COMPARATIVE GRAIN BAIT TESTS FOR CONTROLLING 

 MEADOW MICE IN ORCHARDS 



Cafeteria-type preference tests were conducted during October 1961 in a 

 Massachusetts orchard to determine whether cracked corn or stearaed-crushed oats 

 were preferred by meadov; mice. Test results indicated that at twenty- five of the 

 thirty sites oats were preferred. After a 24-hour period, however, both piles of 

 grain had been consumed at most stations. Although the te.sts showed that steamed- 

 crushed oats were accepted first, the significance of this preference is not 

 definitely knoi-m. 



Twenty-three comparative bait tests, broadcasting 2 per cent Zinc Phosphide- 

 treated grain baits, v/ere conducted in the region during the fall of 1961 after 

 the apples were harvested. The average per cent control of meadow mice with each 

 bait was as follov^s: steamed-crushed oats, 78%; cracked corn, 67%; and a mixture 

 of oat groats and cracked corn, 71%. 



It was interested to note that in 1959, twelve tests were conducted in 

 orchards throughout the region by the same personnel using 2 per cent Zinc 

 Phosphide-treated steamed-crushed oats broadcast by hand seeder, fertilizer 

 spreader, and by aircraft. The average control of meadov; mice in these tests was 

 also 78 per cent. 



These comparative bait tests pointed out that control in some orchards was 

 very successful with one bait; whereas in other orchards treated with the same 

 bait control was not satisfactory. The variability in control with all three 

 baits makes it difficult to ascertain v/hether the differences in per cent control 

 are significant. 



The importance of favorable weather for at least two days following applica- 

 tion v<ras reflected in the success of the control. Further, an even distribution 

 of bait is equally important to insure good control. Although broadcast baits 

 can be easily and quickly applied, the degree of control attained is considerably 

 less than the 95 per cent average control consistently obtained with the Orchard 

 Mouse Trail Builder. 



John U. Peterson, 



Asst. District Agent 



U. S. Fish and Wildlife Service 



I I I I I I I I I I I I I I I I 



WHAT'S ;^niONG WITH PEARS? 



Fruit growers are constantly asking us what variety of apple to plant. Less 

 frequently, they are asking what varieties of peaches to plant, and rarely ask 

 what variety of pears to plant. 



Most growers remember difficult times in producing pears. They recall poor 

 production, small fruit, and worst of all, fireblight. 



Pear production in the East has followed a very dtefinite cycle. At one time 



