491 



are probably quite safe, as are larger quantities if sealed in tin boxes, 

 but the danger of re-infestation after treatment is too great in the 

 case of very large consignments. 



Bodkin (Gr. E.)- An Invasion of British Guiana by Locusts in 1917. 



Cleare (L. D.). With a complete Illustrated Account of the Life- 

 history of the Species. — Bull. Entom. Research, London, ix, no. 4, 

 July 1919, pp. 341-357, 8 figs. 



An accoimt of the invasion of locusts in British Guiana from 

 Venezuela in 1917 has already been noticed [see this Review, Ser. A, 

 vi, p. 335]. The species in question has not been definitely determined. 

 In appearance the locusts were similar to specimens of migratory 

 locusts that visited Trinidad and were identified as Schistocerca 

 paranensis. Specimens from British Guiana were however identified 

 in London as S. vicaria, Wlk., and in the United Stated as S. ainericana, 

 Drury. It is thought that the darker individuals agree with 

 S. jyiceifrons, Wlk., and that the type of S. vicaria may be merely a pale 

 form of that species. S. piceifrons may be only a northern representa- 

 tive of S. paranensis but presents some constant differences. 



A sketch-map shows the area on the north-west coast infested by 

 the swarm. A full account is given of the life-history of the insects, 

 with a description of the various stages. The campaign of 1917 

 proved that the previously described mechanical methods of control 

 [lac. cit.], combined with a judicious administration of the Plant 

 Diseases and Pests (Prevention) Ordinance, were adequate to deal 

 with such an invasion. Tarpaulin sheets smeared with molasses, 

 when used under favourable conditions, gave better results than any 

 other method. The destruction of eggs, when practised on a large 

 scale, gave excellent results, but was not widely utilised, as farmers had 

 scarcely begun to reaUse the gravity of the situation before the eggs 

 had already hatched. A httle experience was necessary to discover the 

 hkely spots for the deposition of eggs ; when they were located it was 

 only necessary to fork up the soil to the depth of a few inches to 

 secure the egg-masses. A figure is given of Scelio venezuelensis, Marsh., 

 a parasite of the eggs of Schistocerca. 



Entomology. — Arkansas Univ. Agric. Expt. Sta., Fayetteville, Bull, 

 no. 158, December 1918, pp. 45-49. [Received 12th September 

 1919.] 



The work of the year included experiments to prevent the round- 

 headed apple-tree borer [Saperda Candida] from depositing eggs in 

 the trees, for which purpose a mixture of asphaltum and raw linseed 

 oil was found to be the most successful. Worming the trees in August 

 and April and spraying so as to poison the adults are also recommended. 



Experiments were also carried out against the peach-tree borer 

 [Aegeria exitiosa] [see this Revieiv, Ser. A, vi, p. 448] and the wooUy 

 aphis [Eriosoma lanigerum] in the Ozarks \loc. cit., p. 311]. 



Further investigations are being made with regard to the lesser 

 apple worm [Enarmonia prunivora], codling moth [Cydia pomonella] 

 and other apple pests. Damage to crops reported in July was probably 

 due to the fall army worm [Laphygnm fncgiperda] or the grass vrorni ; 

 the latter was seriously injurious to rice. A serious outbreak of 



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