361 



stopped, side-shoots are thrown out and a bunchy top is formed. The 

 larvae pupate inside the tunnels. Collection of the egg-masses is 

 advised, and these should be kept to allow the Chalcid "parasites to 

 escape. Plants showing dead-heart and wilting top-shoots should be 

 cut out and destroyed with the larvae within them. As the moths 

 breed freely in a species of Cyperus that grows wherever sugar-cane 

 is grown under tanks, it should be destroyed if possible. Sesamia 

 inferens, Wlk., causes rather similar damage in sugar-canes and less 

 frequently in cholam and wheat. The remedy is to cut out the plants 

 showing dead and wilting central shoots and destroy them. A Tachinid 

 parasite reduces the numbers considerably. Diatraea spp. attack 

 the canes in a similar manner and require the same treatment. 



Watson (J. R.). Control of Root-knot, II.— Florida Agric. Expt. 

 Sta., Gainesville, Bull. 159, April 1921, 16 pp. [Received 9th 

 May 1922.] 



Root-knot is one of the most widespread and destructive diseases 

 of vegetable crops in Florida, its cause being the Nematode, Heterodera 

 radicicola, which bores into the roots and feeds upon the sap. A list 

 of forty-three common food-plants grown in Florida is given. Grasses 

 are practically resistant, and trees and shrubs are not much attacked, 

 but almost all vegetable and garden crops are more or less susceptible. 

 It is impossible to grow profitably such susceptible crops as okra 

 [Hibiscus esculentus], tomatos, eggplants, etc. on infested land. The 

 Nematodes are least active during the cool, dry weather from about 

 November to April, and are most destructive during the summer ; 

 plants such as celery and early lettuce, planted in autumn or late 

 summer, are generally severely damaged. 



For those who farm on a large scale, the cheapest method of treating 

 infested land is to grow immune or resistant crops for three years. 

 For smaller areas, where this is not possible, the numbers of Nematodes 

 can be reduced by growing during the summer resistant or immune 

 cover crops in rows that can be constantly cultivated, by summer 

 fallowing, by applying one ton per acre of fresh cyanamide a month 

 or two before planting, or by flooding the land for a week or two. 

 Seed-beds should be planted on newly cleared land or the land should 

 be treated with sodium cyanide, 600-800 lb., and ammonium 

 sulphate, 900-1,200 lb. per acre; this is too expensive for large 

 areas. In small home gardens fallowing should be practised and 

 chickens should be turned loose. Perennial plants should be planted 

 on newly cleared land and should be mulched and watered well but 

 not cultivated. Figs should be planted near a building, and peaches 

 should be grafted on plum roots. All dirt should be cleaned from 

 ploughs and other implements before taking them into a field free 

 from Nematodes, and water should not be allowed to flow from an 

 infested into a clean field. 



Blackman (M. W.). North American Ipidae of the Subfamily 

 Mieraeinae, with Descriptions of New Species and Genera.— 



Mississippi Agric. Expt. Sta., Agric. Coll., Miss., Tech. Bull. 9, 

 December 1920, 62 pp., 5 plates. [Received 9th May 1922.] 



This paper forms a contribution towards a revision of the North 

 American Scolytidae, based largely upon studies and collections 



