THE MONTHLY BULLETIN. 137 



Commercial Orchard Control. 



The usual practice in. the control of insect pests in the commercial 

 orchards of our State is to keep them so reduced that the cost of fight- 

 ins: is ahvays less than the damage done had control measures not been 

 employed. If an additional application of a spray or another fumiga- 

 tion would cost more than the damage due to the insect pest, it is the 

 usual practice to withhold such a spraying or fumigation. This plan 

 has adjusted itself througliout the State with regard to almost every 

 insect pest and is as applicable to the mealy bugs as to any other pests, 

 and should be enforced in exactly the same way. In the districts where 

 the citrus mealy bug has been the most serious it should be stated 

 tliat prior to the infestations little or no control work had been em- 

 ployed and the infestations gradually grew until it looked as if many 

 orchards would be entirely destroyed. When this peculiar situation 

 had arrived it was found necessary to do something, and, due to the 

 tremendous quantities of mealy bugs present where the first experimental 

 work was done, the results were very unsatisfactory and so varied that 

 the general impression immediately made was that the control of the 

 mealy bug was almost a physical impossibility. Continued work, how- 

 ever, indicates that if control measures are as consistently adopted 

 against the mealy bug as against other scale insects, its ravages need 

 be feared no more than those of the l)lack scale, red scale, yellow scale, 

 purple scale, etc. ; and while it is not the purpose of the writer to inti- 

 mate that the presence of the mealy l)ug in the orchard is not a serious 

 tiling, yet he desires that the seriousness of the case be not over esti- 

 mated, as has apparently been the case in the past. 



Artificial control work naturally falls under two heads, spraying and 

 fumigation. 



SPRAYING. 



In the years 1901) and I'JlO the writer conducted some rather exten- 

 sive experiments Avith sprays, in ordei- to find, if possible, one that might 

 be of value in controlling the citrus mealy bug. In all of the experi- 

 ments eoiulueted it was found that an oil ennilsion which would readily 

 dissolve the cottony wax gave the best results, and the work then 

 resolved itself into the selection of a spray that would not only give 

 good efficiency in killing the mealy bugs, hut which would cause less 

 injury to the fruit and foliage of the trees and would be the least 

 expensive. The spray that more nearly fulfilled the.se requirem.ents 

 proved to be the carbolic acid emulsion prepared as follows : 



^r?*^/ --, 40 gallons 



Whale-oil soap 40 pounds 



Lrude carbolic acid : 5 gallons 



The water should be brought to the boiling point in an iron kettle and 

 the whale-oil soap chopped into small pieces and thoroughly dissolved 

 in it. After this add the crude carbolic acid and boil for ten or fifteen 

 minutes. The resulting mixture should be a thick light creamy emul- 

 sion. For orchard use one gallon of this stock emulsion is added to 

 every twenty gallons of water, the resultant spray being milky-white 

 in color. We had considerable trouble in procuring good whale-oil soap 

 and crude carbolic acid. We found the best whale-oil soap to be rather 

 light in color and easily dissolved in hot water, while the best crude 



