10 



Pine voles travel either in surface trails, or in burrows at depths up 

 to 3 feet or more, depending somewhat on soil conditions. In solid grass 

 sods they may be almost total ly subterranean, but where the ground cover 

 contains a high percentage of broadleaf herbs, surface pine vole trails may 

 be numerous. During the cold months, their activity is pretty much limited 

 to the underground burrows. When herbage is abundant, pine voles put away 

 caches in the tunnel system for later use. They feed upon bark and cambium 

 primarily below the soil line, and chew off small roots up to about pencil 

 diameter. 



Commercial apple cultivars and their seedlings, as well as the 

 available rootstocks, are very susceptible to vole feeding. A selection of 

 Mai us sublobata has been found to be quite resistant, however. The selec- 

 tion was named "Novole" and has been introduced as an apple root and trunk 

 stock for areas with severe vole problems. As a rootstock, "Novole" pro- 

 duces a large, vigorous tree. Use of a dwarfing interstem is suggested for 

 tree size control . 



Identification of Pest Species 



It is important to determine whether pine voles are present, because 

 some of the management practices used for meadow vole are not effective 

 against pine vole. Identification of the species may require trapping. Use 

 snap traps baited with breakfast rolled oats, or peanut butter, or a 50:50 

 mix of these two. Fresh apple pieces are also a good bait. Place traps 

 across active runs, including those that lead into underground burrows, if 

 present. Cover the trap with an apple box, or similar cover to exclude 

 birds and cats, and to aid in locating the trap trees in the orchard. Set 

 enough traps to be sure of catching 5-10 voles, from various locations in 

 the orchard. Check the traps after only one or two days. Tail length is 

 useful for identification. The pine vole tail is very short; about the same 

 length as the hind foot (not leg!), measuring 2>/k inch or less. The meadow 

 vole tail is about twice the length of its hind feet reaching 1 1/2 - 1 3/^ 

 inch on adults. Both species have chunky bodies, small beady eyes, and 

 their ears are small and almost concealed in fur. Fur color is dark brown 

 or gray-brown. If you catch a long-tailed specimen, it is likely to be a 

 white-footed mouse ( Peromyscus ) . The Peromyscus ' tail is well over 2 inches 

 long, and all underparts of this mouse are covered with white fur. It is 

 reported to eat bark of young trees occasionally, but is generally con- 

 sidered a non-pest species in orchards. Your traps may also catch a shrew, 

 which is a beneficial small mammal, or a mole. Shrews can be identified by 

 their long pointed snout and needle-pointed front teeth. Voles have chisel- 

 shaped front teeth. Moles differ from all others in their front feet, which 

 are very large, with prominent digging claws. 



Orchard Floor Management 



Prevention of vole population build-ups offers the most practical 

 method of reducing tree injury. 



1. Mow orchard floor sod frequently during the growing season. On 

 soils where erosion is not a problem, clean cultivate young 

 orchards. 



