440 



d'Emmerez de Charmoy (D.). Moth-Borers affecting Sugar-Cane in 



Mauritius. — Dep. Agric. Mauritius, Port Louis, Scient. Series. 

 Bull. no. 5, October 1916, 27 pp., 6 plates. [Received 26th July 

 1917.] 



The borers affecting sugar-cane in Mauritius include the Noctuid, 

 SesamiO' vuteria, Stoll (pink borer), which is distributed throughout 

 the Island and is particularly abundant where certain graminaceous 

 weeds are prevalent ; these should always be buried after weeding 

 and not left exposed to the borer. The eggs are laid beneath the 

 leaf-sheaths of these weeds and here the larvae tunnel into the stems 

 and do not attack the sugar-canes until a later stage of development. 

 The best remedy is to keep the fields free from weeds, but other 

 methods suggested are cutting out the borers at the first sign of 

 infestation, rotation of crops and growing of catch-crops, such as 

 tomatoes, potatoes and Canavalia beans between the rows, or the 

 planting of trap-crops such as maize. Straw-burning is not recom- 

 mended. The Pyralid, Diatraea venosaia (saccJiaripkaga, Bojer) is a 

 less serious pest. Eggs are laid on various parts of the plant and the 

 tunnels made by the larvae considerably weaken the canes. Means 

 of control are the same as those suggested for the pink borer ; cutting 

 out of the borer should be practised in virgin canes during the summer, 

 when the insect is most abundant. Natural enemies common to both 

 these species are Telenomus sp., TricJiogramma mtstralicum, Henico- 

 sjyilus mauritii and H. antmicarus, all of which are described. 



The Tortricid, Argyroploce schistaceana (white borer), oviposits on 

 the blade or sheath, the young larva crawling down and entering the 

 undergroimd portion of the shoot, whence it constructs an ascending 

 spiral gallery to the heart and then tunnels do\vnwards again to the 

 outside where the cocoon is spun. The borer should be cut out by 

 severing the shoot as near as possible to its point of attachment to the 

 stool. This should be done once a week as long as infection lasts, and 

 the cut-out shoots should be at once burned or buried. Trichogramma 

 australicum parasitises the eggs of the borer. 



The Tineid, Ahicita sacchari (brown borer), is frequently found in 

 galleries abandoned by other borers, and is very injurious in young 

 plantations reared from cuttings that have begun to ferment. Cuttings 

 so affected should either be discarded or they may be soaked in a 

 kerosene and soap emulsion for 24 hours before planting. 



The larvae of Diatraea venosata are attacked by Apanteles simplicis, 

 Vier. A Tachinid fly is occasionally known to parasitise the cocoons, 

 which are attacked also by various mites. Several predators are 

 useful auxiliaries in control, such as ants, musk-rats, tenrecs, 

 partridges, minahs and hzards. The big lizard, Galeote versicolor, was 

 imported from Reunion, where it is considered an efficient enemy of 

 the borer. 



Lima (A. da Costa), Consideracoes sobre a Campanha contra a Formiga 



Sauva. [Note on the Campaign against Atta sexdens, L.] — 

 A Lavoura, Rio de Janeiro, xxi, no. 2-4, Februarv- April 1917, 

 pp. 3-8, 3 figs. [Received 1st August 1917.] 



Clayton gas and liquid sulphurous anhydride have proved useful 

 against the leaf-cutting ant, Atta sexdens, L. The author condemns 



