The maggot feeds on the shoots of young growing seedlings resulting in “dead hearts” in wheat and maize. Small circular cuts are visible at the point of entrance on new shoots, usually just above the first leaf sheath. The symptoms of damage become more prominent on the emerging leaf 6-7 days after infestation. Cut leaves turn pale green or yellowish-green and droop, folding inwards from the margins. Severely infested seedlings wilt, terminal growth ceased and the plant remained stunted. Usually, only one larva is found per seedling, although more eggs may be laid by females.
The damage is cause by the larvae of a number of flies of the genus Atherigona. These small gray-colored flies are polyphagous and attack main crops such as wheat, maize and sorghum. Other plants, such as peppers, beans or lentils, can also be affected. Females lay eggs singly, or more rarely in pairs, on the stems or on the soil near the base of the seedlings (the 3-4-leaf stage is preferred). The application of farmyard manure to the soil seems to attract more female flies and increase ovoposition. Newly emerged larvae are cylindrical and white. They move up the plant and use their mouthhooks to masticate the tender parts of the new shoots, usually just above the first leaf sheath. Pupation usually occurred at the base of the stem. These flies can be a very damaging pests in agriculture in Central and Southeast Asia.
To this day no biological control for this pest is know. Please contact us if you know of any.
Always consider an integrated approach with preventive measures together with biological treatments if available. Currently the recommendations to suppress infestations in the crops are to sow early to avoid peak populations of these insects. The use of pyrethroid insecticides can also help to control populations.