Sticky traps and water pan traps to monitor Delia planipalpis (Diptera: Anthomyiidae), an emerging pest of broccoli in Mexico

Abstract

The radish fly, Delia planipalpis (Meigen), is an emerging pest that infests broccoli in Mexico. Females oviposit near the stem of broccoli plants or in the inflorescence. Effective monitoring systems are necessary for the development of integrated pest management programs against this insect. Laboratory and field experiments were performed to determine the fly's responses to stick traps and water pan traps. Both yellow and blue sticky traps captured significantly more males than females. Yellow traps captured higher numbers of D. planipalpis than blue traps, but with a lower capture of Delia platura (Stein) and other non-target insects. Sticky traps or yellow water pan traps captured similar numbers of D. planipalpis in broccoli crops, but water pan traps captured significantly more females than sticky traps. The addition of the host attractant allyl isothiocyanate significantly increased the capture of flies when used in sticky traps but not in water pan traps. Sticky traps or water pan traps could be used for surveillance of D. planipalpis. Water pan traps require more servicing time as specimens need to be dried before identification. In contrast, sticky traps allow rapid identification of insects, but some insects become damaged on the sticky surface.