503 



King (H. H.). The Migratory Locust {Schistocerca peregrina, Oliv.). — 

 Wellcome Trop. Res. Lab., Khartoum, Ent. Bull. 12, July 1921, 

 14 pp., 7 figs. 



Schistocerca peregrina, 01., is one of the most destructive 

 insect pests in the Anglo-Egyptian Sudan, although during the last 

 few years it has been less abundant than usual. As a series of years in 

 which locusts are relatively scarce may be followed by a series in 

 which they are extremely abundant, every precaution should be taken 

 to prevent an outbreak. It is essential that the Government should 

 organise some definite scheme of control, and this, to be effective, 

 must be supported by the co-operation of the people living in the 

 districts liable to be affected. This necessitates a knowledge of the 

 hfe-history and habits of the locust, the facts of which are briefly 

 sketched with suggestions for control [R.A.E., A, ii, 94; iii, 461]. 

 A brief outhne is also given for the organisation of general remedial 

 measures. 



The natural enemies of S. peregrina include various birds, the larvae 

 of the Muscid flies, Stomatorrhina liinata, F., and Sarcophaga sp., and 

 at least one species of Cantharid beetle. The value of Coccobacillus 

 acridiornm is extremely limited under local conditions. 



Control would be greatly facilitated if it were known what happens 

 to the locusts when they leave the Sudan, whether they breed in the 

 Libyan desert and perhaps return to it, and whether they breed during 

 the -winter. Further questions requiring elucidation are : whether 

 Schistocerca peregrina ever oviposits in dry soil, the eggs retaining their 

 vitality until the rains begin ; whether there are certain definite areas 

 to which the locusts return each year for oviposition ; what distance 

 the hoppers can travel during their 40 to 50 days of development ; 

 and how long after acquiring wings do they remain pink. 



The Locust. — Wellcome Trop. Res. Lab., Khartoum, Ent. Bull 

 15, 1st June 1921, 1 p., 7 figs. 



The life-history of the locust [Schistocerca peregrina^ is briefly 

 described and illustrated. The discovery of any of its stages should 

 at once be reported to the authorities. 



Mazzaccara (G.). La CoccinigHa del Gelso. [The Mulberry Scale.] 

 — Allevamenti, Palermo, ii, no. 8, 1st August 1921, pp. 237-238. 



The life-history and morphology of the mulberry scale, Diaspis 

 pentagona, are briefly described. In winter the branches may be 

 brushed with wire brushes, but a better result is obtained by 

 spraying. The following formula is required in Ital}-' by law : 

 Heavy tar oil (specific gravity 1,052) 91b., pure Solvay "sodium 

 carbonate 4-J- lb., and water 10 gals. This must be prepared only a 

 short time before use. Natural control, based on the use of Pros- 

 paltella berlesei, Rhizobius lophantae, and other predaceous and 

 parasitic enemies, has given very gratifying results, but artificial 

 measures should not be entirely abandoned, and it is well to spray 

 with a 2 per cent, solution of tobacco extract any larvae that may 

 be observed. 



