Sorghum Shoot Fly: An Integrated Pest Management Guide

Sorghum Shoot Fly is a major pest that threatens the productivity of sorghum crops worldwide. It is considered to be one of the most important and destructive pests of sorghum. The insect, Atherigona soccata, infests sorghum plants during early growth stages, damaging the developing leaves and shoots. Infestation can lead to reduced yield and in severe cases complete crop failure can occur. This article will give complete information about causes, symptoms and management of sorghum shoot flies. 

They are small grey colored flies which are polyphagous in nature attacking various other gramineous crops. Because of high humidity and moderate temperature, late sown crops generally suffer from sorghum shoot fly damage. Cloudy weather favors the development of sorghum shoot flies.  

Type of Infestation

The maggot bores into the central shoots of the sorghum plant and produces typical dead heart symptoms. 

Scientific Name: Atherigona soccata  

Most Affected States

Sorghum Shoot Fly is a major pest of sorghum crops in India. The pest is found in almost all the sorghum-growing states, but the major affected states are Maharashtra, Karnataka, Andhra Pradesh and Tamil Nadu.   

Symptoms of Sorghum Shoot Fly

The most common symptoms of sorghum shoot fly are: 

• After hatching, the maggot moves towards the upper surface of the leaf and enters the area between the leaf sheath and stem.
• The maggot bores inside the stem and cuts the growing point.
• Infested central shoots become dry and produce “dead heart” symptoms.
• As a result of infestation, plants produce side tillers.

Control Measures

Sorghum shoot flies are a common pest of sorghum and can cause significant damage if not managed effectively. To control these pests, an integrated approach that combines several management strategies is necessary.   

Cultural Meausres

• Immediately after the harvest, plough the field and remove and dispose of the stubble.
• To reduce the incidence of shoot flies, sow sorghum immediately at the onset of monsoon rains.
• Rotate sorghum with non-susceptible crops.
• Grow resistant sorghum varieties like Co-1, CSH 15R, Maldandi, Hagari, Swati, CSH7, ICSV 705 etc.
• Use higher seed rate of 12.5 kg/ha and during thinning remove shoot fly damaged seedlings. Or else raise nursery and then transplant only healthy seedlings.
• Avoid the application of farmyard manure after the plant emergence to avoid the oviposition sites for female flies.

Mechanical Measures

• Pull out and destroy the plants that show dead heart symptoms at the time of thinning.
• Install plastic fishmeal trap at the rate of 12 traps per hectare until the crop reaches 30 days old.

Biological Measures

• Release natural enemies like parasitoids such as Trichogramma toideasimmonalsi, Trichogramma chilonis, Neotrichoporoides nyemitawus and predators such as spiders, coccinellids, lacewings etc to keep the shoot fly populations in check.
• Ecotin Insecticide is a neem based biological insecticide containing Azadirachtin, which can be used effectively to control shoot flies. The recommended dosage is 0.5 ml per liter of water.

Chemical Measures

When the infestation is severe, chemical methods may be necessary. Some of the commonly used commercial chemicals for controlling sorghum stem borers are, 

Product Name	Technical Content	Dosage
Seed Treatment
Iffco Taiyo Plus Insecticide	Thiamethoxam 30% FS	10 ml/kg of seeds
Shamrock CP Gold Insecticide	Chlorpyriphos 20% EC	3 – 4 ml/kg of seeds
Gaucho Insecticide	Imidachloprid 48% FS	12 ml/kg of seeds
Foliar Spray
Tafgor Insecticide	Dimethoate 30% EC	1.5 – 2.5 ml/lit of water
Ekalux Insecticide	Quinalphos 25% EC	2 ml/lit of water