Other

Shoot Flies

Atherigona sp.

Insect

In a Nutshell

  • The maggot feeds on the shoots of young growing seedlings resulting in “dead hearts”.
  • Small circular cuts visible at the point of entrance on new shoots.
  • Leaves turn yellowish-green and droop, seedlings are stunted.

Can also be found in

6 Crops

Other

Symptoms

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.

Recommendations

Organic Control

To this day no biological control for this pest is know. Please contact us if you know of any.

Chemical Control

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.

What caused it?

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.


Preventive Measures

  • Do not to move soil from infested to healthy plots.
  • Choose resilient varieties if available.
  • In some cases, sowing early can sometimes allow the crop to pass the vulnerable stage (young seedlings) before the peak emergence of the fly.
  • Late sowing has also been shown to reduce incidence of dead heart in maize.
  • Remove weeds in and around the field.
  • Plan a good and balanced fertilization program.
  • Avoid the application of farmyard manure after plant emergence.
  • Control insecticide use in order not to affect beneficial insects.
  • Plan a crop rotation with non-susceptible crops after harvest.

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