Dusky cotton bug and other

Dusky cotton bug and Others

6. Dusky cotton bug
  • Common name: Dusky cotton bug
  • Scientific name: Oxycarenus laetus
  • Family: Lygaeidae
  • Order: Hemiptera
  • Distribution: All over the Indian subcontinent
  • Host range: Cotton, okra, hollyhock, and other malvaceous plants.
Damage:
  • Nymphs and adults are damaging
  • Suck the cell sap from leaves and fruits
  • Reduces the vitality of the plants
Life cycle
  • Eggs hach in 5-10 days
  • Nymphal period is30-40 days
  • 7 stages.
  • Total life cycle is completed in 36-50 days
Salient features
  • The pest is active throughout the year, but during winter only adults are found
  • During spring cigar shaped eggs are laid on the leaves of okra or Hibiscus
  • Eggs initially are whiteish but turns light pink before hatching
Management:
  • Same as cotton jassid
7. Cotton leaf roller
  • Common name: Cotton leaf roller
  • Scientific name: Sylepta derogata
  • Family: Pyralidae
  • Order: Lepidoptera
  • Distribution: Orient, Africa, Indian sub continent
  • Host range: Cotton, okra and other malvaceous plants
Damage:
  • Newly emerged caterpillars feed on epidermis of ventral surface of leaves
  • Roll the leaves and feed within eating away large proportion of the rolled leaves.
  • Initially more than one larvae can be found in one leaf roll
  • Later on caterpillars disperse and attack more and more leaves.
Identification
  • The eggs are round in shape and yellowish green in colour
  • Caterpillars are shiny green in colour and more or less transparent
  • Pupae are reddish brown
  • Moths are yellowish white with both the fore and hind wings having brown lines and distinct markings
  • Wing expanse is 30-38 mm.
Life cycle
  • Each female lay 200-300 eggs
  • Incubation period is 2-6 days
  • Larval development is completed in 15-35 days
  • 7 stages.
  • Pupal period is 6-12 days
  • Adult longevity is about a week
  • Total life cycle is completed in 23-53 days
  • There are 5-6 overlapping generations in a year
Salient features
  • The pest is active from March to October
  • Passes the winter as a full grown caterpillar in plant debris or soi
  • The hibernating larvae pupate by the end of February
  • Moths emerge during March
  • Lay eggs singly on the underside of the leaves
  • Pupate inside the rolled leaves or plant debris in the soil
  • Low temperatures, high RH, cloudy and rainy days favour hibernation
  • Warm weather is conducive for rapid multiplication.
Management:
  • Collect and destroy the rolled leaves with caterpillars inside.
  • Irrigate & plough the field after harvesting to kill the hibernating caterpillars
  • Chemicals recommended for E. vittella also control this pest.
  • Parasitiods like Trichogramma spp. Apanteles spp.
8. Blister beetles
13.4
  • Discussed under bean
9. Phytophagous mites
  • Discussed earlier
10. Cutworms, Agrotis spp
  • Discussed earlier
11. Leaf miner
13.5
12. Beetles:
13.6
Last modified: Saturday, 3 March 2012, 6:33 AM