K'taka: Eucalyptus facing attack from 'gall insect'

Sirsi (Karnataka), June 19: Eucalyptus, a primary pulp wood species widely used as raw material in paper and rayon industries, is under threat from a new pest 'gall insect'(Leptocybe invasa) widely present now in south India.

Agricultural Research Station (ARS) scientist S T Prabhu, who is doing a research on Eucalyptus, said the new insect, basically found in Australia, made its way into Andhra Pradesh, Tamil Nadu, Kerala, Pondicherry and Karnataka.

Recently, the Andhra Pradesh Forest Development Corporation brought to notice of the Institute of Forest Genetics and Tree Breeding (IFGTB), Coimbatore about the new insect attack on Eucalyptus.

He said in Karnataka, the insects were on an attacking spree and damaged 25 lakh Eucalyptus saplings in the nurseries of two major paper and rayon industries - West Coast Papers and Harihara Polyfibres.

The insects also damaged Eucalyptus in and around Sirsi and Uttara Kannada district.

''Leptocybe invasa'' is currently spreading in many countries around the Mediterranean basin and in Africa, causing damage to Eucalyptus plantations.

Presently, it is seen in countries like Algeria, France, Israel, Italy, Jordan, Morocco, Portugal, Spain, Turkey, Kenya, Morocco, Syria, Tanzania, Uganda, Iran, Thailand and Vietnam.

In India, it was first noticed in 2001 at Mandya district in Karnataka and later in 2002 at Marakkanam in Villupuram district of Tamil Nadu.

Dr Prabhu said to assess the spread of the pest problem, three teams led by entomologists of IFGTB had carried out extensive surveys in Tamil Nadu, Andhra Pradesh, Kerala and Puducherry during February-March, 2007. The survey revealed that the pest was spreading to new areas and if the problem was left unattended, it may cause severe problem in all eucalyptus growing areas.

He said said 'Leptocybe invasa,' a tiny wasp measuring 1.1 to 1.4mm, more prevalently creates galls on the mid-ribs, petioles and stems of new shoots of eucalyptus trees.

Heavy infestations can lead to deformed leaves and shoots and subsequently affects the growth of the tree.

The adult females (1.1-1.4 mm) insert their eggs in the epidermis of young leaves, on both sides of the mid-rib, in the petioles and in the parenchyma of twigs. Larvae develops inside the round galls (about 2.7 mm wide), he added.

He said experts from IFGTB conducted a detailed study on the pest attack and would soon come out with strategies to contain the same.

A meeting of the experts from various agricultural and pest control institutes had recommended setting up of a cell at IFGTB to monitor the pest and also a GIS facility to track its movement and spread.

The meeting also recommended use of chemical control measures and favoured biological control measures to tackle the pest. They also advised the Department of Plant Quarantine to adopt a stricter quarantine measures while exporting and importing eucalyptus germplasm.

Dr Prabhu said the meeting suggested formulation of an all-India coordinated programme for pest management to be implemented by the IFGTB and setting up of a National Centre for Gall Research at the institute.

UNI