Metisa plana Walker and Pteroma pendula Joannis are important pests of the oil palm, Elaeis guineensis Jacquin, which is the primary agricultural crop in Malaysia. Although there is a history of integrated management of the bagworms, information gaps exist with regard to their incidence, biology, dispersion and population dynamics. Such new information is needed to improve the current integrated management of these pests. Analysis of historical records of bagworm infestations over 63 955 ha of oil palm in 69 estates in Peninsular Malaysia showed M. plana and P. pendula to be the primary pests. Infestations were of single or mixed species, and ranged from nil to 7811 ha yr-1. Cumulative infestations were 18 297 ha, 4904 ha and 14 607 ha for single species of P. pendula and M. plana, and for mixed species of P. pendula and M. plana, respectively. This shows P. pendula to be the predominant species, and is attributed to its ability to survive very wet weather (>200 mm rain per month) and .....

2012 hits

An attempt was made to determine optimum sampling unit of between-palm and within-palm distribution of bagworms and their interspecific association distribution in oil palm using aggregation indices or distribution models. The within-frond distribution of bagworms varied significantly within the oil palm crown. Peak bagworm density was recorded between frond numbers 9 and 19. Through polynomial regression, standardised residual and relative net precision analyses, frond number 17 was established as the representative sampling unit for experimental work, and frond numbers 10-19 should be used when a greater precision is required as in life-table construction. A lack of interspecific association suggested these sampling units to be applicable for single and mixed infestations. Evaluation of between-palm dispersion revealed that Taylor’s Power Law gave a more appropriate fit with highly significant r2 values for all categories of assessment. The bagworms were regularly dispersed in oil .....

1838 hits