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 > 



Local i- Per o to o 



County 



Albany 



Cayuga 



Chautauqua 



Clinton 



Columbia 



Dutchess 



Erie 



Genesee 



Livingston 



Monroe 



Niagara 



Onondaga 



Ontario 



Orange 



Orleans 



Rensselaer 



Seneca 



Tompkins 



Wayne 



No. 



Locali- 

 ties 

 12 

 3 



Average *- 



per 



per cent 



6.12 



6.67 



4.48 



2.60 



10.72 



16.33 



14.79 



29.82 



16.37 



19.69 



4663 



24-85 



10. 11 



10.67 



37-62 



12.98 



8.97 



7.46 



1925 



0/00 



per cent 



11 



2 



11 



1 



3 

 3 



7 



4 

 4 



2 

 13 



2 

 2 

 S 

 2 

 3 



10 to 19 



per cent 



1 

 1 



20 to 29 

 per cent 



1 



9 



2 

 7 

 3 



2 



2 



s 



6 



over 29 

 per cen 

 1 







j 











2 





2 

 3 

 3 

 I 

 3 

 10 







7 

 7 



15 

 8 



15 

 9 

 8 



13 





1 

 2 



13 

 2 

 4 



11 





5 

 11 

 I 

 5 

 3 

 3 



I 







9 

 3 

 5 





IS 

 1 







IS 





4 





2 



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



The data secured in 1921 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 192 1 



Number of infestations 



10 to 19 20 to 29 Over 29 

 County ties cent per cent per cent per cent per cent 



No. 

 Locali- 

 ties 



Average «- 

 per 

 cent 



to 9 

 per cent 



S 



4 

 7 



7 



6.93 

 9 97 

 8.23 

 7.61 



5 

 3 



5 

 6 



17 



8 

 7 

 11 

 3 

 6 



4.29 



2.84 

 12.38 



4.1 

 10.67 



2.66 



23 

 8 

 4 



13 

 2 

 7 



3 



4 

 11 

 9 



12.44 

 6.40 

 9 36 

 4.94 



2 

 3 



7 

 10 



Cayuga 



Columbia 4 9 . 97 3 1 



Erie 7 8.23 5 2 



Genesee 7 7.61 6 2 



Livingston 17 4. 29 23 4 



Monroe 



Niagara 7 12 . 38 4 5 



Ontario 11 41 13 1 



Orleans 



Tompkins 



Ulster 4 6.40 3 1 



Wayne 11 9 . 36 7 3 



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 : 



