Apricot Slug Caterpillar
Parasa consocia
Chewing Insects Moderate Risk 20–25 mm wingspan (adult); 15–18 mm (mature larva)
📖 Description
Parasa consocia is a limacodid (slug caterpillar) moth whose larvae are defoliators of temperate fruit trees across the Himalayan belt. The family Limacodidae is famous for its urticating larvae — P. consocia spines contain a venom that causes pain comparable to a bee sting and can trigger allergic reactions in sensitive individuals. Indian apricot acreage (~13,000 ha, producing 12,000 tonnes) is concentrated in Ladakh, Kashmir, Himachal Pradesh, and Uttarakhand; outbreaks are sporadic but severe, with 2020 reports from Kargil describing 60 % defoliation of seedling orchards. The species is univoltine in the Himalayas, with a brief adult flight in July–August.
⚠️ Symptoms to watch for
- Larval feeding produces skeletonised patches on the lower leaf surface, leaving the upper epidermis intact initially — later the entire leaf is consumed except for the midrib. Heavy infestations defoliate young shoots and reduce fruit set the following year. Contact with the urticating spines causes immediate intense burning pain, localised swelling, and erythema in orchard workers — historically a significant occupational hazard during hand-harvest of apricots in Kashmir and Ladakh.
🩹 Treatment
- Hand-pick larvae using thick rubber gloves — never touch with bare skin. Spray Bacillus thuringiensis var. kurstaki (Btk) at 1 g/L against early instars. Apply spinosad 45 SC at 0.3 ml/L or emamectin benzoate 5 SG at 0.3 g/L for severe infestations. Avoid broad-spectrum insecticides that kill parasitoids.
🌿 Organic treatments
- Btk (1 g/L) at first hatch. Neem oil (1 % Azadirachtin) at 5 ml/L. Encourage predatory bugs (Anthocoridae) and lacewings by maintaining ground cover. Apply Beauveria bassiana at 5 g/L if humidity is high. Crush egg clusters (laid in groups of 10–30 on leaf undersides) — easily visible as flat yellowish discs.
🧪 Chemical treatments
- Spinosad 45 SC (0.3 ml/L), emamectin benzoate 5 SG (0.3 g/L), or chlorantraniliprole 18.5 SC (0.3 ml/L). Apply at dusk to protect pollinators and avoid UV degradation of Btk.
🛡️ Prevention
- Prune lower branches to improve airflow and reduce oviposition sites. Clean cultivation in winter removes overwintering cocoons from bark crevices and ground litter. Plant apricot cultivars with thicker leaves ('Kaisa', 'Shakarpara') which are less preferred.
🪴 Affected plants
- Apricot (Prunus armeniaca) is the primary host; also feeds on almond, peach, plum, pear, apple, walnut, and occasionally rose and hawthorn in mixed Himalayan orchards.
🦋 Natural predators
- Predatory bugs (Anthocoridae — Anthocoris nemoralis), lacewings (Chrysoperla zastrowi sillemi), and birds (Parus major, Aegithalos concinnus) feed on eggs and young larvae. Parasitoids include Apanteles spp. (Braconidae) and tachinid flies (Compsilura concinnata) — though the urticating spines provide substantial protection against generalist predators.
🌱 Host plants
- Prunus armeniaca (apricot — primary host), Prunus dulcis (almond), Prunus persica (peach), Prunus domestica (plum), Pyrus communis (pear), Malus domestica (apple), Juglans regia (walnut), Rosa spp. (rose), Crataegus spp. (hawthorn).
🔄 Lifecycle
- Egg (7–10 days, laid in clusters of 10–30 on leaf undersides) → Larva (35–50 days, 6 instars, slug-like) → Pupa (8–9 months, overwinters in tough brown cocoon attached to bark or in litter) → Adult (10–15 days, July–August flight).
- Univoltine.
📅 Season
- Adult flight: July–August.
- Oviposition: July–August.
- Larval feeding: August–October.
- Pupation: October onward.
- Overwintering pupal stage: November–July.
🔎 Appearance
- Adult moths are brown with a greenish central patch on the forewings and two silvery spots.
- Larvae are unmistakable — oval, slug-like, flattened, bright green with a yellow lateral stripe and seven pairs of lateral fleshy lobes covered in stinging urticating spines.
- The larva's head is retractable and hidden beneath the thorax, giving it a featureless 'blob' appearance.
💥 Damage level
- Moderate
🔁 Reproduction rate
- Moderate
🗺️ Geographic regions
- Indian Himalayan temperate fruit belt (J&K
- Ladakh
- Himachal Pradesh
- Uttarakhand); also reported from China
- Japan
- Korea
- and the Russian Far 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