1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Science and Technology / Fakulti Sains dan Teknologi

Title:	Insectidical effects of selected plants against sitophilus zeamais weevil (coleoptera : curculionidae), a pest of stored rice grains
Authors:	Asmanizar (P29220)
Supervisor:	Idris Abdul Ghani, Prof. Dr.
Keywords:	Pest Insectidical Rice grains Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	7-Dec-2012
Description:	The insecticidal effects of selected plants on the weevil, Sitophilus zeamais (Coleoptera: Curculionidae) infesting stored rice grain, and their toxicity on mice, Mus musculus were studied. The objective was to evaluate some locally available plants which may have insecticidal properties that could be used for the controlling of S. zeamais. The leaf, flower, rhizome and /or seed of twelve plants collected from around Medan, Indonesia, were made into crude extracts and evaluated through surface protectant method. Results showed that the crude extracts of Jatropha curcas seed, J. curcas leaf, Annona muricata and Azadirachta indica seed caused significant (P < 0.05) higher mortality on the weevil than by other plant extracts at 0.5% concentration. When applied in crude extract and powder form, the crude extract of J. curcas seed, J. curcas leaf, A. muricata seed and A. indica seed seemed to be more potent (LC50 = 0.013, 0.15, 0.079 and 0.487%, respectively) than the powder form (LC50 = 0.28, 1.15, 0.33 and 3.63%, respectively). The effectiveness of J. curcas and A. muricata seed crude extracts was further evaluated through dipping and surface protectant methods as well as their repellency effect. Jatropha curcas and A. muricata seed crude extract had both contact (94 and 78% mortality when weevils were dipped in 20% concentration) and stomach poisoning effect (100 and 52.71% mortality when fed on treated rice at 0.1%). However, both extracts showed poor repellency (60.75 and 46.5%) even at the highest dose (1.04 µl/cm2). Jatropha curcas seed crude extract was then subjected to different extraction methods (soaking with acetone, Petroleum Ether, Methanol, Soxhlet with acetone and kneading method using distilled water) before being used in residual activity testing (0, 1, 2, 3, 4, 5, 6, 8 and 12 weeks of residue period). Toxicity was higher (LC50 = 0.013 to 0.022%) when extraction was done using organic solvent (acetone, PE, MeOH) than when extracted using distilled water (LC50 = 0.45%). However, there was no significant difference between toxicity of crude extracts (extracted by Soxhlet extractor) and soaking methods. Prolonged residue period on treated rice grains significantly decreased the toxicity of J. curcas seed crude extract on weevils, but 100% mortality was recorded with 2 and 4 weeks of exposure time at 0.2 and 0.4% concentration, respectively. Sitophilus zeamais can be effectively controlled when rice is stored in woven plastic bags and when the bags were dipped into 2.5% J. curcas seed acetone crude extract. A similar result was observed when rice grain was mixed with J. curcas acetone seed crude extract at 0.2% concentration and J. curcas water crude extract at 0.8%. However, the combination of dipping woven bag in 1.25% and treating rice grain with 0.1% of J. curcas seed acetone crude extract showed similar results as the above. Acute oral toxicity of the J. curcas seed crude extract on mice, Mus musculus was also investigated and the results showed that J. curcas seed crude extract which was obtained by soaking with acetone or Soxhlet with acetone were relatively non toxic (the LD50 value was 10.66 and 12.33 g/kg body weight, respectively) to the mice. There was no significant difference (P > 0.05) on mice growth between the control and those diets treated with 0.2% concentration of J. curcas seed crude extract. Future research should attempt to measure the potential residues left on rice grains after washing and also after cooking as well its toxicity on mammals. It needs the cooperation of the government (national logistic agency) for applicability of this botanical insecticide as a complement to IPM of S. zeamais and other insect pests of stored rice.,Certification of Master's/Doctoral Thesis" is not available
Pages:	170
Call Number:	QL596.C9A849 2012 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.