Major Insect Pests of Sesame and their Management

Sesame (Sesamum indicum L.), is commonly known as gingelly, til and simsim. Sesame oil is considered to be one of the healthy cooking oils due to rich source of oleic (40-50%) and linoleic (35-45%) fatty acids. Sesame seeds are used in large number of confectionary products and sweets in addition to industrial, nutraceutical and pharmaceutical uses.

India is the largest producer of sesame in the world with a production of 7.84 lakh tonnes from 15.62 lakh hectares (2018). The crop is mainly cultivated in the states of Rajasthan, Uttar Pradesh, Madhya Pradesh, Gujarat, West Bengal, Andhra Pradesh, Tamil Nadu, Karnataka and Maharashtra. </p

Insect pests cause yield losses ranging from 10-60% under different climatic conditions contributing to low productivity of the sesame. The sucking pest, leafhopper (Orosius albicinctus) is a vector of serious disease viz. phyllody. Major insect pests of sesame, their characteristic symptoms and recommended management practices are furnished below.

Leaf webber or roller and capsule borer (Antigastra catalaunalis)

Symptoms of damage

Larvae web together a few top leaves and feed them. In the early stage of infestation, the plant dies without producing any branch or shoot. In later stage of attack, infested shoots stop growing. At flowering, larvae feed inside the flowers and on capsule formation, larvae bore into capsules and feed on developing seeds. The pest remains active during July to September.

Management

• Collect and destroy the larvae from the leaf webs during the initial stages of plant growth.
• Erect bird perches @ 40-50/ha to facilitate predation of larvae.
• Spray neem seed kernels extract (NSKE) 5% or neem oil @ 5 ml/l or spinosad 45SC @ 0.2 ml/l or flubendiamide 480SC @ 0.3 ml/l or chlorantraniliprole 18.5SC @ 0.4 ml/l or quinalphos 25EC @ 2 ml/l or profenofos 50EC @ 2 ml/l.

Gall fly (Asphondylia sesami) and Bud fly (Dasineura sesami)

Symptoms of damage:

Maggots feed inside the floral bud leading to formation of gall like structure which do not develop into flower/capsule. The affected buds wither and drop. The pest remains active at the time of bud initiation.

Management

• Clipping of the galls, picking and burning the shed buds may help as prophylactic measure.
• Spray neem seed kernels extract (NSKE) 5% or dimethoate 30EC @ 1.5 ml/l or quinalphos 25EC @ 1.5 ml/l or imidacloprid 17.8SL @ 0.3 ml/l at bud initiation stage.

Sesame leafhopper (Orosius albicinctus)

Symptoms of damage:

Nymph and adults suck the sap of tender parts of the plants. Infestation of the pest lead to curling of leaf edges, leaves turn red or brown and then dries up and drop. The jassid or leafhopper is a serious pest of sesame and is known to transmit phyllody disease. The pest remains active from vegetative to capsule stage.

Management

• Seed treatment with imidachloprid 70WS @ 7.5 g/kg or thiamethoxam 25WG @ 5 g/kg seed. </li.
• Spray neem seed kernels extract (NSKE) 5% or dimethoate 30EC@ 1.5 ml/l or oxydemeton methyl 25EC @ 1.5ml/or imidacloprid 17.8SL @ 0.3 ml/l or acetamiprid 20SP @ 0.3 g/l or thiamethoxam 25WG @ 0.3 g/l or thiacloprid 21.7 SC @ 1 ml/l.

Hawk moth or Sphinx caterpillar (Acherontia styx)

Symptoms of damage:

Caterpillars feed on the leaves and defoliate the plant. The pest remains active throughout the crop season on young and grown-up crop.

Management

• Deep ploughing exposes the pupae for predation to insectivorous birds.
• Collection and destruction of caterpillars.
• Spray neem seed kernels extract (NSKE) 5% or quinalphos 25EC @ 1.5 ml/l or chlorpyrifos 20EC @ 2 ml/l.

Bihar hairy caterpillar (Spilosoma obliqua)

Symptoms of damage

In the early stages, larvae are gregarious feeders and are concentrated on few plants. Mature caterpillars migrate to other plants and feed voraciously leaving only the stem. The pest incidence occurs from vegetative stage and continues till maturity.

Management

• Collect and destroy infested plant parts, egg masses and young larvae during gregarious phase.
• Erect bird perches @ 40-50/ha to facilitate predation of larvae.
• Install one light trap per hectare to catch the adults.
• Use Bacillus thuringiensis var. kurstaki @ 1 g/l or neem seed kernels extract (NSKE) 5% or chlorpyrifos 20EC @ 1.5 ml/l or quinalphos 25EC @ 1.5 ml/l or acephate 75SP @ 1.5 g/l or indoxacarb 15.8EC @ 0.5 ml/l.

Source : P. Duraimurugan, ICAR - Indian Institute of Oilseeds Research, Hyderabad, Telangana, India