Presentation on

LEAF MINER

Introduction (Identification)

Flies of Order Diptera

Wide host range (vegetable, fruits & ornaments)

Recently known as a key pest of potato in central region of Nepal

Important sps are:

1) Liriomyza trifolii (unofficial 'serpentine' leafminer)

2) L. brassicae (official 'serpentine' leafminer)

3) L. sativae (vegetable leafminer) &

4) L. huidobrensis (pea and potato leafminer)

All are similar in appearance except black and yellow markings

Introduction (Identification)

1) L. sativae-vegetable

leafminer-shiny black on upper

surface

-area between the eyes

yellow

-area just behind eyes black

2) L. trifolii

-more grayish upper thorax

-area behind the eyes is

mostly yellow

3) L. Brassicae

similar to L. sativae

L. huidobrensis-pea leaf

miner

-slightly larger

-normally darker colour

All have similar life history except pea leafminer ( slighty longer)

Eggs laid in leaves & oviposition punctures leaves to form

'stipples'

Opt. Tempr21°C - 32°C (feeding & egg laying)

Egg-laying reduced below 10°C

After 2 - 3 days of incubation, eggs hatch

Larvae tunnel within the leaf tissue forming mine

Pupae can survive for up to 90 days when temperatures are cool or

host plants are not available

Life cycle 14 days at 30°C or as long as 64 days at 14°C

Mating, egg-laying, larval emergence from leaves and adult

emergence from pupae tends to occur mostly in the morning

Biology

Biology (Life cycle interval)

Life cycle of Leafminer fly

Adult female punctures leaves for

feeding & oviposition

Feeding & oviposition ratio- 6:1 to

14:1

Male also uses feeding punctures

made by females

Larvae feeding on mesophyll region

leaving a serpentine structure (mines)

Nature of Damage

Reduce yield, fruit size &

condition of sunburn may prevail

Heavily mined leaves have large

whitish blotches or speckles between

0.13 and 0.15 mm in diameter.

Premature dropping of injured

leaves

Nature of Damage

beet leaf cucumber

Nature of Damage (Gallery)

pea

bean cucumber potato

Sanitation

Remove plant debris/ weeds

Removal of infected plant material

Management

Tolerant varieties

Use tolerant varieties

Susceptible varieties have to be grown in isolation

Management

Mechanical control

Use yellow sticky trap [2m x 50cm

white polythene sheet painted with

the glue prepared by well mixed

wood gum (0.5 litre) and yellow

dye (20g)] in the crop field for

monitoring and mass trapping

purposes.

Use of net.

Crop RotationAlternating leafminer susceptible crops with resistant crops

Leaving greenhouses empty during the winter

Management

Weed Management

Remove wild host plants

Maintain weed free condition in field

Pheromone Lure

Tomato leaf miner lure

Parasitic wasps Diglyphus isaea & Dacnusa sibirica

Diglyphus works better in the summer & Dacnusa in the winter

Fig. Diglyphus isaea Fig. Dacnusa sibirica

Management (Biological)

Management (Botanical)

Apply 1-1.75 kg fine ash of Lantana camera per 200 sq m plot;

Neem product- Margosom (0.15% w/w Azadiractin)@ 5ml/litre

of water

Spray fruit extract of chinaberry Melia azedarach as a feeding

deterrent to adults and to reduce oviposition rates.

Apply abamectin 2% EC @ 1.5ml per litre water at 3-4 days

interval. Abamectin is a biopesticide derived insecticide seems to

kill the leafminers but not their predators.

Spray Nuvan 76% EC (dichlorovos) @ 1ml per litre water or

Deltamethrin 2.8% EC @ 1ml per litre water for managing

adults.

Management (Chemical)