الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 95 |  |  |
| | | from | 95 | | |
Abstract
plant species belonging to family Euphorbiaceae
were investigated for their feeding deterrent effect,
stomach poison, contact effect and biological effects
on further development of larvae of Spodoptera littoralls
(Boisd.).
The plant species investigated were :-
(1) Euphorbia pulohrrima (Willd).
(2) Phyllanthus nivosus ~ atropurpureus (Bull).
(3) Euphorbia laetea (How.).
(4) Euphorbia aphylla (Brouss).
In the first plant leaves, stems and flowe~s were
used and in the second one leaves and stems were used.
The other plants, aerial parts were examined as a whole.
The dry powder of pl.antorgans were prepared and extraoted
with the following solvents successively 1.e.
ethanol, acetone, chloroform, petroleum ether and distilled
water respectively. Castor leaves were treated by
impregnation with the extracts and introduoed to fourth
instar larvae of oatton leaf worm the peroentage of
reduotion in feeding of, treated leaves Was determined
compared to leaves treated With the solvent alone as
control. The results showed that petroleum ether leaf
extracts of Phyllanthus nivoBus var atropurpureuB
produoed the maximum feeding deterrence.
Extracts were tested for their contact effect by
topical application to fourth inetar larvae. Mortality
was recorded after 24 and 48 hours. Results revealed
that the chloroform extract of the stems of Euphorbia
]ulchrrima was the most effective. The fact that
chloroform on ita own produced considerable mortalities
shed some doubt on the result. Further detailed studies
on this extract are needed.
Some extracts were investigated for their biological
effect on the development of 6 is instar larvae and
results showed that petroleum ether extract of the
leaves of Euphorbia pUlchrrima caused maximum adverse
effects on development when it was topically applied to
6 ib inatar larvae of Spodoptera littoralis. However,
no juvenoid-like effects were noticed. The adverse
effects were confined to small percentages of mortalities,
deformities in later stages and little depression in
fertility among females.
Preliminary phytochemical screening was carried
out and showed that petroleum ether extract of leaves
of Fhyllanthus nivoBus ~ atropurpureus whioh showed
feeding deterrenoe had only one group; terpenes.
Acetone extract of the above-mentioned plant organ
contained several phytochemical groups i.e glycosides,
flavonoids, alkaloids and saponins. A trial to separate
these groups was carried out by column chromatography
and the different fractions were eValuated by
bioassay. Results showed that the most effective fractions
were separated by elution with chloroform and
ethanol. Phytochemical teste were run for these
fractions and sh~Jed that chloroform separated saponins
and alkaloids and ethanol separated glycosides and
flavonoids. from the results and by comparison of the
reduction percentages in feeding in the crude extract
and in the fractions mentioned above, it Was concluded
that the crude extract act s through a combinat ion of
all these components.
Qualitative chemical tests of the petroleum ether
extract of the leaves of Euphorbia Eulcbrrima revealed
that it contained flavonoids, glycosides and terpenes.
The active material may be one or all these components.