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Molecular Entomology 2013, Vol.4, No.2, 6-12
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9
Table 4 ANOVA
Source of Variation
SS
df
MS
F
*P-value
F crit
Between Groups
35360.79
3
11786.93
829.953
3.81E-21
3.098391
Within Groups
284.0385
20
14.20193
Total
35644.83
23
*significant at 5% level of probability
Table 5 Efficacy of CEB against subterranean termite on Plywood
*Average percentage damage/attack (%)
CEB (10% w/v)
concentration (%)
6 MAE
12 MAE
24 MAE
30 MAE
2.5% CEB
0
0
0
4.91
3.0% CEB
0
0
0
4.22
5.0% CEB
0
0
0
3.41
Control
9.4
89.84
100
100
* Average of six samples
Table 6 ANOVA
Source of Variation
SS
df
MS
F
*P-value
F crit
Between Groups
41322.91
3
13774.3
1548400
8.1E-54
3.098391
Within Groups
0.177917
20
0.008896
Total
41323.09
23
*significant at 5% level of probability
The results of both the test viz., solid wood and
plywood against subterranean termites were subjected
for Analysis of Variance (ANOVA) (Table 4 and 6).
From the ANOVA it was found that there is a
significant difference between the concentration of
CEB and the attack of subterranean termite on solid
wood and plywood. The attack of subterranean termite
decreases as the increase in concentration of CEB
chemical in both the solid wood and plywood.
2 Discussion
Rubber wood is prone to attack by PPB and
subterranean termite. New generation pesticides are
effective at very low usage rate. Hence, the present
study was designed to explore how different doses of
CEB affect the durability of rubber wood against PPB
and subterranean termite.
Preservation of wood has been considered to increase
the life of wood 5 to 8 times. Many formulations like
CCA, CCB, ACC (Acid Copper Chrome), BCCA
(Boron Copper Chrome Arsenic) contains Copper,
Arsenic, Boron, etc., either individually or as a
mixture using Chromium as a fixative agent are being
used worldwide. The use of Arsenic and Chromium
based compositions are under constant review for
environmental reasons and these formulations face the
threat of being phased out in the future. Hence, before
it will be phased out an alternate wood preservative
chemical has to be found out. Moving in this direction
an attempt has been made in the present study to
assess the bioefficacy of CEB against PPB and
subterranean termite.
The absorption of preservative chemical was found in
the range of 2.39 kg/m
3
to 3.36 kg/m
3
in half an hour
dipping. This may be due to the reason that Rubber
wood is highly permeable in nature and hence
absorption of preservative was found to be adequate.
The most important criteria for judging performance
of a newly developed preservative system is the field
efficacy tests. Hence, in the present investigation the
field efficacy test was performed to assess the
performance of CEB in actual service condition.
CEB (10% w/v) at 2.5% was proved to be the best
insecticide in this study. No doubt, that the highest