IKSEOTS OF THE SEASOK m IOWA. 



By Herbert Osborn, Special Agent. 



LETTER OF SUBMITTAL. 



Ames, Iowa, December 5, 1891. 

 Sir: I submit herewith my report on the more important insects of the season in 

 Iowa. The year has been one of unusual prosperity and excellent crops in the State 

 and the ravages of insects have attracted correspondingly little attention. Observa- 

 tions on some other species than those here mentioned are still in a condition too 

 fragmentary to warrant detailed report. 

 Very respectfully yours, 



Herbert Osborn. 

 Dr. C. V. Eiley, Entomologist, 



Washington, D. C. 



The past season has been quiie free from any sweeping insect inva- 

 sion, and, aside from the prominence of plant-lice and their great mul- 

 tiplication upon plums and wheat and the spread of the Clover- seed 

 Midge, there were none to attract special attention or to cause serious 

 alarm. There were of course the ordinary species present in their 

 usual abundance, and there is no doubt that crops were affected in con- 

 siderable degree 5 but the loss was not such as to attract unusual atten- 

 tion, and it is of course a matter of regular occurrence for a certain 

 amount of loss to occur in all crops without causing much inquiry from 

 cultivators. In fact, it is the common rule to consider these attacks of 

 little moment, or to believe them too little to be worthy the expenditure 

 of time and money to attempt their prevention. For some crops, and 

 where the cost of application of remedial measures would be large, it 

 is doubtless true, but there are certainly many instances where the 

 expense of applying some remedial agent or the trouble of adopting 

 some method of culture to avoid insect increase would be abundantly 

 repaid. 



The White-winged Bibio (Bibio albipennis) attracted considerable 

 attention in the spring, appearing in great numbers in many parts of 

 the State, and in a number of cases it was sent in with the statement 

 that it was eating foliage of various plants. The evidence gained, how- 

 ever, did not suffice to establish any case where actual damage was 



57 



