758 EXPERIMENT STATION RECOED. 



Papers on deciduous fruit insects and insecticides. — Spraying experiments 

 against the grape leaf hopper in the Lake Erie Valley in 1911, F. Johnson 

 (U. S. Dept. A(ji:, Bur. Eiit. Bui. 116, i)t. 1, pp. 13, pis. 3, figs. 3).— This is a 

 report of experiments conducted during 1911 in continuation of those previously 

 noted (E. S. R., 25, p. 152). Owing to the more rapid development of the imma- 

 ture stages of this insect in 1911 than in 1910 there was a partial second brood 

 of considerable proportions in 1911, which greatly augmented the injury toward 

 the ripening season. 



Two forms of commercial tobacco extract were used in the exiieriments, the 

 first (blackleaf extract), containing 2.7 per cent nicotin; the second (blackleaf 

 40), containing 40 per cent nicotin sulphate. The first, used at a dilution of 1 

 part of extract to 150 parts water, killed all nymphs that were thoroughly wet 

 with the spray, especially the smaller nymphs, between the first and fourth 

 molts. The second was effective at a dilution of 1 part extract to 1,500 parts 

 water. 



"The field experiments made during the season . . . show that a single 

 application of the tobac(*o extracts applied against this insect in the nymphal 

 stage as a contact spray will reduce its numbers to such an extent that the in- 

 fested vines will remain in good foliage throughout the season and mature a 

 crop of high-quality fruit. 



"As indicated by the variation in the time and rapidity in development of 

 the nymphs in 1910 and 1911, it is evident that no definite date for making the 

 spray application can be given. Where the winged adults are at all numerous 

 in the early part of the season the vineyardist is urged to examine the under- 

 side of the grape leaves toward the middle and the end of June and to observe 

 the number and size of the nymphs. The spray application to be most effective 

 should be made at about the time the first nymphs to hatch are near the last 

 molt. This is indicated by the length of the wing pads. At this time the under- 

 side of badly infested leaves will be covered by the nymphs in all stages of 

 development. Generally speaking, this condition is likely to occur in the Lake 

 Erie Valley from July 1 to 15. All of the field experiments conducted in 1910 

 and 1911 were made between these dates and in every instance very Siitisfac- 

 tory results were secured." 



The aphids attacking Ribes, with descriptions of two new species, F. V. 

 Theobald {Jour. Econ. Biol., 7 {1912). ]\o. 3, pp. 9J,-116, pis. 2, figs, l-i)..— 

 Seven species which attack cultivated and wild currants and gooseberries are 

 dealt with, namely, Aphis grossitlariw, Macrosiphum lactucw, Rhopalosiphum 

 lactucw, R. brittcnii n. sp., Myzus rihis, M. ichitei n. sp., and ScMzoneura ulmi. 



Recent results of spraying experiments for the control of the white fly on 

 citrus, W. W. YoTHERs {Proc. Fla. State Hort. Soc, 2i {1911), pp. 53-6-'f).— 

 This paper gives further information as to the value of the formulas previously 

 recommended (Bu S. R., 25, p. 153) when used in combating the white fly. 



The biology and the treatment of the eudemis and cochylis moths in 1911, 

 J. Capus (Rev. Vit., 37 (1912), Nos. 959, pp. 593-600; 960, pp. 633-638; 961, pp. 

 681-686; 962, pp. 707-712; 96h, pp. 773-778; 965, pp. 818-821; 966, pp. 8//6- 

 851). — This article reports investigations of the biology of and remedial meas- 

 ures for the cochylis and eudemis moths. 



A fungus disease of bagworms (Isaria psychidse), I. B. P. Evans {Agr. 

 Jour. Union So. Africa, // (1912), No. 1, pp. 63-67, fig. 1). — The author's studies 

 show that the fungus I. psycMdce caused a disease among the bagworms from 

 which, when once infected, there was no chance of recovery. Experiments con- 

 ducted in the laboratory showed that if healthy bagworms were fed on wattle 

 leaves contaminated with the spores or germs of the fungus, the insects con- 

 tracted the disease in from 4 to 5 days' time and were dead at the end of 7 to 



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