Fences excluding cabbage maggot flies and tiger flies (Diptera : Anthomyiidae) from large plantings of radish

• Published in: Environmental entomology 1999-12, Vol.28 (6), p.1124-1129
• Main Authors: PÄTS, P, VERNON, R. S
• Format: Article
• Language: English
• Subjects: Anthomyiidae; Biological and medical sciences; Coenosia tigrina; Control; Delia radicum; Fundamental and applied biological sciences. Psychology; Physical control; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates
• ISSN: 0046-225X; 1938-2936
• DOI: 10.1093/ee/28.6.1124

The influence of a specially constructed insect exclusion fence on the number of cabbage maggot flies, Delia radicum (L.), and tiger flies Coenosia tigrina (F.) (a predator of cabbage maggot flies) entering large plots of radish was determined. Plots with or without the exclusion fence or with an exclusion fence surrounded by a trap crop of radish were evaluated in a single growing season in 1995. Overall during the growing season, the mean cabbage fly catch per trap in the completely fenced plots was 90% fewer than in the unfenced control plots. Fewer cabbage flies were caught inside the completely fenced plots than inside the fence surrounded by a trap crop, suggesting that trap crops do not ultimately impede the movement of cabbage flies into fenced enclosures. The general pattern of trap catch of tiger flies in the various treatments was similar to that observed for cabbage flies. During the heaviest infestation of cabbage maggot flies, infestation was highest in the control plots (84.5%), followed by the fence + trap crop plots with 39.8% infested radishes, and the completely fenced plots with 24.7% infestation. The potential of exclusion fences for use in pest management programs for Brassica crops is discussed.