TL;DR: It is concluded that female beetles may have a particular hygropreference in oviposition as total egg production increased with increasing relative humidity.
Abstract: 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.
TL;DR: Development of Dinoderus minutus was studied under laboratory conditions at five constant temperatures to estimate developmental thresholds and thermal requirements of the egg, larva, pupa, and egg-to-adult stages.
Abstract: Development of Dinoderus minutus was studied under laboratory conditions at five constant temperatures (15, 18, 25, 28, and 30°C) to estimate developmental thresholds and thermal requirements of the egg, larva, pupa, and egg-to-adult stages. Adults began to burrow along the grain into bamboo pieces within 24 h after cutting and continued across the grain. Female beetle oviposited an average of 9.1 eggs in the ensuing 24 h, all in the metaxylem. The average period for development of eggs, larva, and pupa were 5.4, 43.8, and 4.6 d at 30°C, respectively. The development rate data were regressed through the x-axis to derive the thermal constants of 4.3, 6.8, and 4.5°C and thermal requirements of 113.6, 909.1, and 96.2 DD to predict D. minutus egg oviposition to hatch, larva-to-pupa development, and adult emergence from pupa, respectively. The thermal threshold for egg-to-adult development was 6.4°C, with total thermal requirements of 1,111.1 DD. Oviposition, emergence, and thermal requirements for de...
TL;DR: The potential of the use of alternative prey species for the production of T. nigrescens prior to its possible use as a bio-control agent for control of P. truncatus in Africa is discussed.
TL;DR: Larvae and other stages of the beetles were clearly recognizable in the CT images with a voxel size of 61.9 μm, and they were distinguishable from the bamboo, insect tunnels, and frass.
Abstract: The bamboo powder-post beetle Dinoderus minutus is a major pest of felled bamboo in Japan. In this study, X-ray computed tomography (CT) was utilized to non-destructively trace the movement of the larvae of D. minutus inside infested bamboo specimens and to evaluate the bamboo consumption of the larvae. The infested specimens, which had been enclosed with adult D. minutus beetles, were scanned using a microfocus X-ray CT system every 2 to 5 days. Larvae and other stages of the beetles were clearly recognizable in the CT images with a voxel size of 61.9 μm, and they were distinguishable from the bamboo, insect tunnels, and frass. The larvae were traced until pupation, and the length and volume of their tunnels were measured to evaluate their bamboo consumption. The tunnel length and volume bored by one larva was estimated to be 0.98 mm and 1.06 mm3 (0.70 mg of oven-dry mass) per day within the average observation period of 22 days, respectively, and the active larval period was estimated to be 39 days in our experimental conditions.
TL;DR: A broader host range of A. lacunatus is suggested than initially suspected and the possibility of its use as a biological control agent in integrated pest management programs in storage units is favoured.