Insect Pests and Their Damage on Tea Plants in Myanmar
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International Journal of Zoology and Applied Biosciences ISSN: 2455-9571 Volume 5, Issue 2, pp: 105-110, 2020 http://www.ijzab.com https://doi.org/10.5281/zenodo Research Article INSECT PESTS AND THEIR DAMAGE ON TEA PLANTS IN MYANMAR Wah Wah Min* Department of Zoology, Myeik University, Myanmar - 14051 Article History: Received 5th April 2020; Accepted 15th April 2020; Published 20th April 2020 ABSTRACT A total of 11 insect pests and their damages inflicted were observed in three tea plantations at weekly intervals during 2012-2013 in Tarpon, Lashio Township, Myanmar. The infestation was high during July associated with heavy rainfall followed by cool conditions, and it was also high in the sites nearer to orchards and crop fields. Keywords: Infestation, Insect pests, Tea, Camellia sinensis. INTRODUCTION MATERIALS AND METHODS Tea (Camellia sinensis) is one of the most favorite The study was made during 2012-13 in three sites located beverages of people in Myanmar, being extensively in Tarpon, Lashio Township, Northern Shan State lying cultivated in Myanmar. Usually, tea leaves are picked up between N 22o 59' 42.7" and E 97o 49' 04.7". Sampling was done at weekly intervals from an experimental plot from tea plants and then processed for dried (Zhu et al., with size of 50 m x 50 m from each of three study sites in 2002). Tea is coming among priority cash crops in tea garden. The insects were identified and classified based Myanmar and is grown in the mountain regions, such as on (Blackman & Eastop, 1994; Ghauri, 1975; Lee et Shan State. Tea being a long term; permanent mono- al.,1995; Pellizzari & Camporese, 1994; Roy et al., 2015; cultural crop can be exposed to insect pest infestations. Scott & Emberson, 1999; Wagner, 2005). However, all the plant parts - leaf, stem, root, flower, bud and seed - are fed upon by insect and mite pests which RESULTS AND DISCUSSION typically cause losses to tea plants. Only scanty scientific Characteristics of insect pests and their damage inflicted on work is available on the insect pests of tea plantation. Tea tea plant recorded are given in table 1 and figure 1. The plantations continue to face the insect damage and heavy present study recorded a total of 11 species of insect pests loss of the cash crop in Myanmar. Hence the present work with the highest number of species under order Hemiptera followed by Lepidoptera, Orthoptera, Trombidiformes and was carried out the insect pests in tea plantations. Insects Homoptera. The minor insect pests that damaged a little on are not only of economic importance but also threatening as tea plants were found to be camellia scale, weaver ant, slug potential pests, thus taxonomic studies on the local insects caterpillar, stinging nettle caterpillar, small rice have been conducted to certain extent but all areas have not grasshopper and yellow tea mites. However, the major been covered. However, there is evidence that the pest insect pests that caused heavy damage were found to be tea mosquito bug, leafhopper, tea aphid, Florida red scale and status in tea of Myanmar is changing so the current stink bug (Table 1). situation may also change. Also, deliberate research on the prevention and control of tea pests has not been carried out According to Hamasaki et al., (2008) tea pests vary between regions, even though they usually belong to the in Lashio Environs, Shan State, Myanmar so this same groups notably mites, leafhoppers, mosquito bugs, investigation would be supplementing some new plant bugs, aphids, thrips, leaf rolling and leaf folding information on some insect pests in tea plantations. caterpillars and stem boring insects. Similar to this, the *Corresponding Author: Dr. Wah Wah Min, Lecturer, Department of Zoology, Myeik University, Myanmar Email: [email protected], Mobile: +95-9403710924 105 Wah Wah Min Int. J. Zool. Appl. Biosci., 5(2), 105-110, 2020 present study recorded the highest infested tea plants (72%) located nearer to many orchards and other crop fields in the site 2 and lowest (51%) in the site 3. The site 2 was which served as the source of food for the insect pests. Table1. Identified insect pests, characteristics and their damage caused on tea plants. Symptom and damage caused on No. Order Family Species Characteristics tea plant 1 Lepidoptera Limacodidae Thosea sinensis Body is slug-like, The larvae feed on leaf-blades it (Walker, 1855) short and rather stout, can cause holes in leaves due to quite flat, beneath removal of leaf tissues and veins green in color, and damaged leaves curl up and 3mm long. Along the wither off. They were frequently middle of the back is a found eating on tea leaves but row of tufts of hairs or rarely occurred in large numbers. slender hairs. 2 Macroplectra Caterpillar is soft Young caterpillars feed on young nararia (Moore, body, dark brown leaves and mature larvae prefer 1859) brightly coloured 1.2 older leaves so it may cause mm long, many sting severe defoliation. The damage spines. caused by young larvae is in the form of small, irregular patches on the under surface of the leaf where the larvae have nibbled and scraped away the lower portion of the leaf leaving the upper epidermis intact and then gradually turned brown and fall off. 3 Hemiptera Diaspididae Chrysomphalus Adult female scales The florida red scales mainly aonidum are conical and 2 mm infest only on leaves, where they (Linnaeus, 1758) in diameter. Immature feed on plant sap and then spread male scales are smaller to other plant parts. When their and paler. They are population were very highly elongated, oval and infested leaves drop off half the size of adult prematurely in dry condition. females. The scales appear as dark circular spots on leaves especially on the lower surfaces. They found near the tip of the cone appears pale of leaves. 4 Miridae Helopeltis Head is brown with a They suck the sap of young theivora broad yellow stripe, leaves, puncturing the plant (Waterhouse, long antennae and the tissues with their needle-like 1886) back has a small club rostrum and injects toxic saliva. striking out of it. Eyes So the leaves are curled up, badly are brown to black. deformed and damaged mostly in Legs are dark red shaded areas. colour, size 13 mm long. The abdomen is 106 Wah Wah Min Int. J. Zool. Appl. Biosci., 5(2), 105-110, 2020 green colour. They hide generally under surface of leaves and move actively. 5 Diaspididae Lepidosaphes The adult shell has Large population of the adult camelliae Hoke, dark brown, slightly scales occurred in sooty mould on 1921 convex, pear-shaped, the leaves that can cause host anterior rounded and plant death. elongated posterior to meso-thorax, 23 mm in length. 6 Nezara viridula The body is shield- Stink bugs sucked juices from (Linnaeus, 1758) shaped with a V- leaves, flowers, fruits and stems. shaped marking Damage caused to the crop by dorsally with brightly sucking sap of adults and nymphs yellowish colour and from the growing shoots and orange or red edges, developing fruits. So shoots and 4.3 mm in length. It developing fruits were withered has black spots on or retarded their sides and has sharp mouth parts. It discharges large amounts of foul- smelling liquid when disturbed. 7 Aphididae Toxoptera Body is tiny soft, Tea aphids have piercing-sucking aurantii (Boyer black and pear-shaped mouthparts that enable them to de Fonscolombe, with long legs, 1.5 mm feed on plant sap. They excrete 1841) in length and vary in sweet and sticky honeydew colour from black to attractive to ants and a substrate dark brown. They live for sooty mold fungus. Infested in groups on the tea shoots become cupped and underside of leaves at distorted. The aphid infestation the shoot tips, results in the plants turning generally wingless and yellow and stunted then the leaves can move very slowly. drying up. Tea leaf hopper is very They use their needle-like mouth 8 Cicadellidae Jacobiasca small insect, 1.3 mm parts to suck sap from the shoots, formosana (Paoli, in length with light causing wounds and discoloration 1932) green colour, a few of leaf margin that turns white spots in belly. brownish, dry and fall off. It may The wings are almost cause to reduce the yield and transparent and the quality of tea. edges of the wings are light green and a little yellow. It prefers to stay on the underside of leaves. They can jump very rapidly. 9 Orthoptera Acrididae Oxya chinensis Body is slender, They feed upon leaf tips or leaf 107 Wah Wah Min Int. J. Zool. Appl. Biosci., 5(2), 105-110, 2020 (Thunberg, 1815) cylindrical abdomen, margins so it causing to wither anterior pro-thorax is and then fall off. large, narrow forewings, broad and membranous hind wings, head large, slender; jointed antennae, fine sensory bristles, large and unstalked compound eyes. The broad upper lip, under slender sensory palps are bright yellow and the back pale brown in colour, 2.5 mm in length and they can move actively. 10 Trombidiformes Tarsonemidae Polyphagotarsone The body is flattened They feeds plant sap on the upper mus latus (Banks, bright yellowish surface of leaves and scarring and 1904) brown and more easily so the leaves are distortion. The seen under the scarred tissue of leaves may microscope, four legs appear to be a greasy darkened are extending forward discoloration and later turns to a and four legs brown surface on the undersides extending behind of leaves. The results of leaves move very slowly, 0.6 infestation can see in appearance mm in length.