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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #126432
Title: PREDICTIVE MODEL FOR EMERGENCE OF SUNFLOWER MIDGE

Author
item TATTA, V - NDSU, DEPT OF ENTOMOLOGY
item BREWER, G - NDSU, DEPT OF ENTOMOLOGY
item Charlet, Laurence

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 9/28/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Adults from the overwintering generation of the sunflower midge lay eggs in sunflower buds and the resultant larval feeding causes head growth deformities and reduced yield. Chemical control measures have not been successful because of inaccurate timing of adult flight. Developing a predictive model of adult emergence would help in timing control measures. Our objectives were to describe the emergence of the sunflower midge in terms of heat units and to determine the distribution of the sunflower midge at difference plant growth stages and distances from the field margin. Our analysis showed the best fit of the data to the model for air temperature was at a 5 deg. C base temperature beginning on June 1st. The model predicted the first emergence of sunflower midge adults at 540 +/- 38 degree days. In most years the first emergence of midge adults would occur between July 3rd and 8th. These findings will aid in the prediction of sunflower midge emergence for preventive control measures. In commercial fields an edge effect was detected, especially at growth stages R3 and R4, up to 60m into the field with midge populations declining with distance in the sunflower field. These results can be used to refine pest management strategies for the sunflower midge.

Technical Abstract: Adults from the overwintering generation of the sunflower midge lay eggs in sunflower buds and the resultant larval feeding causes head growth deformities and reduced yield. Chemical control measures have not been successful because of inaccurate timing of adult flight. Developing a predictive model of adult emergence would help in timing control measures. Our objectives were to describe the emergence of the sunflower midge in terms of heat units and to determine the distribution of the sunflower midge at difference plant growth stages and distances from the field margin. Our analysis showed the best fit of the data to the model for air temperature was at a 5 deg. C base temperature beginning on June 1st. The model predicted the first emergence of sunflower midge adults at 540 +/- 38 degree days. In most years the first emergence of midge adults would occur between July 3rd and 8th. These findings will aid in the prediction of sunflower midge emergence for preventive control measures. In commercial fields an edge effect was detected, especially at growth stages R3 and R4, up to 60m into the field with midge populations declining with distance in the sunflower field. These results can be used to refine pest management strategies for the sunflower midge.