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CONTENTS. 



Page. 



Introduction 9 



First appearance of the alfalfa weevil in the United States 9 



Spread of the pest 10 



Investigations by the Utah Experiment Station 11 



Cooperation of the Bureau of Entomology and the Utah Experiment Station . . 12 



Cooperation with other bureaus of the United States Department of Agriculture. 14 



Variety experiment 14 



Investigations of vertebrate enemies 15 



The insect not correctly determined 15 



Appearance of a second species in Utah 15 



Description and seasonal history of the alfalfa weevil 15 



Egg-laying period 19 



Evidence of a partial second generation 20 



The larva 21 



Larval period 22 



Cocooning and pupating 23 



Food plants 24 



Migration and diffusion 25 



Field experiments in destroying the alfalfa weevil 26 



Street-sweeper experiments 27 



Wire-brush experiment 27 



Cultivation in connection with irrigation 29 



Burning machine 29 



Reduction in quality of hay caused by the alfalfa weevil 30 



Natural enemies 30 



Invertebrates 31 



Predaceous enemies 31 



A native true parasite 34 



Introduced parasites 34 



Egg parasites 35 



Mymarid egg parasite 35 



Pteromalid egg parasite 35 



Parasites of larvae and pupae 36 



Pteromalid larval parasite . 36 



Other parasites 38 



Vertebrates 40 



Fungous enemies 41 



Index 43 



5 



