This document discusses several common insect pests that affect onions: Thrips (Onion thrips and Western flower thrips) cause discolored and distorted leaves with a silvery appearance. Leafminers (Lyriomyza spp.) cause thin, winding trails on leaves that can result in white blotches and premature leaf drop. The onion maggot (Delia antiqua) stunts or wilts seedlings, causing plants to break at the soil line or deforming bulbs. Bulb mites (Rhizoglyphus spp. and Tyrophagus spp.) stunt growth and cause bulbs to rot in the ground or storage. The onion fly (Delia antiqua) causes

2. Onion Insects
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan

3. • Crop: OnionScientific name: Allium
cepaFamily: Solanaceae

5. 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

6. Leafminers
Lyriomyza 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

7. Onion maggot
Delia 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

8. 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

9. 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

10. Identification of Pest:
• 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

11. Ear wig: Euborellia annulipes
Symptoms of damage:
• Both nymphs and aduts
bore into the onion bulb
and feed.

12. Identification of pest:
Stages
• Eggs: are laid only in the
tender leaf
• Adult: The colour of the
insect varies from pale
yellow to grey