Population fluctuation of rice leaffolder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)
—Rice leaffolder, Cnaphalocrocis medinalis is the major insect rice pest in Asian countries. Their occurrence was not successfully controlled and can cause economic yield loss for heavy infestation. Very few studies had been conducted on their life cycle and population fluctuation which are impo...
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Main Authors: | , , , , , |
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Format: | Conference or Workshop Item |
Language: | English |
Published: |
2015
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Subjects: | |
Online Access: | http://eprints.unisza.edu.my/698/1/FH03-FBIM-15-03872.pdf http://eprints.unisza.edu.my/698/ |
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Summary: | —Rice leaffolder, Cnaphalocrocis medinalis is the
major insect rice pest in Asian countries. Their occurrence was not
successfully controlled and can cause economic yield loss for heavy
infestation. Very few studies had been conducted on their life cycle
and population fluctuation which are important as baseline
knowledge for their control program. Hence, this study was
conducted to observe the population fluctuation of C. medinalis and
to investigate the relationship of C. medinalis with environmental
factors; temperature and relative humidity. Sampling of C. medinalis
was carried out weekly for ten weeks from April 12, 2015 which 20
days after sowing (DAS) until June 14, 2015 (83 DAS). The larvae
were collected randomly by hand-picking from 10 hills per plot in
three 15m x 4m plots from 0800 – 1100 hours. Population of C.
medinalis was observed as early as 20 DAS and continue with similar
pattern with no significant difference (P>0.05) until 48 DAS. The
highest population was during 62 DAS with mean population 4.3
larvae per 10 hills which significantly different (P<0.05) with other
weeks except with 55 DAS with mean population 4.0 larvae per 10
hills. Leaves at this plant stage were found to be most favourable to
all larval instars. However, during last three weeks (69-83 DAS),
there was no C. medinalis found as the plant stage at 69-83 DAS
were not favourable for larval consumption. From correlation
analysis, the population of C. medinalis were not influenced by
temperature and relative humidity |
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