Home About us Contact
|
Home About us Contact | ||
|
|
||
Trap Samples (trap + sample)
Selected AbstractsDenil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamicsECOLOGY OF FRESHWATER FISH, Issue 4 2001C. M. Bunt Abstract , Two different Denil fishways on the Grand River, Ontario, were used as check-points to evaluate the upstream movement of fishes past a low-head weir and to examine the proportions and inferred swimming performance of non-salmonid warmwater fishes that used each fishway type. Traps installed at fishway exits were used to collect fish during 24-hour sampling periods, over 40,51 days each year, from 1995 to 1997. Passage rates, size selectivity, water temperature, water velocity and turbidity for the periods of maximum passage for each year were examined. General species composition from trap samples shifted from catostomids to cyprinids to ictalurids to percids and centrarchids, with some overlap, as water temperatures increased from 8 °C to 25 °C in the spring and early summer. Water depths, and therefore water velocities in each fishway, were independent of river discharge due to variable accumulations of debris on upstream trash-racks. Relationships between the water velocity and the swimming and position-holding abilities of several species emerged. Turbidity was directly related to river discharge and precipitation events, and many species demonstrated maximum fishway use during periods of increased turbidity. This study 1) provided evidence of strongly directional upstream movements among several species that were previously considered non-migratory and 2) describes physical and hydraulic conditions during fishway use for 29 non-salmonid fish species., [source] Effects of fires on butterfly assemblages in lowland dipterocarp forest in East KalimantanENTOMOLOGICAL SCIENCE, Issue 2 2007Toshiya HIROWATARI Abstract The post-fire butterfly fauna in lowland dipterocarp forest of the Bukit Soeharto Education Forest (BSEF), East Kalimantan, Indonesia, was assessed during the period November 1998,April 2000 by means of consecutive Malaise trap samples, with supplementary field observations for March,April 1999. A total of 514 butterflies belonging to 61 species and representing six families were caught in the traps. Melanitis leda (Nymphalidae: Satyrinae), Charaxes bernardus (Nymphalidae: Charaxinae), and Danaus genutia (Nymphalidae: Danainae) were the species most frequently caught (60, 52 and 47 individuals, respectively), representing 31% of the total. These three species are generalists and "disturbance indicators" for tropical rainforest, being characteristic of disturbed or secondary forests, being distributed widely, and having larvae that feed on a wide range of host plants. In contrast, other species, such as Trogonoptera brookiana and Troides amphrysus, were recorded before the fires but were not recorded again afterwards. The pre- and post-fire butterfly fauna of East Kalimantan were compared on the basis of butterfly specimens deposited in the Tropical Rain Forest Research Center that were collected in and around the Bukit Soeharto Education Forest before the fires (1988,1995). On the basis of the post-fire survey, based on Malaise trap samples and field observations, only 43% of the butterfly species (not including Lycaenidae and Hesperiidae) were confirmed to have persisted. The data suggest that refugia that are not affected by fire are necessary for the conservation of specialist butterflies, as well as many other forms of wildlife. [source] Composition and Longitudinal Patterns of Aquatic Insect Emergence in Small Rivers of Palawan Island, the PhilippinesINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 4 2004Hendrik Freitag Abstract This study presents the first emergence trap samples from streams in the Philippines and Greater Sunda. Aquatic insect emergence from two small rivers and longitudinal patterns including estuaries are compared. A decline of total emergence towards estuaries was observed, affecting all major orders. Diptera, namely Chironomidae, dominated all sites. High abundances in Ceratopogonidae, Odonata, and Coleoptera were found, compared to other emergence studies from tropical and temperate latitudes. Ephemeroptera displayed a highly variable contribution to the emergence from Palawan as well as in other comparative studies either supported by the appropriate conditions for certain functional groups or limited by environmental variables such as pH. Trichoptera are likely to tolerate a wider range of environmental conditions and they are consequently able to fill further niches where Ephemeroptera are under-represented. Except for scarce abundances of Plecoptera observed in this and other studies from the tropics, no substantial differences in emergence composition at order level existed between temperate and tropical rivers, however, with a remarkable local variation. Components of riparian and non-aquatic insects and non-emergent fauna contributing to the collections are discussed based on trap features. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The introduced English wasp Vespula vulgaris (L.) (Hymenoptera: Vespidae) newly recorded invading native forests in TasmaniaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2000Robert W Matthews Abstract The social wasp Vespula vulgaris (L.), an introduced species that has caused extreme ecological damage in New Zealand, is reported from southern Tasmanian forests for the first time. In mainland Australia, this wasp has been present in the Melbourne area since 1958 and our retrospective analysis places it in Hobart since 1995. In the present paper, we document V. vulgaris in natural areas in southern Tasmania, well away from human habitation. Malaise trap samples collected since 1997 from nine sites at the Warra Long-term Ecological Research area in southern Tasmania revealed the widespread presence of both V. vulgaris and V. germanica (F.), another introduced species of concern. Analysis of microsatellite DNA markers showed no evidence of hybridisation between the two species. The potential impact of this newest social insect threat to Australian native biota is discussed. [source] Survival of Flower-visiting Chrysomelids during Non General-flowering Periods in Bornean Dipterocarp ForestsBIOTROPICA, Issue 5 2008Keiko Kishimoto-Yamada ABSTRACT In SE Asian rain forests, general flowering, a community-wide synchronous flowering, occurs at irregular and supra-annual intervals. During general flowering periods (GFP), most Dipterocarpaceae and many other trees flower profusely, while flowering plants are scant between GFP. During flowerless periods, anthophilous animals that depend on floral resources for food may suffer food shortages and subsequently decrease in abundance. Flower-visiting chrysomelid adults are major pollinators for some canopy tree species that flower during GFP. Although such chrysomelids feed on flower petals, the means by which they survive flowerless periods remains unknown. We determined the abundance of flower-visiting chrysomelids in GFP and non-GFP through light trap samples and examined the effects of the presence of young leaves and flowers of dipterocarps on local abundance, and feeding preferences of flower-visiting chrysomelids. We found no clear tendency that the chrysomelid species number and the abundance during GFP were consistently higher than those during non-GFP. Chrysomelid adults were more abundant on trees with many young leaves or flowers than on trees lacking young leaves and flowers. At least a few flower-visiting chrysomelids were observed feeding on young dipterocarp leaves and visiting young leaves and flowers of non-dipterocarps in the canopy during non-GFP. All results consistently suggest that chrysomelids are able to survive flowerless periods by feeding on the young leaves of dipterocarps and on the young leaves and flowers of non-dipterocarps; through this alternate feeding, chrysomelid populations are maintained at sufficient levels to function as effective pollinators of trees that flower during GFP. [source] | ||||||||||