a b s t r a c tThe sediment characteristics of hydrate-bearing reservoirs profoundly affect the formation, distribution, and morphology of gas hydrate. The presence and type of gas, porewater chemistry, fluid migration, and subbottom temperature may govern the hydrate formation process, but it is the host sediment that commonly dictates final hydrate habit, and whether hydrate may be economically developed.In this paper, the physical properties of hydrate-bearing regions offshore eastern India (KrishnaGodavari and Mahanadi Basins) and the Andaman Islands, determined from Expedition NGHP-01 cores, are compared to each other, well logs, and published results of other hydrate reservoirs. Properties from the hydrate-free Kerala-Konkan basin off the west coast of India are also presented. Coarser-grained reservoirs (permafrost-related and marine) may contain high gas-hydrate-pore saturations, while finer-grained reservoirs may contain low-saturation disseminated or more complex gas-hydrates, including nodules, layers, and high-angle planar and rotational veins. However, even in these finegrained sediments, gas hydrate preferentially forms in coarser sediment or fractures, when present. The presence of hydrate in conjunction with other geologic processes may be responsible for sediment porosity being nearly uniform for almost 500 m off the Andaman Islands.Properties of individual NGHP-01 wells and regional trends are discussed in detail. However, comparison of marine and permafrost-related Arctic reservoirs provides insight into the inter-relationships and common traits between physical properties and the morphology of gas-hydrate reservoirs regardless of location. Extrapolation of properties from one location to another also enhances our understanding of gas-hydrate reservoir systems. Grain size and porosity effects on permeability are critical, both locally to trap gas and regionally to provide fluid flow to hydrate reservoirs. Index properties corroborate more advanced consolidation and triaxial strength test results and can be used for predicting behavior in other NGHP-01 regions. Pseudo-overconsolidation is present near the seafloor and is underlain by underconsolidation at depth at some NGHP-01 locations.Published by Elsevier Ltd.

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The antennal sensilla of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), were examined using scanning and transmission electron microscopy. Male and female antennae have a scape, pedicel, and nine ßagellomeres. Both male and female antennae share Þve sensillum types: sensilla chaetica (mechanoreceptors), three types of sensilla basiconica (olfactory), and uniporous gustatory/taste sensilla. Apical depressions containing large sensory Þelds of uniporous sensilla were seen on the eight most distal ßagellomeres of both sexes. Counts of sensillum types showed that males possessed signiÞcantly more uniporous sensilla than females. We hypothesize that antennal contact is important for mate recognition by male A. planipennis. The distal apices of the eight outer ßagellomeres were seen to have "tufts" composed of two types of sensilla basiconica. A third type of sensilla basiconica was observed within the perimeter of the uniporous sensory Þelds. The structure and putative function of each sensillum type are discussed.

The antennal receptors of Sirex noctilio F. (Hymenoptera: Siricidae) were examined using scanning and transmission electron microscopy. Male and female antennae share five sensillum types: Böhm bristles, sensilla chaetica, sensilla basiconica, sensilla ampullacea, and uniporous contact chemoreceptors. Contact chemoreceptors make up ≈85 and 78% of the total sensilla on male and female antennae, respectively. On the most proximal flagellomere of the antennae, contact chemoreceptors are located in a shallow depression on the ventral surface. The number of contact chemoreceptors increases toward the distal end, covering two thirds of the circumference of each flagellomere. Contact chemoreceptors seem to be innervated by two sensory dendrites that terminate near the tip. In longitudinal section, a single subterminal pore is seen to be associated with each sensillum. Males had significantly more uniporous sensory pegs than females on the proximal half of the antennae. These receptors may play an important role in mate identification, suggesting that a female-released contact pheromone may be used by this insect. The putative function of these sensilla types is discussed.

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