The potential of black ant (Dolichoderus sp.) as a biological control agents of the coconut leaf beetle (Brontispa longissima)

The study of coconut leaf beetle infestation, Brontispa longissima on palms and the effectiveness of biological agents as a method of control have been carried out in the laboratory. The study involves the effectiveness of potential black ants as biological agents in controlling beetle populations. The results of laboratory studies on the ability of black ant predation on the B. longissima found that the percentage of mean beetle are eaten by the group that has the number 100 black ants were higher and significantly different (P <0.05) as compared to group numbers 5, 20, 50 and 75 black ants. In addition, black ants also tend to attack and devour the B. longissima larvae and pupa stage compared to adult’s beetle via laboratory studies. It can be concluded that the B. longissima beetle has a great potential for causing considerable damage to the coconut tree which could affect coconut palm industry in Malaysia. However, the usage of biological agents as a control method had shown promising results in order to control the beetle infestation in coconut palm areas

Spatial and seasonal ionospheric error growth in DGPS measurement: a case study in Malaysia

This paper tackles the Equatorial ionosphere and its effects on Differential Global Positioning System (DGPS) error growth over Malaysia by using a network of GPS Continuously Operating Reference Stations (CORS). Seasonal variation of ionospheric delay has been examined and findings show that the effect of spatial variation of ionospheric errors in DGPS is very significant during the equinoctial seasons. Furthermore, a DGPS regression model was developed and tested during the solar maximum year in 2013 by using internet-based DGPS. The results show that the model is capable of estimating DGPS positional errors for distances of user to reference station less than 680 km