INSECT AND MITE PESTS OF TEA AND THEIR MANAGEMENT

Transcription

1 14 INSECT AND MITE PESTS OF TEA AND THEIR MANAGEMENT Gireesh Nadda, S.G. Eswara Reddy* and Adarsh Shanker CSIR-Institute of Himalayan Bioresource Technology, Palampur (H.P.) , India. Tea, Camellia sinensis (L.) O. Kuntze is grown within the tropics and in diverse agro ecological conditions such as temperatures from - 12ºC to 40ºC, annual rainfall from 938 to 6000 mm and relative humidity from 30 to 90%. It is grown on over 2.71 million ha in more than 34 countries (Hazarika et al. 2009). In India, tea is grown in Darjeeling, Assam and Nilgiri (Tamil Nadu), Himachal Pradesh, Kerala, Karnataka, Uttaranchal, Sikkim, Orissa, Bihar, Arunachal Pradesh, Tripura, Manipur, Nagaland, Mizoram, Meghalaya and in the adjacent plain areas of Dooars and Terai of West Bengal. Tea consisting of genetically diverse cultivars, and is a perennial monoculture crop. It provides a relatively steady microclimate and food supply for insect and mite pests. Each tea growing country has its own distinctive insect and mite pests, diseases and weeds. However, several of them are common. Globally, 1031 species of arthropods are associated with tea monoculture (Hazarika et al. 2009) and is attacked by nearly 250 insect species (Barthakur 2011). Tea plantations roughly resemble a single species forest and insect and mite species are thought to coexist by way of intra tree distribution (Hazarika et al. 2009). Besides some perennial pests, most of the tea pests are seasonal; some attack only during dry season while a few are abundant in wet weather. Weeds

2 318 Science of Tea Technology serve as alternative hosts for pests as well as a refuge for natural enemies and hence are a major component of the tea ecosystem (Kawai 1997). Common insect and mite pests of tea are grouped in this chapter includes sucking, lepidopteran, coleopteran, soil and mite pests. Some of the common pests of tea are as follows: Sucking pests 1. Tea mosquito bug, Helopelhis theivora, H. antonii, H. schoutedeni (Hemiptera : Miridae) 2. Mealy bug, Nipaecoccus viridis, N. vastator (Hemiptera: Pseudococcidae) 3. Thrips, Scirtothrips bispinosus, S. dorsalis, Heliothrips haemorrhoidalis, Mycterothrips setiventris (Thysanoptera: Thripidae) 4. Aphid, Toxoptera aurantii (Homoptera : Aphididae) 5. Scale insects Soft scales (Homoptera:Coccidae) a. Green scale, Coccus viridis b. Brown scale, Saissetia coffeae c. Ceroplastes spp. Hard scales (Homoptera : Diaspididae) Aonidiella spp., Aspidiotus destructor 6. Leafhopper, Empoasca flavescens, E. onukii, E. viti (Homoptera : Cicadellidae) 7. Painted bug, Bagrada cruciferarum (Hemiptera: Pentatomidae) Lepidopteran pests 1. Tea Tortricids/bud tier, Homona coffearia, H. magnanima, Adoxophyes honmai (Tortricidae) 2. Leaf roller, Gracilaria theivora (Gracillaridae) 3. Red borer, Zeuzera coffeae (Cossidae) 4. Black inch worm, Hyposidra talaca (Geometridae),

3 Insect and Mite Pests of Tea and their Twig caterpillar, Ectropis bhurmitra (Geometridae), Looper caterpillar, Buzura suppressaria (Geometridae) 6. Case worm, Eumeta spp., Bag worms, Cryptothelea spp. 7. Cluster caterpillars, Euproctis pseudoconspersa (Lymantriidae), Andraca bipunctata (Bombycidae) 8. Nettle caterpillar and saddle back caterpillar, Aphendala recta, Cania bilinear, Chalcocelis albiguttatus (Limacodidae) Coleopteran pests 1. Shot hole borer, Xyleborus fornicatus, Euvallacea fornicatus (Scolytidae) 2. Cockchafer beetles/white grubs, Holotrichia spp., Schizonycha spp. (Scaraebidae) Soil pests 1. Termites, Microtermes spp., Odentotermes spp., Postelectrotermes militaris, Coptotermes spp. (Isoptera : Termitidae) Mite pests (Acarina) 1. Red spider mite, Oligonychus coffeae (Tetranychidae) 2. Scarlet mite, Brevipalpus californicus, B. phoenicis (Tenuipalpidae) 3. Pink mite, Acaphylla theae (Eriophyidae) 4. Purple mite, Calacarus carinatus (Eriophyidae) 5. Broad mite, Polyphagotarsonemus latus (Tarsonemidae) 6. Kanzawa spider mite, Tetranychus kanzawai (Tetranychidae) Minor pests 1. Leaf miner, Topicomyia theae (Diptera: Agromyzidae) 2. Gross hopper, Hieroglyphus banian (Orthoptera : Acrididae) This chapter describes the nature of damage, symptoms and management of economically important insect and mite pests of tea and their management.

4 320 Science of Tea Technology SUCKING PESTS Tea mosquito bug (Hemiptera : Miridae) About 41 species of mirids in the genus Helopeltis have been reported in Asia, Australia and Africa. Two species of Helopeltis viz., H. schoutedeni and H. theivora have become the greatest enemies of tea planters in Africa and Asia causing 55% and % crop loss, respectively (Wilson and Clifford 1992, Sundararaju and Sundara Babu 1999, Hazarika et al. 2009). Both males and females look like mosquito. Young nymphs look a bit like ants, and range in color from copper or orange to green. Nymphs and adults are more visible in early and late hours of the day and take shelter under tea leaves especially in the lower frame during day time or when disturbed. The nymphs often drops from the plant when disturbed. Nymphs and adults suck the sap from tender stems, young leaves and buds forming circular feeding punctures. The feeding spots develop watermarked area, which turn circular and pale green and subsequently dark brown within hours of feeding. Damaged leaves curl upward and desiccate in severe infestations. Initiation of new shoots is prevented due to the death of the stem and may result in total loss of the crop; H. schoutedeni causes dieback and stem canker. Female lay eggs singly or in groups of 2 to 3 eggs, inside tender green stems. It lays 4 to 10 eggs per day, total 220 to 224 eggs in her lifetime. The egg is oval, white in color with two long hairs of unequal length at the smaller end of the egg. Incubation period varies from 4 to 20 days and the life cycle is completed within 12 to 40 days. The species has many overlapping generations. However, the population peaks from June to September, coinciding with the rainy season. a. Plucking every days will be helpful for reducing the infestation as the eggs are removed during plucking. Try to pluck out all the badly damaged buds which will stimulate the growth of new shoots. Light or moderate pruning will limit the population in the seriously affected fields. b. Weed and alternate host plants (wild plants having feeding stains) should be removed from and around the tea fields. Regulation of shade is important as the heavily shaded and moist areas is relatively more damaged.

5 Insect and Mite Pests of Tea and their 321 c. Encourage natural enemies (spiders, dragonflies, praying mantis, predatory coccinellids) to reduce the pest population. d. Spray thiamethoxam 25% 1 g/l or profenofos 50% 2 ml/l during severe infestation. Mealy bug (Pseudococcidae : Hemiptera) N. viridis is widespread throughout the tropics and subtropics, attacking numerous plant species and often causing considerable damage (Clausen 1978, Sharaf and Meyerdirk 1987). It is an economically important pest of tea. Besides other tea growing regions of the country, this pest was reported in Kangra valley of Himachal Pradesh (Shanker et al. 2002, Sharma and Kashyap 2002, Gupta and Shanker 2007). Mealy bugs are covered with white powdery substances and waxy filaments. Females are soft bodied sluggish oval, flattened and dark brown colour. Males undergo four and female three nymphal instars. Both nymphs and adults congregate on shoot, stem, branches and suck the sap which results in drying of branches. In severe cases, the mealy bugs secrete honeydew on the plant parts from which black sooty mould develops, which affects the photosynthesis and quality of tea leaves. In severe cases it leads to death of the tea plants. Juvenile mealybugs can crawl from an infected plant to another plant and small crawlers are readily transported by wind, rain, birds, ants, clothing, vehicle and may settle in cracks and crevices, usually on new plants. Ants, attracted by the honeydew carry mealybugs from plant to plant helping in their spreading and invading into new areas and fields. Plant protection products are not very effective in controlling mealy bugs because of waxy covering on their body and their habit of hiding in crevices. Systemic insecticides are found effective and used to control during severe infestation. a. Destroy ant colonies during land preparation because their nests are located near the soil surface or drenching soil with chlorpyriphos 20 4 ml/l or apply 5% malathion 25 kg/ha. b. Remove weeds and alternate host plants like Hibiscus spp., okra, custard apple, guava, etc., and destroy. c. Sanitize equipments before moving to uninfected portions in a crop.

6 322 Science of Tea Technology d. Spraying with strong jet of water may help in removing the bugs. e. Apply sticky bands like Track-trap or Bird Tangle Foot on arms or main stem to prevent crawlers from reaching the bunch. f. Encourage predatory coccinellid beetles viz., Cheilomenes sexmaculata, Rodolia fumida, Scymnus coccivora and Nephus regularis to reduce infestation. g. Release Australian ladybird, Cryptolaemus montrouzieri and Anagyrus pseudococci, Leptomastix dactylopii, Hypoaspis spp. to suppress mealy bugs population. h. Spray commercially available entomopathogenic fungus, Lecanicillium lecanii (5 g/l) to reduce mealy bug population at weekly intervels. i. Spray chlorpyriphos 20 2 ml/l or imidacloprid ml/l at 15 days intervals during severe infestation. Thrips (Thysanoptera : Thripidae) S. dorsalis is highly polyphagous minute insects. It is present in tropical Asia (from Pakistan to Japan), in Oceania, Subsaharan Africa, Venezuela and Central America. Wings are narrow and fringed (PRA Scirtothrips dorsalis, 2009). Thrips prefer tender/mature leaves, buds and flowers. It undergoes through five developmental phases: egg, two active larval instars that feed, followed by two relatively inactive pupal instars and winged, feeding adults. The first and second larval stages are found on the green plant parts from which the second stage larvae seek out some sheltered place (leaf litter or crevices of bark) and then pass through two resting stages called propupa and pupa, respectively. Winged adults, male and female, are found normally on the green plant parts, where they feed. Eggs are inserted into young and soft tissues of leaves, stems and fruit. Eggs hatch after 7-8 days. Both nymphs and adults lacerate and suck the sap on leaves, buds and flowers. The underside of the affected leaves become silvery with black spots. Feeding marks on the unopened buds and parallel brown lines on the leaves which affect the quality. The growing shoots are stunted with shortened internodes and defoliation often occurs.

7 Insect and Mite Pests of Tea and their 323 a. Yellow/blue sticky traps (10-15 traps/ha) to be installed at crop canopy level for monitoring and mass trapping of thrips. b. Timely pruning of tea bushes to be followed to avoid thrips infestation. c. Spray neem formulation containing azadirachtin 3 ml/l or azadirachtin 1 ml/l. d. Spray deltamethrin 2.8% 0.3 ml/l or profenofos 50% 2 ml/ L in severe infestation. Black citrus aphid/tea aphid (Homoptera : Aphididae) Tea aphids are minute, dark brown to black insects which infests tender shoot and foliage of the tea plant (Gupta and Shanker 2007, Devi et al. 2010). Aphids seen on tender shoots of tea immediately after pruning. Both nymphs and adults found in the colonies on tender buds, leaves, shoots and suck the sap leads to reduction of growth. Continuous feeding makes the leaf wrinkled forming a boat shaped structure. Severe infestation leads to delayed recovery of the plant leading to poor crop productivity (Muraleedharan 1991). In severe cases, aphid secretes honeydew on the leaves which results in the development of black sooty mould. This affects the photosynthesis of the plant. Presence of honeydew and ants on the plants indicate the aphid infestation. a. Collect and destroy the affected parts of plants to prevent the further spread. b. Encourage predatory coccinellids beetles to reduce the population. c. Spray any commercial botanicals insecticides containing azadirachtin 5% (1 ml/l)/ or azadirachtin 1% (3 ml/l) or neem seed kernel extract 4%. d. Spray phosalone 35% 2 ml/l in severe infestation. Scale insects (Hemiptera : Coccidae) Scale infestation is usually localized. They tend to remain confined to the individual bush and start feeding by sucking the sap

8 324 Science of Tea Technology by inserting their mouth parts. Feeding may lead to severe defoliation, stunting and dieback on young tea. However, the effects may not be very serious in case of mature tea. Soft scales feed on green stem or on the underside of the leaves mainly along the midrib, and produce honeydew. Sooty mould grows on the honeydew which affects the photosynthesis of the plant. Yellow feeding spots appear on the upper side of the leaves, the damaged leaves eventually drop off. The ants feeding on honeydew are sometimes the only sign of their presence. Scales insects are some of the most difficult pests to control because their scales protect them from contact with chemicals and their mouth parts are inserted in the plant tissue. a. Select planting material free from scale insects from mother plants. b. Spray ethion 50% ml/l in severe infestation. LEPIDOPTERAN PESTS Tea Tortricids (Lepidoptera: Tortricidae) Among the leaf feeders, 19 species of tortricids mostly of the genera Homona and Adoxophyes are economically important pests of tea in Japan, China, India, Sri Lanka, Taiwan, Turkey, Republic of Georgia, Azerbaijan, and Bangladesh (Cranham 1966, Nabeta et al. 2005). Adoxophyes honmai is a major pest of tea in central and southern Japan, whereas Homona magnanima is prevalent in southern Japan. H. coffearia occurs in India, Indonesia, and Sri Lanka; it causes 50% yield reduction in Sri Lanka (Hazarika et al. 2009). Female of A. honmai lays oval shaped egg masses on the under surface of young tea leaves. Eggs hatch in pale yellow coloured neonates which disperse individually to construct leaf webs for feeding on the growing leaves and shoots. They pupate inside the web after completing five to six instars. H. magnanima has a seasonal occurrence similar to that of A. honmai, with four generations per year in central Japan. No development occurs below 10.3ºC and 417 degree days are required to complete development from egg to adult emergence (Nabeta et al. 2005).

9 Insect and Mite Pests of Tea and their 325 Leaf roller (Lepidoptera : Gracillaridae) This is a minor pest of tea. Caterpillars are dark-green in colour with shiny brownish black head. Caterpillars roll the leaves and feed, and can be seen inside the rolled and tied leaves. In severe cases, it causes complete defoliation and drying of the plant. Some buds cannot be plucked because they are ruined by leaf nests. Red borer (Lepidoptera:Cossidae) The pest is recognized by the presence large pieces of sawdust, on the ground under the bush. This is a minor pest. Moths have white wings with many black spots. Eggs are laid like beads on a thread. Mature larva is about 3.5 cm long, purplish or reddish brown in colour. Larval duration is 4-5 months and it pupates in a special chamber for a month. Caterpillars emerge in 10 days. Larvae bore into young stems and tunnel downwards, devouring the woody parts, especially the pith. Tunnels are extended to thicker branches. As the larva grows, the tunnel is also extended which may run even up to root. Holes are made at intervals to eject the excreta and wood particles. of Lepidopteron insect pests a. Collection and destruction of egg mass and late instar larvae. b. For red borer, cut the affected branches and destroy. c. Release egg parasitoid, Trichogramma chilonis for six 20,000 parasitoids/release (1 tricho card) at fort nightly interval depending upon the incidence of pest. d. Spray neem based formulation containing azadirachtin 1 ml/l or profenofos 50% 2 ml/l or deltamethrin 2.8% 0.3 ml/l for the control of different caterpillars. e. Spray deltamethrin 2.8% 1 ml/l against leaf roller 0.25 ml/l against loopers. COLEOPTERAN PESTS Shot hole borer (Coleoptera : Scolytidae) Eight to nine species of scolytids attack tea, of which Xyleborus fornicatus is the most serious pest in Sri Lanka, causing up to 91 to 100% infestation in the mid country wet and dry zones. Female lays

10 326 Science of Tea Technology upto 45 eggs, male female ratio 1:8. Eggs are laid singly inside the gallery, three larval instars. Population reaches high levels during April, May, July, October and December. All life stages are seen throughout the year. The newly emerged females construct galleries in stems leads to branch breakage and cultivate the ambrosia fungus, Monacrosporium ambrosium. Infested stems or shoots are more common in the second year after pruning than in the third year because the wood becomes hard. a. Prune the affected twigs 2 to 3 inches beyond the shot-hole and burn. b. Remove and destroy all the unwanted/infested twigs/branches to avoid breeding. c. Spraying of Beauveria 5g/L or azadirachtin 5% (1 ml/l at weekly intervals reduce the infestation. d. Spray fipronil 1ml/L or fenthion 82.5% 3ml/L to reduce the borer infestation upto 40% e. Encourage the natural enemies helps to keep the pest under check. Cockchafer beetle/white grub (Coleoptera : Scaraebidae) Beetles attack nursery or in newly planted field especially during dry period. The grubs are white, C-shaped and live in soils at a depth of 5 to 20 cm. The adult beetle emerges at the beginning of the rains. Cockchafers grubs are found in moist soils, early instar grubs (2 nd & 3 rd ) feed on organic matter, later instars (4 th & 5 th ) feed on roots and cause wilting. The adult beetles feed on leaves and cause defoliation. a. Collect the beetles during night and destroy to avoid further infestation. b. Dig the soil around the base of the stem to expose grubs to the natural enemies. c. Set up light traps (2-3 traps/ha) or bone fire to attract the beetles during evening hours for monitoring and mass trapping. d. Spray any commercial neem based insecticides containing azadirachtin 5% (1 ml/l)/ azadirachtin 1% (3ml/L).

11 Insect and Mite Pests of Tea and their 327 e. Apply neem 100 kg/ac or neem based 5 kg/ac. to the soil or in severe infestation apply carbofuran 0.3 g/plant to kill the grubs present in the soil. f. Drench the soil with chlorpyriphos 20% 4ml/L at the base of the tree to kill grubs in severe infestation. MITE PESTS (ACARINA) Mites are the most serious pests of tea in almost all tea producing countries. Red spider mite, Oligonychus coffeae was reported in Assam (India) in This mite is widely distributed in India, Bangladesh, Sri Lanka, Taiwan, Burundi, Kenya, Malawai, Uganda, and Zimbabwe (Gotoh and Nagata 2001). Tetranychus kanzawai is important in Japan, China, Taiwan, and the Philippines (Ho 2000). Likewise, Brevipalpus phoenicis, Acaphylla theae and Calcarus carinatus occur in most of the tea growing Asian and African countries (Wilson and Clifford 1992, Takafuji et al. 2000). Red spider mite (Tetranychidae) The red spider, O. coffeae is the most widely distributed and probably also the most serious pest of tea in north-eastern India, and also occurs on tea in other parts of India and in other countries. This mite prefers the middle zone of the bush (30 cm below the plucking surface). Leaf temperature and light penetration within tea bushes influence mite distribution. Nymphs and adults lacerate cells, producing minute characteristic reddish brown marks on the upper surface of mature leaves, which turn red in severe cases, resulting in crop losses from 17 to 46% (Hazarika et al. 2009). High temperature, dry conditions, and absence of shade are conducive to outbreak of this pest. The optimal temperature for growth and development is 30 o C; the lower threshold for development is 10 o C, and degree days are required to complete the life cycle (Gotoh and Nagata 2001). O. coffeae normally attack the upper surface of the mature leaves in which the sap is not flowing freely. In a severe infestation, particularly under conditions of dry weather, the lower surface and the young leaves are almost equally attacked. The affected leaves turn brown, then bronze, and may eventually dry up and fall off. Scarlet mite (Tenuipalpidae) Adult is scarlet red in colour and ovate in shape. It occurs in almost all the tea growing Asian and African countries, causing crop

12 328 Science of Tea Technology losses of 13% in Indonesia, 8 to 17% in South India, and 12% in Kenya (Wilson and Clifford 1992, Kumar et al. 2004, Hazarika et al. 2009). Eggs are bright red colour and elliptical in shape and laid on the leaf petiole, at the base of the leaf hair, or inside cracks and crevices of the stem. The life cycle is completed in 30 to 60 days. Mites congregate on the under surface of mature leaves. Both nymphs, and adults suck the cell contents from the under surface of leaves, mainly along the midribs and base of the petiole. Infested leaves have brown scurf followed by splitting of petiole and defoliation. Pink mite (or) Orange mite (Eriophyidae) It is an important mite in India. Adult is very minute, orange coloured and carrot shaped. Adults and nymphs found on the under surface (abaxial) of young leaves. Damage is restricted to top cm of tender leaves. Affected leaves turn pale and show upward curling. In severe infestation, leaves become leathery and brownish. Assam type of tea is susceptible to this mite. Purple mite (Eriophyidae) This is a major pest in South India. Adult is very small, spindle shaped and dark purple in colour with five longitudinal white waxy ridges on the dorsal side. Adults and nymphs suck the sap from under surface of mature leaves. Damaged leaves show coppery brown discolouration. Assam type of tea is more susceptible to purple mite. Broad/ Yellow mite (Tarsonemidae) It is polyphagous pest. Besides tea it is reported to attack tomato, cinchona, cotton, pulses, potato, chillies etc. In India and Sri Lanka it is called the "yellow tea mite. Male mites are small and white to pale yellow in colour. Females are yellowish and bigger than the males. Yellow mites are active and fast moving mite. Adults and nymphs of this mite are seen on younger leaves especially the top two to three leaves and the bud. Due to sucking affected leaves become rough and brittle. In severe infestation affected leaves curl downward. The damage resembles that caused by herbicides. The mites prefer areas of high humidity and low temperature. Kanzawa spider mite (Tetranychidae) Both nymphs and adults suck the cell contents from tea leaves, producing tiny, pale spots or scars. A female lays 2 to 3 eggs per day

13 Insect and Mite Pests of Tea and their 329 on the leaves; lifetime fecundity ranges from 40 to 50 eggs. It completes its life cycle within 40 to 41 days and undergoes a seasonal change in habitat. It is a polyphagous pest. Within the tea ecosystem, it moves from one part of the tea plant to another and can migrate from the tea plant to another host, more particularly to weeds. Development of the mite is temperature-dependent within 12ºC to 37ºC; development ceases at 12ºC (Ho 2000). of mite pests i. Follow good agricultural practices (GAP). Mite infestation can be reduced greatly by following good agricultural practices. a. Use shade and mulching to increase humidity, as mites are favoured by dry and hot weather conditions. b. Spraying foliage with water (or water mixed with a little soap) might be helpful in reducing mite population. c. During farm operations, workers should avoid their movement from mite infested part to the other parts of the field. d. Use less pesticides (insecticides and fungicides) to protect beneficial organisms (natural enemies i.e. predators and beneficial fungi). e. Pruning greatly reduces the population of scarlet mites. f. Eliminate alternate host plants that provide food for spider mites. ii. Encourage the natural enemies to reduce the mite population (predatory mite, Phytoseiulus, Amblyseius, Typhlodromus and Mexecheles), tiny black lady beetle, Stethorus spp, spiders, Chrysoperla spp., to keep mite population under check. iii. Spray azadirachtin 0.5 ml/l or fenpyroximate 5% 0.75 ml/l or dicofol 18.5% 5 ml/l or fenazaquin 10% 2.5 ml/l or phosalone 35% 2 ml/l or profenofos 50% 2 ml/l, propargite 57% 2 ml/l or fenpropathrin 30% 0.4 ml/l or hexythiazox 5.45% 0.75 ml/l or ethion 50% ml/l for effective control of mites.

14 330 Science of Tea Technology SOIL PESTS Termites (Isoptera : Termitidae) Termites are social insects, comprising queen, king, soldiers and workers. Workers are small sized pale white soft bodied wingless and soldiers with powerful mandibles are found under earthen sheathing in the damaging site. Queen, eggs and nymphs are found inside the termitaria or nest. Reproductive forms are winged. Workers feed on the roots and stem in all stages and cause wilting and drying. Odentotermes sp builds cylindrical closed mounds above the ground level, where as Microtermus obesi constructs their nests underground (sub terranian). If infestation occurs in the nursery stage, it causes sudden wilting and death of the plant. Termite attack is more in dry conditions than wet. Ancistrotermes spp. feed on crop debris and woody litter. The termites enter the roots or the collar at below ground level, and often penetrate stems and branches. Roots are completely eaten out or tunnels are made into the stem. Pseudacanthotermes spp. (including P. militaris) is a wide spread dark coloured litter feeder. a. Proper water management helps in reducing the termite damage in tea plantation. b. Destroy termite mounds in the field followed by drenching the soil with chlorpyriphos 4ml/L. MINOR PESTS Grasshoppers Adults and nymphs found on the crop and feed on leaves by making holes. In severe infestation, defoliate the leaves. Adult female insert proboscis into the soil and lay eggs. a. Collect the hoppers by hand and kill. b. Spray any contact insecticides viz., chlorpyriphos 30 2ml/L or 2ml/L.

15 Insect and Mite Pests of Tea and their 331 Leaf miner (Diptera: Agromyzidae) Leaf miner infests young plants in the nursery, whereas in matured plantations, infestation occurs after pruning particularly during new flush. Incidence is more in tender leaves compared to matured leaves. Initially adult female punctures the leaves and feeds on oozing sap. After hatching maggots/larva mines the leaves and feed by leaving characteristic mines. In severe incidence, affected leaves bears extensive mines, turn brown, dry and drop down. Severely affected mined leaves become unfit for consumption. a. Collect and destroy the affected leaves. b. Spray any commercial botanicals insecticides containing azadirachtin 5% (1ml/L)/ azadirachtin 1% (3ml/L). c. Spray deltamethrin 2.8 EC (1ml/L) for effective control. Most of the above mentioned chemical control measures are based on the recommendations of Central Insecticides Board and Registration Committee, India (Central Insecticide Board, 2011). However, there are certain formulations of newer molecules which are found effective and recommended by different research groups/ organizations against different pests of tea and other crops (UPASI, TRA, TNAU etc.). Some of new pesticides and botanicals at recommended doses may be effective against different pests of tea which include acetamaprid (1g/L), thiacloprid (0.5 g/l) for control of sucking pests, spinosad (0.3 ml/l), novaluron (2.5 ml/l) and flubendamide (25 ml/ha) for caterpillars; abamectin (0.5 ml/l), spiromecifen (0.8 ml/l), neem oil (5 ml/l), pongamia oil (0.5-1%) and neem seed kernel extract 4% and horticultural mineral oils for mites. In conclusion, plant protection strategy has significant importance in the overall crop production programme aiming at minimizing crop loss due to pests of tea. Integration of cultural, physical, mechanical, biological and chemical control methods plays major role for effective pest management in tea plantation. REFERENCES Bathakur BK (2011) Recent approach of Tocklai to plant protection in tea in North East India. Sci Cult. 77(9-10): Central Insecticide Board,

16 332 Science of Tea Technology Clausen CP (1978) In: Introduced parasites and predators of arthropod pests and weeds: a world review. United States Department of Agriculture, Washington, DC. 545 pp. Cranham JE (1966) Tea pests and their control. Annu Rev Entomol. 11: Devi KD, Maisnam S, Varatharajan R (2010) Density, diversity and differential feeding potentials of aphidophagous insects in the tea ecosystem. J Biopest. 3(1): Gotoh T, Nagata T (2001) Development and reproduction of Oligonychus coffeae (Acarina :Tetranychidae) on tea. Int J of Acarol. 27: Gupta M, Shanker A (2007) Bioefficacy of imidacloprid and acetamiprid against Nippaecoccus vastator and Toxoptera aurantii in tea. Appl Entomol. 21(2): Hazarika LK, Bhuyan M, Hazarika BN (2009) Insect pests of tea and their management. Annu Rev Entomol. 54: Ho CC (2000) Spider-mite problems and control in Taiwan. Exp Appl Acarol. 24: Kawai A (1997) Prospect for integrated pest management in tea cultivation in Japan. Jpn Agr Res Q. 31: Kumar A, Thakur M, Nigam SK, Nadda G, Shanker A (2004) Omite bioefficacy against scarlet mote, Brevipalpus phoenicis (Geijskes) in Kangra Tea. Pestology 28(2): Muraleedharan N (1991) Pest in Tea. UPASI Tea Research Institute, Valparai, Coimbaore, pp130. Nabeta FH, Nakai M, Kunimi Y (2005) Effects of temperature and photoperiod on the development and reproduction of Adoxophyes honmai (Lepidoptera: Tortricidae). Appl Entomol Zool. 40: NCIPM, Delhi, PRA Scirtothrips dorsalis, May 2009, Plant Protection Service, the Netherlands. Shanker A, Sood C, Kumar V, Ravindranath SD (2002) Insect and mite pests attacking tea plantation of Kangra Valley and their management. Indian J Entomol. 64(1): Sharaf NW, Meyerdirk DE (1987) A review on the biology, ecology and control of Nipaecoccus viridis (Homoptera: Pseudococcidae). Miscellaneous Publications of the Entomological Society of America 66: Sharma DC, Kashyap NP (2002) Impact of pesticidal sporay on seasonal availability of natural predators and parasitoids in the tea ecosystem. J Biol Control. 16(1): Sundararaju D, Sundara Babu PC (1999) Helopeltis spp. (Heteroptera: Miridae) and their management in plantation and horticultural crops of India. J Plant Crops. 27:

17 Insect and Mite Pests of Tea and their 333 Takafuji A, Ozawa A, Nemoto H, Gotoh T (2000) Spider mites of Japan: their biology and control. Exp and Appl Acarol 24: Tea Board of India, TNAU agritech portal, Tocklai, UPASI, Wilson KC, Clifford MN (1992) Tea: Cultivation to Consumption. London: Chapman & Hall, pp 769.