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Molecular Entomology
2014, Vol.5, No.3, 18-29
Research Report
Open Access
Relative Susceptibility and Proximate Composition of Some Imported and Local
Rice Varieties to Infestation and Damage by
Sitophilus oryzae
L. (Coleoptera:
Bamisile, B. S.
Adesina, J. M.
Ofuya, T. I.
1. Department of Crop, Soil and Pest Management, Federal University of Technology, P.M. B. 704, Akure, Ondo, State. Nigeria
2. Department of Crop, Soil and Pest Management Technology, Rufus Giwa Polytechnic, P. M. B. 1019, Owo, Ondo State, Nigeria
Corresponding Author email:;
Molecular Entomology, 2014, Vol.5, No.3 doi: 10.5376/me.2014.05.0003
© 2013 Bamisile et al. This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Ten rice varieties were assessed for their comparative susceptibility and proximate composition to post harvest infestation
and damage by
Sitophilus oryzae
L. (Coleoptera: Curculionidae). The damage parameters used to compare the susceptibility of the
rice varieties to
S. oryzae
were; percentage mortality 4 weeks after adult insects infestation, number of F
progeny, percentage
grains weight loss and F
adult emergence. Four weeks post infestation (WPI), almost all the adults introduced to ITA 315 had died
(95% mortality rate) which was significantly (P<0.05) higher than death recorded in all other varieties, except Caprice (where 92.5%
mortality was recorded). At 8 WPI, there were significant differences (P<0.05) in F
adults emergence. The highest mean number of
adult emergence was recorded for Isan, which was significantly higher (P<0.05) than adult emergence (F
) in other varieties. The
lowest mean number of F
adults was recorded in ITA 315. At 8 and 12 WPI
there was significant difference (P<0.05) in weight loss
among the ten varieties. Weight loss was similar among the imported varieties and Ayede Ekiti rice. There was also no difference
(P>0.05) in the weight loss of Igbemo, Ofada and Erio varieties. Highest and lowest weight loss was obtained for Isan and ITA 315,
at week 8 and 12 respectively. The extent of damage done by the introduced adult
S. oryzae
were observed to be reduced in ITA 315,
Caprice, ITA 257 and Cisadene varieties, as they may have found it hard to puncture into or oviposit in the grains, resulting in
reduced weight loss, and low F
progeny and F
adult emergence. Grain hardness, moisture content and anti-nutrient compositions of
the selected varieties were investigated whether it may be used as indicators of resistance. Only moisture content could be established
as an indicator of resistance, as the grain moisture content was significantly positively correlated with both F
and F
adult emergence.
The imported varieties which recorded higher resistance had lower moisture content compared to the local varieties. Grain hardness
and anti-nutrient composition did not affect susceptibility of the rice varieties to infestation and damage of
S. oryzae
because there
was no significant (P>0.05) correlation between the two variables and susceptibility to the weevil.
Adult emergence; Anti-nutrient compositions; Grain hardness; Grain moisture content; Mortality; Weight loss
Rice as a cereal grain, it is the most important staple
food for a large part of the world's human population,
especially in Asia and the West Indies. It is the grain
with the second-highest worldwide production, after
maize (corn), according to data for 2010 (FAO, 2011).
Rice is the staple food of over half of the world's
population. It is the predominant dietary energy source
for 17 countries in Asia and the Pacific, 9 countries in
North and South America and 8 countries in Africa.
Rice provides 20% of the world’s dietary energy
supply, while wheat supplies 19% and maize 5%
(FAO, 2004). it is central to the food security of over
half the world population.
The high and rising population growth rate in Africa
has led to the high demand for rice in Sub Saharan
Africa and its consumption is growing faster than that
Preferred citation for this article:
Bamisile et al., 2014, Relative Susceptibility and Proximate Composition of Some Imported and Local Rice Varieties to Infestation and Damage by
Sitophilus oryzae
L. (Coleoptera: Curculionidae), Molecular Entomology, Vol.5, No.3 18-29 (doi: 10.5376/me.2014.05.0003)
Received: 04 Feb., 2014
Accepted: 14 Feb., 2014
Published: 26 Mar., 2014