Ramle Moslim

The effects of mortality and influence of pheromone trapping on the infestation of Oryctes rhinoceros in an oil palm plantation.

Abstract The infestation levels of O. rhinoceros were investigated in the oil palm trunk heaps in three replanting blocks (Blocks A, B and C) at Sepang, Selangor, Malaysia. These blocks had different densities of pheromone trapping: high (11 traps per ha, Block B), normal (1 trap per 2 ha, Block C), while no pheromone trapping was conducted in (Block A. Without pheromone trapping, the infestation levels of O. rhinoceros can reach a maximum density of between 25 to 50 individuals per m2 (IPMS). The O. rhinoceros population was still detected in the heaps up to more than two years (at 26 months after replanting). With high density trapping, infestation levels were maintained below 10 IPMS and was not detected in the heaps after a period of 16 months of replanting. In the normal trapping density, the population was also maintained below 10 IPMS but had sustained itself in the heaps for up to 24 months. The mortality factors associated with the larval stages sampled within these replanting blocks was determined by visual symptoms with subsequent verification with microbial analysis. The analysis was narrowed down to detect only bacteria (Bacillus thuringiensis and B. popillae), virus (Oryctes virus) and fungus (Metarhizium). In Block A, the population of O. rhinoceros in the trunks was reduced drastically at 14 months after replanting (MAR), which could be due to the high mortality (88%) of the third instar larvae, 3 months earlier. In Block B, the percentage mortality for the larval stage was always highest at the third instars (between 21–82%). In Block C however, the mortality of the third instars was low, never exceeding 35%. In these sampling blocks, the infection of Metarhizium seem to be less dominant compared to virus or bacteria The k factor analysis indicates density dependence among the third instar larvae had contributed to the change in its population density in Block A. Therefore, with proper manipulation of pheromone traps and targeted application of disease agents (i.e virus, fungus and bacteria), the population of O. rhinoceros can be managed more effectively in an oil palm replanting.

Monitoring insect pest infestation via different spectroscopic techniques

ABSTRACT Nowadays, monitoring and observing insect pest populations is a major and crucial issue in agriculture, especially for crop protection. Spectroscopic techniques are well recognized for detecting and monitoring insect pests in the field and also the internal quality of fruit. There are several spectroscopic techniques with specific characteristic features, including mass spectrometry, ultraviolet–visible spectroscopy, infrared spectroscopy, and nuclear resonance spectroscopy. Nevertheless, limitations and complexity are the constraints of these technologies. In this paper, the spectroscopic and imaging spectroscopic techniques are discussed, compared, and investigated, namely fluorescence light detection and ranging (LIDAR) to study the fluorescence of diverse types of planthopper (Hemiptera) and moth (Lepidoptera), visible and near-infrared (Vis/NIR) spectroscopy to detect internal insect-infested jujubes, NIR spectroscopy to determine spectral properties of oil palm bagworms, hyperspectral transmittance image for detecting insect-damaged vegetable soybeans, and remote sensing measurement to detect bagworm infestation in oil palm plantations. These techniques are found to be reliable methods for better monitoring of insect pest movement in the harvested plant and in the ground, for the detection of insect-damaged vegetable soybeans and internal insect infestation in jujubes, and for the determination of oil palm bagworm spectral properties.

Targeted cattle grazing as an alternative to herbicides for controlling weeds in bird-friendly oil palm plantations

The use of agrochemicals is expected to increase with the global expansion of oil palm plantations. In line with environmentally sustainable palm oil certification, targeted grazing can minimize the dependency on herbicides for controlling weeds in plantations. Here, we show for the first time that targeted grazing would control weeds and improve biodiversity of desired animal species. We sampled birds at 45 oil palm plantations in Peninsular Malaysia that were systematically grazed, non-systematically grazed, or herbicide-controlled plantations without cattle grazing. We found that bird species richness increased with size of grazing area, but decreased with number of cattle. Bird abundance was higher in the systematic grazing system, but negatively related to number of cattle. These factors explained 18.41 and 25.34% of the observed variations in bird species richness and abundance, respectively. Our findings suggest that targeted cattle grazing can be instrumental for transforming conventional oil palm agriculture into more biodiversity-friendly agroecosystems. Targeted grazing is likely to be practical under field conditions in major palm oil producing countries. In addition, the use of targeted grazing as a biological control method for weeds would be welcomed by palm oil consumers and encouraged by sustainable palm oil certification bodies such as the Roundtable on Sustainable Palm Oil (RSPO).