415 



Herrtck (G. W.). The Increasing Menace of Cherry Maggots. — 

 Canadian Horticulturist, Toronto, xli, no. 6, June 1918, pp. 149-150. 



The cherry fruit-flies [Rhagoletis cingulata and R. fausta] first became 

 serious pests in Canada in the late nineties, and have gradually become 

 more widely distributed and more prevalent, attacking all the late 

 sour and sweet varieties of cherry rather than the early ones. The 

 flies appear early in June and oviposit just under the skin of the fruit, 

 the larvae later burrowing in the fruit and causing it to decay, though 

 frequently there is no external evidence of their presence. 



They are easily controlled by poison-sprays, owing to their habit 

 of eagerly sucking up drops of liquid from the leaves and fruit, and 

 also to the fact that an interval of a week or ten days elapses between 

 their emergence and oviposition. Tests have shown that the best 

 spray consists of 2 or 2|- lb. lead arsenate, with or without | ga]. 

 cheap molasses to 40 gals, water, and this should be applied at the rate 

 of 1 gal. for a large tree, during the early part of June, and again 

 two weeks later. Though sweetened baits have proved admirably 

 effective, the absence of molasses hardly affects their efficacy, while 

 it reduces the cost and increases the adhesiveness. To obtain the 

 best results, such spraying should be compulsory throughout a com- 

 munity, as o^-ing to the activity of the flies, an unsprayed orchard 

 is a source of re-infestation. 



BuEGER (0. F.) A: Swain (A. F.). Observations on a Fungus Enemy 

 of the Walnut Aphis in Southern California. — Jl. Econ. Entom.,. 

 Concord, N.H., xi, no. 3, June 1918, pp. 278-289. 



Chromaphis juglandicoh , Kalt. (walnut aphis) was so abundant 

 in certain walnut-growing sections of S. California in the spring and 

 early summer of 1917, that in many places remedial measures were 

 instituted. Dusting with a mixture of dry sulphur and tobacco 

 dust, and spra\ang with nicotine sulphate and lime-sulphur, or \y\th. 

 nicotine sulphate and soap, gave good results. However, shortly after- 

 wards it was noticed that living Aphids were no more abundant on 

 untreated than on treated trees, to both of which very many bodies 

 of dead individuals were clinging, and these proved to be infected 

 with a fungus, a new species of Entomophthora. 



Among the natural agencies which contribute to the control of 

 C.juglandicola, the heat of summer must be regarded as very important 

 in certain localities, since the Aphids thrive best in cool, humid weather, 

 and it was before the period of extreme heat that in one place 88 per 

 cent, of them were killed by this fungus. 



Insect enemies, especially predaceous ones, are a very important 

 factor in the control of this Aphid, especially the Coccinellid. OUa 

 abdominalis, ^aj, the larvae of which feed extensively upon it during 

 the latter part of May : Hippodmnia conrergens, Guer., the larvae 

 and adults of which are present from May to September ; Chrysopa 

 californica, Coq. (green lace-wing), very plentiful in May and June ; 

 the larvae of various Syrphid flies, particularly Lasiophthicvs {Cata- 

 bomba) pyrastri, L., and occasionally larvae of Sympherobius angitstus, 

 Bks. ; and adults and larvae of Scymnus sp. 



Practically three months after the hot period, it was foimd that 

 the Aphids had been able to effect an extensive re-infestation, the 



