368 



causing the disease is Bacillits lathyri, which also causes streak in sweet 

 peas and stripe in tomatos. The organism probably gains entry into 

 the leaf through the stomata, and the apparent spread of the disease 

 eastwards would suggest dispersal by wind. It is also carried in the 

 seed of winter beans, especially those injured by Bruchus nifimanus. 

 It is possible that the plant may be inocalated at the time of 

 oviposition, and the young larvae developing in the pod may infect 

 the seeds as thev bore into them. 



CoRKiNS (C. L.). Notes on the Migration o£ Melanoplus atlantis, 

 Riley, in northern North Dakota in 1920. Observations in 

 Bottineau and Renville Counties. — Canadian Ent., Orillia, liv, -no. 1, 

 January 1922, pp. 1-4. 



The effect of the intensive grasshopper campaign carried out in 

 1920, in Renville County, North Dakota, was adversely influenced 

 by the migration of Melanophis atlantis, Rile}^ from untreated areas. 

 The habits of flight observed during this extensive migration were 

 unlike those usually attributed to this species, resembling rather those 

 of M. spretus, Uhl. A swarm would frequently settle in a wheat field 

 and leave the next day, although there was an abundance of palatable 

 food. In August the altitude of flight was taken in an aeroplane, 

 and the swarm was found to be densest at 500 to 800 feet, a few 

 individuals being found at 1,650 feet above ground. The speed of 

 flight was determined by means of a motor car to be 20 miles an hour. 



i^ Douglas Fir Seed Fly {Megastigmus spermotrophtts, Wachtl).— 

 Forestry Commiss., London, Leaflet no. 8, October 1921, 3 pp. 

 [Received 13th May 1922.] 



A large proportion of seed of the Douglas fir [Pseudotsuga taxifolia] 

 is rendered useless by the attack of the Chalcid, Megastigmus spermo- 

 trophus. Eggs are laid in fertilised flowers or young cones in May or 

 June ; the larvae feed on the contents of the seed during the summer 

 and remain in it during the winter. Pupation occurs in March and 

 April, and the adults are found from April to June. Occasionally the 

 larvae may spend two winters in the seed. The presence of the larvae 

 can only be detected by cutting the seed open. The only remedial 

 measure that can be suggested at present is fumigation with carbon 

 bisulphide at the rate of one ounce to every 100 lb. of seed or to every 

 cubic foot of space. All light seed discarded in winnowing and cleaning 

 should be swept up and burnt. 



Fetch (T.). The Diseases and Pests of the Rubber Tree. — London, 

 Macmillan & Co., Ltd., 1921, x + 278 pp., 6 plates, 38 figs. Price 

 20s. 



One chapter of this book is devoted to the animal pests of rubber 

 occurring chiefly in Ceylon and the East Indies. The noxious insects 

 include the Longicom, Batocera rubns, the Scolytids, Xyleborus perforans 

 and X. parvulus, the locust, Cyrtacanthacris nigricornis, and 

 Coptotermes (Termes) gestroi. Up to the present, insect pests of Hevea, 

 with the exception of the last named, have proved of minor importance 

 in comparison with fungous diseases. 



