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Metcalf (Z. p.). Dipping Tobacco Plants at Transplanting Time for 

 the Control of the Tobacco Flea Beetle [Epitrix parvula, Fabr.).— 

 Jl. Econ. Entom., Concord, N.H., xiii, no. 5, October 1920, 

 pp. 398-400. 



The losses caused by Epitrix parvula, F. (tobacco flea-beetle) may 

 be greatly reduced by dipping the leaves, before transplanting, into a 

 solution of 1 lb. of powdered lead arsenate to 10 U.S. gals, of water. 

 The moisture should be shaken from the leaves, leaving them covered 

 with white powder when dry. 



Fenton (F. a.) & Hartzell (A.). The Life History of the Potato 

 Leafhopper {Empoasca mali, Le Baron). — //. Econ. Entom., 

 Concord, N.H., xiii, no. 5, October 1920, pp. 400-408, 1 fig. 



Owing to the connection of Empoasca mali, Le B., with hopper-burn, 

 extensive observations on its life-history' have been made. 



Hibernation takes place in the adult stage. The leafhoppers become 

 active again about April, and may be found on weeds — yellow dock 

 {Riimex crispiis) being a favourite food-plant — until June. Early 

 in that month these adults migrate to early planted potatoes, and 

 begin ovipositing. The eggs hatch in from 10 to 15 days, but under 

 laboratory conditions an average of 7 days only was required. A 

 general migration from early to late potatoes was noticed in July, and 

 by August the majority of nymphs had become adult. In July the 

 nymphs rnay mature in about a week, but in cooler weather this stage 

 may last as much as 26 days. The adults of this summer generation 

 are most abundant about 10th July. The eggs laid by them hatch 

 towards the end of August and beginning of September, giving rise 

 to the second generation. Many of the resulting adults live until the 

 following August, a period of about 11 to 12 months. This generation 

 does not oviposit until the spring. The total life-cycle is thus 10 weeks 

 for the first generation, and over a year for the second generation. 

 Attempts to produce a third generation failed under laboratory 

 conditions. 



Dudley (J. E.). U.S. Bur. Entom. Control of the Potato Leafhopper 

 {Empoasca mali, Le B.) and Prevention of " Hopperburn." — Jl. 



Econ. Entom., Concord, N.H., xiii, no. 4, October 1920, pp. 408-415, 

 1 plate. 



Observations show that one adult or nymph of Empoasca mali, 

 Le B., is sufficient to produce decided symptoms of hopper-bum. 

 Although this leafhopper appears on a variety of plants, it is apparently 

 only capable of reproduction on potato, beans, hemp, apple, Dahlia 

 and hollyhock. A disease similar to the hopper-burn of potatoes has 

 been found on these plants and also on raspberry and box elder. Field 

 observations show that, on potato at least, the extent of disease is in 

 close relation to the number of leafhoppers present. Certain 

 varieties of potatoes with tender fohage are apparently preferred, and 

 these are more susceptible. The disease also affects the potato tuber, 

 but in what way has not j-et been determined. Plants grown from 

 seed from the diseased crop of the previous year are evidently more 

 susceptible, as they were seriously damaged in spite of sprajang. 



The materials tested as sprays include kerosene emulsion, nicotine 

 sulphate, Bordeaux mixture and a combination of the last two. 



