الفهرس 
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Abstract
The objective of this work was to study the toxic effect of
acetone and petroleum ether extracts as well as dusts of the african
chillies (Capsicum frutescens) fruits, the leaves ofClerodendron
(Clerodendron inerme), Eucalyptus (Eucalyptus globulus) and
Duranta iDuranta plumieri) on mortality, reduction in F} progeny,
and repellency effect on some stored products insects, namely the
rice weevil (Sitophilus oryzae L.)~ the lesser grain borer
(Rhizopertha dominica F.), and the red flour beetle (Tribolium
castaneum Herbst). Tests were conducted at the stored product
pests laboratory of the plant protection Department, Faculty of
Agriculture Moshtohor, Zagazig University. The obtained results
could be summarized as follows:
1- Toxicity and effect of acetone extract of the various plants:
Results concerning the toxic effects of acetone extracts of
the different plants on mortalities and reduction in Fj progeny of
S. oryzae, R. dominica and T. castaneum showed the following:
S. oryzae: Mortalties increased with increasing concentration and
time of exposure. After 15 days from the initial treatment,
mortality percentages were 1000/0 at all tested concentrations (1 0,
5, 2.5, 1.25 and 0.625%) w/v with Capsicum fruit extract.
Mortality percentages resulted from the other plant extracts were
considerably lower.,td ranged from 25-880/0, 10--60% and 18-320/0
at various concentations for the leaves extract of Duranta,
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Clerodendron, and Eucalyptus, respectively. Reduction in F1
progeny ranged from 99-1000/0, 20-700/0, 66-86% and 56-950/0 at
various concentrations with Capsicum, Clerodendron, Eucalyptus
and Duranta acetone extract, respectively.
Results of R. dominica indicated that mortalities were
increased with rising concentration and exposure period. After 15
days following treatment, mortalities were between 4-23%, 47-
680/0, 10-19%, and 13-250/0 at various concentrations for
Capsicum, Clerodendron, Eucalyptus and Duranta acetone extract,
respectively. Higher reduction in F1 Progeny was achieved in
range from 74-940/0, 72-92%, 58-780/0 and 63-880/0 at all
concentrations with the extracts of Capsicum, Clerodendron,
Eucalyptus and Duranta, respectively.
In case of T. castaneum, very low mortality percentages
were recorded after 15 days from treatment at all concentrations of
the various plant extracts. Mortalities ranged from 3-120/0, 8-170/0,
0-15% and 2-70/0 for Capsicum, Clerodendron, Eucalyptus and
Duranta acetone extract, respectively. Contrarly, higher reduction
in Fl progeny was obtained for the various plant extracts and it
was between 57-83%, 87-99%, 74-84% and 68-79% for
Capsicum, ’Clerodendron, Eucalyptus and Duranta acetone extract,
respectively.
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2- Toxicity and effect of petroleum ether extract of the various
plants:
Results concerning the toxic effect of petroleum ether
extracts of the various plants on mortalities and reduction in F1
progeny of three insect species under investigations showed that
mortalities were increased with increasing concentration and time
of exposure.
s. oryzae: After.15 days following treatment, complete mortalities
were achieved at various concentrations of Capsicum extract.
Also, 100% reduction in F1 progeny was recorded at all
concentrations of this plant extract. Meanwhile, mortalities of the
other plant extracts ranged from 5-980/0,80-980/0and 80-1000/0 for
Clerodendron, Eucalyptus and Duranta extract, respectively.
Reduction in Fj progeny was between 32-1000/0, 88-1000/0 and 83-
100% for the petroleum ether extract of the mentioned plants,
respectively.
Results of R. dominica indicated that after 15 days from
initial treatment, mortalities were in range from 3-320/0,73-1000/0,
5-42% and 15-850/0 at the various concentrations of Capsicum,
Clerodendron, Eucalyptus and Duranta extract, respectively.
Reduction ’in F 1 p•.•• ny was relatively higher than mortality and
ranged from 82-1ocJYo, 78-1000/0,60-84% and 68-92% at various
. concentrations of ~um, Clerodendron, Eucalyptus and
Duranta extract, resj;ctively.
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T. Castaneum: Mortalities recorded after 15 days from treatment
were very low for the various plant extracts and ranged from 5-
130/0) 5-15%, 5-80/0 and 0-7% at the various concentrations of
Capsicum, Cler~dendron, Eucalyptus and Duranta extract,
respectively. Reduction in Fl progeny was significantly higher
than mortality and was in range from 5-69%), 30-880/0,44-770/0 and
11-57% for the various plant extracts) respectively.
Data revealed also that S. oryzae adults were the most
susceptible insect species followed by R. dominica and T.
castaneum adults to acetone and petroleum ether extracts of the
different plants under study.
3- Toxicity and effect of the various plant dusts:
Results of the toxic effect of the various plant dusts at 4, 2
and 1% concentrations on mortalities and reduction in F1 progeny
of S. oryzae, R. dominica and T. castaneum revealed the following:
s. oryzae: After 15 days from treatment) mortalities ranged from
7-25%) 25-50%, 8-18% and 10-200/0at various concentrations for
Caps icurn, Clerodendron, Eucalyptus and Duranta powder)
respectively. Reduction in Fj progeny were between 6-230/0, 16-
56%,.3-21 % and 12-530/0for the various plant dusts, respectively.
R. dominica: Recorded mortalities after 15 days from treatment
were in range from 11-35%, 50-60°/0) 25-450/0 and 50-65% for
Capsicum fruit dust, Clerodendron, Eucalyptus and Duranta leaves
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dust, respectively. Reduction in F} progeny ranged from 5-640/0,
57-79%, t4-64% and 57-86% at various concentrations of the
various plant dusts, respectively.
T. castaneum: After 15 days following treatment, mortalities
ranged ,from 12-IS%, 25-35%, 10-250/0 and 18-38% at all
concentrations of Capsicum fruit powder, Clerodendron,
Eucalyptus and Duranta leaves powder, respectively.
Reduction in Fl progeny was between 32-52%, 50-68%,2-
370/0 and 3•.31%for the various plant powders, respectively. At the
highest concentration of 4%, results indicated clearly that the
reduction in FI progeny was considerably greater than mortal ity of
the various insect species with all tested plant dusts. Also, R.
dominica was themost.sensitive species’ to the various plant dusts
than S. oryzae andT. eastaneum. Dusts were less effects than the
extracts.
4.RepeileDcyeffeet4;f~”tone exUKtsoftile variolas plants:
Results ..of the·.~ effect of acetone extract of the
various plants againlt -$1 oryzae, R. dolIti1tica and T. castaneum
revealed the followiq:
Relatively hirj.,jI1ues of average repellency during the
.observation period’1~~ys were recorded for S. oryzae with the
various plant ~ valueswere·ranged from 4>64%, 33-
t’!.’’•’.’..::’’>:, ..--:.
-~:’::,’.; ’-~’’’’_.
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780/0, 14-61 %, and 21-51 % at all concentrations for Capsicum,
Clerodendron, Eucalyptus and Duranta acetone extract,
respectively. These values were also relatively high for T.
castaneum and were in range from 30-56%, 45-710/0, 20-52% and
32-590/0 with the various plant extracts, respectively.
In case of R. dominica, repellency values were lower and
ranged from ,3-14%, 14-57%, 1-23% and 5-330/0 for the different
plant extracts, respectively.
5- Repellency effect of petroleum ether extracts of the various
plants:
S. oryzae: Mean repellency was from 26-610/0, 22-600/0, 20-
530/0 and 18-530/0 at various concentrations for Capsicum,
Clerodendron, Eucalyptus and Duranta petroleum ether extract,
respectively.
Lower values were obtained with R. dominica in range from
2-240/0, 8-180/0, 6-240/0 and 9-180/0 for the extracts of the different
plants, respectively.
The repellency vaules of T. castaneum ranged between 26-
490/0, 20-52%, 31-58% and 17-38% with petroleum ether extract
of Capsicum fruits, Clerodendron, Eucalyptus and Duranta leaves,
respectively.
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Conclusion:
The obtained results indicated clearly that the powders of the
various tested plants were obviously less effective against S.
oryzae, R. dominica and T. castaneum than aceton and petroleum
ether extract. Reduction in F 1 progeny was generally much higher
. than mortality percentages at all tested concentartions and plants.
The susceptibility ’ofthe insects under study varied from species to
another. The, extracts of the various plants under investigation
especially at the highest concentrations of 5 and 10% proved to be
effective against the various insect species and could be
recommended for use in frame of an integrated pest management
programme for protection of stored grains against postharvest
pests.