377 



Dipteron, Leucopis annulipes, Zett., the mite Hemisarcoptes coccistigus, 

 Lign., several pseudoscorpions, Chelifer cancro'ides, L., Chthonius 

 tromhidioides, Latr., etc.) and insectivorous birds, especially blue tits, 

 naturally control scale-insects in France, while the American species, 

 Aspidiotus uvae, Comst., is checked by a mite of the genus Tyro- 

 glyphus. 



Powdering with sulphur or lime, spraying with copper or nicotine 

 solutions during the period of vegetation, and mechanical treatments, 

 such as close pruning, the crushing of the insects, brushing and decorti- 

 cation, are only partly effective against scale-insects, the best results 

 being obtained by the winter use of gaseous or liquid insecticides. 

 The best gases are sulphur dioxide, tobacco smoke and hydrocyanic 

 acid, and the best liquids pure petroleum or petroleum emulsion 

 according to Riley's formula : — petroleum 10 quarts, water 6 quarts, 

 ordinary soap 1 pound, diluted for use with 7 to 10 times its own 

 volume of water. Barsacq's formula is 8 pints of petroleum, Ig pints 

 of 90° alcohol, and 4|- oz. of Panama wood [QuiUaia sapoymria], which 

 must be macerated in the alcohol for several days and then mixed 

 with the petroleum, being stirred all the while. For use, it must be 

 diluted with 10 times its volume of water. Marchal's formula is If 

 pints of petroleum, 2f pints of seed oil, 4 lb. of black soap and 9f pints of 

 water. This mixture may be used as a wash, or as a spray, if diluted 

 vaih. once or twice its owti volume of water. In America the use of 

 badly prepared emulsions is avoided by means of the Kerowater 

 machine, which mixes the petroleum and water in the required 

 proportion. A control measure practised in Gironde is the white- 

 washing of the vine stocks with milk of lime, the application of which 

 has also a mechanical value in dislodging the insects. In Italy, a 

 lime-sulphur wash is largely used, composed of 20 lb. of fat lime, 40 

 lb. of sulphur and 20 gals, of water. Preventive measures must 

 include the inspection of imported stock and fruit products, the 

 fumigation of suspected consignments, and the immediate and 

 complete destruction of locally infested vines. 



GouGH (L. H.). The Rate of Increase of the Pink Boll Worm in Green 

 Bolls in the Period July to November 1916. — Ministry Agric. 

 Egypt, Tech. Sci. Service, Cairo, Entom. Sect. Bull. no. 13, 

 25th November 1916, 26 pp., 13 tables. [Eeceived 28th June 

 1917.] 



Pectinophora {Gelechia) gossypiella was imported into Egypt less 

 than 10 years ago, and its increase has been enormous. The July 

 infestation of 1916 was due to the progeny of moths which had 

 hibernated as larvae, and the increase in numbers continued uniformly, 

 owing to breeding being continuous and unchecked, till the maximum 

 was reached during the third week in September, at which time there 

 were at least 4,500 individuals to each 1,000 cotton plants. This pest 

 now occurs wherever cotton is grown in Egypt ; in the last week of 

 October 87 per cent, of the green bolls in Lower, 78 per cent, in 

 Middle, and 60 per cent, in Upper Egypt were attacked by it. 

 Earias [insulana] (cotton boll worm) appears to have sunk to the 

 position of a minor pest, not only relatively to the pink boll worm, 

 but also absolutely. 



