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United States Department of Agriculture

Agricultural Research Service

Research Project: SUNFLOWER GERMPLASM DEVELOPMENT FOR IMPROVED INSECT AND DISEASE RESISTANCE Title: Biology of Sunflower Seed Maggot (Neotephritis finalis) (Diptera: Tephritidae): Results from 2008 Field Studies

Authors
item Ganehiarachchi, Mangala -
item Knodel, Janet -
item Charlet, Laurence
item Beauzay, Patrick -

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 30, 2009
Publication Date: March 30, 2009
Repository URL: http://www.sunflowernsa.com/research/research-workshop/documents/Gane_Maggot_09.pdf
Citation: Ganehiarachchi, M., Knodel, J.J., Charlet, L.D., Beauzay, P.B. 2009. Biology of Sunflower Seed Maggot (Neotephritis finalis) (Diptera: Tephritidae): Results from 2008 Field Studies. Proceedings 31st Sunflower Research Workshop, National Sunflower Association, January 13-14, 2009, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Gane_Maggot_09.pdf

Interpretive Summary: The sunflower seed maggot, Neotephritis finalis, can be a serious pest of sunflower and is distributed throughout North America. Recent field observations revealed that N. finalis was widely distributed throughout North Dakota and can cause substantial damage to sunflower heads. No studies have been reported on the biology of this species in ND. The objectives of the present study were to elucidate the biological and behavioral aspects of N. finalis. Field studies on the biology of sunflower seed maggot were carried out in 2008 at Prosper, ND. Yellow sticky traps were used to monitor populations of adult N. finalis to determine the number of generations per year. Results showed that the sunflower seed maggot has two generations per year in ND. Adults of the first generation started to emerge in late June when plants were at V-12 to R1 stage and the second generation emerged in mid-August. The adult sunflower seed maggot is about 6 mm long with a wing span of approximately 7 mm and the wings have a brown lacelike appearance. Females can be distinguished from males by the shape of their abdomen; the tip of the abdomen is pointed in females and rounded in males. Eggs are elongate, tapered at both ends, white in color, and about 1.2 mm long. Eggs hatched 4 days after oviposition and the total larval period ranged from 14-16 days and pupation occurred in the sunflower head. The development period of the pupae ranged from 8-9 days. Pupae are barrel shaped, brown in color and about 4 mm long. Development from egg to adult emergence ranged from 26-29 days. Adult longevity varied from 64-87 days. There were no significant differences among the number of eggs laid on different sunflower flowering stages. One pupal parasitoid, Pteromalus spp. (Hymenoptera: Pteromalidae), was observed in field-collected cocoons and percentage parasitism ranged from 50-90%.

Technical Abstract: The sunflower seed maggot, Neotephritis finalis, can be a serious pest of sunflower and is distributed throughout North America. Recent field observations revealed that N. finalis was widely distributed throughout North Dakota and can cause substantial damage to sunflower heads. No studies have been reported on the biology of this species in ND. The objectives of the present study were to elucidate the biological and behavioral aspects of N. finalis. Field studies on the biology of sunflower seed maggot were carried out in 2008 at Prosper, ND. Yellow sticky traps were used to monitor populations of adult N. finalis to determine the number of generations per year. Results showed that the sunflower seed maggot has two generations per year in ND. Adults of the first generation started to emerge in late June when plants were at V-12 to R1 stage and the second generation emerged in mid-August. The adult sunflower seed maggot is about 6 mm long with a wing span of approximately 7 mm and the wings have a brown lacelike appearance. Females can be distinguished from males by the shape of their abdomen; the tip of the abdomen is pointed in females and rounded in males. Eggs are elongate, tapered at both ends, white in color, and about 1.2 mm long. Eggs hatched 4 days after oviposition and the total larval period ranged from 14-16 days and pupation occurred in the sunflower head. The development period of the pupae ranged from 8-9 days. Pupae are barrel shaped, brown in color and about 4 mm long. Development from egg to adult emergence ranged from 26-29 days. Adult longevity varied from 64-87 days. There were no significant differences among the number of eggs laid on different sunflower flowering stages. One pupal parasitoid, Pteromalus spp. (Hymenoptera: Pteromalidae), was observed in field-collected cocoons and percentage parasitism ranged from 50-90%.

Last Modified: 11/22/2014
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