Eggs laid on foliage hatch and the larva forms a gall. When the gall dries and splits the pupa fall to the ground and adults emerge next season. Adults only live for about a day.
Origin and History:
Damage caused by the maggot.
Management and Control:
As adults only live for about a day the populations in the crop may vary widely from day to day as new adults emerge or migrate from adjoining areas. Monitor daily and spray when there is more than 1 midge per head. Rates of insecticide are often increased in heavy infestations and repeat spraying may be required.
Zeuxidiplosis giardi (introduced to control the weed St Johns Wort).
Flies and midges. Bean root maggot fly.
CSIRO. The Insects of Australia. Melbourne University Press. (1991) p749.
Goode, J. Insects of Australia. Angus and Robertson. p145.
Jacobs, W. and Renner, M. Taschenlexikon zur Biologie der Insekten. Gustav Fischer Verlag. p300.
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