337 



Report on the Agricultural Department, Tortola, 1917-1918. — Barbados, 

 1919, 12 pp. [Received 5th June 1919.] 



During the period under review the cotton crop suffered from 

 severe attacks of cotton worm [Alabama argillacea] in December, 

 while internal boll disease appeared later, infection probably being 

 carried by the bugs, Nezara viridida and Dysdercus andreae (cotton 

 stainer). Onion seeds were shaken up in red-lead powder before 

 sowing, and this was found a very effectual method of protecting 

 them from the depredations of ants. Young bay trees were consider- 

 ably damaged by Diaprepes abbreviafus spengleri (sugar-cane root- 

 borer), the larvae attacking the roots and the adults the leaves and 

 young twigs. 



Insects of the Season.— 4tf^/i Ann. Uepl. {1918) Ontario Agric. Coll., 

 Toronto, 1919, pp. 15-18. [Received 5th June 1919.] 



Owing to the extreme severity and long continuance of the winter 

 in Ontario, insect life during the summer of 1918 was far less abundant 

 than usual, and many pests that had threatened in the previous year 

 to become a serious menace to crops [see this Review, Ser. A, vi, p. 412] 

 proved to be of comparatively little importance. Aphids, on the 

 other hand, were more abundant and widely destructive than ever 

 before. White grubs and wireworms were troublesome, particularly 

 on land that had been cultivated after being for some years under 

 grass. Psila rosae (carrot rust-fly) was unusually prevalent ; its 

 attacks are especially noticeable in early summer, when the leaves of 

 young carrots turn reddish and on examination the root-s are found 

 covered with rusty blotches. The eggs are laid on the stem of the 

 carrot just below the surface of the ground and the larvae make their 

 way to the root and tear the tissues ; this injury may continue after 

 the roots are placed in winter storage. Celery and parsnips are liable 

 to damage in the same way. Sprinkling the rows of young carrots 

 with sand or plaster mixed with coal-oil, using half a pint to a pailful^ 

 or spraying with kerosene emulsion ^deters the fly from ovipositing 

 on the plants. This should be done as soon as they are ready for 

 thinning out and should be repeated weekly until about the end of 

 June. The parsnip webworm [Depressaria heracleana] has again been 

 prevalent, destroying the umbels in the second year of growth when 

 the plant is about to seed. The potato stalk borer [Goriyna micacea] 

 has appeared in the extreme south-west of Ontario but is not yet 

 very numerous ; cutting out and destroying infested stems appears to 

 be the only remedy. Many threatened losses by insect pests were 

 avoided by timely entomological assistance ; for example, in orchards 

 where large quantities of sour cherries had been destroyed in the 

 previous year by fruit-flies, there was very little loss in 1918 owing to 

 the growers having followed instructions given them. 



Experiments have shown that for the control of Rhagoletis pomonella 

 (apple maggot) the gathering and destruction of fallen fruit is not 

 the only remedy, but that spraying with lead arsenate and water, if 

 applied at the proper times, will completely control this fly and in 

 a couple of years almost annihilate it. A bulletin on this insect is 

 now being prepared. Tests with spray mixtures showed that Bordeaux 

 mixture and lead arsenate gave as good results as lime-sulphur and 



