Effect of trap type and height in monitoring the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) and its parasitoid, Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae)

Abstract

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a common pest of wheat that is frequently parasitized by Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae). Both species need to be detected and quantified using a reliable monitoring system to assess the risk for wheat crops and, if necessary, determine the timing of insecticide treatments in order to ensure their efficiency against the pest and prevent adverse side-effects on beneficial insects. Four trap types, placed at 0.6 m above ground level, were compared for their efficiency in catching S. mosellana and M. penetrans: yellow sticky traps, white sticky traps, yellow water traps and pheromone-baited traps. For the pheromone-baited and yellow water traps, three heights (0.2, 0.6 and 1 m above ground level) were tested. For S. mosellana, the pheromone-baited trap was the most efficient and 0.2 m was the best height. In non-source fields with important flights of immigrant female midges, however, yellow water traps could be more efficient than pheromone-baited traps, capturing males almost exclusively. For M. penetrans, the most efficient traps were the sticky and yellow water traps and the best height was 0.6 m. These relative efficiencies of traps and height positions were clearly related to differences in flight behavior between the species and between the sexes.