lo JuLV. 191 i-l f-fiiits oil Cut Worm Dalruciion. 459 



Preventive Methods. 



A predisposing cause of trouble is the presence of an abundant crop of 

 weeds at the time the moths lay their eggs. The.se appear to instinctively 

 realize the pre.sence of food for their offspring on dirty land, and to avoid 

 laying their eggs on ground free from weeds. 



The ground of the young vineyard should be clean and well cultivated 

 from the commencement of winter. Attention to this point alone will 

 greatly reduce the prevalence of the insects. Subsequent cultivation, no 

 matter how thorough, will not give security once the eggs have been laid. 

 In fact, it only aggravates the trouble. As the caterpillars cannot find 

 any plants to feed on but the young vines, their concentrated efforts are 

 all the more severely felt. In the keeping clean of the ground on which 

 young vines are to be planted, or of young resistants which it is intended to 

 field-graft in the following spring, we have a means of prevention, the 

 value of which is not sufificiently realized. 



Preventive treatment, by destruction of the moths before they hiy their 

 eggs, is also worthy of consideration. Judgment and close observation 

 are necessary in order to hit upon the most propitious time of operation, 

 when the moths are abundant and ready to lay their eggs. Acetylene 

 lamps of special construction are used for this purpose'. The 

 burner is situated a few inches above a shallow tray, lllled with water, on 

 the surface of which is poured a small quantity of kerosene. The insects, 

 attracted by the strong light, get their wings singed and fall into the tray, 

 where they are found in large numbers in the morning. 



Lamps of this description have been successfully used at the Wah- 

 gunyah Nursery during the past two seasons. It is not easy to estimate 

 to what extent subsequent invasions were prevented by this means, but 

 there is no doubt that large numbers of moths were destroyed. The lamps 

 available were far from perfect, the automatic regulation of the gas supply 

 being more particularly defective. 



In France, trap lamps of this kind are largely used for the destruction 

 of Cochylis and Pyrale moths, the larvae of which, in the shape of minute 

 green caterpillars, are responsible for an enormous amount of damage in 

 some districts. In parts of Champagne, Avhere such lamps have been used 

 on a large scale, six lamps per acre are considered sufficient. The type of 

 lamp most largely u.sed was one fitted with Bray's patent " Ceto " burner, 

 burning 10 litres (alxjut \ cubic ft.) per hour, and taking a charge of 

 7 ozs. of carbide, sufficient to last five or six hours. The tray is 20 inches 

 in diamett-r and if inches deep.'*' 



Though capable of giving gfx)d results in nurseries, trap lamps are not. 

 owing to the large number re(]uired, and the difficulty of attending to 

 the lamps at night, .so practical in the vineyard. 



Arsenical Poisoning. 



This is the method of protection which has given the l)e>l results in 

 Victoria. Two distinct systems have been largely used : -• 



1. Spraying with lead arsenate in suspension in wairr. 



2. The use of baits, in close proximity to the young vin -s. 



ilacli has its partisans, and each has given excellent results when pro 

 perly a|)plied. According to circumstances, one or other nicthiid may be 

 more suital)le for a given case. It will often be found advisal'Ie to combine 

 both methods. 



• MM. Mirtiii-Iliit null I'iii^nnl in Pnvr.* A(jricuU, ix\\\ .K\\\i\\-\, IVUii. 

 R 2 



