Showing papers in "Vidyodaya Journal of Science in 2012"

Nutritional Evaluation in Five Species of Tuna

Abstract: Proximate composition was determined in different body parts (skin, white muscle, red muscle, head muscle and belly flap of five species of tuna; Katsuvonus pelamis (skipjack, balaya), Thunnus Albacares (yellow fin tuna, kellawalla), Auxis rochei (Bullet tuna, ragoduwa), Auxis thazard (frigate tuna, alagoduwa) and Euthvnnus affinis (kawakawa, attawalla) obtained from the Negambo fish landing site. Fatty acid profiles were also analyzed in the akin, red and white muscle of the five species. No significant differences between the tuna species were observed with respect to protein, total fat. and moisture contents. The ash content in Frigate tuna and Kawakawa were significantly higher than the other species. The muscle tissue in all the species was rich in protein (20-25%) and low in fat (

Seasonal changes in the abundance of biological agents killing Microcystis aeruginosa in a hypereutrophic pond

Abstract: Seasonal changes in abundance of the heterotrophic flagellates Polytomella sp., rotifers Cephalodella sp., Brachionus caliciflorous and the testate amoeba Penardochlamys sp. as grazers, cyanophages and algicidal bacteria as infectious agents on mortality of cyanobacterium, Microcysis aeruginosa was intensively studied in a hypereutrophic pond from September to November 2000. Abundance of the rotifers Cephalodella sp., B. caliciflorous and the Penardochlamys sp. were relatively high with large fluctuations. The cell density of M. aeruginosa ranged between 3.0 x 10 5 to 1.9 x 10 7 cells ml -1 , whereas those of algicidal bacteria were between 0.3 x 12 to 3.7 x 10 2 PFU ml -1 and cyanophages were between 0.9 x 10 3 to7.1 x 10 3 PFU ml -1 . Algicidal bacteria were relatively high with fluctuation between0.3 x 10 4 to 3.7 x 10 4 PFU ml -1 and bacterial peaks were followed with M. aeruginosa peaks. Occational cyanophages peaks on 2 and 20 October were followed by sudden collapse of M.aeruginosa bloom. Percentages of M. aeruginosa cells in food vacuole of Penardochlamys sp.was high (77%) during September following increase of the M. aeruginosa cell density. The flagellate Polytomella sp. was increased to a peak (2.5 x 10 5 indi. M -1 ) from 10 to 17 November with decrease of M. aeruginosa cell density. The percentage of B. caliciflorous individuals ingesting colonies of M. aeruginosa during the bloom period was significantly high (t-test, P Percentage of testate amoebae Penardochlamys sp. ingesting M. aeruginosa cells was very high (˃77%) during the bloom period. The food vacuoles of Penardochlamys sp. contained only Microcysis indicating its specific preference of Microcysis . The overall results of the study suggest the grazers’ protozoa; Polytomella sp., and the testate amoeba Penardochlamys sp., zooplankton; Cephalodella sp. and Brachionus caliciflorous , cyanophages and algicidal bacteria successively involved in suppressing M. aeruginosa bloom in a freshwater environment. Key words : Microcysis aeruginosa ; cyanophages; algicidal bacteria; Penardochlamys sp.; Cephalodella sp.; Brachionus caliciflorous Vidyodaya Journal of Science Vol.14(2) 85-101

Laboratory evaluation of some Sri Lankan plants as post-harvest grain protectants for the control of rice weevil Sitophilus oryzae

Abstract: Powdered leaves of thirty seven plant species were screened under laboratory conditions with the temperature of 29±2°C and 84±2% relative humidity for their repellent properties against rice weevil, Sitophilus oryzae (L). The screening was carried out with the view of producing more eco-friendly agents suitable for post-harvest rice protection and as sustainable alternatives to synthetic pesticides in the control of S. oryzae. Reared weevils were exposed to 15.0g of leaf powders admixed with rice grains in laboratory screening test using a modified cup-bioassay. The results revealed that twenty treatments caused significant repellency of adult S. oryzae than the control. Out of these, Ocimum gratissimum (Lamiaceae), Cinnamomum verum (Lauraceae), Mentha viridis (Lamiaceae), Plectranthus amboinicus (Lamiaceae) and Citrus reticulate (Rutaceae) showed the highest repellent activity. M. viridis elicited the highest and the strongest repellency (89.0 %) in the weevils when compared with the other three treatments. However, the weevils demonstrated considerably high rates of repellency to C. verum, O.gratissimum, C. reticulate and, P. amboinicus which were 76.0%, 74.0%, 68.0% and 64% respectively. When weevils were further tested against 5.0, 10.0 and 15.0g of leaf powders, all treatments showed significantly (p S. oryzae than the control. M. viridis at 15.0g dose elicited the highest and the strongest repellency (89%) in the weevils when compared with the other treatments and concentrations. The overall results indicated that repellency rate increased proportionately with the increase of the dose of the powder. A similar trend of repellency was also observed with time. However, the effects of all plant powders on the insects were highest within 6 hours post treatment. The overall results of the research provide scientific corroboration for the use of the four plant powders as effective grain protectants against the rice weevil. Key words : Sitophilus oryzae; Rice weevil; repellency; plant powders Vidyodaya Journal of Science Vol.14(2) 69-83

Mineral spectrum in different body parts of five species of tuna consumed in Sri Lanka

Abstract: The mineral spectrum of five species of tuna namely; Skipjack (Balaya, Katsuwonus pelamis ), Yellow fin tuna (Kelawalla, Thunnus albacores ), Bullet tuna (Ragoduwa, Auxis rochei ), Frigate tuna (Alagoduwa, Auxis thazard ) and Kawakawa (Atawalla, Euthynnus affinis ) were detected in skin, red muscle, white muscle, head muscle and belly flap using an Atomic Absorption Spectrophotometer (GBC 932 plus). Both macro and micro elements were detected in all tunas studied. Accordingly from the recorded minerals K was the most abundant macro element as its mean concentration among the tunas studied ranged from 246.94±62.27 to 293.84±77.78 mg/100g and the highest K level among the different body parts, was recorded in the skin (p Key words : Tuna; macro elements; micro elements Vidyodaya Journal of Science Vol.14(2) 103-111

Size related changes in fat content and fatty acid composition of Amblygaster sirm (Spotted sardinella, Hurulla)

Abstract: In the present study the fat content and fatty acid composition in three size classes ( 20cm) of male and female Amblygaster sirm (Spotted sardinella, Hurulla) were evaluated. The fat content increased gradually with increasing size of the fish. While both males and females showed the above increase with size, the fat content of the female (mean value 4.15%) was consistently higher than that of the male (mean value 3.6%). Like most other fish unsaturated fatty acids were dominated by two members of the n-3 family, EPA and DHA. Key words : Fat content; Fatty acids; EPA; DHA; Ambligaster sirm Vidyodaya Journal of Science Vol.14(2) 59-67

A study of water quality of Bolgoda North Lake

Abstract: Bacterial populations were investigated in relation to the environmental parameters in Bolgoda Lake for a period of six months from January 2000 to June 2000. Surface water samples were collected from six sampling stations in the Bolgoda Lake at monthly intervals. Total viable bacterial colony forming units (assumed to be equal to the density of bacterial population), total coliforms and faecal coliforms were studied as biological indicators. Physico-chemical environment parameters included, temperature, pH, electrical conductivity, salinity, Secchi disk depth, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), orthophosphate and nitrate contents. These were measured using standard methods. Correlations among bacterial densities and selected water quality parameters were investigated. High densities of bacterial populations were recorded at several sampling points in the vicinity of outlet drains which bring domestic and industrial effluents. Low densities of bacterial populations were recorded in samples taken at upstream and downstream of the North Lake. Results also revealed that some chemical parameters may have an effect in the density of bacterial populations. Density of bacterial populations showed a significant negative correlation with Biochemical oxygen demand (BOD) and with phosphate concentration. However, the density of bacterial population did not show a significant correlation with the nitrate content of the surface waters of the Lake. Further the DO, BOD values and PO 4 -3 content indicated organic and inorganic nutrient pollution of surface waters of Bolgoda Lake. However, samples collected from downstream had lower values for above parameters indicating that self- purification is taking place to a certain extent in the Lake. However, results revealed that at present Bolgoda Lake is heavily exposed to pollution from industrial and residential effluents. To avoid catastrophe, measures should be taken to reduce pollution by curtailing sewage disposal and treatment of effluents of nearby factories before being discharged into this Lake. Key words: water quality; Bolgoda Lake; evaluation of water quality Vidyodaya Journal of Science Vol.14(2) 113-133

Anopheles culicifacies complex: Geographical distribution of sibling species and existing methods for their identification

Abstract: Meaningful epidemiological studies and effective vector control programmes depend on efficient methods for differentiating among major vector, poor vector and non-vector of anopheline species complexes. Anopheles culicifacies, has a wide distribution in India, extending to Ethiopia, Yemen, Iran, Afghanistan and Pakistan in the West and Bangladesh, Myanmar, Thailand, Laos and Vietnam in the East. It is also found in Nepal and Southern China to the North and extends to Sri Lanka in the South. This species exist as a complex of five sibling species provisionally designated as A, B, C, D and E. Species A and B are predominant in Northern and Southern part of India whereas species B is recorded all over the Indian subcontinent. Species B and E are found in Sri Lanka to date. Various methods and techniques have been used for identifying sibling species ranging from crossing experiments cytogenetics, isoenzymes, hydrocarbon profile, DNA probes, rDNA-PCR, mt DNA-PC'R and RAPD-PCR. Studies of the suitability among different methods delineating the complex of An. culicifacies, the major malaria vector, mainly in the Indian subcontinent and in Sri Lanka have been discussed here. Key words : Anopheles culicifacies; mosquito control Vidyodaya Journal of Science Vol.14(2) 1-28

Confidence Intervals for the Median of a Gamma Distribution

Abstract: The gamma distribution is often used as a model for positively skewed distributions. The median is better than the mean as the representative of the 'average' in such situations. Literature is available for inference concerning the mean of a gamma distribution, but the literature concerning the median of a gamma distribution is rare. In this paper we present a method for constructing confidence intervals for the median of a gamma distribution. The method involves inverting the likelihood ratio test to obtain 'large sample' confidence intervals. A difficulty arises as it is not possible to write the likelihood function in terms of the median. In this paper we propose a method to avoid this difficulty. The method works well even for moderately large sample sizes. The methodology is illustrated using an example.

Zooplankton assemblage in Hambanota port and adjacent coastal waters of Sri Lanka

Abstract: Present study was to investigate zooplankton assemblage in Hambantota port and adjacent coastal waters in Sri Lanka. Samples were collected from the port before the commencement of commercial operations in order to have baseline information on zooplankton assemblage that can be used in the future to study any community change. Species composition, abundance, spatial distribution and diversity of zooplankton were investigated over a period of six months from January 2011 to June 2011. Monthly samples were collected from both inner-harbor and outer-harbor. Physico-chemical parameters such as temperature, pH, salinity, density, conductivity, nitrate, orthophosphate, DO, BOD5 and Ch a were also measured. Zooplankton diversity, species richness and evenness were calculated using Shannon-Weiner diversity index (Hˊ ), Simpson‟s index (D) and Pielou‟s evenness (E). A total of 72 zooplankton types were identified throughout the research project mainly Calanus sp., Paracalanus sp., Sapphirina sp., Acartia tranteri, Barnacle nauplii, Crustacean cypris larvae, Oikopleura sp., Tunicate larvae, Brachionus calyciflorus calyciflorus, Brachionus forficula, Fish larvae, Discorbis sp., Actinula larvae and Sagitta sp.. Copepod nauplii dominated the zooplankton. According to percentage occurrences arthropods (71%), protozoans (10%) and ichthyoplankton (9%) were abundant in the inner harbor. In the outer harbor also arthropods (66%), ichthyoplankton (11%) and protozoans (7%) were recorded in higher numbers. Highest species diversity (Hˊ =2.685), highest species richness (S=39) and highest evenness (E=0.856) were recorded from outer harbor locations (HFHB1 and HPM). Several species such as Ceratium furca, Chaetoceros sp., Thalassiosira sp., Rhizosolenia sp. and Protoperidinium sp. known to form harmful algal blooms were also observed in this study. Key words: Zooplankton assemblage, Hambantota port, Ballast water, Invasive Alien Species (IAS)

A study on the breeding patterns of Toxorhynchites splendens and Aedes albopictus in the natural environment

Abstract: This study aimed to investigate the breeding patterns of Toxorhynchites and Aedes mosquitoes in Kesbewa in the District of Colombo. The number of Ae. albopictus larvae per tyre dropped markedly with increasing number of Tx. splendens larvae per tyre (Pearson correlation = - 0.588, P Ae. albopictus pupae per tyre with a weekly average of 6.7 was recorded in the presence of Tx. splendens larvae with a value of 1.7 weekly average. Tx. splendens larvae per tyre per visit showed positive linear correlation with temperature (Pearson correlation = 0.622, P no linear correlation with relative humidity (Pearson correlation= 0.020, P>0.05). Container Indices (CI) of 50.00% and 12.50% for cement tanks and tyres respectively were recorded for Tx. splendens while the respective values for Ae. albopictus amounted 50.00% and 62.50%. For discarded receptacles and others such as bird baths the values were respectively 2.45% and 0% for Tx. splendens and 27.87% and 50.00% for Ae. albopictus. Key words : Toxorhynchites splendens; Aedes albopictus Vidyodaya Journal of Science Vol.14(2) 35-45

The carotenoids of the fruit pulp of palmyrah (Borassus flabellifer) from Hambantota

Abstract: The Hambantota district has relatively new plantations of palmyrah {Borassus flabellifer) and appear to be the future for industrial products from this tree. The tree with morphological type IIB fruit dominates plantations (>90%). Specimens of this type were selected for carotenoid analysis. Total carotenoid content was relatively low; 15.5 to 35.4 mg 100g -1 on the basis of dry weight (DW). Carotenoids were dominated by those of the hydrocarbon type. No oxygenated carotenoids were detected in the petroleum ether and diethyl ether extracts. Highest contents of carotenoids were phytofluene; from 2.8 to 4.8 mg100g -1 DW, phytoene from 5.7 to 10.3 mg100g -1 'DW and unidentified carotenoids I, II, III and IV from 0.7 to 1.9 mg100g -1 DW, 0.7 to 3.4mg100g -1 DW, 4.7 to I6.4mg100g -1 DW and 0.6 to 1.1 mg100g -1 DW respectively. β-Carotene and ζ-Carotene were present in traces. Retinol equivalent (RE) was negligible. As is usual for palmyrah, lycopene and the right fork of carotenoid biosynthesis pathway were absent. Key words: Palmyrah; Fruit Pulp; Borassus flabellifer; Carotenoids Vidyodaya Journal of Science Vol.14(2) 29-34

Information and Communication Technologies (ICT) and university freshmen

Abstract: Young people who grow up with the Internet are called the Net generation and they might be more impressively technologically literate, more accepting new technology and more technically facile than the former generations. The Net generation is very fluent with ICTs to participate and meet the demands of the 21st century. In this context, this study is an attempt to see the level of ICT literacy of new entrant undergraduates to Sri Lankan universities by examining their usage of digital technologies and communication tools, self rated skill levels on digital technology related activities and finally their perceptions of the impact of ICT on academic work in the universities. The study is compiled with data from questionnaires, placed with 1601 first year students, in thirteen universities of Sri Lanka. Questionnaire for the study was designed to gather data in three major areas; background Information, access to ICT and perceptions on the impact of ICT on academic experience. The data collected from the questionnaire was analyzed using the Minitab® Release 14.1 and the SPSS (Statistical Package for Social Scientists) 13.0 for windows, occupying a variety of statistical techniques. Descriptive statistics was used to produce statistics for each variable or for subsets within a variable. Chi-square test, Kruskal-Wallis one-way analysis of variance test and Friedman test were employed was occupied to reach the objectives of the study. The results reveal that there is a rapid trend towards becoming university freshmen as much as be digital literate. Most of the first year students use the computer applications and have indicated that they are much more skillful with them. Results also reveal that ICT usage frequencies and the self rated skills of ICTs are greater for the male students than females. First years who belong to urban communities believe that they are more skillful and use ICT more frequently. ICT skills and usage amongst students of the Arts streams are somewhat lower than the rest. The majority of freshmen believe that using ICTs is likely to help them to improve their learning in the university and are willing to use ICTs to search for information for academic purposes. They wish to have more access to Internet/E-mail facilities and ICT related equipment such as laptop computers, pen drives. It is recommended that more facilities and ICT related training are provided for freshmen, and at the village level literacy is improved by providing more facilities. Keywords: ICT literacy, digital technology skills, use of ICT

Hypercarotenaemia in Wistar rats and ICR mice and correlation to humans

Abstract: Hypercarotenaemia can occur at any age but it is more commonly seen in infants and young children due to the excessive intake of carotenoid bearing food. The objective of this study was to induce hypercarotenaemia and trace the fate of excess carotenoids in Wistar rats and ICR mice. Wistar rats (n=20) and ICR mice (n=28) were used. Rats and mice were divided into two groups (Test and Control). The controls were fed with standard rat/mice pellets while test group was fed with freeze-dried carrot incorporated standard rat/mice feed with boiled carrot. After a month and 2.5 months, blood was drawn for analyses of carotenoids and metabolites and after 2.5 months liver, adipose and digesta of rats were collected. Faeces were freeze dried and then analyzed for carotenoids of metabolites (RP-HPLC). Serum, adipose, liver and bile of test and control mice were also analysed as above. Wistar rats and ICR mice fed on excess carrot and papaw did not show outward signs of hypercarotenaemia. Their serum, adipose tissue, liver, digesta (in the case of rats) and bile (in the case of mice) did not show detectable amounts of carotenoids or their metabolites. However the faeces of both rat and mice had high levels of α and β carotenes. This indicates that one method of control of hypercarotenaemia may be at the level of absorption.

Monitoring aflatoxin contamination risks in red pepper spice produced in Turkey

Abstract: Even though Turkey is the third leading producer of fresh pepper, currently it only supplies 3-5% of processed red pepper spice in the international trade market because of high aflatoxin contamination. This study was designed to determine the presence and levels of aflatoxins in red pepper spice collected from three major producer provinces in Southeast (K. Maras, G. Antep, Hatay-Kilis) and one province in Central Turkey (Ankara), This pilot study also included companies that are actively involved in international red pepper spice trade. Nearly, half of the samples showed significant levels of contamination above the European Standard of 5 ng/g for AFB1 and 10 ng/g for total aflatoxins. Over ninety percent of contaminated samples contained AFB1 with levels ranging from 5 to 85.55ng/g. The overall mean level of total aflatoxins was 22.I8 ng/g with the highest level being 144.41ng/g. These results indicate that there is a necessity for establishing stricter and continuous national surveillance schemes for improving safely and quality of red pepper spice in Turkey.

Effects of Gymnema lactiferum leaf on serum glucose and cholesterol levels ofnormo-glycaemic Wistar rats

Abstract: Gymnema lactiferum var. lactiferum is a twining plant which belongs to the family Asclepiadaceae(milk weed family). This plant is distributed in many South Asian countries including, Assam,Malay Peninsula, Malaysia and Sri Lanka. It is reported that G. lactiferum leaf powder is usedpopularly by the people in Jaffna, as a treatment for diabetes. The present study indicates that theleaf powder does not result in a significant reduction of FBS (p=0.64) or serum total cholesterollevels (p=0.49) when tested with normo-glycaemic Wistar rats following feeding for 4 weeks.Further the leaf extract did not produce any significant effect on blood glucose levels on theglucose challenge (p=0.26) in the normo-glycaemic Wistar rats.

Trends in the incidence of Filariasis in rapidly urbanizing areas

Abstract: Incidence of Lymphatic Filariasis by microfilaraemic prevalence in a study area of Kalutara district, Sri Lanka has been analyzed here. Trends of annual prevalence data are parsimoniously identified by least square method. There are no marked fluctuations in microfilaraemic prevalence at the initial stage of the whole study period from 1977 to 2005. Middle period is associated with fluctuations and continuous decrease is evident at the final stage. These prevalence patterns are interpreted in terms of adverse effects of urbanization and also in terms of beneficial effects of the mass treatment programme.

Preliminary Study of Mineral Constituents in Selected Cultivars of Root and Tuber Crops in Sri Lanka

Abstract: A study was done to determine the levels of minerals (Calcium, Magnesium, Iron, Potassium and Zinc) in three different cultivars of yams (D. alata and D. esculenta), Xanthosoma sp and four different cultivars of sweet potatoes (Ipomea batatas Lam) from different regions in Sri Lanka. Yams (Rajala, Hingurala and Kukulala), Xanthosoma sp (Kiriala) and sweet potatoes (Swp3, Swp4, Swp5 and Swp7) were prepared for analysis 2 – 3 days after harvesting. Flour samples were subjected to ashing using AOAC (1980) method and mineral constituents were analysed using Atomic Absorption Spectrophotometer (AAS). Variation in mineral constituents on dry weight basis were analysed using ANOVA, Tukey‟s HSD test (p< 0.05) Minitab. All three cultivars of yams had significant levels (p< 0.05) of Calcium and Iron and high level of Magnesium was observed in Kiriala (45.27± 0.31 mg 100g-1). A significantly high level of Iron and Potassium (p<0.05) was observed in Rajala and Sweet potatoes respectively. Swp5 cultivar contained a comparatively high amount of Calcium and Magnesium while Swp3 and Swp7 contained a high level of iron (p<0.05). Comparatively high level of Zinc was present in Hingurala, Swp3 and Swp7 cultivars. Key words: Dioscorea , Ipomea batatas, minerals, Xanthosoma sp

A simplified non radioactive DNA probe technique for the field detection of sibling species A of the Anopheles culicifacies (Diptera: Culicidae) complex

Abstract: Three cloned highly repetitive DNA sequences Rp36, Rp217 and Rp234 isolated from An. culicifacies Giles, sensu lato were developed as non radioactive DNA probes by using a biotinylated labeling and colorimetric detection system. These non radioactive DNA probes distinguish sibling species A from species B and C of the An. culicifacies complex in a dot blot hybridization assay using single mosquito DNA extracts diluted 50 fold. The biotinylated Rp217 probe was further assayed in a more simple procedure which involves the hybridization of blots prepared from squashed mosquito heads. This technique avoids the separate extraction of mosquito DNA and facilitates a number of samples to be processed rapidly while also allowing several field analyses to be carried out on one mosquito specimen.

Aspects of the binding of acyclic carotenoids to flabelliferins from palmyrah fruit pulp

Abstract: The fruit pulp of palmyrah ( Borassus flabellifer) contains flabelliferins which are glycosides of β-sitosterol. Naturally bound to flabelliferins is an UV active compound, phvtofluene, which affects biological activity. This UV active compound shows intense blue fluorescence and can be dissociated from flabelliferins. The objectives of this study were to determine the main carotenoid binder to flabelliferin-II (F-II, a tetraglycoside) in a sample of PFP from Kalpitiya, Sri Lanka by HPLC and some of the chemical features of this complex (F-II+ carotenoid binder). HPLC studies showed that the major binder to F-II in a sample of PFP from Kalpitiya was phytofluene. No correlation was found between the stoichiometry of binding of phytofluene and F-II (r 2 =0.406) as well as for Fb (r 2 =0.007) indicating that the binding ratios of phytofluene with F-II or Fb are not constant in different PFP samples tested. Computational calculations(- ΔΔ H f /KJ mol -1 ) suggest that binding is less stable between F-II and phytofluene compared to the other flabelliferins tested. This was probably due to phytofluene distorting the conformation of the carbohydrate moiety of F-II. Computer modeling provided confirmatory evidence for this assumption. Key Words : Palmyrah; Borassus flabelifer ; Flabelliferins Vidyodaya Journal of Science Vol.14(2) 47-57

Potential of Olax zeylanica (Olacaceae) as a botanical insecticide for the control of the Maize Weevil Sitophilus zeamais Motschulsky

Abstract: The possible use of leaf powder of Olax zeylanica in managing the maize weevil, Sitophilus zeamais was investigated in the present study. Mortality of one week old adults was obtained for five different doses each for their insecticidal effect (1.0, 2.0, 3.0, 5.0 and 7.5g) and fumigation toxic activity (2.0, 3.0, 5.0, 7.5, 10.0g) separately. In each bioassay, the mortality was recorded after 3, 6, 9, 12, 18 and 24 hours after they were exposed to different doses of the plant powder. The results of both bioassays revealed that the leaf powder of this plant elicited a very high insecticidal activity as well as fumigation toxic activity in S. zeamais weevils. Mortality effect of the powders on the weevils was found to be dose and time dependent. The observations indicated that the adult mortality increased with the increase of the exposure time and the dose. No mortality was observed 3 hours after the exposure of weevils to leaf powder at all doses. A high mortality rate was observed after 9 hours of exposure with all doses except for the lowest and a 100% mortality was recorded with 7.5g after 24 hours. Fumigation toxicity of plant powder against the weevils also gave similar results where no weevil deaths were observed at all doses of leaf powder after 3 hours of exposure. At the highest dose of 10.0g, 98% mortality was observed after 24 hours. The overall results imply the strong possibility of using leaves of Olax zeylanica as a potent bio-insecticide in protecting maize grains from S. zeamais infestations.