The Emergence of Insects from Dying Pine Trees

1977年5月初め実験室内に持ち帰ったマツの枯死木からの昆虫群集の羽化状況を調べた. 秋には枯れが目立たず,年を越してから枯死したマツからはマツノマダラカミキリは羽化してこなかった. シラホシゾウムシ一種,ヒメムツテンチャタテ,キイロホソナガクチキムシ,マツノマダラカミキリ,ヒゲナガモモブトカミキリ,ムナクボサビカミキリの6種の羽化曲線を示した. 1977年度の岡山のマツノマダラカミキリの羽化期は例年よりやや遅れていたと考えられる. マツノマダラカミキリの羽化虫数は,マツの樹幹の地上からの高さのちがいによって異なり,地上3～4mの高さの樹幹から最も多く羽化した

Meteor Radar Study of Ionospheric Wind at Kyoto

This paper describes the results of meteor radar observations which have been carried out at Kyoto University since December, 1977. The radar, a coherent pulse doppler radar with a transmitting frequency of 31.57 MHz and a nominal peak power of 10 kW, is able to detect wind fields at meteor regions of 80-110 km. The solar semidiurnal tide generally dominates the wind oscillations at these heights, while a diurnal tide of comparable magnitude reveals itself in a less regular manner. Some anomalies in the amplitude and phase characteristics of the tides are shown, which might be related to a possible interaction with winds and waves, or to some disturbed conditions in the earth's atmosphere. Also planetary scale waves such as quasi-2-day oscillations and resonantly magnified gravity-mode waves have also been found there. Hence, the meteor radar, together with its cooperation with other observations, will helps us understand the dynamical process of atmospheric waves on a global scale

Structural and infrared spectral changes of silicon oxide grains by heat treatments

In order to elucidate the relationship between crystallographic structures of amorphous silicon oxide grains and infrared (IR) spectra, ultrafine grains produced by the gas evaporation method have been studied on the basis of IR spectral measurements and electron microscopic (EM) observations. The shifts and disappearance in the IR absorption peaks of specimen heat-treated in air have been found. The spectral changes have been discussed in the relation with the polymorphism of silica

Electron microscopic and infrared spectral studies on the structure of alumina phases

Alumina produced by oxidation of aluminum in air was studied by infrared spectroscopy and electron microscopy. Infrared spectra of both alumina particles and alumina film oxidized in air showed an absorption peak at 10.8μm, though that of γ-Al_2O_3 particles showed a broad 13μm peak. On the basis of the infrared spectra and electron diffraction pattern, it was concluded that alumina produced by the oxidation of aluminum in air is η-Al_2O_3. The phase transition from η-phase to γ-phase and to α-phase took place at 900℃ and 1100℃, respectively. The relationships between infrared spectra and crystal structure of some alumina phases are discussed

Transmission Dynamics of Dirofilaria immitis in a Southwestern Part of Japan

The transmission dynamics of Dirofilaria immitis were studied by using reported data in Nagasaki City and Omura City, Japan. The catalytic model was applied to the age distribution of positive rate for microfilariae of D. immitis in dogs. Using the force of infection obtained by applying the catalytic model, the critical vector density for the disappearance of D. immitis was estimated. Transmission frequencies of D. immitis in the two places were calculated by densities and infective rates of the principal vector, Culex pipiens pallens, and numbers of infective larvae of D. immitis in the vector. Roles of some factors influencing the transmission frequency of D. immitis were also evaluated with a simple mathematical model, and it was concluded that the continuation of extensive infection with D. immitis in dogs in spite of the presumed decrease of the vector density in recent years is ascribable to the increase of dog density and the increased protection of humans from mosquito bites

Evaluation of effective period of a juvenile hormone mimic, pyriproxyfen, against Aedes albopictus : Preliminary experiments in the laboratory and the field.

Effective period of pyriproxyfen against Aedes albopictus was evaluated in the laboratory and the field. Experimental containers were treated with 3 different concentrations of pyriproxyfen and placed in the laboratory. In the field, the experimental containers were placed for 3 weeks, and then treated with the same concentrations as the laboratory experiment. Pupae were collected and the emergence of adults was examined every 2 weeks for 8 weeks. Pyriproxyfen was more effective in the laboratory than in the field. The change of water amount was one of the important factors determining the efficiency of pyriproxyfen in the field. No significant differences were observed in the number of collected pupae among concentrations in the laboratory, while smaller number of pupae were collected from the higher concentrations in the field. The duration for the complete inhibition of adult emergence at the highest concentration (0.1 ppm) was 4 and 6 weeks in the field and in the laboratory, respectively