INSECT PESTS OF POTATO CROP AND THEIR MANAGEMENT

INSECT PESTS OF POTATO CROP AND THEIR MANAGEME

1. INSECT PESTS OF POTATO CROP Mr. Khushwinder singh Assistant Professor Guru Kashi University Talwandi Sabo, Punjab

2. POTATO TUBER MOTH Scientific name : Phthorimaea operculella Family : Gelechiidae Order : Lepidoptera

3. LIFE CYCLE : Egg:   Oval eggs are laid singly on the underside of potato leaves and exposed tuber. Whe n first laid they are pearly white changing to yellow on maturity and black just before hatching Egg period is 2-6 days Caterpillar:  Yellow coloured caterpillar with dark brown head. On hatching is 1-2mm long and grows through four instars to reach a length of 15-20mm . All instars have a dark brown head . Larval period 16-24 days Pupa:  Pupae formed in a cocoon covered with soil particle .pupation occurs among dead potato leaves pupal period is 6-9 days Adult:  Small narrow winged moth, greyish brown forewings and hind wings are dirty white Body size is 10mm in length mainly active in dark but in during the day can be seen flying sporadically within potato crops

4. Adult Larvae Pupae

5. SYMPTOMS OF DAMAGE : It is a pest of field and storage Larva tunnels into foliage, stem and tubers Galleries are formed near tuber eyes It also bores into petioles (leaf stalks) and terminal shoots. The main danger is to tubers both in the field and under storage. Tuber-mining larvae usually enter through the "eyes" from eggs laid nearby, and make slender, dirty-looking tunnels throughout the tuber. The caterpillars bore the tubers and feed, as a result of damage, the potato tubers rot

6. MANAGEMENT : Construct potato stores away from godowns Timely earthing -up of the crop to cover the exposed tubers helps in reducing the intensity of infestation. Two sprays with 0.05% quinalphos, 0.05% endosulfan or 0.1% carbaryl at 15 days interval starting 60 days after planting controls the pest effectively. Heaps of harvested potatoes should not be kept exposed in the field but covered with straw and infested tubers should be rejected before storage. Experience with Copidosoma koehleri B. an egg-larval parasite of potato tuber worm found to reduce the pest infestation by 50-55% when released at the rate of 20,000mummies/ha at 7 days interval starting 45 days after planting.

7. POTATO CUT WORM SCINTIFIC NAME : Agrotis ipsilon {greasy cut worm} Agrotis segetum {black cut worm} FAMILY : Noctuidae ORDER: Lepidoptera

8. Agrotis ipsilon : Fore wing is pale brown with dark purplish brown along costal end . Hind wing is white with brown tinge .Male has bipectinate antenna and female has filliform antenna Agrotis segtum : Fore wing is gery with peg and spot like marking Hind wing is dull white.male has bipectinate antenna and female has filliform antenna

9. LIFE CYCLE EGG : A female lays 300-350 eggs (maximum 1800) in 10-15 clustors of 20-35 eggs on ventral leaf surface or moist soil. The incubation period is 4-7 days .Eggs are creamy white ,dome shaped and are very difficult to see LARVA: Newly emerged young larva is yellow or blackish green in colour .1.5mm along with a shiny black head , full grown larva is about 42-45mm long and dark brown.They have stripped markings running down the sides of their bodies , larval stage varies from 30-34 days PUPA : Pupae are brown to dark brown ,about 1.5to2.0cm in length .Pupation takes place underground in an earthen chamber is completed in 10-30 days ADULT : It measures about 25mm and look dark with grayish patches on the back and dark streaks on forewings .Adults live 7-10 days and emerge at night , life cycle is completed in 48-77 days

10. Egg Larvae Adult Pupa

11. DAMAGE SYMPTOMS : These pest damage plants and tubers during dark Early instars cause make round hole in leaves. The larvae also make holes in stalk and enter to petioles, make tunnels, causing wilting of the plants. They attack young plants by severing their stems ,pulling all parts of the plant in to the ground and devouring them This pest can cause serious damage particularly when crops are at 25-35 days after planting and on tuber the boreholes larger than those of potato tuber moth

12. MANAGEMENT: Clean cultivation and mechanical destruction of caterpillars also help in reducing pest infestation Grow Marigold on bunds Irrigations also brings them on the surface and birds shall predate them. Plough the soil during summer months to expose larvae and pupae to predators Conserve Braconids , Microgaster sp., Bracon kitcheneri , Fileanta ruficanda ( parasitods ) and Broscus punctatus, Liogryllus bimaculatus (predators) Set up light trap Pheromone traps @12/ha to attract male moths Spray chlorpyriphos 20EC @1lit/ha or neem oil@3%

13. POTATO LEAF MINER SCINTIFIC NAME : Liriomyza huidobrensis Family : Agromyzidae Order : Diptera

14. LIFE CYCLE : EGG : E ggs are laid inside leaves ,they are very small and clear In color .larva hatch after about 2-3 days .Adult flies produce an average of 166 eggs MAGGOT: The larvae are minute maggots that are mine into leaves many maggots may be found mining the same leaf 2.5mm in length ADULT: These are extremely small at 2-4 mm in length black in color with two yellow spots on their back .Active in morning .The female punctures upper surface of leaf to lay eggs singly

15. DAMAGE SYMPTOMS : The leaf miner flies damage plants during its larval and adult stages mainly on the lower third of plants Larva begins eating the inside of leaves immediately after hatching and bore mines inside them, Affected leaves become dry and drop off the plants Adult flies puncture holes in leaves in order to lay eggs and feed on plant jucies

16. MANAGEMENT: Using of yellow sticky traps Crop rotation with carrot Adopt proper weed management 75 % cryomazine wp and 2.5%deltamethrin U sing neem based pesticides

17. POTATO APHID SCINTIFIC NAME. Myzus persicae Family : Aphididae Order : Hemiptera

18. Life Cycle EGG : Initially yellow or green and become shiny black as they mature, egg measure about 0.02m,m NYMPH : Smaller that develops into winged adults in pinkish ADULT: Soft pear shaped body with red eyes Wingless adults are yellowish and the winged adult has yellow-green abdomen and its oviparous

19. DAMAGE SYMPTOMS : Nymph and adult suck sap from leaves and damage the young and soft parts of plants Severe infestation can cause shoots to wilt and dry out The infested plants turn pale with sticky appearance The leaves curled and crinkled Honeydew excrete - development of sooty mould Spreading of viral diseases like Potato leaf roll virus and act as vector for virus

20. MANAGEMENT Natural enemies like lady bird beetle and lace wing etc Remove or destroy the infested plants Spray any one of the following insecticide Insecticide Dose Fipronil 5 % SC 1.0 ml/lit. Imidacloprid 17.8 % SL 3.5 ml/10 lit. Oxydemeton –Methyl 25% EC 1.6 ml/lit. Phosalone 35 % EC 2.0 ml/lit. Quinalphos 25 % EC 1.0 ml/lit. Quinalphos1.5 DP 20kg/ha