number of egg-clusters collected and the percentage of parasites found 

 in them. A new infestation is best checked by the collection of the 

 egg-clusters at the earliest possible time, certainly not later than 

 about three weeks after the canes have been cut. The destruction 

 of the borers in the " dead hearts " [see this Bevieiv, Ser. A, i, 

 p. 104] and in refuse material prevents egg laying ; trap lights 

 for the moths are advantageous for small areas. Natural checks are 

 the most effective of all controls and great harm is done by burning 

 the fields before the canes are cut, a practice which results in a far 

 greater destruction of the parasites than of their hosts ; the cutting 

 down of the field does similar harm, unless the parasites can be pre- 

 served in neighbouring grass or cane fields. All collecting gangs should 

 be made to recognise the distinction between the earlier and later 

 stages of the eggs of D. saccharalis, as the latter are likely to contain the 

 parasite, Prophanunis alecto. The lists given, show the number of 

 egg-clusters collected, and the percentage of those parasitised, for 

 nearly every day of the year ; the figures show a marked reduction 

 in the number of egg-clusters, often with increase of the parasite 

 percentage, indicating the value of the control work, which consisted 

 in early egg- collection and the preservation and re-distribution of the 

 parasites. The results are more satisfactory in small than in large 

 areas. It is often advisable to collect parasitised black clusters from 

 fields of high canes, before they are burnt or cut, for distribution among 

 young, infested ones. It is suggested that hard-backs and frog- 

 hoppers may shortly have to be dealt with as cane pests. 



Severin (H. H. p.) & Severin (H. C). Relative Attractiveness of 

 Vegetable, Animal and Petroleum Oils for the Mediterranean Fruit 



Fly {Ceratitis capitata,Wied.) — Jl. N.Y. Entom. Soc, New York, 

 xxii, no. 3, September 1914, pp. 240-248, 1 fig. 



An account of a further series of experiments is given [see this 

 Revieiv, Ser. A, i, p. 517], in which the number of fruit-flies captured 

 in kerosene (Star oil about 120° Be.) compared with that caught in 

 other oils, is taken as giving the relative attractiveness of the oils for 

 the fruit-fly. Traps containing many kinds of oils were hung in 

 orange, lemon, and other fruit trees. The relative attractiveness of 

 various oils for the fly — kerosene being taken as 100 per cent. — was 

 found to be as follows : — Vegetable oils : citronella, 1 per cent. ; 

 turpentine, '04 per cent. ; coconut, "0 per cent. — A^iimal oils : whale, 

 •0 per cent. ; fish, "0 per cent. — Mineral oils : naptha distillate, 

 103 per cent. ; benzine, 82 per cent. ; gasohne (about 63° Be.), 61 

 per cent. ; gasoline (about 86° Be.), 27 per cent. ; export oil, 34 per 

 cent. ; Star oil (kerosene), 100 per cent. ; mineral seal oil, 14 per 

 cent. ; colza burning oil, 1 per cent. ; " Perfection" signal oil, "1 per 

 cent. ; " Renown " engine oil, 6 per cent. ; Atlantic red engine oil, 

 •0 per cent. ; crude petroleum, 68 per cent. The attraction of Ceratitis 

 capitata to these oils was confined almost entirely to the male sex, 

 though female flies were present in the orchards, himdreds being 

 caught by sweeping with an insect net. A bibliography of the subject 

 is given. 



