AND OTHER INJURIOUS INSECTS OF I907 AND I908. 89 



Cost of Jarring: The cost of spraying is insignificant in com- 

 parison with the cost of jarring. During the first part of the Cur- 

 culio season the trees should be jarred at least every other day for 

 the first three weeks, and after that every three or four days for 

 a week. This entails an enormous expense of time and labor, while 

 in spraying, the work of protection is all done in, at the most, three 

 applications of the spray. 



Spraying Apparatus: An ordinary barrel pump, with a Bor- 

 deaux nozzle was used in these experiments. Possibly more strik- 

 ing results would have been obtained if other nozzles, which ex- 

 perience has shown are to be preferred, had been used. The writer 

 hopes to carry the work further another season, experimenting with 

 such nozzles as the Vermorel and Mistry. 



Other Methods of Control: The destruction of windfalls, 

 either by means of cultivation during the latter part of July and 

 August, or by turning hogs into the orchard during this period, 

 will control this insect. Chickens being allowed free run in a plum 

 orchard will also keep it down to a large extent. 



A Co-operative Experiment: In one co-operative experi- 

 ment the Grasselli Bordeaux Arsenate of Lead Paste was 

 used on twenty trees of the Duchess apple, the fruit of 

 which had already begun to show signs of being marked 

 by the Plum Curculio. When the apples were picked, while 

 the unsprayed trees bore only 75% of marketable fruit, 

 82.5% of perfect fruit was taken from the sprayed tree — a slight 

 advantage in favor of the sprayed tree. On these trees only two 

 sprayings were given, both after the fruit had formed. In picking 

 up windfalls, a slight difference was noted in the number from 

 the sprayed and unsprayed trees. Fifteen thousand were picked 

 up from under an unsprayed tree, while 13,800 were found under 

 a sprayed tree, the two trees being about equal in size. This 

 data is not sufficient to base any conclusions in regard to Gras- 

 selli's mixture. 



At the suggestion of the writer eight or nine hundred other 

 apple trees were sprayed in this same orchard during the spring 

 of 1908, Paris green and arsenate of lead each being used once, 

 with Bordeaux mixture. At the time of our first visit the Curculios 

 were very abundant among these trees, and much of the growing 

 fruit was already marked, so the advice was "Spray at once thor- 

 oughly." As arsenate of lead was not immediately available, Paris 

 green (one-half pound) was used with the Bordeaux mixture (5 



