Red palm weevil (RPW), Rhynchophorus ferrugineus, is a polyphagous insect that caused economic damage in various palm species, particularly coconut plantation in Malaysia. Therefore, entomopathogenic fungus Metarhizium anisopliae was being introduced in attempts to control biologically the RPW. The entomopathogenicity of an indigenous (Met-Gra4) and foreign (Met-TH) strains of M. anisopliae isolated from the soil of Malaysia and Thailand, were tested against RPW adults in laboratory bioassays at 50, 70, 90% relative humidity (RH). Bioassays indicate no significance differences in efficacy between both the conidia of M. anisopliae strains against RPW adults. Met-Gra4 showed the highest efficacy at 90% RH (LT50 = 6.17 days). However, LT50 only slightly differed from Met-TH (6.33 days; 90% RH). Scanning el ectron microscopy for the treated RPWs showed that Met-Gra4 (90% RH) was densely sporulated within the abdomen, while Met-TH can be found mainly across cuticular surface of RPW.
The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae) is one of the most dangerous pests of major cultivated palms including coconut, oil palm, and sago. The larval stage of the weevil causes the most destruction of the palms as it completely destroys the palm cabbage. In this study, the larvae were given three different diets-coconut cabbage, oil palm cabbage, and sago stem, under laboratory conditions for food consumption and developmental time experiment. The protein profiles of the digestive systems of the larvae fed on these three diets were also determined. Although the coconut diet was the most consumed by RPW larvae compared to oil palm and sago diets, the growth rate of RPW larvae on oil palm diet was however significantly shorter than those on the coconut and sago diets: the RPW only need 1 mo and 9 d to complete the larval duration. Proteins profiling of eight 2-DE gel protein spots that range 50-20 kDa were identified by mass spectrometry sequence analysis. Based on the Matrix Science Software, the most dominant protein was cationic trypsin. However, based on the NCBI BLAST tool, aminopeptidase N was the most dominant enzyme. This finding can lead to the development of pest control strategies based on the antinutritional protease inhibitors as potential biocontrol agents. Urgent action to find effective control methods should be taken seriously as this weevil is presumed to be one of the serious pests of oil palm industry in Malaysia.
Rhynchophorus ferrugineus or red palm weevil (RPW) is a destructive insect pest of major cultivated palms such as coconut, date and oil palm. One of the control management of RPW is trunk injection using monocrotophos or methamidophos, but these chemicals are found to affect ecosystems and human health. Thus, we aimed to determine a bio-pesticide to replace these synthetic chemicals. We tested the antifeedant activity of three eugenol-based compounds as potential control agent against RPW larvae in vitro condition for two weeks. All these compounds show significant effect as feeding deterrent agent on 4th instar larvae, while WN16 (4-allyl-2-methoxy-1-(4-trifluoromethyl-benzyloxy)-benzene) shows the highest feeding deterrent index (FDI = 64.42%). Here we present the data regarding the biological aspect on treated RPW larvae as well as antifeedant activity index of these eugenol derived compounds.
Coconut palms in Malaysia are infested by a destructive invasive pest, RPW since 2007, and the pest's population is difficult to control. At present, RPW control management mainly relies on the use of monocrotophos, which is administered by the trunk injection method. However, this pesticide can negatively impact human health and the ecosystem. Plant EO that can be used as a bio-pesticide is highly recommended as an alternative to monocrotophos because of its target-specific and eco-friendly properties. The antifeedant activity of eight eugenol and thymol derivatives from clove and thyme EOs were tested against the fourth instar larvae of RPW through oral bioassay for 14 days. Relative growth rate (RGR), relative consumption rate (RCR), the efficiency of conversion of ingested food (ECI), and the feeding deterrent index (FDI) were compared and analyzed. All of the derivatives showed antifeedant activity, particularly the eugenol derivative, 4-allyl-2-methoxy-1-(4-trifluoromethyl-benzyloxy)-benzene (FDI = 54.14%) and the thymol derivative, 2-isopropyl-4-methyl-2-((4-nitrobenzyl) oxy) benzene (FDI = 53.88%). Both of them showed promising results on their ability to be the most effective antifeedant agents in each derivative group. There was no significant difference in the effectiveness of the eugenol-based and thymol-based derivatives, but the ether derivative group (FDI = 45.63%) had a significantly stronger effect than the ester derivative group (FDI = 39.71%). This study revealed that the compound in ether form is more effective than the compound in ester form as an antifeedant agent against RPW larvae, regardless of the plant EO that the compound is derived from.
The red palm weevil (RPW) is a stem boring Coleoptera that decimates host palm trees from within. The challenge of managing this pest is due to a lack of physical symptoms during the early stages of infestation. Investigating the physiological changes that occur within RPW-infested palm trees may be useful in establishing a new approach in RPW detection. In this study, the effects of RPW infestation were investigated in Elaeis guineensis by observing changes in physical and physiological parameters during the progress of infestation by visual inspection and the comparison of growth, gas exchange, stomatal conductance, and chlorophyll content between the non-infested control, physically wounded, and RPW-infested E. guineensis groups. During the study period, four distinct levels of physical infestation were observed and recorded. The RPW-infested group displayed significantly lower maximum photosynthesis activity (Amax) starting from the third week post-infestation. However, growth in terms of change in plant height and stem circumference, leaves' stomatal conductance, and chlorophyll content were not significantly different between the three groups during the duration of the study. The significant drop in photosynthesis was observed one week before physical changes appeared. This suggests the promising utilisation of photosynthesis activity as a signal for detecting RPW infestation at the early stage of attacks, which could be useful for integration in integrated pest management (IPM).
Rockmelon (Cucumis melo Linnaeus (Cucurbitales: Cucurbitaceae)) is a novel commercialized fruit in Malaysia and has great potential to become an important horticultural crop for the international market. In this study, we investigated the effects of pollination by the Indo-Malaya stingless bee Heterotrigona itama Smith (Hymenoptera: Apidae) on measures of yield and quality of rockmelon cultivated in the greenhouse, compared with hand cross-pollination and self-pollination. Results showed that rockmelon produced from plants pollinated by stingless bees and hand cross-pollination had higher fruit set, were heavier and larger, and contained higher numbers of seed per fruit compared with those produced by self-pollination. Pollination by stingless bees produced fruit with greater sweetness than either hand cross-pollination or self-pollination. This study demonstrated that stingless bee pollination produced rockmelon fruit of similar quality, but better yields compared to the other pollination treatments. We showed that stingless bees should be considered as an alternative, effective pollinator for the improved production of high quality rockmelon in commercial greenhouse cultivation.
As the global human population continues to grow, the demand for food rises accordingly. Unfortunately, anthropogenic activities, climate change, and the release of gases from the utilization of synthetic fertilizers and pesticides are causing detrimental effects on sustainable food production and agroecosystems. Despite these challenges, there remain underutilized opportunities for sustainable food production. This review discusses the advantages and benefits of utilizing microbes in food production. Microbes can be used as alternative food sources to directly supply nutrients for both humans and livestock. Additionally, microbes offer higher flexibility and diversity in facilitating crop productivity and agri-food production. Microbes function as natural nitrogen fixators, mineral solubilizers, nano-mineral synthesizers, and plant growth regulator inducers, all of which promote plant growth. They are also active organisms in degrading organic materials and remediating heavy metals and pollution in soils, as well as soil-water binders. In addition, microbes that occupy the plant rhizosphere release biochemicals that have nontoxic effects on the host and the environment. These biochemicals could act as biocides in controlling agricultural pests, pathogens, and diseases. Therefore, it is important to consider the use of microbes for sustainable food production.