DAMAGES BY FIELD MICE. 2 < 



enough to enable us to judge of the extent of injury that field mice 

 are likely to inflict upon new plantations. The experience in the 

 Arnold Arboretum, already referred to, is probably an example of 

 what may be expected. 



Dr. C. A. Schenck, forester of the Vanderbilt estate. Biltmore, 

 N. C, in a recent communication to the Biological Survey, states 

 that plantations of locust and black cherry suffer badly from the 

 girdling of mice, " especially the locust, which are killed outright, 

 usually the best specimens." And he adds, " Plantations of acorns, 

 chestnuts, and hickory nuts are rendered imjDossible because of 

 ravages of mice." 



In our native forests the injury to young trees by mice has usually 

 been unnoticed or disregarded; but hereafter, as more attention is 

 given to forest extension, a corresponding increase in interest in mice 

 as enemies of forest trees may be expected. 



DAMAGE TO PARKS AND LAWNS. 



Field mice destroy bulbs, perennial herbaceous plants, woody 

 shrubs, and ornamental vines. To name all the kinds subject to 

 attack is unnecessar}\ as but few are immune. The animals invade 

 botanic gardens and public parks as well as private grounds. In 

 the public parks of Hartford, Conn., during the winters of 1901 and 

 1905 much damage was done, especially to common laurel (Kalmia 

 Jati folia) and various thorns (Crataegus). Rosebushes and the 

 crowns of hollyhocks are often attacked. Pine mice usually are 

 responsible for the injury to bulbs — tulips, hyacinths, crocuses, etc. 

 Often the straw or other litter used to protect tender plants furnishes 

 shelter for the animals. Hedges, while often subject to injury from 

 voles, also afford protection under which the animals gain access to 

 ornamental plantations. 



During the winter of 1901-5 pine mice invaded dooryards near 

 Lanham, Md., and destroyed many plants. In one case 50 choice 

 hyacinths and tulip bulbs in a bed were badly eaten, so that only 

 4 or 5 sickly plants came up in spring. In an adjoining dooryard. 

 in the spring of 1907. the animals girdled a considerable number of 

 young white pines (Pinus strohus) and ate the roots. 



STUDIES IN AN ORCHARD. 



In December, 1903, I examined a large 6rchard in Marion County, 

 Ivans., where field mice were causing much damage. As the case of 

 this orchard is in many respects typical, details of its treatment will 

 be given. The orchard comprised 180 acres and contained about 

 20,000 trees, mostly apple, eight to ten years transplanted. The trees 

 averaged about 1 inches in diameter, but many measured 5 or 6 



