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INSECTICIDES AND FUNGICIDES. 



Many experiments have been conducted with a view to combine substances which 

 are known to have both insecticide and fungicide qualities. While the results have been 

 variable, it would appear on the whole that the combination of an insecticide does not 

 add to the efficiency of a fungicide, but often detracts from it ; but the reverse of this 

 does not hold true, as experiments have proved that while Bordeaux mixture combined 

 with arsenites does not act well as a fungicide, it is decidedly beneficial as an insecticide, 

 as the arsenites can be used so much stronger. Professor Maynard found that one pound 

 of Paris green in 500 gallons of sulphate of copper solution proved very injurious to his 

 trees, but that one pound of Parit, green in 200 gallons of Bordeau mixture secured a very 

 large crop of plums while other trees not treated lost their fruit from curculio. He also 

 decided that black knot was less upon the trees sprayed with this latter mixture. — Dr. 

 G. V. Riley ; Address before the Massachusetts Horticultural Society. ' 



ARSENITES IN THE ORCHARD. 



Recent experiments made at a few of our experiment stations, which have sufficient- 

 ly competent Entomologists, have thrown much light on the comparative value of 

 different arsenical mixtures as insecticide.s, and as to the relative injury they do the 

 foliage of di9erent trees. The testimony of some experimenters would indicate that the 

 peach is more susceptible to the influence of London purple than to Paris gr^en, and that 

 there is less danger of injury when the leaves are young than when they are old. The 

 cause of injury by London purple is doubtless due to excess of soluble arsenic. Pro- 

 fessor Bailey found that heavy spraying with one pound of Paris green to three hundred 

 gallons of water did not injure the foliage. But perhaps the most valuable results 

 obtained are those given by Professor Gillette, who states that London purple used with 

 Bordeaux mixture in the proportion of one pound to fifty gallons was entirely harmless 

 to the peach and plum ; that the oldest leaves are most liable to injury ; that dews and 

 probably direct sunlight increase injuries done by arsenites to foliage ; that leaves kept 

 perfectly dry can hardly be injured by them ; that leaves suffering from fungous disease 

 are more susceptible than healthy ones ; that freshly mixed and applied London purple is 

 most injurious, while freshly mixed and applied white arsenic is least injurious to foliage, 

 but the longer the mixed white arsenic stands the greater the danger of inj ury ; that lime 

 added to London purple or Paris green in water lessens the injury they will effect on 

 foliage, while lime added to white arsenic in solution increases the liability to injure the 

 same unless the poison is wholly dissolved, when the opposite effect is produced ; that 

 London purple can be applied without injury, eight or even ten times as strong, if com- 

 bined with common Bordeaux mixture instead of water ; that arsenites cannot, by ordin- 

 ary methods, be mixed in a kerosene emulsion ; that they mix readily in rosin compounds 

 and seem no more injurious than when applied in water ; that when put into strong, 

 soapy water they do much more harm than in clear water ; that they mix readily in 

 carbonate of copper .solution and are as harmless as when in clear water ; that London 

 purple in sulphate of copper solution is vastly more harmful than when in water only. 

 —Dr. C. V. Riley; ibid. 



TilE FLUTED SCALE. 



No more striking event has happened during the past two years than the extermina- 

 tion of this insect, most destructive to the orange growing interests in Southern Califor- 

 nia. It is difficult for one unfamiliar with the facts to realize that this scale, which two 

 and a half years ago hung like a blight and plague over leaf, branch and trunk of all 

 citrus, and many other kinds of fruit trees and shrubs of Southern California, has been so 

 effectually swept away by the little Australian lady bird, Vedalia cardinalis, which was 

 imported for this purpose. In the language of Assistant Secretary Willits, -'It seems 

 almost like an entomological romance." The history of this scale Icerya purchasi, has 

 made everything pertaining to the genus interesting and during the past year four other 



