Leaf miner

Several species of leafminers may attack a wide range of vegetable and ornamental crops in the field and in the greenhouse.

1. Wel -Come

2. P resentation on LEAF MINER Bishnu Prasad Ghimire - BSc . Ag. 6 th Sem. Economic Entomology (ENT 321) IAAS Lamjung

3. 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: Liriomyza trifolii (unofficial 'serpentine' leafminer ) L. brassicae (official 'serpentine' leafminer ) L. sativae (vegetable leafminer ) & L. huidobrensis (pea and potato leafminer ) All are similar in appearance except black and yellow markings

4. 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

5. All have similar life history except pea leafminer ( slighty longer) Eggs laid in leaves & oviposition punctures leaves to form 'stipples' Opt. Temp r 21°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

6. Biology (Life cycle interval)

7. Life cycle of Leafminer fly

8. 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

9. 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

10. beet leaf cucumber Nature of Damage (Gallery) pea bean cucumber potato

11. Sanitation Remove plant debris/ weeds Removal of infected plant material Management Tolerant varieties Use tolerant varieties Susceptible varieties have to be grown in isolation

12. 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. U se of net .

13. Crop Rotation Alternating 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

14. Parasitic wasps Diglyphus isaea & Dacnusa sibirica Diglyphus works better in the summer & Dacnusa in the winter Fig. Diglyphus isaea Fig. Dacnusa sibirica Management (Biological)

15. 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.

16. 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)

17. Thank You!