Life Cycle: There are two generations of this maggot in North Dakota and likely Canada. In North Dakota, the adults emerge during early July and eggs are laid on the developing bud.
Damage: The extent of damage depends on the stage of larval and plant development. Historically damage has been minimal. However, reports of field damage were made in 2006 in ND and MN. More damage was recorded in 2007. The annual NSA Crop Survey found 8% of the ND crop impacted by the maggot. In SD the number was 3%. No other states reported damage. Damage is a deformed or misshapen area of the head. However, it has not been determined if this is yield impacting.
Economic Thresholds: There are no thresholds established.
Scouting Method: None has been established.
Management: None has been established.
Research: The NSA has funded a post doctoral scientist for the 2008-2011 seasons to work on the maggot. The goal of this research project is to investigate the biology and impact of this pest. Strategies include developing a management system in the event this insect is of economic consequence. This would include scouting methods and economic thresholds. Work on insecticide control and hybrid resistance is part of the overall strategy.
Photos: Visit the Photo Gallery.
Crop Surveys: The Sunflower Crop Survey is conducted bi-annually prior to harvest. Volunteers from all levels of the sunflower industry visit sunflower fields to survey the crop condition. Teams survey for yield and production practices, weeds, insects, diseases and bird damage.
Another resource about Insects can be found in the Archive section of The Sunflower magazine.