Delia flavibasis (Stein)
(Formerly known as Hylemyia flavibasis Stein)
Taxonomic placing: Insecta, Holometabola, Diptera, Brachycera, Anthomyiiae.
Common name: Cereal root maggot.
Geographical distribution: North and East Africa, the Middle East, Southern Europe.
Morphology: The body is dark-brown, about 5-6 mm long. The maggot is white, 3-4 mm in length.
Host plants: Cultivated cereals, especially barley and wheat.
Life cycle: The females lay their eggs on the ground during early winter, as the cereals begin to sprout. The hatching maggots penetrate the young leaves and move towards the root collar. They pupate in the soil, emerging in late winter. Adults live for 1-2 weeks and a generation is completed in 3-4 weeks.
Economic importance: In the Middle East this maggot is an occasional pest of wheat and barley, its damage is usually seen only when early seeding combines with late rains. Up to 40% of the plants may then be affected. The larvae gnaw tunnels in the root collar (“heart”), causing liquefaction and promoting rot. Attacked plants may however recover after timely rains; furthermore, in the spring the stems of growing plants harden, becoming immune to the pest. In Ethiopia D flavibasis is a major pest of wheat and malt barley, frequently causing 100% damage to susceptible cultivars, and is a major constraint on barley cultivation in the Bale highlands of southern Ethiopia.
Management
Horticultural control: Deep plowing (down to about 40 cm) reduces pest survival in the soil. Other methods include crop rotation (e.i. alternating cereals with non-cereals), burning any remaining cereal stubble in the field, including the volunteers and leaving the soil fallow for at least 2 years.
Plant resistance: Some East-African barley cultivars are tolerant or resistant to the pest.
Chemical control: Insecticides like carbamates and pyrethroids control the pest. Seed coating with imidacloprid is recommended in Israel. .
References
Giladi, Y., Naftaliyahu, U. and Richker, E. 2013. Wheat and fodder cultivation for seeds and fodder. Nir VaTelem 44: 14 (in Hebrew).
Goftishu, M., Tefera, T. and Getu, E. 2009. Biology of barley shoot fly Delia flavibasis Stein (Diptera: Anthomyiidae) on resistant and susceptible barley cultivars. Journal of Pest Science 82: 67–71.
Macharia, M. and Mueke, J.M. 1986. Resistance of barley varieties to barley fly Delia flavibasis Stein (Diptera: Anthomyiidae). International Journal of Tropical Insect Science 7: 75-77.
Tafa, J. 2007. Delia flavibasis Stein (Diptera: Anthomyiidae) as a major pest of wheat in the major cereal belt, southern Ethiopia. African Crop Science Conference Proceedings 8: 965-969.