Insect Pests of Vegetable, Ornamental and Spice Crops (2+1)

Pea pod borers and Leaf Miner

1. Pea pod borer/ Lentil pod borer, Etiella zinckenella (Phycitidae: Lepidoptera)

• Distribution : India, Myanmar, Sri Lanka
• Host range : Serious pest of lentil, peas and other pulse crops

Damage

• Damage is caused by the caterpillars.
• Feed on floral parts, newly formed pods and seeds inside the developing pods
• Heavy reduction in the yield.

Identification

• Newly emerged caterpillars are greenish
• Full grown larvae are rosy with purpulish tinge
• The moths are grey with a wing expanse of about 25 mm
• The forewings have dark marginal lines and orcheous scales.

Life cycle

• Eggs hatch in 5 days at 25oC,
• The larval stage is completed in 10-27 days.
• Pupal development is completed in 10-15 days.
• Completes five over lapping generations.

Salient features

• The moths emerge during February-March
• Lay eggs singly and/or in clusters on various parts
• The newly emerged larvae feed on floral parts
• Subsequently bore into the pods and feed on the developing seeds.
• Pupate in the soil at a depth of 2-4 cm
• Breeds throughout the year

Management:

• At flower initiation, spray the crop with deltamethrin @ 0.0028%
• Insecticides recommended for the control of H. armigera are also effective

2. Tomato fruits borer, Helicoverpa armígera

• Discussed under the insect pests of tomato.

3. Pea Leaf miner, Chromatomyia horticola (Agromyzidae: Diptera)

• Hosts: Peas, Brassica crops and some ornamentals.

Damage:

• Maggots mine in to leaves
• feed on mesophyll leaving the two epidermal layers intact
• The mines start from the periphery and ends up towards the mid rib
• Photosynthesis is considerably reduced
• Under severe infestation leaves wither away and are shed
• Flowering and fruiting is reduced considerably.

Identification

• The eggs are oval, spherical, translucent white when freshly laid but turns dull white before hatching
• The larva is translucent white and the inverted ‘Y’ shaped oral hook is clearly visible
• Pupa is fusiform with distinctly defined segments
• Initially it is light brown but turns dark towards maturity.
• Adults are two winged flies having grayish black mesonotum.
• Females are black with brown head

Life cycle

• Incubation is 1-2 days.
• Larval period is 6 days.
• Pupal stage lasts for 9-10 days
• Adult longevity is 27 days (females) and 10 days (males)
• Mating occur after 1-8 days of emergence
• A female on an average lays 294 eggs during its life.

Salient features

• Lay eggs inside the leaf tissue.
• One egg is laid in one insertion.
• Most of the eggs are laid near the leaf margin.
• Pupate inside the mine

Management:

• Application of oxy- demeton methyl, dimethoate, chlorpyriphos, have been reported effective against this pest.
• Large number of larval (Diglyphus sp, Neochrysocharis sp, Asecodes spp, etc.) and larval- pupal (Opius sp) parasitoids are active in nature
• Avoid insecticides when parasitoids are active.