284 



Pettey (F. \V.). The Fruit-shed in relation to the Control of the 

 Codling Moth. — S. African Jl. Sci.. Johannesburg, xvi, no. 3, 

 October-December 1919, pp. 193-195. [Received 11th May 1920.] 



Large numbers of the larvae of Cydia pomonella are brought into 

 fruit-sheds with the pears and apples that are stored there and are able 

 to leave the infested fruit and seek shelter in the cracks and crevices, 

 where they make their cocoons, hibernate, and develop into moths 

 which emerge in the spring. Fumigation with hydrocyanic acid or 

 sulphur is not likely to give satisfactory results ; in the cold weather 

 the gas will not penetrate small openings, and the respiration of the 

 hibernating insect is very slight, while the construction of the sheds 

 often makes fumigation impossible. 



If the sheds are so constructed that they can be kept j^erfectly 

 closed against the exit of moths till the end of the fruit season this 

 affords the best method of control ; but if they are not so constructed, 

 they should be left as open as possible, so that the moths may emerge 

 at the same time as those outside. If on the other hand the sheds are 

 kept partly closed, the majority of moths will emerge about six weeks 

 latsr than those outside and the larvae hatching from their eggs will 

 b? difficult to control ; firstly, because the spray applications will not 

 have been timed to destroy them, and, secondly, because the later 

 the eggs hatch the greater will be the number of larvae that attempt 

 to enter the sides of the fruit, where they are harder to poison than in 

 the calyx cup. 



The sorting and temporary placing of the infested fruit of the |)acking 

 house in shallow ])ens with no cracks in the floor or sides, and surrounded 

 by strips of hessian or loose boards full of crevices so arranged as to 

 attract the larvae to make cocoons where they may be collected and 

 destroyed, might be of advantage. During the winter all cracks and 

 corners in open houses should be examined thoroughly, and all cocoons 

 found should be crushed or destroved. 



Pettey (F. W.). Insect Enemies of the Codling Moth in South 

 Africa and their Relation to its Control. — ^'. African Jl. Sci., 

 Johannesburg, xvi, no. 3, October-December 1919, pp. 239-257, 

 8 tables. 



A full account is given of the Chalcid. Trichograniniatoidea lutea, 

 Oir., which is considered to prevent the hatching of 50 per cent, of eggs 

 of the later broods of Cydia pomonella [R.A.E., A, vi, 324]. Other 

 Hymenopterous parasites attacking the larvae are the Ichneumonids, 

 Piinpla heliophila, Cam., and Trichomona cariniventris, Cam. 



Of predaceous insects the Argentine ant, Iridomyrmex humilis, is 

 of considerable importance in localities where it is numerous, but it is 

 inadvisable to encourage its increase as in many respects it is harmful, 

 directly or indirectly, to the fruit grower. Other predators are a 

 cricket, Liogryllus bimaodatas, Del^.. the Reduviids, Coranus papillosus 

 and Pirates sp. : a Pentatomid, Diploxys hastata. F. : a C^arabid. 

 Chlaenius dichrous, Wied.. and the ant, Dorylus helvolus, L. 



These enemies of the codling moth however cannot be relied upon 

 to control it, chiefly because they begin to be active too late in the 



