456 



the direct result of the severe cold of the preceding winter. Previous 

 work had shown that remedies and methods usually recommended for 

 the control of the onion fly were of no use in large fields, both because 

 of the initial cost and the great expense of labour necessary to apply 

 them. Naphthalene, soluble sulphur, powdered tansy, etc., had had 

 the effect of preventing germination to a large extent. In 1914, 

 naphthalene was diluted with a substance less powerful as a repellent ; 

 the retarding effect on germination was not observed and the scarcity 

 of maggots in the experimental plots was very pronounced. The 

 mixture was at first applied by hand to the rows of onion seeds ; later, 

 a special planting machine was adapted to carry out both operations 

 at once. 



Olenn (P. A.). The Apple Flea-Weevil in Illinois. — Jl. Econ. Entom., 

 Concord, vii, no. 2, April 1915, pp. 279-286. 



Orchestes canus, the apple flea- weevil, has been recorded from several 

 locahties in Illinois. Injmy is caused by both larvae and adults, both 

 stages feeding on the leaves. The reduction of leaf surface by the 

 adult may reach 50 per cent. There is one generation annually. The 

 adult hibernates among leaves or grass or in the soil ; activity is 

 resumed in March. As soon as the leaves appear, eggs are deposited 

 in the large veins of the under surface. Egg-laying continues for about 

 a month. The larva hatches in 4-5 days and mines through the leaf 

 towards the tip. Pupation takes place within the leaf after about 

 3 weeks, and the adult emerges a few days later. The mines develop 

 a conspicuous red colour. The adults feed until late in June and then 

 descend to hibernate. Control measures tested during 1913 included 

 sticky bands, arsenical and contact sprays. It was estimated that 

 bands from 3 to 5 inches wide placed round the trunks of trees reduced 

 the number of larval mines by about 50 per cent. Beetles which 

 emerged late in spring were active and flew directly from the ground 

 to the branches. Sprays could only be appHed against the adult stage, 

 as the larvae are leaf -miners. Arsenical compounds sprayed on to the 

 under surface of the leaf had little effect on the adult. It was found 

 that the beetles would not feed on leaves sprayed with Hme-sulphur or 

 Bordeaux mixture. During 1914, a lead arsenate and water spray 

 was found to give satisfactory results ; the spray consisted of 4 lb. 

 lead arsenate, 8 lb. flour and 100 gals, water. Spraying should be 

 begun before the trees are in bloom, in order to destroy the beetles 

 before eggs are deposited. Later, spraying should begin in the first 

 week in June to destroy the adults of the new generation. The spray 

 should be applied at a pressure of 200 lb., and should be directed over 

 the entire leaf surface. In early experiments, it was found that the 

 beetles were easily kifled with kerosene emulsion and nicotine sprays. 

 Large canvases were spread beneath the trees ; the spray was directed 

 against the under sides of the leaves at a pressure of 200 lb., and the 

 beetles, as they fell into the canvas, were killed by the kerosene. 

 A 7 per cent, kerosene emulsion and Black Leaf 40 at the rate of 

 1 pint to 100 gals, water were used. This method works well when 

 the trees are not large and have no low-growing branches. It gives 

 immediate results, but has the disadvantage of requiring more than 

 one application. 



