224 



of adults lasted from 30th July to 4th September. Some of the adults 

 remained alive for four months after oviposition was completed. 

 The two generations show a considerable degree of overlapping and 

 adults of the second generation begin to appear when some of the 

 previous generation are still reproducing. Similarly, adults of the 

 third generation, which constitute the first generation of the following 

 year, begin to emerge before those of the second generation have 

 finished oviposition. It is also possible that some adults of the second 

 generation may hibernate before egg-laying is complete, and then 

 continue to reproduce in the following year, and also that certain 

 adults of the third generation may begin to oviposit before hibernation. 



Degrully (L.). Les Traitements de Printemps centre la Cochylis et 

 I'Eud^mis. [Spring treatment against Clysia atnbiguella and 

 Polychrosis botrana^ — Progres Agric. Vitic, Montpellier, Ixv (33rd 

 year), no. 10, 5th March 1916, pp. 221-224. 



Immediate control is necessary unless the injury done in 1915 by 

 Clysia ambiguella and Polychrosis botrana is to be repeated. The com- 

 bination of insecticidal and anticryptogamic treatment may be effected 

 in two ways, the simplest being the addition of 1 lb. of commercial 

 lead arsenate to every 10 gals, of cupric spray. Another, and more 

 economical method, is to use sodium arsenate alone. 



To prepare a cupro-arsenical spray, 10 lb. of copper sulphate is 

 dissolved as usual in about 25 gals, of water and then from 12 oz. to 

 1 lb. of sodium arsenate — previously dissolved in 2 gals, of water — is 

 added. After mixing for a few minutes, the liquid must be neutralised 

 by adding a sufificient quantity of milk of lime or a dilute solution of 

 sodium carbonate, so that a total bulk of 50 gals, is obtained. It 

 should be noted that lead arsenate is generally held to be more efficient 

 than this formula. Commercial lead arsenates sometimes produce 

 somewhat heavy precipitates which adhere badly to the foliage. 

 Makers seem to have avoided this trouble by modifying the form under 

 which they now sell these products. A cupro-arsenical spray may be, 

 however, prepared in the following manner from sodium arsenate and 

 lead acetate : — Two solutions are made, one containing a double dose 

 of copper, and the other a double dose of arsenic. Thus, if a solution 

 containing 2 per cent, of copper sulphate is required, the copper 

 solution may be prepared by dissolving 20 lb. of copper sulphate in 

 50 gals, of water with sufficient lime or sodium carbonate to neutralise 

 it, and the arsenic solution is obtained by dissolving 2 or 3 lb. of sodium 

 arsenate and 6 or 9 lb. of lead acetate in 50 gals, of water. On mixing 

 the two solutions, 100 gals, of spray at the proper strength results. 

 In regions with a damp climate the stronger arsenical solution should 

 be used, but in the south the weaker one will suffice, unless caterpillars 

 are present at the end of the season or there are many pupae 

 beneath the bark. While arsenicals are infallible against Haltica and 

 the leaf-roUer of the vine, they have not always given in the field the 

 results against Clysia and Polychrosis which might have been expected 

 from experimental work. This is due to the difficulty of ascertaining 

 the proper moment for spraying, owing to the overlapping of the 

 generations, and to the fact that the moths can pass from a neighbouring 

 untreated vineyard to one where spraying has been carried out. 



