626 



the rings occur above one another. The older larvae attack the 

 young wood as well. Feeding appears to take place at night, and the 

 larva remains in the mine by day. Roepke believes that it is able 

 to migrate from one stem to another. It is possible that the eggs are 

 deposited on the ground, as is the case with European Hepialids. 

 At the Forest Experiment Station only one adult was obtained from 

 a number of larvae, possibly owing to the wood becoming too dry. 



In 1917 the first signs of infestation were noticed in January; by 

 March the injury was quite apparent; by May several young larvae 

 were seen, and more or less mature larvae early in July. In September 

 the pupa under observation had not yet given rise to an adult. There 

 thus seems to be only one generation a year. 



In former years the chief injury was done to cinchona, from 20 to 

 50 per cent, of the trees being infested in some places. Roepke states 

 that later on this attack decreased, but that cacao was affected — with 

 some severity on some estates in 1911. Wild timber plantations were 

 in some instances considerably injured in 1917. Remedial measures 

 are needed where conditions in such plantations favour the pest. The 

 larva should be killed at the beginning of its attack, if possible, a 

 piece of pointed or hooked wire being used. 



Bedefluens Levevis og Bekaempelse. [Life-history of the Beet Fly 



and Measures against it.] — Statens Fors0gsvirksomhed i Plante- 

 knltur, Lyngby, Medd. 91, June 1922, 4 pp^, 3 figs. 



The life-history of the beet fly {Pegomyia hyoscyami), the larva of 

 which mines in beet, spinach, A triplex, etc., is recorded. Two to four 

 generations a year occur in Denmark. Formerly the larvae of the 

 second generation, occurring in July, did the most damage, but now 

 the first generation, occurring in May and June, is the most injurious, 

 as at this time the young leaves are often entirely occupied by the 

 mine. As soon as the attack is discovered and while the larvae are 

 young, the rows must be thinned out in order to let the remaining 

 plants have a better chance of growing ; steps must be taken to 

 prevent the larva thus removed from pupating. Spraying has not 

 proved effective. 



Aadselbillens Levevis og Bekaempelse. [Life-history of the Carrion 

 Beetle {Blitophaga opaca) and Measures against it.] — Statens 

 Fors0gsvirksomhed i Plantekultur, Lyngby, Medd. 92, June 1922, 

 4 pp., 3 figs. 



The life-history of Blitophaga opaca, which causes great damage to 

 beet in Denmark every year, is recorded. In spring the beet fields 

 are often destroyed by the adult beetles, the attacked leaves showing 

 black edges. The larval attack begins in May or June, and is finished 

 in three weeks, when the larvae are full-grown. During serious attacks 

 thinning must be avoided, as this would increase the infestation on 

 the remaining plants. Spraying with arsenic or barium chloride has 

 proved effective when used stronger than usual, e.g., Paris green 

 three or four times as strong as normally, viz., 3-4 lb. to 100 gals. 

 water, to which solution is added 3-4 lb. chalk and -i lb. gelatine 

 to make it adhesive. Soap should not be added. Of barium chloride 

 a 4 per cent, solution is used. 



