Photo: Khan, Kakar & Kamran (2024) · CC BY 4.0 · source ↗
Sorghum shoot fly (Atherigona soccata)
The sorghum shoot fly Atherigona soccata Rondani is the most important early-season insect pest of sorghum (jowar) across India. It is responsible for 30-90% deadheart loss in late-sown kharif and rabi sorghum and is the single biggest reason farmers shift sowing dates or use seed-treatment insecticides. The pest also damages pearl millet to a smaller extent and overlaps biologically with A. approximata on bajra.
Identification
- Adult: small grey-yellow Muscid fly, 3-3.5 mm long, with a distinct shining black abdomen
- Egg: white, cigar-shaped, laid singly on the underside of young sorghum leaves close to the midrib, 1-3 weeks after seedling emergence
- Larva (maggot): yellowish-white, legless, 4-5 mm at maturity; it bores into the central shoot and feeds on the growing tip
- Damage symptom — deadheart: the central whorl leaf dries while older leaves remain green; the dried whorl pulls out easily with a foul smell. This deadheart symptom is the field signature of the pest
Hosts and lifecycle
Sorghum (Sorghum bicolor) is the primary host; secondary hosts include pearl millet and several wild grasses (Echinochloa, Setaria). The lifecycle completes in 17-21 days. Females lay eggs only on seedlings between the 5-25 day stage; older plants are not attacked. Damage potential is therefore concentrated in the first three weeks after emergence. Multiple overlapping generations occur during the kharif season, with peak activity in July-August on late-sown crops and again in October-November on rabi sorghum.
Damage and economic impact
In endemic Maharashtra-Karnataka-Telangana sorghum tracts and Anantapur-Kurnool kharif sorghum, deadheart incidence on susceptible cultivars routinely reaches 40-70%. Affected plants either die or produce side-tillers with smaller panicles, so even surviving plants yield 30-50% less. Late-sown crops past the optimum monsoon window are particularly hit. ICAR-IIMR multi-year network data attribute roughly 30% national yield gap in kharif sorghum to shoot fly alone.
Management
The ICAR-IIMR and AICRP-Sorghum integrated package is:
- Cultural / agronomic:
- Early sowing with the first monsoon rains — escapes peak fly activity in mid-July
- Higher seed rate (12-15 kg/ha instead of 10) and thinning at 15-20 DAS to remove deadheart plants
- Avoid staggered sowing of sorghum within a 1 km radius (continuous egg supply)
- 1:1 intercropping with pulses (cowpea, blackgram) reduces oviposition
- Resistant cultivars: ICSV 705, CSV 15, CSV 22, IS 18551, M-35-1, Phule Chitra and the IIMR-bred shoot-fly-tolerant lines combine non-preference (glossy leaves, trichome density) with antibiosis
- Seed treatment: imidacloprid 600 FS at 10-14 ml/kg seed or thiamethoxam 30 FS at 10 ml/kg seed gives 25-30 days of systemic protection — the standard recommendation
- Foliar sprays at 7-12 DAS: cypermethrin 10 EC at 1 ml/L, lambda-cyhalothrin 5 EC at 1 ml/L, or thiamethoxam 25 WG at 0.2 g/L if seed treatment was missed
- Biological: parasitoid Neotrichoporoides nyemitawus gives natural control in undisturbed fields; conserve by avoiding broad-spectrum sprays
Related pages
See also: Sorghum (jowar) crop, Pearl millet cultivation, Fall armyworm in maize, Pheromone traps.
Sources
- Shoot fly of sorghum: management. ICAR-Indian Institute of Millets Research, Hyderabad.
- Atherigona soccata factsheet. CABI Plantwise.
- Shoot fly resistance in sorghum. ICRISAT, Patancheru.