Abstract
Aim:
To evaluate the effect of abiotic factors such as temperature, relative
humidity, wind velocity, sunshine hours and rainfall on the distribution and
relative abundance of stem borer species in rice ecosystem.
Methodology: Seasonal incidence of stem borer species was
monitored using light trap catches and were correlated with the weather
parameters. The relative abundance of stem borer species during Kharif and
Rabi was estimated based on light trap catches and larval incidence.
Results:
Seasonal incidence revealed the occurrence of three stem borer species
(yellow stem borer, pink stem borer and dark headed borer) populations in
rice ecosystem. Yellow stem borer was found to dominate in rice ecosystem
during Kharif, (80.61%) whereas during Rabi, pinkstem borer was
found to be dominant (72.60%) than yellow stem borer (21.92%) and dark headed
borer (5.48%). Weather parameters such as temperature, rainfall and wind
velocity negatively influenced the occurrence of stem borer species in rice,
whereas relative humidity and sunshine hours had positive effect. Regression
analysis revealed the increased effect of abiotic factors such as
temperature, relative humidity and wind velocityon the population of pink
stem borer against yellow stem borer and dark headed borer.
Interpretation: The present study reveals that, the
change in weather parameter during seasons, such as temperature (25 - 27°C),
relative humidity (69 - 80 %) and wind velocity (3 - 4 km hr-1)
increased the fitness of pink stem borer species population than yellow stem
borer and dark headed borer species in rice ecosystem, which was evidenced by
the occurrence and relative abundance of pink stem borer population during Kharif
2018 and Rabi 2019 respectively.
Key words: Abiotic factors, Light trap catches, Rice, Stem
borer
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