10 



were present in enormous numbers and doing great damage to sugar- 

 beet and lucerne crops. Injury by this brood ended about 26th June, 

 and circulars were distributed warning growers to take measures 

 against the heavy infestation expected from the next generation in 

 August and September. There are three complete generations during 

 the year in Nebraska, with a partial fourth in late autumn, these 

 generations overlapping considerably. The larvae of the third genera- 

 tion enter the ground and remain there until the following spring ; 

 a few of them pupate and emerge during late September, forming 

 the fourth generation. The life-history and habits of the moth are 

 described. A Braconid, Cremnops {Disophrys) vulgaris, Cress., 

 parasitises the larva or pupa of L. sticticalis and is a very effective 

 check on the webworm, its activities being, however, somewhat 

 lessened by an Ichneumonid hyperparasite, Mesochorus agilis, Cress. 



Remedial measures are discussed. A collecting machine, modelled 

 on the hopperdozer, is described and illustrated. A single sweeping 

 of a field resulted in the collection of about 20 per cent, of the 

 webworms, but had a tendency to break the leaves of the best plants ; 

 the apparatus should be used during the hottest part of the day, when 

 the leaves are driest and least liable to break. 



SwENK (M. H.) & Wilcox (E. M.). Spraying Potatoes for Insects and 

 Diseases. — Nebraska Coll. Agric., Lincoln, Emergency Bull. no. 10, 

 25th May 1917, 4 pp. [Received 2nd November 1918.] 



This bulletin discusses the usual methods of control for the Colorado 

 potato beetle [Leptinotarsa decemlineata], which is the principal insect 

 enemy of potatoes in Nebraska. 



SwENK (M. H.). Controlling Insect Pests of the Garden. — Nebraska 

 Coll. Agric, Lincoln, Emergency Bull. no. 15, 30th June 1917, 

 4 pp. [Received 2nd November 1918.] 



The usual remedial measures for the commoner insect pests of 

 garden vegetables are described in this popular bulletin. 



Caesar (L.). The Fruit-tree Leaf-Roller {Tortrix argyrospila). — 

 Canadian Entomologist, London, Ont., 1, no. 10, October 1918, 

 pp. 321-323. 



Tortrix argyrospila has only been noticed in Ontario in the 

 case of three bad outbreaks that occurred almost simultaneously 

 about six years ago. These were in the counties of Northumberland, 

 Wentworth and Norfolk, and it is noteworthy that all surrovmding 

 orchards in each locality have remained practically free from the 

 pest, which is restricted almost exclusively to the locahties in which it 

 first appeared. Arsenical sprays were tried without much success. 

 Scalecide proved much more effective, but is an expensive material. 

 In one locality natural factors, including parasites, disease and 

 unfavourable weather, gradually controlled the pest, while in another 

 district they failed to do so although the miscible oil spray was continued 

 for another season. In Norfolk county, where the leaf-rollers persisted, 

 there were at least two species of Dipterous parasites and four or five 

 species of Hymenoptera, though it is possible that cold weather may 



