141 



claimed were the old style migratory species which he had so often 

 " lierded off" the garden "when he was a kid." They cover a strip of 

 country about 20 miles in extent, or from Uva to Wendover, near old 

 Fort Laramie. He had not noticed them flying nor migrating ; said 

 they were quite plentiful, but nothing like when they visited Nebraska 

 years ago. Had also noticed large numbers of the long-billed curlew 

 among them all summer. Not having the authority to do so, we did not 

 visit this region ; hence can give no more detailed information concern- 

 ing these insects than what has just been said. 



Unless other swarms of locusts are present in portions of country not 

 visited, there need be but little apprehension of invasions during next 

 yea c. True, the extended drought for several successive years has been 

 quite favorable generally to the increase of this class of insects, and we 

 may expect local injuries at many points throughout the United States. 

 But, as far as the migratory species are concerned, little danger is to be 

 looked for. 



ON THE USE OF CONTAGIOUS DISEASES IN CONTENDING WITH 

 INJURIOUS INSECTS.* 



By Herbert Osborn. 



Four years ago I presented a paper before the Eastern Iowa Horti- 

 cultural Society in which I discussed the possibilities of treating inju- 

 rious insects by means of their various contagious diseases and the lim- 

 itations which seemed to me must be recognized in such treatment. 

 Further observation has impressed me with the correctness of the 

 ground then taken, and the subject seems to me of such importance that 

 I venture to bring it up here and repeat, in part, the substance of my 

 earlier paper. 



Considering the possibilities of the subject and the importance evi- 

 dent even after a brief study of it, it seems strange that these diseases 

 have received so little attention as they have. 



This may have been in part due to the fact that there seemed so little 

 hope of making any i>ractical use of such diseases, but, probably, more 

 on account of the ditficulties involved in the study and the lack of pos- 

 itive knowledge as to the nature of all diseases of an epidemic character. 

 Of late years, however, and largely on account of the stimulus given to 

 the study by the progress of the germ theory of disease, this subject 

 has been claiming wide attention and is receiving extended study at 

 the hands of a number of investigators. 



While there can be no question that the subject has been too much 

 neglected in the past, there seems at present some danger of the other 



* Read before the Entomological Club of the American Association for the Advance- 

 ment of Science, at Indianapolis, August 22, 1890. 



