490 



outbreak of leaf -burn, has shown that in every case the injury was 

 in direct proportion to the number of leaf-hoppers {Empoasca mali, 

 Le B.) present. The nymphs, feeding on the imder-sides of the leaves, 

 first produce a AAa'inkling of the whole surface, with a slight upward 

 rolling of the margin, and then the marginal burning appears. 



In cage experiments, typical leaf-burn was produced in 4 days, 

 the marginal burn being often so definite as to suggest the injection 

 of some substance, rather than the mere mechanical extraction of 

 the sap. 



Carr (E. G.). An Unusual Disease of Honey Bees. — Jl. Econ. Entom., 

 Concord, N.H., xi, no. 4, August 1918, pp. 347-351. 



A disease, first brought to the notice of the Department of Apiary 

 Inspection in June 1915, appeared in 1917 in an alarming manner in 

 well kept apiaries in New Jersey and many other States, as well as in 

 Canada. 



The disease, which resulted in the death of thousands of bees of 

 a good stock, was at first thought to be due to poisoning from a 

 contaminated w^atering place, but no definite conclusions were reached. 

 The abdominal contents of affected bees were found to be watery 

 and to give off an unpleasant, somewhat pungent odour, workers, 

 drones, and even queens being similarly affected. The conditions 

 characteristic of the bee disorder known as paralysis were absent, 

 and the brood ^dthin the hives appeared to be healthy. An abnormal 

 condition in the hives was the great abundance of stored pollen and 

 the imusually small amount of unsealed honey in the combs. From 

 this fact, and from the fact that the appearance of the disease coincided 

 with a period of dull weather, while ensuing fine weather caused its 

 disappearance, it was believed that the bees were suffering from a 

 digestive disturbance caused by a diet containing an excess of nitro- 

 genous matter. 



The striking similarity between the symptoms of this disease and 

 those of Isle of Wight disease, thought to be caused by Nosema apis, 

 which also affects the digestive system, further supports the theory 

 that this disease is due to improper feeding and is thus preventable. 



Paddock (F. B.). Foul Brood Eradication Work in Texas. JZ. Econ. 

 Entom., Concord, N.H., xi, no. 4, August 1918, pp. 351-353. 



The foul-btood inspection service estabhshed in Texas under the 

 law passed in 1913 has resulted in a state- wide co-operation among 

 beekeepers and a general improvement of 50 to 75 per cent, in the 

 efficiency of the industry. In some few counties foul-brood has 

 been eliminated, and in many more the disease will be stamped out 

 in a very short time. 



Holland (E. B.) & Buckley (J. P.). Calcium Arsenite and Arsenate 

 as Insecticides. — Jl. Econ. Entom., Concord, N.H, xi, no. 4, 

 August 1918, pp. 354-357. 



The present intensive production of orchard and garden crops tends 

 towards a maximum consumption of arsenicals in combating leaf- 

 eating insects, with a corresponding scarcity of lead arsenate. The 



