October, '11] HARTZELL: SWEETENED POISONS 421 



with beetles this summer were sprayed with the same material and 

 the disappearance of the beetles occurred in from a few days to a 

 week. The finding of their dead bodies told the story of their 

 departure. 



Let us now return to our failures and seek an interpretation. The 

 portions of the vineyards where the use of Bordeaux and. arsenate of 

 lead gave poor results were composed of vines having a luxuriant 

 growth of foliage so that the spraying of these vines, using four fixed 

 nozzles on a side, applying 100 gallons per acre, showed between 80 

 and 90 per cent of the fohage covered with the spray. If any of the 

 beetles migrated to other vines we were not aware of the fact but there 

 were many of them feeding on the 10 per cent of foliage that remained 

 uncovered. 



At the time these insects are feeding on the foliage, the growth of 

 the vines is very rapid so new leaves are developing and by two days 

 after spraying there is fresh unsprayed foliage for them to feast upon. 

 Thus they feed unmolested and in time lay their eggs thereby accom- 

 pUshing the very thing we are aiming to prevent. 



We beheve that either the inability to cover the foliage especially 

 where dense, with the present use of fixed nozzles or the use of im- 

 proper nozzles accounts for all the failures to control the grape root 

 worm by means of the Bordeaux mixture and arsenate of lead. Exper- 

 iments show that the use of the molasses-arsenate of lead mixture 

 gives superior results, since the inability to cover all the foliage is 

 balanced by the habit of the beetles seeking the sweet and also the 

 insects are killed instead of being driven to other vines as appears to 

 be the case with other mixtures. 



The formula we recommend is six pounds of arsenate of lead, two 

 gallons of molasses and 100 gallons of water. 



Rose Chafer. The behavior of this insect towards arsenate of lead 

 alone or with Bordeaux mixture is similar to that of the root worm. 

 This has been determined by cage experiments as well as field obser- 

 vations. The reasons that we find so many failures in attempts to 

 control this pest are as follows: (1) the beetles come in enormous 

 numbers, every blossom cluster having from one to a dozen feeding on 

 it; (2) The first feeding on grape is confined largely to the blossoms and 

 blossom buds. The attempts to spray the vines with fixed nozzles, 

 often results in covering the foliage but not covering the blossoms and 

 buds, so the beetles are not inconvenienced in feeding on these delicate 

 structures. A single beetle can destroy a number of the flowers before 

 eating sufficient poison to kill it, even though these parts should have 

 some poison on them. Thus the crop of fruit will often be ruined in 

 a few days and the migration of the insects to other plants will be of 



