Safflower Aphid
Uroleucon carthami
📖 Description
Uroleucon carthami, the Safflower Aphid, is a monophagous aphid pest that feeds exclusively on safflower (Carthamus tinctorius). Safflower is an important rabi oilseed crop in India, grown on over 200,000 hectares primarily in Maharashtra (over 50 % of national area), Karnataka, Telangana, Andhra Pradesh, and Madhya Pradesh. The crop is valued for its drought tolerance — it is one of the few oilseeds that can be grown on residual soil moisture without irrigation in the Deccan plateau — and for the high linoleic acid content (over 75 %) of its oil, which is among the healthiest edible oils. The crop is also important for its flowers, which are used as a natural food colouring (kesar substitute) and in traditional medicine. Uroleucon carthami is the single most damaging insect pest of safflower in India — the species is monophagous, feeding exclusively on safflower, which means that safflower fields are the only significant habitat for the aphid and populations build up specifically on the crop. The aphid is most damaging during the December–February period when the crop is at the rosette to flowering stage and temperatures are cool (15–25 °C) — the aphid’s optimum range. Under favourable conditions, an aphid population can increase 10-fold per week, and the entire field can be infested within 2–3 weeks of initial colonisation. The damage is compounded by the fact that safflower is grown on residual moisture — aphid-infested plants cannot replace the phloem sap removed by the aphids, and the combined water stress of aphid feeding and limited soil moisture causes rapid plant decline. IPM packages developed by ICAR-IIOR Hyderabad emphasise early sowing, natural-enemy conservation, balanced nutrition, and need-based insecticide application as the core management tactics.
⚠️ Symptoms to watch for
- Curling and yellowing of leaves — the early symptom
- stunting of new shoots
- sooty mould growth on honeydew on lower leaves
- reduced flowering and seed set
- plant decline under heavy infestation.
- In safflower crops in Maharashtra (Ahmednagar, Solapur, Aurangabad, Latur), Karnataka, Telangana, Andhra Pradesh, and Madhya Pradesh, heavy infestation can reduce seed yield by 30–50 %.
- The damage is particularly damaging because safflower is largely grown as a rabi crop on residual soil moisture with no irrigation — aphid-infested plants cannot recover from the water stress imposed by aphid feeding.
🩹 Treatment
- Cultural: conserve natural enemies by avoiding broad-spectrum insecticides
- adopt early sowing (mid-September to mid-October) so the crop completes the vulnerable rosette stage before the December–January aphid peak.
- Mechanical: install yellow sticky traps at 8/ha to monitor aphid activity.
- Biological: release Chrysoperla zastrowi (green lacewing) larvae at 5,000/ha
- apply Beauveria bassiana at 5 g/L.
- Chemical: spray imidacloprid 17.8 SL @ 0.3 ml/L or dimethoate 30 EC @ 1.5 ml/L — both effective systemic insecticides
- pymetrozine 50 WG @ 0.5 g/L is a selective aphicide that conserves natural enemies.
🌿 Organic treatments
- Spray neem oil (Azadirachta indica) at 3 % emulsion at 7-day intervals
- apply Beauveria bassiana at 5 g/L
- release green lacewing larvae (Chrysoperla zastrowi) at 5,000/ha
- install yellow sticky traps at 8/ha
- spray garlic-chilli-soap repellent
- conserve natural enemies.
🧪 Chemical treatments
- Imidacloprid 17.8 SL @ 0.3 ml/L, Dimethoate 30 EC @ 1.5 ml/L, Pymetrozine 50 WG @ 0.5 g/L, Thiamethoxam 25 WG @ 0.4 g/L.
- Pre-harvest interval 7 days for imidacloprid, 14 days for dimethoate.
🛡️ Prevention
- Conserve natural enemies — the single most important preventive measure
- adopt early sowing (mid-September to mid-October) so the crop passes the vulnerable rosette stage before the December–January aphid peak
- maintain balanced nitrogen nutrition — excessive nitrogen promotes soft succulent growth attractive to aphids
- plant resistant or tolerant safflower varieties (e.g., Bhima, A-1, Nira) where available
- adopt a 2-year rotation with non-host cereals (wheat, sorghum)
- install yellow sticky traps at 8/ha to detect aphid activity early.
🪴 Affected plants
- Safflower (Carthamus tinctorius) — the only known host.
- The species is monophagous, feeding exclusively on safflower.
🦋 Natural predators
- Ladybirds (Coccinellidae — Coccinella septempunctata, Menochilus sexmaculatus, the most important aphid predators in safflower)
- green lacewing larvae (Chrysoperla zastrowi)
- hoverfly larvae (Syrphidae)
- aphid parasitoids (Lysiphlebus, Diaeretiella rapae, Aphidius — parasitise 20–40 % of aphids in unsprayed fields)
- predatory bugs (Geocoris, Nabis)
- and predatory midge larvae (Aphidoletes aphidimyza).
🌱 Host plants
- Carthamus tinctorius (safflower) — the only known host (monophagous).
🔄 Lifecycle
- In tropical India, reproduction is entirely parthenogenetic (anholocyclic) — females give birth to live female nymphs without mating.
- Each female produces 60–100 nymphs in her 20–25 day lifespan.
- Nymph passes through four instars over 7–10 days.
- Adult longevity 20–25 days.
- Total lifecycle (birth to reproduction) 7–10 days in winter, 12–15 days in cool winter nights.
- Twenty to thirty overlapping generations per year in tropical India — though the species is largely confined to safflower fields and population dynamics track the safflower cropping cycle.
📅 Season
- Active November–March across the Indian safflower belt; peak infestation December–February when the crop is at the rosette to flowering stage and temperatures are cool.
- Population crashes during the hot dry season (April–June) — the species apparently over-summers as parthenogenetic females on volunteer safflower plants.
🔎 Appearance
- Adult is a medium-sized pear-shaped aphid — colour dark reddish-brown to almost black; legs and antennae are dark and relatively long; cornicles (siphunculi) are long, slender, and dark, about 1/3 the body length; cauda is short and pale.
- The body is somewhat shiny and lacks a waxy powder.
- Winged forms (alatae) have a dark thorax and transparent wings with dark veins.
- Nymphs are smaller, paler versions of adults — typically dark green to brownish.
💥 Damage level
- Severe
🔁 Reproduction rate
- Fast
🗺️ Geographic regions
- Cosmopolitan in safflower-growing regions worldwide — wherever its monophagous host is cultivated.
- India, USA, Mexico, Ethiopia, Australia, parts of Europe and the Middle East.
Have an Insect to Identify?
Upload or take a photo of an insect on your plant and our AI will identify it and recommend treatments.
📷 Diagnose from Image