Scientific name: Contarinia sorghicola (Coquillett)
Common name: Sorghum Midge
Main hosts: Sorghum spp. (cultivated and wild)
IMPORTANCE IN ETHIOPIA:
Major pest of: Sorghum
DISTRIBUTION IN ETHIOPIA:
Probably this is only a pest below an altitude of 1000 meters above sea level.
The larvae feed on developing grains. This causes the seeds to shrivel and become malformed. In heavy attacks the whole head may be empty of normal grains.
INSECT BIOLOGY & RECOGNITION:
Egg: The elongate egg is 0.4 mm long and 0.1 mm wide. The colour is orange yellow. The female lays the eggs near the spikelet tip while the spikelet is in bloom. The eggs hatch after 2-4 days.
Larva: The full grown maggot is 1.5-2.0 mm long. It has an orange red to red colour and dark mouthparts. The maggots feed on the developing grain and arrest its growth. The larval stage takes 9-11 days.
Pupa: Pupation takes place in the spikelet or in the soil. The colour is reddish with a darker anterior part. It is 1.8-2.0 mm long. Sometimes pupation takes place in cocoons.
Adult: Adult females are, including ovipositor, 2.3-2.8 mm long. Without ovipositor, the length is 1-1.5 mm. They are red to orange red in colour. The wings are covered with small hairs and have a fringe at the margin.
Plant as soon as possible after the rains begin and plant the whole crop in the area at the same time.
Use varieties which do not tiller and which flower at the same time.
Use resistant varieties when available.