Mango stem borers: New threat to mango in India

Mango stem borer has been observed to cause an alarming situation in old and young orchards posing a great threat to mango cultivation in India during the last decade. Five species of Batocera namely B.rufomacuata de Geer, B.rubus Linnaus, B.roylie Hope, B.numitor Newmen and B.titana Thompson have been reported infesting mango trees. Among them, B. rufomaculata, is increasingly becoming a menace in mango orchards across the country. The infestation is reported to be in the range of one to eight per cent depending upon maintenance of the orchards. Affected trees gradually loose their vigour, manifest drying of branches to in severe cases and even death ensues. The grubs are the damaging stage, they bore and eat below the bark, making tunnels, subsequently entering into main stem following feeding on wood causing damage. The fross coming out of the entry point indicates the presence of trunk borer in the mango tree. The severe damage results in yellowing of branches followed by drying of terminal shoots and branches ultimately leading to the death of whole tree, if not managed properly. This paper presents a detailed review of informations on their symptoms of damage, distribution, varietal reactions, alternate hosts, life history and the control measures.

Five species of Batocera namely B. rufomacuata de Geer, B. rubus Linnaus, B. roylie Hope, B. numitor Newmen and B. titana Thompson have been reported infesting mango trees. Among these, the B. rufomacuata, previously observed damaging old trees are now being observed even in 8-10 years old mango plants, calling for immediate attention. Batocera rufomaculata (De Geer, 1775) the Lamiinae beetle under the tribe Batocerini of the family Cerambycidae and commonly known as mango borer, fig borer and tropical fig borer is a serious pest of many economic plants species including mango plants. Besides, these Stromatium barbatum F. also damages the mango tree and reduces its vigor (Wadhi & Batra, 1964). Other long horned beetles attacking mango trees in India include Acolestes haloserica F., Pachydissus velutinus Thompson, P.similus Gahan, Neocerambyx holoseriecus Cotes, Acanthophorus serraticornis Olivier, Anaplophora versteggi Ritseema, Epepeotes ficicolola Fisher, E.luscos F., Glenea multiguttata Guerin Meneville, Microtoma crenata F., Olenecamptus bilobus F., Pharsatia proxima Gaham, Plocaedrus obesus Gahan, P. pedestris White, Rhytidodera bowringi White, R.simulas White and Xylotrech smei Laporte & Gory. However, these are not of major significance. Mango buprestids, Balinota prasina Thunberg, Xyleborus affinis Eichhoff, Crossotarus saundersi Chapius, and Platypus solidus Walker have also been reported feeding on the inner side of bark and boring inside the sapwood but causing negligible damage to mango trees.

Mango (Magnifera indica) is a tropical fruiting tree of great economic importance. Besides its fruits, every other plant part viz., leaves, flowers, wood, bark and trunk are of significant importance. The leaves are fed to cattles during scaracity of fodder, dried flowers are used to cure dysentry, cattarah of bladder and the wasp string wood is used to prepare various type of furniture, high quality charcoal bark provides tannins used in taining hides, the mangifern, a bioactive ingradient having antioxidant quality, is used as an effective therapeutic agent against several disorders, the trunk produces resinous gums that help in curing cracks in the skin, the pulp used as laxative and the stone in the kernals are fed to pigs.

The mango fruit, one of the most delicious fruit in India, is famous as national fruit of India, Pakistan, Philippines and as a national tree in Bangladesh. It is a good source of Vitamin A, Mg, Na, K and iron etc. It is used at its all developmental stages. Raw mango is used in various ways ranging from chutnee, pickles and curries while ripe fruit is used in preparation of jams, jelly, syrup and juice. India, as per National Horticulture Database, published by National Board India, produced 90.2 million tonnes of fruit during 2015-16.

About 175 insect species have been reported damaging mango fruit and trees. Of these, the stem borer of genus Batocera are the most serious and destructive pest in India.