Bioactivity of Azadirachta Excelsa Jack. Extractives on Selected Insects
Azadirachta excelsa Jack. is a fast growing timber species that has been newly chosen as a potential forest plantation species to overcome timber deficit for domestic consumption in future. This species like Azadirachta indica is suspected to contain biologically active compounds that is detrime...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English English |
| Published: |
1998
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/9952/1/FH_1998_1_A.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Azadirachta excelsa Jack. is a fast growing timber species that has
been newly chosen as a potential forest plantation species to overcome
timber deficit for domestic consumption in future. This species like
Azadirachta indica is suspected to contain biologically active compounds
that is detrimental on insects. Many studies have been done on the A.
indica, a relative species to A. excelsa, however, studies on A. excelsa are
still in preliminary stages. Therefore, the aim of this study was to evaluate
the effect of A.excelsa crude extractives towards three selected insect pests,
(i.e. Spodoptera Iitura, Callosobruchus chinensis and Coptotermes
curvignathus). A preliminary test to evaluate the susceptibility of A. excelsa
wood towards termites, compared to Koompasia malaccensis, Hevea
brasiliensis and Pinus caribaea was also conducted. In the first part of the study, the A.excelsa plant extracts were extracted
from different plant parts (i.e. leaf, bark, trunk, twigs and branch) using a range of
polar to non-polar solvents, namely hexane, petroleum ether, toluene, ethyl acetate
and methanol. The plant extractives were sampled and analysed through Thin
Layer Chromatography (TLC) and Infrared Spectrocopy (IR). In the second part of
the study, bioassay tests were conducted on the selected insects. The insects were
exposed to the plant extractives prepared at three concentration levels (i.e. 250
ppm, 500 ppm and 1000 ppm) and the solvents (0 ppm) as the control, by feeding
the insects with treated food source. The S. litura larvae were fed with castor leaf
discs soaked in the respective extractives. The C. chinensis adults were exposed to
mungbean seeds that had been soaked in the plant extrctives while the C.
curvignathus were fed with treated filter paper. In the last part of this study, the A.
excelsa wood together with the other three wood species mentioned earlier, were
exposed to the termites both in the laboratory and field. |
|---|