NEW YORK STATE MUSEUM 53 



The figures of 1920 given below show a very material increase 

 in the percentage infestation in all of the more important wheat- 

 producing counties. 



Percentage of wheat straws infested with Hessian fly puparia, 1920 



Number of infestations 



No. Average ■ • 



Lorali- per o to Q lo to IQ 20 to 39 ovir 29 



County ties per cent per cent per cent per cent per cen 



Albany 12 6.13 11 i i 



Cayuga 3 6.67 2 i 



Chautauqua 12 4- 48 it i 



Clinton I 2 . 60 I 



Columbia 2 10.72 2 



Dutchess 7 16 • 33 3 3 i i 



Erie 7 14-79 3 3 2 



Genesee j IS 29.83 7 i 9 13 



Livingston 8 16.37 4 3 2 2 



Monroe 13 19.69 4 10 7 4 



Niagara 9 46 . 63 3 n 



Onondaga 8 24. 85 2 5 2 I 



Ontario 13 10. 11 13 11 2 



Orange i 10.67 I 



Orleans 9 3762 2 5 5 15 



Rensselaer 3 12. 98 2 3 1 



Seneca 5 8.97 5 3 



Tompkins i 7 . 46 2 



Wayne 15 19.25 3462 



The average percentage of infestation for the State based on 246 samples is 16. 11 -4/19. 



The data secured in 192 1 summarized below show a marked 

 reduction in the numbers of this insect and a correspondingly small 

 probability of serious injury the coming season. 



Percentage of wheat straws infested with Hessian fly puparia 1921 



Number of infestations 



Nc. Average ^ 



Locali- per o to 9 10 to 19 20 to 29 Over 29 



County ties cent per cent per cent per cent per cent 



Cayuga 5 6.93 5 



Columbia. 4 9-97 3 i i 



Erie 7 8.23 



Genesee 7 7.61 6 2 i 



Livingston 17 4- 29 23 4 



Monroe 8 2 . 84 8 



Niagara 7 12.38 4 S 



Ontario 11 4.1 13 i 



Orleans i ■ 10.67 2 i 



Seneca 6 2 . 66 7 



Tompkins 3 1 2 . 44 2 i 



Ulster 4 6 . 40 3 i 



Wayne 11 9-36 7 3 i 



Wyoming 9 4. 94 10 3 



A comparison of the average percentages of infestation for the 

 counties of such data as are available from 191 7 to 192 1 goes far 

 to show that there has been a progressive increase in the numbers 

 of the pest from 1917 to 1920. Apparently this has been fol- 

 lowed by a material decrease in 192 1, as shown by the following 

 tabulation : 



