of 20 to 28 da3^s ; in September this period was reduced to a minimum 

 of 10 to 14 days. From this it may be assumed that the larval periods 

 during the same time were at least 60 to 80 days and 30 to 40 days, 

 respectively. The average full life-cycle from eggs laid in June was 

 120 days ; in September, 62-63 days ; in October, 48-59 days ; and in 

 November, 31-33 days (one observation only). During the winter 

 months the rate of mortality amongst newly emerged adults was 

 very high. 



A predacious beetle {Plaesius javanus) has been obtained from Java 

 and liberated, but as the life-cycle of this Histerid is long, no conclusions 

 can be arrived at for some time. No indigenous parasites have been 

 found other than those mentioned in the first Report [R.A.E., A, ix, 

 •616]. Further observations have failed to show any difference in the 

 relative frequency of attack or relative degree of damage to different 

 varieties of banana plants by C. sordidiis, neither have they shown 

 that the presence of disease in a plant influences the selection of the 

 site for oviposition. 



The best baits with the corms are obtained by splitting the corm so 

 as to include a smah portion of the base of the stem, as these present a 

 moister surface for a longer time than those composed of the heart of 

 the corm. Experiments have been undertaken with poisoned baits, 

 but no conclusions are yet available. The weevil should be prevented 

 from breeding by the destruction of breeding-grounds and harbourage, 

 and all beetles should be trapped as soon after emergence as possible. 



Bogdanov-Katkov (N. N.). KanycTHafl Tnn m Mepbi BopbSbi c 

 Hen. [Cabbage Aphis and its Control.] — BcepocCMMCKMM Coi03 

 CenbCKO-Xo3flMCTBeHHOM KoonepauMM ("CenbCKOcowa"). [All 

 Russian Union of Rural-Economic Co-operation], Petcrshun^, 1922, 

 20 pp., 14 figs., 1 plate. [Received 14th March 1922.] 



During 1919-21 the cabbage aphis, Brevicoryne [Aphis] brassicae, 

 L., became one of the chief pests of Cruciferous plants in Russia. 

 Its life-history and remedial measures for it are described [R.A.E., 

 A, ix, 552]. In addition to those already mentioned, instructions are 

 also given for the preparation of quassia sprays. 



CoELHo DE SouzA (W. D.). Servigo de Expurgo pelo Processo de 



" Ar Quente." [Disinfestation [of Cotton Seed] by the " Hot Air " 

 Process.] — Bol. Minist. Agric, Ind. & Cofnm., Rio de Janeiro, x, 

 no. 1, January-February 1921, pp. 27-44, 3 plates. [Received 

 4th March 1922.] 



This report describes a hot air machine for disinfecting cotton seed 

 infested with the pink bollworm, Platyedra [Gelechic^ gossypiella, 

 Saund. The essential part of the apparatus consists of five discs 

 placed one above the other and rotated by a vertical shaft passing 

 through them. The seed passes from a hopper to the uppermost 

 disc, where it is spread out and then delivered to the one beneath. 

 This and the three lower ones, to which the seed passes in succession, 

 are fitted with rollers that ensure a thin, even layer. Suitable 

 mechanism causes the seed to fall at the periphery of some discs and 



(6239) o 



