306 



No other bird equals the starling in the destruction of millipedes. 

 It has recently been shown that millipedes are injurious, and damage 

 to beans, strawberries, melons, potatoes, etc., has been attributed 

 to Julus caerideocinctiis, which is a favourite food of the starling. 



The most serious economic objection to the starling is its destruction 

 of cherries. It only secures an extremely small portion of its sustenance 

 from either sweet or field maize. The adult bird is primarily a feeder 

 on insects and wild fruit — less than 6 per cent, of its yearly food being 

 secured from cultivated crops. The damage it does is mainly due 

 to its habit of concentrating in flocks. 



The protection of this bird by law, except when it is actually doing 

 or threatening harm, is considered advisable. 



DooLiTTLE (S. P.). The Mosaic Disease of Cucurbits. — U.S. Dept. 

 Agric, Washington, B.C., Bull. 879, 15th November 1920, 69 pp.. 

 10 plates. [Received 27th April 1921.] 



A large part of the dissemination of mosaic disease is often due to 

 insects, including Aphis gossypii, Glov. (melon aphis), Diahrotica 

 vittata, F. (striped cucumber beetle) and D. duodecimpnnctata, Oliv. 

 (twelve-spotted cucumber beetle). Transmission experiments were 

 made with positive results and are tabulated. 



The high percentage of infection obtained from inoculation by 

 means of Aphids from diseased plants is probably due to the fact that 

 Aphids, being sucking insects, introduce the virus into those tissues 

 that will distribute it most rapidly throughout the plant. But though 

 A. gossvpii may be responsible for severe epidemics, D. vittata is 

 probably the most important insect carrier, as it is common in most 

 cucumber-growing districts and is usually abundant throughout the 

 season. Experiments indicate that it can transmit the disease for 

 only a short time after feeding on infected plants. D. dnodccim- 

 puiidata is so similar to D. vittata that the above probably applies 

 equally well to it. 



While other cucumber pests may also transmit the disease, they 

 are probably of less importance. Lygns pratcnsis (tarnished plant 

 bug) probably carries it, but the few tests made with it proved nega- 

 tive. Thrips tabaci, Lind., Tetranychns felariiis, L., and Asterochiton 

 {Aleurodes) vaporariorinn, Westw., have shown no indications of being 

 carriers. As regards bees, the evidence thus far secured indicates 

 that little, if any, infection is carried by them. 



DiFTz (H. F.) & Zetek (J.). The Black Fly of Citrus and other sub- 

 tropical Plants. — U.S. Dept. Agric, Washington, D.C., Bull. 885, 

 11th December 1920, 55 pp., 7 figs., 11 plates. [Received 20th 

 .\pril 1921.] 



This report is based on an intensive study of the black Hy, Aleiiro- 

 canthus woglnmi, Ashby, made in the Panama Canal Zone from June 

 1918 to August 1919. It includes information, some of which has 

 not previously been published, from other sources, to which full 

 reference is made. 



A. icoghtmi was introduced into Jamaica from India on infested 

 plants wkhin the last 10-15 years and has now spread to Cuba, New 

 Providence, the Canal Zone, the Republic of Panama and Costa Rica. 

 Nursery stock or infested individual food-plants, including cuttings 



