Sorghum midge, Contarinia sorghicola, is a small fly belonging to the Family Cecidomyiidae of Order Diptera and is native to tropical and subtropical regions of the world. It feeds on developing panicles of Sorghum, robbing the plant of its ability to produce viable seeds. The presence of other pests like aphids, thrips, and beetles can further intensify the damage.
If the infestation is severe, the crop can be completely lost. To effectively manage this pest, it is important to understand its life cycle, its preferred habitats, and the best methods for controlling it. This article will provide an overview and discussion of the sorghum midge pest, including its symptoms, identification techniques, and control.
Sorghum Midge Management in Sorghum
Life Cycle of Sorghum Midge
The lifecycle comprises four stages: egg, larva, pupa, and adult. The female midge will lay its eggs on the stem, and the developing florets of sorghum plants’ inflorescence result in pollen dispersal at varying times. Adult females can lay 25-40 eggs at 7-11 pet florets. The incubation period for an egg is 3-4 days.
These eggs will now hatch into larvae known as maggots. The maggots feed on the pith of the stem, and its span is approximately 9-11 days comprising of 4 instars. The larval phase remains dormant in a cocoon between December to January in a spikelet. The duration of the pupal phase is 3-4 days. The adult arises from the pupa and feeds on nectar and pollen from flowers of sorghum plants.
The female midge lays eggs in the stems, beginning the cycle again. One lifecycle is completed in 15-17 days. So, each female can produce 10-12 generations. The sorghum midge pest is most damaging when it attacks young plants early in the vegetative phase. Sorghum midge infestation can also increase Sorghum’s susceptibility to other pests and diseases.
Occurrence of Sorghum Midge
- Location of Sorghum midge: The pest occurs in India, Pakistan, Bangladesh, Sri Lanka, Africa, South East Asia, China, West Indies, the USA, and Italy.
- Host range: The pest can cause an infestation in Sorghum’s cultivated and wild species.
Factors Favoring Population Increase in Sorghum Midge in Field
- Weather conditions: Warmer temperatures with higher relative humidity are the most favorable conditions for the development and reproduction of sorghum midge.
- Host plant availability: Sorghum midge attracts host plants with high sugar content, such as Sorghum. The sorghum midge population increases when host plant availability is high.
- High reproductive rate: The midge can produce several generations per season, leading to a rapid buildup of its population in a short amount of time. Additionally, the female midge can mate multiple times, resulting in an increased production of offspring.
- Lack of natural enemies: If no natural enemies are present, such as predators, parasitoids, and pathogens, the population of sorghum midge can increase.
- Poor Cultural control practices: Poor cultural control practices, such as crop rotation and timely destruction of crop residues, can increase the population of sorghum midge pests in sorghum crops.
- High-fertility soils: High-fertility soils, with ample nutrients and organic matter, can favor a higher population of sorghum midge pests in sorghum crops.
Identification of Sorghum Midge in the Sorghum field
- Egg: The eggs are very small, measuring about 0.04-0.05 mm in length, are either laid in solitary or bundles, and are white.
- Larva: The larval stage of the Sorghum Midge is the most destructive stage of its lifecycle. The larvae are white, spindle-shaped, and measure about 4 mm in length.
- Pupa: The pupal stage of the Sorghum Midge is the