20 research outputs found
Comunidade de Colêmbolos em florestas decíduas e em plantações da conífera Cryptomeria japonica no Japão central
Collembolan communities in conifer plantations (Japanese cedar, Cryptomeria japonica) and secondary deciduous broad-leaved forests of varying ages were investigated to determine the extent to which forest conversion (broad-leaved to coniferous) affects the species richness and assemblage composition of Collembola in central Japan. Density and total species richness of Collembola not differed between the broad-leaved and cedar forests except immediately after clear-cutting. The amount of forest-floor organic matter was larger in cedar forests and positively correlated with the species richness of detritus feeders. Species richness of fungal feeders and sucking feeders positively correlated with the species richness of forest-floor plants. There was difference in collembolan species composition between the forest types. The age of the forests seemed to have only small importance for the collembolan community, except during the first four years after clear-cutting. The conversion to artificial cedar stands has not reduced the abundance or species richness of collembolan communities, but has affected community composition. Differences in species composition may be related to the ground floras.As comunidades de colÛmbolos nas plantaþ§es da conÝfera Cryptomeria japonica (cedro japonês) e florestas decíduas secundárias de várias idades foram investigadas para determinar até que ponto a conversão da floresta decídua em conífera afeta a riqueza das espécies e a composição das comunidades de colêmbolos no Japão central. A densidade e a riqueza total de espécies de Collembola não foram diferentes entre as florestas decíduas e de cedro, exceto imediatamente depois do corte raso. A quantidade de matéria orgânica acumulada no solo foi maior sob cedro e positivamente correlacionada com a riqueza de espécies de detritívoros. A riqueza de espécies de fungívoros e sugadores foi positivamente correlacionada à riqueza de espécies de plantas do estrato herbáceo da floresta. Houve diferença na composição das espécies de colêmbolos entre os tipos de floresta. A idade das florestas parece ter pouca importância para a comunidade de colêmbolos, exceto nos primeiros quatro anos após o corte raso. Concluiu-se que a conversão da floresta decídua em plantações de cedro japonês não causou diminuição na abundância e na riqueza das espécies das comunidades de colêmbolos, mas afetou a composição dessas comunidades. As diferenças na composição das espécies podem ser relacionadas ao desenvolvimento de plantas do estrato herbáceo da floresta
HEAT PRODUCTION BY THE FOUNDRESS OF VESPA SIMILLIMA, WITH DESCRIPTION OF ITS EMBRYO NEST (HYMENOPTERA : VESPIDAE)
BIONOMICS OF VESPA ANALIS INSULARIS AND V. MANDARINIA LATILINEATA IN HOKKAIDO, NORTHERN JAPAN, WITH NOTES ON VESPINE EMBRYO NESTS (HYMENOPTERA : VESPIDAE)
A Preliminary Report on the Blowing Snow Observation using the Light Scattering in High Winds at Syowa Station, Antarctica
The present study describes the optical technique that has been developed to measure the variation of the spatial density of blowing snow particles suspended in air. The light source (the emitter) used was an incandescent lamp (12V, 20 W), and a diameter of light beam was 46mm. The receiver was used a photo transister. This instruments were set in two levels of 1 m and 2m at Syowa Station (69° S, 39.5°E) in 1973. The transmission path of light were 4.5m in both case. If it is assumed that snow particles in blowing snow are the same size and the same shape, then the attenuation of a light beam should depend on the spatial density of blowing snow. The emprical correlations between the attenuation of a light beam (the transmittivity) and the mean visibility, and between the transmittivity and the drift flux were given for practical use. Observations made only in night time and during the period of high winds (also called Antarctic blizzards). For example, when the mean wind speed at 10m level was 30 m/s, the drift flux at 1 m level changed quickly between 80 and 400g/m^2・s
HEAT PRODUCTION BY THE FOUNDRESS OF VESPA SIMILLIMA, WITH DESCRIPTION OF ITS EMBRYO NEST (HYMENOPTERA : VESPIDAE)
BIONOMICS OF VESPA ANALIS INSULARIS AND V. MANDARINIA LATILINEATA IN HOKKAIDO, NORTHERN JAPAN, WITH NOTES ON VESPINE EMBRYO NESTS (HYMENOPTERA : VESPIDAE)
Sphaerularia vespae sp. nov. (Nematoda, Tylenchomorpha, Sphaerularioidea), an Endoparasite of a Common Japanese Hornet, Vespa simillima Smith (Insecta, Hymenoptera, Vespidae)
Sphaerularia vespae sp. nov., an endoparasite of a common Japanese hornet, Vespa simillima is described from Hokkaido, Japan, and its molecular sequence profiles are given. This newly discovered nematode appears to belong to the genus Sphaerularia, judging from its characteristic parasitic form, the uterium, which looks like a sausage with many verrucae on its surface. Sphaerularia vespae sp. nov. is distinguished from S. bombi, the only other nominal species of the genus, by the morphology of the male bursa, female tail, and anterior end of parasitic juveniles. SSU, ITS, and D2D3 (LSU) DNA sequences were determined for S. vespae sp. nov. and compared with those from related nematodes obtained from the GenBank database. The sequences from S. vespae sp. nov. were close to those of S. bombi and several another tylenchid entomoparasitic nematodes. Sphaerularia vespae sp. nov. parasitizes overwintering gynes of the hornet and practically sterilizes them, as S. bombi does for bumblebee gynes