Ecology and control of saddle gall midge, Haplodiplosis marginata von Roser (Diptera; Cecidomyiidae)

Summary

The saddle gall midge, Haplodiplosis marginata, is a sporadic pest in the UK and central and northern Europe.

Adults emerge from overwintering sites in the soil to mate and lay eggs on cereals (primarily wheat and barley, rarely oats) and grasses, especially couch grass, Agropyron repens, at the stem extension stage (GS31-39). Eggs hatch and larvae crawl down the stem to feed under the leaf sheath, where their feeding causes characteristic saddle-shaped galls. These galls restrict movement of nutrients to the ears, resulting in weak stems and small or blind ears. This causes yield losses when there are more than 5-7 galls per tiller. Damage is locally important on heavy soil types where wheat and/or barley are grown in continuous rotation.

Cultural control is best achieved by including a non-cereal crop, such as sugar beet or oilseed rape, in the rotation, as the adults do not fly far from their emergence locations.

There are no label recommendations for chemical control of saddle gall midge but some control can be obtained by one or two applications of insecticides applied to control other pests. Pyrethroids, such as alpha-cypermethrin, deltamethrin, esfenvalerate and lambda-cyhalothrin, and organophosphorous products, such as dimethoate, may give good control when the timing of applications is targeted at the moment eggs hatch and larvae migrate down the stem.