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

Pea leaf miner, Cabbage semilooper and Leaf folder

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

• Distribution: Widely distributed in northern India.
• Host range: peas, cruciferous crops, chrysanthemum, antirrhinum, nasturtium, potato, linseed, etc.

Damage:

• Larva is the destructive stage
• Adult females also puncture the leaves for oviposition and feeding.
• Larvae feed by making the prominent tunnels between epidermis of leaves
• Interfere with the photosynthetic activity
• Growth of the plants is reduced.
• Tunnels make the leaf unattractive and give yellowish look
• Reduces the quality and market value

Identification (Also see under insect pests of peas)

• The adults are small (2-2.5 mm in length) flies
• Transparent and shining wings
• Grayish black mesonotum and yellowish frons.
• Females are slightly bigger than males with pointed ovipositor.

Life cycle:

• Adults emerge in December and lay eggs singly in the leaf tissue
• The eggs hatch in 2-3 days
• Larvae become full fed in about 5 days
• Pupate within the galleries
• Pupal period is 6 days
• total life cycle is completed in 13-14 days
• Several generations from December to April- May.

Management

• Removal and destruction of severely mined leaves
• Spray of triazophos (0.04%) or oxy-demeton-methyl (0.025%) at weekly intervals help in controlling the pest.
• Parasitoids also check the pest

4. Cabbage semilooper, Thysanoplusia orichalcea (Noctuidae: Lepidotptera)

• Distribution: Through out the North western India.
• Hosts: Many vegetable and ornamentals

Damage:

• Larvae bite round holes in the leaves
• Under severe infestation the entire leaf and flower may be eaten.
• Yield and quality is reduced considerably

Identification (Also see insect pests of cole crops)

• The larvae are plump and pale green in colour.
• Adults are light pale brown moths with a golden patch on each fore wing.

Life cycle:

• Eggs hatch in 3-5 days
• Larval period is 15-20 days
• Five larval instars
• Pupal period about 12 days
• Adult longevity is 7-13 days

Salient features

• Eggs are laid singly on the foliage
• Larvae bite holes of varying size according to their stage of development.
• Full grown the larva enters into the plant debris lying on the ground for pupation.
• Moths are very active at dusk and can be seen in large number during spring season.

Management:

• As soon as the attack in noticed spray the crop with malathion @ 0.05%
• The spray can be repeated after 7-10 days if attack persists.

5. Leaf folder, Hedylepta sp. (Pyraustidae: Lepidoptera)

Damage:

• Larvae roll the leaves up wards and feed within on chlorophyll
• Attacked leaves get skeletonized and ultimately get dried
• The damage is more sever if the growing tip is attacked

Identification and life cycle

• Adult moths lay pale white eggs singly or in small batches on leaves and tender shoots
• The larvae are green is colour, about 10-12 mm in length
• Larvae remain hidden inside the leaves by folding them
• Incubation, larval and pupal periods are 4-6, 12-15 and 5-6 days, respectively.
• Adult longevity is 5-6 days.

Management

• Apply deltamethrin (0.0028%) at 10 days interval.