Adult Tuta Absoluta

Larva Tuta Absoluta

Tuta absoluta: A Serious and Immediate Threat to Tomato Production in Nepal

Tuta absoluta is a devastating tomato pest. It was reported to have entered Nepal for the first time in 2016. Because tomatoes are one of the most important vegetable crops in Nepal, iDE and others have undertaken an all out effort to quickly develop and publicize effective control measures. If control measures are not taken, Tuta absoluta will likely cause tomato yield losses in Nepal of up to 80-100% and financial losses of in excess of $50 million USD. In collaboration with experts from the Government of Nepal and others, the IPM-IL and iDE Nepal have developed recommended IPM guidelines and approaches for managing this new infestation.

Background:


THE SOUTH AMERICAN TOMATO LEAF MINER, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) is a native of South America. It was accidentally introduced into Spain in 2006. Since then it has invaded other European, North African, and Mediterranean countries. Tuta absoluta attacks tomatoes with devastating consequences. It is a solanaceous crop that also infects potatoes, eggplants and chilies. The moth deposits its eggs on the underside of tomato leaves, stems and, to a lesser extent, on the calyx of fruit. After hatching, young larvae bore into leaves and fruit on which they feed and develop, creating mines and galleries. On leaves, larvae feed on mesophyll, leaving the epidermis intact. Infestation can be at any developmental stage, from seedlings to mature plants. Tuta absoluta completes its life cycle (egg-larva-pupa-moth) in as few as twenty four (24) days. In favorable climatic conditions (20⁰C to 27⁰C) which regularly exist in Nepal, ten (10) to twelve (12) generations can occur in a single year. A single female moth lays between 250 – 300 eggs.

 

Identification:

During the first quarter of 2016, farmers from Kathmandu, Bhaktapur and Kavre Districts identified a new tomato pest. A team from IPM-IL and others visited the sites and collected samples. Tuta absoluta lures from Pest Control India were also placed in the infested fields. The number of insects trapped in pheromone traps, their external morphology and damage symptoms all indicated Tuta absoluta. Samples of adult moths and larva were sent to the School of Life Science, Arizona State University. Laboratory tests confirmed the new pest was Tuta absoluta. The Government of Nepal’s National Agriculture Research Center, Khumaltar, independently identified the pest as Tuta absoluta on May 16, 2016.

Distribution:

Kathmandu, Bhaktapur, Kavre and Lalitpur are currently the major districts hit by Tuta absoluta. Distribution has, however, been found across the mid-hill region of Nepal. To date, Tuta absoluta has been identified in approximately 15 districts. Preliminary information suggests 25-30% of tomato crops have been lost in the hardest hit areas. That amounts to approximately a loss of $7,200 a hectare. The threat of spread to the Terai region and other regions in the mid-hills is high in the coming months. Appropriate management will be critical to limit significant future losses.

Way Forward:

iDE Nepal is providing training and technical support for developing and promoting IPM solutions for the Tuta tomato pest. iDE Nepal in close coordination with the Department of Agriculture Plant Protection Directorate is conducting verification demonstrations across Nepal’s development regions and working with the private sector to develop supply chains for IPM technologies to address the Tuta pest.  

Contact Person
Lalit Sah, IPM Program Coordinator, iDE Nepal
lpsah@ideglobal.org

Khyam Narayan Paudel is a commercial farmer who controlled a Tuta outbreak using PCI lures and IPM technologies purchased from a supply chain facilitated by the USAID ENBAITA project.


Photos By: Bimala Rai Colavito, iDE Nepal Volunteer