KEPORT ON INSECTS OF THE SEASON IN IOWA. 



By Herbert Osborn. 



LETTER OF SUBMITTAL. 



Ames, Iowa, November 5, 1892. 

 Dear Sir : I inclose herewith a report on some of the observations for the year 

 1892, and beg to acknowledge at this time the many favors received which have been 

 a material assistance in the prosecution of the year's work. 

 Very respectfully yours, 



Herbert Osborn. 

 Dr. C. V. Riley, 



U. S. Entomologist, Washington. D. C. 



Perhaps the most striking features of the insect conditions the 

 present year have been the almost total absence of many of the com- 

 mon pests during the early part of the season, a consequent slight 

 amount of damage from insect attack, and the rapid multiplication of 

 insects during the later months of the year and some quite conspicuous 

 injuries. One of the most striking instances of this is to be noted in 

 the plant-lice which were exceptionally rare during the spring and sum- 

 mer, but in late summer and autumn multiplied prodigiously and caused 

 serious injuries to many kinds of plants. 



The season was unusually backward and the spring months marked 

 by much rain and cold weather, which retarded insect life in general. 



Such reports as were received during the early part of the season 

 indicated little if any damage even from such common pests as cut- 

 worms, squasli beetles, etc. 



The species of " bill-bugs " (Sphenophorus), which have been scarcely 

 noticed in the State heretofore, have become plentiful, and one species, 

 Sphenophorus parvulus, quite threatening in its attacks upon corn. This 

 indicates naturally a considerable damage to grasses and probably 

 Avheat and other cereals, which passes without notice. It is quite prob- 

 able that this species will demand serious attention from Iowa farmers 

 during the next few years. Splienophorous oclireas has attracted some 

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