CONTENTS. 



Page. 



Introduction 5 



Classification of field mice 8 



Species and distribution 9 



Habits of field mice 10 



Nests and trails 10 



Breeding habits 11 



Food habits 13 



Three typical species - 15 



I. The common meadow mouse (Microtus pennsylvanicus) 15 



II. The prairie mouse (Microtus ochrogaster) 18 



III. The pine mouse (Microtus pinetorum scalopsoides) 19 



Damage by field mice 22 



Damage to meadows and pastures 22 



Damage to grains and forage . 23 



Damage to garden crops 23 



Damage to small fruits 24 



Damage to nursery stock 21 



Injury to orchards 25 



Injury to forest trees 26 



Damage to parks and lawns 27 



Studies in an orchard 27 



The relation of field mice to the farmer 30 



Reports from farmers and others 30 



Reports from nurserymen and orchardists 33 



Economic status of field mice 37 



Repression of field inice — natural agencies 37 



Climatic influences 1 37 



Epidemic diseases 38 



Natural enemies of field mice 38 



Mammals that destroy field mice 39 



Birds that destroy field mice 42 



Snakes 53 



Repression of field mice — active measures 54 



Trapping 54 



Cultivation 55 



Other mechanical devices , 50 



Poisoning 56 



Strychnine 56 



Other poisons 57 



Additional methods of poisoning 59 



Fumigation 59 



Micro-organisms 60 



Recommendations to farmers : 60 



Prevention of injury to orchards and nurseries 60 



Remedies for injured trees 62 



Summary 63 



Literature 64 



3 



