Faizah Abood

Effect of humidity on egg hatchability and reproductive biology of the bamboo borer (Dinoderus minutus Fabricius)

Wood products are highly exposed to infestation by powder post beetles. Dinoderus minutus (bamboo borer) is a wood boring beetle that seriously damage dried bamboo and finished bamboo products. Management of D. minutus using pesticides showed negative effects on environment despite being very costly. By understanding influence of natural climatic conditions on their reproductive behaviour, could help us to develop a cost effective and environmental friendly strategy to cope up with this problem. In the present study, reproductive parameters and egg development of the bamboo borer were determined at 20%, 40%, 56%, 75% and 85% r.h. levels at constant temperature of 30° ± 2°C with 8 L-16D photoregime. From the results, eclosion to first instar larva was recorded at all relative humidities tested. The lowest shortest percentage of hatchability was recorded at 20% and 85% relative humidity with a mean incubation period of 4.63 ± 0.25 and 10.43 ± 0.32 days, respectively. It was noted that pre-ovipositional period decreased from 14.20 ± 0.49 to 7.20 ± 0.31 days as relative humidity increased from 20% to 75% and slightly increased to 8.00 ± 0.37 days at 85% relative humidity. We conclude that female beetles may have a particular hygropreference in oviposition as total egg production increased with increasing relative humidity.

Some properties of particleboard panels treated with extractives of Cerbera odollam tree

This study investigated certain aspects of physical and mechanical properties and resistance against biological deterioration of particleboard panels treated with extractives from different parts of Cerbera odollam trees. Particles of rubber-wood (Hevea brasiliensis) treated with extracts of leaf, fruit, wood, bark, flower, and seed of Cerbera odollam were used to manufacture panels in laboratory conditions. Two types of adhesive, namely melamine urea formaldehyde and phenol resorcinol formaldehyde were used as binder for the panels. Treated panels had higher resistance against powder post beetle in laboratory as well as field exposures. Both thickness swelling and internal bond strength values of treated samples satisfied requirements for P4 Type particleboards stated in European Standards (EN 312). It appears that such extractives possess potential to enhance resistance of particleboard against insect damage in tropical countries.

Antibacterial Activity of Different Biomass Components of Cerbera odollam and their Potential to Be Used as New Preservative for Wood Based Products

Cerbera odollam’s tree parts were extracted with methanol and further fractionated using n-hexane, ethyl acetate and ethanol, followed by antibacterial assay against Bacillus subtilis, Bacillus licheniformis, Escherichia coli and Pseudomonas aeruginosa. Hexane soluble parts from flower, fruit, leaf, wood, bark and ethyl acetate soluble part from bark showed antibacterial activity against Bacillus subtilis. Hexane soluble parts from leaf and bark and ethyl acetate soluble parts from wood showed antibacterial activity against Bacillus licheniformis. All fractions appeared ineffective on Escherichia coli and Pseudomonas aeruginosa. Screened extracts were analysed using FTIR. Experiments were continued with impregnation of methanolic extracts of Cerbera odollam into Melamine-urea formaldehyde (MUF) particleboards, Phenol-resorcinol formaldehyde (PRF) particleboards and solid wood samples followed by exposure to wood-boring beetles and natural decaying.