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Volume 19 (1975)
- Issue 4 Pages 223-
- Issue 3 Pages 125-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 19, Issue 2
Displaying 1-10 of 10 articles from this issue
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II. The Economic Injury Level of the Rice Stem Borer and its Predictive EstimationJûrô KOYAMA1975 Volume 19 Issue 2 Pages 63-69
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe economic injury level of the rice stem borer and its predictive estimation was studied to minimize the insecticide application, during three years from 1971 to 1973 at four localities in Akita, Japan. The proportion of injured stems caused by the rice stem borer and the yields of rice were compared between insecticide application and non-application plots in each locality of various injury levels. The experiments revealed that the economic injury level of the rice stem borer was about 5% injured stem at the end of injury period in both the first- and the second-generation of this insect. The predictive estimation of injury level before the spray time was possible in the first-generation by the equation, Y=0.409X+0.229 (Y: the proportion of injured stems at the end of injury period, X: the one at the spray time). In the second generation, however, such a predictive estimation as in the first-generation was unsuccessful.View full abstractDownload PDF (958K) -
Kanji TACHIBANA1975 Volume 19 Issue 2 Pages 70-78
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe cardiograms of the dorsal vesssel in intact insects were obtained with the three methods devised by the author. Although the pulse-frequency in larvae usually fluctuates regularly, an irregular fluctuation ranging from 15 to 19 per minute followed by pausing for a period of 7.2 to 16.2sec was observed in the 3rd instar larvae of Xylotrupes dichotomus. In pupae and adults of Dendrolimus spectabilis and several other species, the fluctuations were observed in sequence of the following three phases: a rapid phase continuing for 73.6sec in an average with beating 60-86 per minute in pupae, or for 74.9sec with 100-200 beating in adults; a rest phase, for 10.9sec without beating in pupae or 17.1sec in adults; a slow phase, for 46.7sec with 5-40 beating in pupae, or 44.8sec with 5-30 in adults. This regularity in fluctuation was not affected by light conditions, but disturbed by the movements of the insect body; viz., a temporary shortening of duration or lacking of a certain phase occurred. In the immature pupae of Dendrolimus spectabilis shortly after pupation, the rest phase was not detected. No artifacts caused by the insertion of an electrode into the insect body were observed on the cardiograms.View full abstractDownload PDF (1268K) -
Tetsu ASAYAMA, Ikuo INAGAKI1975 Volume 19 Issue 2 Pages 79-84
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSUltrastructural changes of the cell organellae in Plutella xylostella larva infected with the granulosis virus were observed by an electron microscope. Endoplasmic reticulum showed multilayered and whorl-shaped figures. Mitochondria changed into balloon-shaped structures with fragmented cristae. These abnormal structures disappeared into the cytoplasmic matrix at the advanced stage of the infection. During the conspicuous changes of cell organellae, 10 to 55 nucleocapsids protruded randomly in the cytoplasm of fat-body cells closely associated with rough endoplasmic reticulum, and regular stacking array of nucleocapsids were formed at the site of their appearance. Agglomerated glycogen granules and large clumps of lipid were seen in the infected cytoplasm.View full abstractDownload PDF (4381K) -
IV. The Effect of Initial Density of Larval Population on Its Growth and DevelopmentJojiro NISHIGAKI1975 Volume 19 Issue 2 Pages 85-90
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSUnder various population densities, newly-hatched larvae of the cupreous chafer were reared in outdoor pots with mixture of fallen leaves and natural soil throughout nearly all the larval period. Head widths of larvae were measured at regular time intervals. From the frequency distribution of head width in each initial population density, it was assumed that the number of larval instar was three, and that the boundary values of head width for separating each larval instar were not varied with different initial densities, although slight differences in the head width distribution were found between the lower initial population density and the higher one in each larval instar, especially in the second instar, i.e., the mean value and the variance of head width decreased with the increase of the initial density. Although the development of the larvae was more rapid in higher initial densities, the effect of initial larval density on the larval growth and development was not considered to be significant.View full abstractDownload PDF (842K) -
Noriaki AGUI, Nobuo OGURA, Michitaka ÔKAWARA1975 Volume 19 Issue 2 Pages 91-96
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe cabbage armyworm, Mamestra brassicae L. was reared for two generations aseptically from the 1st to the 5th instar and semi-aseptically during the last (6th) instar on the artificial diets I and II, in which main ingredients were soy been flour (I) and wheat bran (II). Mamestra larvae reared on the diet I were superior to the one reared on the diet II so far as mean weight of larva and pupa was concerned. In the mean weight of pupa and the rate of pupation, the artificial diets I and II were superior to cabbage leaf. It was also investigated whether six species of lepidopterous larvae other than M. brassicae could grow on the same artificial diets I and II. It turned out that diamondback moth (Pluttella xyostella L.) and mulberry caterpillar (Mamestra illoba BUTLER) could be reared for 2-3 generations on these diets, while five other species were only for one generation.View full abstractDownload PDF (824K) -
1975 Volume 19 Issue 2 Pages 96
Published: 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (101K) -
Michio UEMURA, Masae SHIYOMI1975 Volume 19 Issue 2 Pages 97-104
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe number of Unaspis yanonensis individuals on every leaf or fruit of 38 citrus trees were counted in an experimental field. By using these data, it was clarified statistically that the density of U. yanonensis between trees changed according to a gamma distribution and the number of individuals on each leaf or each fruit within a tree changed according to a negative binomial distribution. These information will be used to build a system model and to set up the initial situation by using random numbers generated by the statistical distributions. Biological implications of the parameters contained in those statistical distributions were discussed; especially it was found that the value of parameter k of the negative binomial distribution, which fitted with the observed count of U. yanonensis individuals, changed with the density on trees, but the value “k/the density” did not change between trees. Based on this finding, a simpler method to estimate the density by using the 0-term of negative binomial distribution was derived. The relationship between the density per leaf and that per fruit was well represented by a regression line. The aggregation of individuals on leaves was higher than that on fruit. The effect of pruning of citrus tree on the density and distribution of Unaspis was also studied.View full abstractDownload PDF (903K) -
Norizumi SHINKAJI1975 Volume 19 Issue 2 Pages 105-111
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe photoperiodic response curves for the determination of diapause in Oligonychus ununguis (Jacobi) showed a long-day type with the critical photoperiod of about 12.5 hours at medium temperatures (15-20°C). The diapause was determined by the daylength during two consecutive developmental stages, from the larval to the adult stage. The temperatures in the light and dark phases did not exert different effects on diapause so that the daily mean temperature appeared to be important for predicting the occurrence of diapause. Even when both of the photoperiod and the temperature were diapause-preventing, females laying winter-eggs appeared either under crowded conditions or on bronzed leaves previously infested with a large mite population. From these results, it was inferred that the appearance of females laying winter-eggs from late July to mid-September is accounted for by the deficient food supply and that the abrupt increase in the number of such a female in late September is a result of the photoperiodic reaction.View full abstractDownload PDF (1004K) -
Sumio NAGASAWA, Shoji ASANO, Sanae SEKI1975 Volume 19 Issue 2 Pages 112-114
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (336K) -
Tetsu ASAYAMA, Ikuo INAGAKI1975 Volume 19 Issue 2 Pages 115-116
Published: June 25, 1975
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (1684K)
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