onion insects a lecture by allah dad khan provincial coordinator ipm minfal islamabad
TRANSCRIPT
Onion Insects A
Lecture To ToT trainees ( FFS) By
Mr. Allah Dad Khan Provincial Coordinator
IPM KPK MINFAL Pakistan
• Crop: OnionScientific name: Allium cepaFamily: Solanaceae
Lesser bulb fly:
Symptoms • 1. Pull up and destroy all plants infected with
these onion pests at the time you know they are in the bulbs and before they have burrowed back into the soil. The fact that these onion pests work in patches or bulb by bulb down a row, makes it easier to spot plants in trouble and get them out.
• Scattering onion planting throughout the garden helps, and removing the soil is also a good idea.
• 2. Press down the soil around seedlings well, cover with paper, cloth or other insect-proof material to stop the onion fly from laying its eggs into the soil.
• 3. Spreading a fine layer of sand or wood ash around the onion plants is also a good deterrent to adult onion flies from laying their eggs at the base of the plants.
Thrips (Onion thrips, Western flower thrips)Thrips tabaci
Frankliniella occidentalis
Symptoms
• Discolored, distorted tissue; scarring of leaves; severly infected plants may have a silvery appearance; insect is small (1.5 mm) and slender and best viewed using a hand lens; adult thrips are pale yellow to light brown and the nymphs are smaller and lighter in color
• Cause• Insect
LeafminersLyriomyza spp.
Symptoms
• Thin, white, winding trails on leaves; heavy mining can result in white blotches on leaves and leaves dropping from the plant prematurely; early infestation can cause yield to be reduced; adult leafminer is a small black and yellow fly which lays its eggs in the leaf; larvae hatch and feed on leaf interior
• Cause• Insects
Onion maggotDelia antiqua
Symptoms
• Stunted or wilting seedlings; plant will commonly break at soil line if an attempt is made to pull it up; if infestation occurs when plants are bulbing, bulbs will be deformed and susceptable to storage rots after harvest; adult insect is a greyish fly which lays white, elongate eggs around the base of the plant; the larvae that emerge from the eggs are tiny and white and bore into the plant; mature larvae are about 1 cm (0.4 in) long with feeding hooks
• Cause• Insect
Bulb mites Rhizoglyphus spp.Tyrophagus spp.
Symptoms
• Stunted plant growth; reduced stand; bulbs rotting in ground or in storage; pest is a cream-white, bulbous mite <1 mm in length, which resembles a pearl with legs
• Cause• Arachnid
Onion Fly: Delia antiqua
Symptoms• of damage:• Onion leaves get rotten,
shredded and rolled up• Growth of onion tubers gets
hampered, tissues get decayed and becoming unfit for marketing
Identification of Pest:
Stages of insects • Egg: long whitish colour
eggs are laid on the undersurface of onion near soil
• Larva: Whitish and adopous• Pupa: Pupation takes place
in soil• Adult: Grey coloured fly
Ear wig: Euborellia annulipes
Symptoms of damage:
• Both nymphs and aduts bore into the onion bulb and feed.
Identification of pest:
Stages • Eggs: are laid only in the
tender leaf• Adult: The colour of the
insect varies from pale yellow to grey