No broccoli without a head - Testing UV light traps and hemp mulch to control the swede midge (Diptera: Cecidomyiidae), an important pest of the Brassicaceae

Summary in the original language of the document

The swede midge (Contarinia nasturtii, Diptera: Cecidomyiidae) is a detrimental pest on brassicaceous plants with no effective method established to control the pest in the field. In this study, we tested and evaluated UV light traps and hemp mulch mats as alternative methods to control the swede midge. In a lab setting, UV light traps recaptured 81% of released swede midges. In a six-week field trial with high pest pressure, UV light traps successfully trapped gall midges but did not reduce swede midge damage on broccoli plants when activated for three days a week. Adjustments to activation time and light colour could increase the efficacy of light traps in catching the swede midge. Further, light traps could be
combined with other management strategies to improve pest control in the field. In a lab setting, hemp mulch mats did not reduce swede midge emergence, despite limiting the area available for swede midge larvae to access soil for pupation. Our study presents the first results on using UV light traps to control the swede midge under high pest pressure and indicates swede midge larvae being more mobile than previously assumed, potentially finding and entering openings in mulching covers for pupation.