Pea leaf miner, Cabbage semilooper and Leaf folder

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.
23.2

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

Last modified: Saturday, 3 March 2012, 8:34 AM