Two Grape Pests, 135 



"You cannot doubt my great gratification in reporting a decisive 

 and complete victory as the result of this year's fight against the 

 root-worm. I sprayed the larger part of my vineyards twice with 

 'Disparene/ and where this was done a critical examination revealed 

 scarcely any eggs and the foliage is almost wholly free from the 

 marks of the beetles ; while in unsprayed vineyards nearby, eggs were 

 very abundant, the foliage is badly marked, and all the indications 

 of a serious infestation are present. From such results there can be 

 but one conclusion, namely, that timely and thorough spraying with 

 'Disparene ' or arsenate of lead affords absolute protection to vine- 

 yards from the grape root-worm and restores the grape industry to its 

 former position as a safe and profitable business." 



Does the spray kill the root-worm beetles? We think it does kill 

 many of them, and it may also act as a preventive. In a day or two 

 after the poison had been applied, we found quite a number of dead 

 beetles on the ground beneath the vines, and some were seen to drop 

 to the ground and die. As the beetles are small and resemble a bit 

 of soil, and as ants soon find and destroy them, it is not an easy 

 matter to find the dead ones on the ground. A few of these were 

 submitted to our chemist to test for arsenic, but none was found, 

 indicating that they may not have been poisoned.* It is not im- 

 probable that some of the beetles may shim the poisoned foliage and 

 go to more attractive unsprayed vineyards. But it matters little 

 to the vineyardist whether the beetles are killed or driven away, so 

 long as they are prevented from laying eggs on his vines and a crop of 

 destructive grubs thus prevented from eating the roots. 



Notes on other methods. — Great claims were made in 1903 for the 

 effectiveness and practicability of various devices for catching the 



^Several of these dead beetles were kept in a tightly corked bottle for ten days, 

 when a lot of small maggots crawled out of them. Thinking that these maggots 

 might be parasitic enemies of the root-worm beetles, we put some soil in the bottle 

 and in this the maggots transformed into a small fly known as Aphiochaeta 

 fungicola Coq. This fly was first bred from a tree fimgus (Can. Ent. XXVII, 

 p. 105). It is doubtless a carrion-feeder and thus works only on the dead root- 

 worm beetles. 



