“Fall army worm”, generally known as the ” sena dalambuwa” in Sri Lanka, a feared crop pest which has brought devastation in Africa has now made its way to Sri Lanka and over 50 percent of the maize cultivation during the 2018/2019 Maha season has been infested by the pest. This species of caterpillars was first detected in Nigeria. The caterpillar is now spreading mainly in the maize cultivation in number of areas in Sri Lanka. The caterpillar infestation has been detected in Ampara, Anuradhapura, Polonnaruwa, Kurunagala and Monaragala areas where the maize is predominantly grown.
The Fall Army Worm, Spodoptera frugiperda, is a lepidopteron pest that feeds on large number of leaves and stems of more than 80 plant species, causing damage to economically important crops such as maize, rice, sorghum and also the other vegetable crops and cotton. From its life cycle, the larvae stage causes the greatest damage to the crops. Fall Army Worm can be easily identified as the large larvae that are characterized by an inverted Y shape in yellow on the head and four black spots arranged in a square on the last abdominal segment. On hatching they are green with black lines and spots and as they grow they either remain green or become buff-brown and have black dorsal and spiral lines.
According to research, the pest possess all the characteristics of being invasive, such as short life cycle and multiple egg-laying cycles. Also the moth can fly up to 100 km per night and the female moth can fly up to 200 eggs at one time. The suppression of the insect was a challenge for every country that it was reported, due to their ability to quickly adapt to insecticides. Based on the research studies Department of Agriculture has recommended five pesticides that could kill Spodopter spp. with techniques that have yielded fruitful results in other instances.
The impact of the pest on crop cultivation has already been left with destruction caused to maize grown mainly to provide part of animal feed. Loss of maize crop will affect farmers’ income, resulting in loss of investments and loss of foreign exchange due to importation of maize to support industries such as poultry. Unless proper control measures are adopted and action is taken to destroy the species, there will be a devastating impact on local crops.
Article by – Chamini Wijethunga
Edited by – Dinisi Nandasena
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