Abstract:The abundance of beneficial insects in the paddy field can be influenced by the abundance of insect pests, water parameters, climatic factors and plant traits. This study was conducted to determine effects of water parameters, climatic factors and plant traits on abundant insects. Findings of the studies showed that there were significant correlations between all beneficial insects in paddy field and water parameters tested, namely, water temperature, salinity, turbidity, pH, dissolved oxygen, biological oxygen demand, chemical oxygen demand, ammonia and total suspended solids. Moreover, the selected water parameters of water temperature, dissolved oxygen, biological oxygen demand and chemical oxygen demand were good predictors for abundant beneficial insects in paddy field at Sungai Burong, specifically for insects of sub-orders Anisoptera and Zygoptera, and insects from families Gerridae and Coccinellidae. The plant height, insect pest, temperature, rainfall and humidity were found to be good predictors on the abundance of beneficial insects; nevertheless, the R 2 value of multiple regression models was relatively low due to significant relationship between water parameters and insects. Consideration factors of water parameters, climatic factors and plant traits were strongly correlated with those parameters and abundance of insects in the paddy field at Sungai Burong, Tanjung Karang, Selangor.
This study investigated the consequence of nutrient concentration levels and pre-infestation of brinjal (Solanum melongena) plant (by whitefly and aphids) on population of whitefly (Aleyrodidae; Hemiptera) over two cropping periods. Both factors, nutrient levels and pre-infestation by pests could also change plant-pest relationship especially with herbivorous insect pests. Variation in nutrient levels applied to the plants could influence different physiological performance of the plants which subsequently affected whitefly population. Populations of whitefly were higher following increasing levels of nutrients in non-pre-infested (control) plants. Lower whitefly populations were observed on whitefly pre-infested brinjal plants compared to aphid pre-infested and control plants. Pre-infested plants were suspected to induce productions of secondary metabolites as a chemical defense system thus lowering the number of whiteflies on them. Considering other management technique in controlling whiteflies on brinjal such as optimum nutrient supplement as plant growth progress and good pest care during seedling stage was proposed.
A field study was carried out at Tangkak, Malaysia regarding Oryctes rhinoceros's infestation and its natural enemies after being treated with selected pesticides from January until October 2017. The objective of this study to examine the effect of different insecticides usages with the presences of Oryctes rhinoceros including unteated area and population of Oryctes's natural enemy in the oil palm areas of smallholders. Three treatments with four replicates were applied in the selected oil palm area, namely Cypermethrin, Carbofuran and Untreated (without chemical). Twelve smallholders with three different insecticides used were chosen randomly and twelve samples were taken as replicates. Effects of the beetles' population over the chemical's treatments were analyzed using analysis of variance (ANOVA) (SPSS-version 23). The results dramatically revealed that the least presence of Oryctes rhinoceros was detected at Untreated area with total mean of 0.21, followed by Carbofuran with total mean of 2.63 and Cypermethrin with 3.12. The result of this study indicated that Oryctes rhinoceros in Tangkak, Johor has developed resistance to the insecticides used by the growers due to high frequency of similar type of chemical. These insecticides had no significant effect towards the natural enemy found in oil palm area in Tangkak which is Platymeris laevicollis. These natural enemies also showed no relationship directly with the presences of Oryctes rhinoceros due to low diversity of plant species or particularly lack of shelter.
A field study was carried out for two cropping periods in the first season in year 2014 and the second season in 2015. This study was carried out at share farm, Agrotechnology Plantation UiTM Melaka, Campus Jasin to examine the efficacy of selected insecticides against whitefly (Bemisia tabaci) on brinjal crops and the effect on natural enemies (Spider) under field conditions. Five treatments with four replications were applied. The treatments were T0= Control (water), T1= Imidacloprid (Confidor), T2= Acetamiprid (Mospilan), T3= Dinotefuran (Oshin) and T4= Cyantraniliprole (Benevia). Pre-treatment and post-treatment observation were recorded which is one day before application and 1, 3, 7 and 14 days after application of insecticides. A total of two applications of treatments were done. The results revealed that Imidacloprid was recorded as the most effective and the highest reduction of whiteflies during the first season with 96.73%, followed by Acetamiprid (92.44%), Cyantraniliprole (82.65%) and Dinotefuran (80.74%) while during the second season, Imidacloprid also was recorded as the highest reduction with 79.99%, followed by Acetamiprid (76.34%), Cyantraniliprole (54.09%) and Dinotefuran (36.87%). Overall, chemical control of Imidacloprid was the most effective against whiteflies populations in brinjal particularly in the first season as compared to second season. The effect of these selected insecticides on natural enemies (Spider) revealed that chemical control of Imidacloprid gave the highest reduction of spider with 65.69%), followed by Cyantraniliprole (64.47%), Acetamiprid (41.44%) and Dinotefuran (15.45%). Imidacloprid and Cyantraniliprole were classified as moderately harmful to spider while Acetamiprid and Dinotefuran were classified as harmless or slightly harmful.
The performance of public universities will be greatly influenced by leaders' capacity to demonstrate the proper leadership styles under various conditions. This study has improved our comprehension of academics' preferred leadership philosophies. The information has been a valuable addition to the literature on leadership in Malaysian universities. In response, this study intends to evaluate academics' opinions of university leaders' leadership philosophies in the public higher education sector. It makes an effort to evaluate academics' preferences for transformational, transactional, and laissez-faire leadership styles as well as to pinpoint the demographic traits of academics that are strongly associated with their preferred leadership philosophies. Using a judgmental sample technique, data were gathered from selected academic staff members employed by public universities in Malaysia. Selected public universities received 500 questionnaires. The poll received 247 responses from academic personnel, yielding a 49.4% response rate. The respondents are made up of academic staff members at various levels, including professors, associate professors, senior lecturers, lecturers, and tutors. The purpose of this study is to determine the preferred leadership style of academics in public higher education institutions in Malaysia.
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