The dispersal of conidia of three Botrytis species, B. squamosa, B. allii and B. cinerea, which are major pathogens of onion, was examined in relation to wind velocity and water droplets falling gently on conidiophores, The dispersal was also examined in the onion field at different levels and different times in a day.
1) In the laboratory experiments, conidia were released at the wind velocity above 1.88 m/sec, whereas the dispersal occurred even at 0.83 m/sec of the wind velocity in onion fields, possibly because of the complicated wind blow in the open air.
2) Conidia were readily released by the gently falling water droplets.
3) In the onion field, the largest number of conidia were trapped by slides placed horizontally at 5 cm below the level of ridges between the ridges, followed by the level of ridges, and much less at 1/2 height of the plant canopy.
4) In the field, the maximum conidial release took place about 3.00 pm when the relative humidity of air just began to rise after being its minimum.
5) The released conidia were mostly single conidia in air, but they also aggregated into masses consisting of more than two conidia.

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A method was devised for testing insecticides in powder formulation against final instar nymphs of Laodelphax striatellus and Nephotettix cincticeps. Using this method, occurrence of resistance to NAC was examined among N. cincticeps populations from six stations in Shiga, and one in Kumamoto (Shinwastrain).
Shinwa-strain showed a high resistance to NAC, suggesting that the population might not be controlled even by a dose five to eight times as much as the normal one (3%D, 3kg/10a). Propaphos, diazinon, diazinon-meobal, however, were highly effective against Shinwa-strain, respectively.
The populations from Shiga showed some reduction of susceptibility to NAC, but the extent of their resistance to NAC was much lower than that of Shinwa-strain.

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The phototactic response of the cuprous chafer was investigated under the dark and normal laboratory conditions for the duration from the 26th July to the 29th August, 1971. The results obtained were summarized as follows :
(1) The cuprous chafers exhibited strong positive phototactic response. When examinations were taken on the rate of the chafers arrived at the light source and on the density in dispersion of the chafers liberated, the minimum luminosity causing the response was 4.08×10^-7 lux for the male and 4.08×10^-6 lux for the female.
(2) The difference of the optimum luminosity between the male and the female was not observed in this experiment, and the optimum luminosity for both sexes was 4.08×10^-4-3.26 lux.
(3) The phototactic reaction curves were similar for the both sexes and at high luminosity such as 100-10000 lux strong phototactic response was not observed.
(4) The period when adults are active coincided with the period chafers showed attraction to the light trap, and adult's flying was observed even in the dark in the field.
(5) Adult's flying started from 7:30 p.m. of dawn and the luminosity of the dawn was about <3.26 lux which coincided with the optimum luminosity causing the phototactic response.
(6) The maximum capture of the chafer by the light trap was obtained for the duration from 8 to 9 p.m., and the luminosity at that time was about 0.02 lux in the field.

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1. Potato virus Y (PVY) was isolated from various cultivars of pepper plants showing symptoms of green vein banding, interveinal chlorosis or mottling on leaves, and chlorotic stripes on stems and fruits in the fields of Osaka, Wakayama and Nara Prefectures during 1972-1974.
2. The virus was readily transmitted by sap inoculation and by aphid, Myzus Persicae.
3. Most of the Solanaceous plants except Datura stramonium were found to be susceptible to the virus. In inoculated leaves of Chenopodium amaranticolor and C. quinoa, the plants revealed necrotic local lesions.
4. Thermal inactivation point of the virus in crude sap from infected Nicotiana glutinosa leaves was between 55 and 60 C by 10 minutes exposure, and dilution end point was between 10^-3 and 10^-4. Longevity of the virus in vitro was between 2 and 3 days at room temperatures.
5. The virus particles were flexuous rod in shape with about 700-750 nm in length. Quadrangular and scroll-shaped fragments of inclusions were found in negatively stained leaf extracts from infected tobacco plants.
6. In thin sections, pinwheel type inclusions were consistently observed in cytoplasm of systemically infected tobacco plants.
7. Positive reaction between PVY antiserum and the virus was demonstrated by the leaf dip serology.
8. From these results, the virus was identified as a strain of PVY. This is the first report on the occurrence of PVY in pepper plants in Japan.

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The smaller green flower chafer, Oxycetonia jucunda Faldermann, is generally only a minor pest of Citrus in southwest of Japan, but occasionally it is necessary to apply control measures.
This beetle had one generation a year and overwintered as adult. Pairing occured soon after hibernation and the ovaries of the females taken at late April to early in May were mostly still before or at the incipient stage of development. Fertilized females with oöcytes and nurse cells increased in middle to late May, and some of them reached the state that each of the ovaries possessed only fully mature oöcyte without nurse cell. After middle July the oösorption occured and each ovary began to degenerate as shown in Fig. 1 C. Oviposition began at late May, and the numbers of eggs laid in the laboratory varied from 9 to 42 with an average of 21.6/female.

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In order to clarify the valuation of selection of rice seeds by specific gravity for the control of Bakanae disease of rice plant, the relation between gravity of the ripening rice seeds and the occurrence of Bakanae disease in seedlings, and the effect of gravity selection on seed disinfection by chemicals, were investigated, using three varieties of rice plant infected by Bakanae fungus, Gibberella fujikuroi (Saw.) Woll., viz., Yamabiko, Manryo and Shiga Asahi No. 27. The seed of Shiga Asahi No.27 was inoculated with conidial suspension of the fungus at the flowering period. The ripening grade was divided into 6 classes according to specific gravity of a rice seed, ranging from 1.00 to 1.25 with an interval of 0.05 or 0.10. Each class of rice seeds was sown in nursery bed. The mycelia in hulls and hulled rice were examined to clarify the degree of invasion of the fungus into seeds. On the one hand, the classes of the seeds were soaked separately in 250-2, 000ppm suspension of Benlate wettable powder containing 50% benomyl for 6 hours. The results were summarized as follows.
1. Percentage of rice seeds with 1.15 to 1.25 of specific gravity was 88% in Yamabiko, 83% in Manryo, and 64% in Shiga Asahi No. 27 which were inoculated. Very few seeds possessed specific gravity higher than 1.25 in any of three varieties of rice plant.
2. As the specific gravity of seeds decreased, the percentage of ungerminable seeds, occurrence of Bakanae disease, and detection of the fungus in hulls and hulled rice increased.
3. The seeds with 1.00-1.15 specific gravity resulted in the same degree of the disease occurrence to the seeds with 1.00 specific gravity, indicating that the degree of disease occurrence of seeds were predominantly influenced by specific gravity higher than 1.15.
4. The better disinfection effect of seed by soaking in different concentration of Benlate was given with the higher specific gravity of seeds. In the case of soaking seeds with specific gravity higher than 1.20, Benlate at 250 ppm gave good controlling effect about equally to that at 2,000 ppm.
5. From these results, it seemed that seed selection by specific gravity was not a perfect protective measure for Bakanae disease, it was, however, of use for increasing the efficiency of seed disinfection by eliminating the severely infected seeds.

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