Microemulsion Formulations Of Rotenone And Their Effectiveness Against The Diamondback Moth (Lepidoptera: Yponomeutidae)

Oil-in-water (O/W) microemulsions were prepared by the titration method through phase diagram study. The mixture consisted of surfactant, oil (as carrier), and water. The surfactants were Agnique PG 8107-U, Agnique PG 9116, and Tween 20 while the oils were Agnique BL 7001, Agnique BL 7002, and xylene. The potential of plant-derived insecticide rotenone (Derris elliptica) microemulsion formulations and their effectiveness against crucifer insect pest namely diamondback moth, Plutella xylostella were investigated in laboratory. The objectives of this study were, therefore, to formulate rotenone as microemulsion formulations through phase diagram study, to characterize the formulations, and to determine their LC50 on diamondback moth by bioassay study.Twelve phase diagrams of ternary systems were constructed and isotropic region were established. The systems having wider isotropic region were selected and they were Agnique 8107-U/Agnique BL 7001/water, Agnique 9116/Agnique BL 7001/water, Tween 20/Agnique BL 7001/water, Agnique PG 8107-U/Agnique BL 7002/water, Tween 20/Agnique BL 7002/water and Tween 20/Edenor ME/water systems. From these phase diagrams, 13 microemulsion solutions were derived. These microemulsion solutions were further evaluated for miscibility, surface tension, and particle size analysis. The phase diagram systems containing Tween 20 as the surfactant showed the greater ability to produce a wider isotropic (microemulsion) region compared to others. The miscibility test showed all surfactants mixed readily with water. In interaction with the all oil phases, Tween 20 showed better miscibility compared with Agnique PG 8107-U and Agnique PG 9116 which produce double layers isotropic emulsion in absence of water. The width of isotropic/transparent region in phase diagrams constructed measured in decreasing order were; Tween 20/Agnique BL 7002/ water > Tween 20/Agnique BL 7001/water > Tween 20/Edenor ME/water > Agnique PG 9116/Agnique BL 7001/water > Agnique PG 8107-U/Agnique BL 7001/water > Agnique PG 8107-U/Agnique BL 7002/water > Tween 20/xylene/water > Agnique PG 9116/Agnique BL 7002/water > Agnique PG 9116/xylene/water > Agnique PG 8107-U/xylene/water > Agnique PG 8107-U/Edenor ME/water > Agnique PG 9116/Edenor ME/water.Three phase diagram systems representing the best microemulsifiable characterization properties and solubility with rotenone were Tween 20/Agnique BL 7001/water, Tween 20/Agnique BL 7002/water and Tween 20/Edenor ME/water systems. Six points in the isotropic regions of the selected phase diagrams were utilized to prepare the microemulsion and coded as M1 to M13. The microemulsions were then subjected to the determination of their surface tensions and particle sizes. The surface tension values of the selected microemulsions were low and their values in decreasing order were; M9 (27.3 mN/m) > M13 (26.9 mN/m) > M2 (26.8 mN/m) > M4 (26.4 mN/m) > M11 (22.8 mN/m) > M7 (22.7 mN/m). The particle size of the microemulsion in decreasing order were; M4 (207.57 nm) > M13 (83.31 nm) > M2 (68.7 nm) > M11 (49.03 nm) > M9 (35.86 nm) > M7 (20.63 nm). The selected microemusions were used to prepare the rotenone microemulsion formulations. The formulations were then evaluated for their toxicity in comparison with the standard commercial EC formulation (Saphyr®) against the early third instar larvae of the diamondback moth by leaf-dipped bioassay in the laboratory. The mortality of the larvae was recorded at 72 and 96 hours following treatment and data were subjected to the Probit analysis to establish the LC50 and LC95. Based on LC50 values, the toxicity of formulations for 72 hours after treatment in decreasing order were M11 (204.82 ppm) > M7 (139.71 ppm) > M13 (129.89 ppm) > M4 (122.8 ppm) > M2 (116.94 ppm) > M9 (96.09 ppm) > Saphyr® (96.05 ppm) while for 96 hours after treatment, the toxicity in decreasing order were M11 (166.63 ppm) > M7 (119.58 ppm) > M13 (105.82 ppm) > M2 (105.22 ppm) > M4 (97.67 ppm) > M9 (87.22 ppm) > Saphyr® (76.86 ppm). The toxicity study indicated that the rotenone microemulsion formulations especially M9 were comparable to commercial rotenone, Saphyr®

Identification of Cordyceps javanica and its effectiveness in Controlling Bagworm, Pteroma pendula JOANNIS (LEPIDOPTERA: PSYCHIDAE)

The application of biological control agents as one of the control methods to suppress the infestation of bagworm in Malaysia has developed steadily with the inundation release of formulated entomopathogenic microbes to the outbreak area. In this study, we isolated and identified the entomopathogenic fungi (EPF) from the dead larvae of the bagworm, Pteroma pendula. Mycoses dead bodies of P. pendula were collected from two locations in Kemayan, Pahang, Malaysia. Morphological characterization of EPF was carried out by observing the macroscopic and microscopic growth on Potato Dextrose Agar (PDA) plates using a compound microscope. It was observed that white colonies on PDA changed into purple or pink shades after sporulation. The colony is slow-growing with floccose mycelium, which produces conidiophores with three to four phialides. The conidia were cylindrical to fusiform, smoothwalled and formed in chains on mononematous conidiophores. All the isolates were observed to be similar to Cordyceps fumosorosea features. Molecular identification using universal primer (ITS4 and ITS5) has identified that the isolates were Cordyceps javanica and Parahevansia koratensis. Bioassays of identified isolates were carried out against the second instar larvae of Pteroma pendula showed that C. javanica isolates BSB01 achieved LT50 - 6.76 days and recorded the shortest lethal time compared to the other isolates

The insect pest management strategies and their influence on the emergence rate of elaeidobius kamerunicus faust (Coleoptera: Curculionidae) from the post-anthesising male inflorescence of oil palm, Elaeis guineensis

Elaeidobius kamerunicus is the main pollinating insect of oil palm, Elaeis guineensis in Malaysia. Elaiedobius kamerunicus feeds and breeds on the oil palms' male inflorescences. The weevil presence is vital for the successful pollination of oil palm, thus ensuring satisfactory fruit bunch production. MPOB recently reported that the declining quality of oil palm fruit bunch, mainly due to insufficient pollination, had affected the national average oil extraction rate. In part, this scenario was caused by the declining pollinator population. As such, the factors affecting the pollinators' population need to be investigated. One of the critical criteria in estimating the population of E. kamerunicus in the field is to measure the emergence rate of the new adult E. kamerunicus from the post-anthesis male inflorescence (PAMI). The study to investigate the rate of E. kamerunicus adult emergence and their sex ratio was conducted for four months at nine oil palm estates in Malaysia by using PAMI samples that were brought to the laboratory and observed for two weeks. The results have shown that the number of adult weevils that emerged from PAMI was about 36-47 individuals, and the female-to-male ratio for the emerged progenies was 2.33-4.46: 1. Indiscriminate application of broad-spectrum pyrethroid insecticide, cypermethrin has negatively influenced the weevil emergence rate in the field. Whereas, minimal impact on the emergence rate was observed in areas applied with biopesticide. This study showed that the application of cypermethrin could threaten the future population of the pollinating weevil in the field. As such, the excessive application of such insecticides in the field is discouraged and should be replaced by biopesticides to complement other Integrated Pest Management (IPM) strategies. In addition, further investigation is needed to understand how the gender ratio of the progeny could affect the future population of E. kamerunicus

Elements of eating morality according to Bediuzzaman Said Nursi’s views: a complementary to the basic concept of food in Islam

The issue of food wastage is considered as a problematic global issue stemmed from lack appreciation of food values gifted to mankind. Learning and taking lessons from historical events are crucial to establish a better future mainly to find solutions in solving arising contemporary issues. The view from Bediuzzaman Said Nursi who is one of the prominent Muslim thinkers (1877-1960), is chosen as a role model to understand the elements of eating morality. His work, Risale-I nur (Flashes of Collection) will be used as the main source of reference. Meanwhile, other Islamic sources derived from Quranic verses, academic journals, book, and reliable websites are used as supportive references. The result of the discussion signifies Bediuzzaman Said Nursi's view on the elements of eating morality are capable to complement the basic concept of food in Islam and it is still relevant to be adopted in facing rapid phases of urbanization process and modernization challenges which lead to morality declination among human beings

The insect pest management strategies and their influence on the emergence rate of Elaeidobius kamerunicus Faust (Coleoptera: Curculionidae) from the post-anthesising male inflorescence of oil palm, Elaeis guineensis

Elaeidobius kamerunicus is the main pollinating insect of oil palm, Elaeis guineensis in Malaysia. Elaiedobius kamerunicus feeds and breeds on the oil palms' male inflorescences. The weevil presence is vital for the successful pollination of oil palm, thus ensuring satisfactory fruit bunch production. MPOB recently reported that the declining quality of oil palm fruit bunch, mainly due to insufficient pollination, had affected the national average oil extraction rate. In part, this scenario was caused by the declining pollinator population. As such, the factors affecting the pollinators' population need to be investigated. One of the critical criteria in estimating the population of E. kamerunicus in the field is to measure the emergence rate of the new adult E. kamerunicus from the post-anthesis male inflorescence (PAMI). The study to investigate the rate of E. kamerunicus adult emergence and their sex ratio was conducted for four months at nine oil palm estates in Malaysia by using PAMI samples that were brought to the laboratory and observed for two weeks. The results have shown that the number of adult weevils that emerged from PAMI was about 36-47 individuals, and the female-to-male ratio for the emerged progenies was 2.33-4.46: 1. Indiscriminate application of broad-spectrum pyrethroid insecticide, cypermethrin has negatively influenced the weevil emergence rate in the field. Whereas, minimal impact on the emergence rate was observed in areas applied with biopesticide. This study showed that the application of cypermethrin could threaten the future population of the pollinating weevil in the field. As such, the excessive application of such insecticides in the field is discouraged and should be replaced by biopesticides to complement other Integrated Pest Management (IPM) strategies. In addition, further investigation is needed to understand how the gender ratio of the progeny could affect the future population of E. kamerunicus

Population abundance of oil palm pollinating weevil, Elaeidobius kamerunicus faust and its relation to fruit set formation in mineral and peat soil areas in Peninsular Malaysia

The oil palm pollinating weevil, Elaeidobius kamerunicus, plays a vital role in the oil palm fruit formation process. An insufficient pollinator population may cause poor fruit set formation, resulting in a high number of parthenocarpic fruitlets and malformed fruit bunches. This study examines the population level of E. kamerunicus at two sites in Peninsular Malaysia and its relation to the fruit set formation. Each site represented different soil types, viz, mineral and peat soil. Preliminary results of the study showed that both sites had high adult weevil population density, averaging at 68662.87/hectare and 89270.93/hectare for peat soil and mineral soil, respectively. The average sex ratio of inflorescences in peat soil area (58.09%) was significantly higher than those at mineral soil area (45.01%, F = 6.75, P = 0.016). The average fruit set percentage in both study areas was satisfactory (more than 60%). The average fruit set in mineral soil area (83.08%) was significantly better than those recorded at the peat soil area (69.47%, F = 4.42, P < 0.05). Even though there are differences in terms of the population level of the pollinator, the fruit set formation in both areas is still satisfactory

Impact of Elaeidobius kamerunicus faust introduction on oil palm fruit formation in Malaysia and factors affecting its pollination efficiency: a review

The oil palm pollinating weevil, Elaeidobius kamerunicus, has become the single most important insect pollinator of the commodity crop in Malaysia and Indonesia, 40 years after its introduction. However, in 2020, the average national oil extraction rate (OER) has decreased from 20.21% to 19.92%. The decline was attributed to the lower oil palm fruit bunch quality. This has raised concerns on the pollination efficiency of the pollinator. As such, the factors affecting the pollination efficiency of E. kamerunicus were thoroughly discussed in this review. Eight factors, which were categorised into intrinsic and extrinsic factors, were discussed in detail. Intrinsic factors discussed are the genetic make-up of E. kamerunicus and its population level. Meanwhile, factors such as planting materials, soil types, plant physiological condition, volatiles emission, diseases/predators threatening E. kamerunicus and climatic factors were discussed in the extrinsic factors. Methods for maintaining a healthy pollinator population were suggested, as well as an emphasis on future studies based on the shortlisted factors