CIRCULAR No. 381 FEBRUARY 1936 ujfev 



UNITED STATES DEPARTMENT OF AGRICULTURE 

 WASHINGTON, D. C. 



RODENTS AND MOLES AS PESTS IN BULB 

 PLANTINGS 



By Theo. H. Scheffer, associate biologist, Division of Wildlife Research, and 

 F. E. Garlotjgh, biologist, Division of Game Management, Bureau of Bio- 

 logical Survey 



CONTENTS 



Introduction 1 



Practices affecting the bulb-pest problem _. 1 



Relative palatability of the common bulbs, 2 



Mammal pests of bulbs 2 



Bulb classes and pest relations, 3 



Narcissus 3 



Tulips 4 



Gladiolus -'-- , 5 



Bulbous irises 6 



Crocuses and hyacinths 7 



Freesias 7 



Page 

 Bulb classes and pest relations— Continued. 



Ixias and sparaxis 7 



Lilies • 7 



Preventive measures 9 



Active deterrents - 9 



Exclusion by barriers 9 



Trapping and other control measures 10 



Moles 11 



Mice and rats 12 



Pocket gophers .- 13 



Rabbits 16 



INTRODUCTION 



Bulb growing in the Pacific Coast States has of recent years 

 developed along progressive lines, particularly in the production of 

 forcing stock. The climate and soils of the Puget Sound and lower 

 Columbia Kiver sections and of western Oregon have been found 

 peculiarly adapted to the growing of the more hardy types of flower- 

 ing bulbs, and those of southern California to the less hardy species. 

 With the extension of bulb culture to fields of many acres, damage 

 by rodents and birds assumed such proportions as to prompt investi- 

 gations to develop remedial and preventive measures, the results of 

 which are presented in this circular. 



While the special investigations in the field of bulb growing and 

 in the control of rodent pests that affect the industry have been con- 

 ducted on the Pacific coast, from Bellingham, Wash., to San Diego, 

 Calif., the findings and recommendations will in the main apply 

 equally well to almost any other section of the country. With the 

 exception of the pocket gopher, which is widely distributed in the 

 western and in the southeastern parts of the United States, repre- 

 sentatives of the groups of small burrowing animal pests of bulbs 

 here considered are likely to be found in any parts of the country 

 where bulbs are grown in garden or field. 



PRACTICES AFFECTING THE BULB-PEST PROBLEM 



Complicating the problem of dealing with rodents and other mam- 

 mals that may interfere with the production of bulbs is the prevail- 

 ing practice among growers of moving their stocks to new ground 



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