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Ibrahim Y.,Sultan Idris University of Education | Tuck H.C.,Southeast and East Asia Regional Center | Chong K.K.,Southeast and East Asia Regional Center
Journal of Oil Palm Research | Year: 2013

The effects of temperature on the development and survival of Pteroma pendula and Metisa plana was investigated over a range of temperatures in the laboratory. Pteroma pendula and M. plana were able to complete their life cycles at temperatures between 20°C-35°C but did not survive at 15°C and 40°C. The duration of life stages of P. pendula significantly decreased with increases in temperature with optimum survival of between 25°C and 30°C, while the highest was at 30°C. In the case of M. plana, except for survivorship of male pupae with five instars at 79% at 25°C, the optimum survivorship was around 30°C for all other life stages. The temperature threshold for P. pendula life stages was 11°C-18°C, while that of M. plana ranged from 2°C-16°C; when subdivided, a threshold of 2°C-8°C was recorded for the egg to adult stages and 9°C-16°C for the egg and larval stages. Thermal constant for P. pendula was 80.3°d, 443.0°d, 566.3°d, 47.5°d, 33.9°d for eggs, female larvae, male larvae, female pupae and male pupae, respectively. Overall egg to female and male adult emergence required 544.0°d and 761.3°d to complete. For M. plana, the readings were 555°d-1083°d for the larval stages, 69°d-200°d for eggs and pupae, while the egg to adult stages recorded the highest at 1440°d-2134°d. Both species recorded significantly highest temperature of 30°C for adult female weight, fecundity and R0 with the most favourable values of T, DT, rc, rm and λ recorded at 35°C. Source


Tuck H.C.,Southeast and East Asia Regional Center | Ibrahim Y.,Sultan Idris University of Education | Chong K.K.,Southeast and East Asia Regional Center
Journal of Oil Palm Research | Year: 2012

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 bet zveen 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 Lazy gave a more appropriate fit with highly significant r2 values for all categories of assessment. The bagzvorms were regularly dispersed in oil palm zvith a general mean-variance relationship of log (2) = 1.780 + 0.821 log (f). Source


Tuck H.C.,Southeast and East Asia Regional Center | Ibrahim Y.,Southeast and East Asia Regional Center | Chong K.K.,Southeast and East Asia Regional Center
Journal of Oil Palm Research | Year: 2011

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 yr1. 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 its propensity to balloon compared to M. plana, which is predisposed to wash-off by rain. Source

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