Retrospection of Outbreaks of Spodoptera mauritia Boisduval in NER India: The Solution Lies in Ecological Engineering, Not in Insecticides

Abstract

Rice cultivation in North East India is organic by tradition; however, the recent outbreaks of the rice-swarming caterpillar, Spodoptera mauritia Boisduval, have compelled rice-farmers to use synthetic insecticides. The outbreak in 2016 affected more than 56,768 ha of winter rice in 28 districts of Assam. About 25,545–42,576 L insecticide was applied in the state to combat the outbreak. This is one of the highest insecticide loads ever to be added to the rice ecosystem of Assam. Such a load, if added repeatedly with the reoccurrence of outbreaks, may affect the innate resilience of the rice ecosystem in the long run. In this paper, the outbreak of RSC has been analysed from an ecological perspective in order to replace the existing policy of exclusive dependence on insecticide. The review will help the researchers, extension workers and policy makers of the rice producing countries, more specifically in Asian countries, which together account for more than 91% of the world’s rice production.

Rapid assessment and management of outbreak of Rice Swarming Caterpillar by drone: a BIG need of the hour

“…The information of the outbreak came from farmers after observing the presence of large flocks of insectivorous birds in vertical physical structures like trees, electric transmission line, bird-perches etc. (Sarma et al, 2021). By that time, the pest got enough time for its spread and damage in new areas.…”

“…To identify the natural RSC hubs Sarma et al (2021) emphasized in locating RSC hubs in each agricultural circle of Assam in order to monitor and predict the RSC populations. Sarma et al (2023a,b) emphasized the application of drone to identify the perennial habitat of rice hispa, rice swarming caterpillars, stem borers, etc.…”

“…The issue of outbreak of RSC has emerged as a major threat to rice cultivation, because of its increased frequency of occurrence and exclusive dependence on chemical insecticides used for its combating. As compared to just 10 times in the past century the outbreaks occurred 9 times in the past 2 decades (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020) in India (Sarma et al, 2021) excluding the local RSC outbreaks many of which remained unreported in scientific journal (Sarma et al, 2023a,b). To combat the RSC outbreak in 2016 in Assam, about 25,545-42,576 L insecticide was applied in more than 56,768 ha of winter rice in Assam, an Indian state known for its organic cultivation (Sarma et al, 2021).…”

“…As compared to just 10 times in the past century the outbreaks occurred 9 times in the past 2 decades (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020) in India (Sarma et al, 2021) excluding the local RSC outbreaks many of which remained unreported in scientific journal (Sarma et al, 2023a,b). To combat the RSC outbreak in 2016 in Assam, about 25,545-42,576 L insecticide was applied in more than 56,768 ha of winter rice in Assam, an Indian state known for its organic cultivation (Sarma et al, 2021). The chemical insecticides were used in a no way-out situation because an outbreak is a disaster that cannot be allowed to continue.…”

“…The chemical insecticides were used in a no way-out situation because an outbreak is a disaster that cannot be allowed to continue. However, it is a matter of concern that such a massive addition of insecticides may pose a threat to the resilience of the rice ecosystem (Sarma et al, 2021). Credible predictions will help in the early adoption of non-chemical preventive measures as well as to avoid injudicious chemical application (Sarma et al, 2023a,b).…”