443 



On oranges, eggs are deposited separately, mostly on the rind, some- 

 times on leaves and twigs, and the average number is eight. The 

 Jarvae spin threads over the rind, burrowing into it ultimately, and when 

 mature they emerge and make a cocoon on the ground, or occasionally 

 in sacks or'boxes. The moths fly at night ; experimentally they lived 

 3-5 days in dry conditions and 8-18 days when moisture was supplied. 



There is no hibernation. In September-February the egg period 

 ranged from 9 to 12 days, and in June-August, from 11 to 14 days. 

 In the hot season the pupal stage lasted 30 days, and from August- 

 February, 27-61 days, while in the cold season (May-July) it lasted 

 38-65 days. 



Notes are given on the life-history of this pest in food-plants other 

 than oranges. 



It appears that moisture has considerable effect in controlling this 

 insect, and where heavy rainfall was recorded, the infestation was only 

 slight. Chalcid parasites are found in the eggs of this pest on oranges 

 and guavas. They are not numerous until January and February, only 

 parasitising the eggs of the second generation, and cannot be relied 

 on for control. 



Spraying with 1 J lb. lead arsenate powder to 50 gals, water to destroy 

 the caterpillars before they burrowed into the rind gave good results. 

 The first application should be made before the 15th January, the 

 second three weeks later, and the third in the last week of February. 

 A fourth spray in the middle of March is recommended if the orchard 

 is near places where native food-plants are growing. Citrus fruits 

 marketed from July-October should not be sprayed in these months, 

 but if they are retained for later marketing, they can be twice sprayed, 

 in the middle of September and October. 



Moths emerging from guava trees grown near citrus orchards deposit 

 eggs on ripening citrus fruits. If the latter are kept on the trees till 

 late in the year, the moths emerge early in December, therefore infested 

 trees should be sprayed before the middle of the month. 



Lamp traps for moths and the banding of trees are of no avail. 



Alternative food-plants should be destroyed and all fallen fruit 

 should be collected and, if infested, buried deeply. Where possible, 

 heavy irrigation of orchards annually in July and August, if there 

 have been no winter rains, kills the larvae and pupae. Otherwise 

 thorough cultivation, particularly underneath the trees, in these 

 months is recommended. 



Thompson (W. R.), U.S. Bur. Ent., c^- Thompson (M. C). Studies 

 of ZeniUia roseanae, B. & B., a Parasite of the European Corn 

 Borer {Pvrausta nuhilalis, Hb.). — Proc. Ent. Soc. 11 ashingion, 

 D.C., xxfii, no. 6, June 1921, pp. 127-139, 3 plates. 



A description is given of various stages of the Tachinid, ZeniUia 

 roseanae, B. & B., a parasite of Pyrausia nuhilalis, Hb. (European 

 corn borer) in southern France and the Mediterranean region, and the 

 methods necessary in rearing and colonisation are discussed. The 

 species was originally described under the genus Myxexorista, and as 

 the original description was rather brief a more detailed one is given. 

 Oviposition of Z. roseanae has not been observed, but probably the 

 larvae are deposited directly on the caterpillars of P. nuhilalis while 

 the latter are feeding on the exterior of the plant or moving from place 

 to place. Parasitic larvae of the autumn generation remain in the 

 adipose tissue of the host during the winter, which they pass in the 



