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Volume 30 (1986)
- Issue 4 Pages 219-
- Issue 3 Pages 167-
- Issue 2 Pages 81-
- Issue 1 Pages 1-
Volume 30, Issue 2
Displaying 1-14 of 14 articles from this issue
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Jojiro NISHIGAKI, Kouji YASUI, Nobuyuki MAKINO, Akira YAMAZAKI1986 Volume 30 Issue 2 Pages 81-86
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSSeasonal prevalence of the adult yellowish elongate chafer, Heptophylla picea, was examined by collecting the insects with light traps in the tea fields. The adults appeared from May 29 to June 23, reaching a peak number at about June 10. The ratio of the females to the total number of adults collected from the light traps was very low, only 0.1%, which was unexpected as the sex ratio of the chafer should be approximately 1:1. To elucidate the cause of this phenomenon the flight activity of the adults was observed in a field insect cage. The results showed that only 0-0.8% of the females flew in contrast with 25.0-35.4% of the males. Thereafter, the adults were forced to fly by using a tethered flight apparatus. Again, the flight ratio of the females was much lower than that of the males. Based on these results, it was concluded that the flying habit of the female chafers is almost inexistent which may occur for the fact that they could not be collected with light traps.View full abstractDownload PDF (703K) -
Yoshiaki KONO1986 Volume 30 Issue 2 Pages 87-92
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSCritical photophase for the vitellogenesis of Henosepilachna adults was 13hr 50min, and all the females developed their ovaries in photophases longer than 15hr. In a short photophase of less than 13hr, vitellogenesis was inhibited, but in very short photophases (0-2hr) some females developed ovaries. Females in the oviposition period showed different reactions to short photophases. Most individuals ceased ovarian development under a 12L-12D regime but other short-day photoperiods lacked a complete inhibitory effect. It was estimated from the night interruption experiments that there were two light sensitive periods in the scotophase, i.e. 9-8hr before dawn and 8-10hr after dusk. It appeared that based on these data the measurement of the night duration could be performed so as to regulate the ovarian development. Adults were able to synchronize their ovarian development with photoperiodic cycles of more or less than 24hr and showed typical photoperiodic-reaction curves in 28, 20, 16hr cycles.View full abstractDownload PDF (782K) -
Osamu SETOKUCHI, Kohjin NAKAGAWA, Masahiro KOBAYASHI1986 Volume 30 Issue 2 Pages 93-98
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSConsumption of sweet potato leaves by larvae of three major defoliators, Aedia leucomelas LINNÉ, Agrius convolvuli LINNÉ and Brachmia triannulella (HERRICH-SCHÄFFER) was evaluated by the measurement of the dry weight of leaves consumed and the leaf area consumed was calculated. The examination was conducted in rearing larvae of three insects at the constant temperatures of 20, 25 and 30°C under a 16hr day-length regime. Amount of consumption by larvae in each instar was measured under a 25°C and 16hr day-length regime, while under other conditions, the determination was performed only in larvae in the final instar. The mean values of dry weight of leaves consumed by A. leucomelas, A. convolvuli and B. triannulella were approximately 654mg, or 170cm2 in terms of leaf area, 5g, 1, 300cm2 and 28mg, 7cm2, respectively, and 83%, 88% and 61% of the total amounts were consumed by the larvae in the final instar in the respective species. The food consumption of A. leucomelas was the highest at 20°C, but that of A. convolvuli was the highest at 30°C, though the effects of day-length on food consumption were not recognized in both species.View full abstractDownload PDF (659K) -
VII. Fate of Bacillus thuringiensis in Larvae of the Silkworm, Bombyx mori, and the Fall Webworm, Hyphantria cuneaYoshio AKIBA1986 Volume 30 Issue 2 Pages 99-105
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSFate of Bacillus thuringiensis orally introduced into the last instar larvae of the silkworm, Bombyx mori, and the fall webworm, Hyphantria cunea, was studied. In the larvae which survived the inoculation of B. thuringiensis, the bacteria were rapidly discharged from the alimentary canal. In contrast, in the cadavers of the larvae which died as a result of the inoculation of B. thuringiensis, the number of viable cells of this bacterium increased 15 to 66 times and the sporulation was evident. However, in the cadavers of the silkworm larvae in the late autumn and in the fall webworm larvae of the third generation, the growth and sporulation of B. thuringiensis were suppressed by coexisting enteric bacteria. These results suggest that the recycling of B. thuringiensis in nature takes place in insect cadavers under the low density of competitive microorganisms.View full abstractDownload PDF (746K) -
Seiichi MORIYA, Masakazu SHIGA1986 Volume 30 Issue 2 Pages 106-110
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSLeaf litter was collected for laboratory observation at overwintering sites of the brown-winged green bug, Plautia stali. No clear phenomenon of aggregation was detected from those leaf litter samples. Values of the index of contagiousness, Iδ were mostly close to unity. Density of over-wintering adults greatly fluctuated year by year, ranging from zero to 3.10, for the mean number of adults per sampling unit. When the total number of adult recruits at a mulberry thicket, one of the main habitats of this species, and the total number of catches in light traps in the spring-summer season were used as indicators of the population size after overwintering, the relationships between the overwintering adult density and each of these indicators were not simple but suggested density dependence. Possibility of utilizing overwintering density to monitor the population after overwintering was also discussed.View full abstractDownload PDF (586K) -
Yoshikazu ANDO1986 Volume 30 Issue 2 Pages 111-116
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSLocal outbreaks of the Japanese beetle have occurred repeatedly since about 1976 at Hirosaki, Aomori Pref. The seasonal prevalence of the adults was determined by collecting all the beetles found on two grapevines every morning and a unimodal pattern was obtained. The first beetles of the season appeared on June 30±2.1 (mean for 7 years±S.D.). The 4-year average of the date of 50% capture was July 21 and that of the date of the last capture was August 17. The flying activity was remarkably prevented by rainfall. There was no sexual difference in the pattern of seasonal prevalence, but more male beetles were captured on food plants than female beetles. The most important factor responsible for the outbreaks of the Japanese beetle at Hirosaki seems to be the increasing number of grassy areas.View full abstractDownload PDF (685K) -
Masaharu MATSUI1986 Volume 30 Issue 2 Pages 117-122
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe photoperiodic response curve of the limabean pod borer reared on an artificial diet and fresh soybeans was analysed. The critical day-length for the induction of diapause at 20°C and 25°C was about 13.75hr and 13.5hr, respectively. When the larvae were reared at 30°C, the percentage of diapause larvae was only 6% under a 12L-12D regime. A photoperiodic exposure of only 2-5 days during the egg or 1st-4th larval periods had a significant effect on the arrest of diapause induction at 25°C. The most sensitive stage was the latter half of the egg stage (after head pigmentation stage). The larvae in which the diapause was induced were oviposited in the last ten days of August when the day-length (add 0.5hr of twilight) was about 13.5-14hr. This day-length period was almost the same as the critical photoperiod obtained in the laboratory test. The development of the mature larvae which were transferred from open air to the laboratory in November was strongly suppressed under short-day photoperiod (12L-12D) at 25°C. However the percentage of the mature larvae which terminated the diapause was high in January and February, and almost all the mature larvae terminated the diapause in March.View full abstractDownload PDF (819K) -
Kimito FURUTA, Hongxin MAO1986 Volume 30 Issue 2 Pages 123-128
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSStudies were carried out in four study plots during the years 1982-1985. A. areolatus parasitized the 1st and 3rd generations of P. californiensis and produced two generations in spring. Though the aphid infests maple trees all the year round, winged females appear several times in a year and produce larvae on the trees which provide a large amount of suitable feeding sites. When the winged females reached the trees and produced larvae, the wasps which emerged on other trees also came and parasitized the larvae intensely. Thus, the number of both the aphids and mummies on the trees increased markedly. The number of mummies in the 2nd generation correlated with the number of mummies in the 1st generation of the same year and the aphid density, and increased with increasing aphid density. However, even on the trees where the density of wasps was high and that of aphids low, less than 40% of the aphids were parasitized. Some aphids escaped from parasitism and deposited aestivating dimorphs which never became parasitized. This parasitoid was one of the important mortality factors of the aphids during the years covering the study. However the mortality of the aphid population was inversely proportional to the density.View full abstractDownload PDF (735K) -
III. Estimation of the Prey Consumption Rate in the Rice FieldsKenichi URABE, Takaya IKEMOTO, Shinichi TAKEI, Chujiro AIDA1986 Volume 30 Issue 2 Pages 129-135
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe prey-predator relationship between Sympetrum frequens nymphs and Anopheles sinensis larvae in rice fields was investigated in the suburbs of Omiya City in Japan during the period from June to July of 1978 and 1980. Sym. frequens developed into 5th-9th instar nymphs at the beginning of June, and they emerged by the beginning of July after developing into the 10th (and final) instar stage. The population sizes of the nymphs were as large as 50, 000 in Field-A (920m2) and 30, 000 in Field-B (1, 000m2) by early June. The density of An. sinensis larvae became higher toward the end of June when the density of Sym. frequens nymphs became low. The distribution patterns of Sym. frequens nymphs and An. sinensis larvae in Field-A were observed to have a non-overlapping tendency, indicating effective predation by Sym. frequens nymphs. By precipitin testing of An. sinensis larvae antiserum against Sym. frequens nymphs collected from the surveyed fields, it was confirmed that Sym. frequens nymphs predated An. sinensis larvae in the rice fields. Rates of Sym. frequens individuals positively detected to have An. sinensis in their guts were estimated to be 0-2.7% at the beginning of June and 33.3-56.5% just before or after June 20th. The rates of individuals of An. sinensis larvae predated by Sym. frequens nymphs inhabiting the surveyed fields were estimated to be 90-100% during the first half of June. It was concluded that Sym. frequens nymphs should be superior predators in the rice fields of this surveyed district.View full abstractDownload PDF (841K) -
Masayuki AKIYAMA, Kazuma MATSUMOTO1986 Volume 30 Issue 2 Pages 136-141
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSBiology and ecology of the pine spittlebug Aphrophora flavipes in the nymphal stage was studied in six year-old Pinus densiflora (12 trees) and P. thunbergii (13 trees) in the University Forest Experiment Station at Tanashi (Tanashi City, Tokyo) in 1984. The nymphs hatched from the end of April through the end of May and developed to the adult stage passing through five instars which lasted about 60 days. The nymphs produced masses of froth (“spittle”) exclusively on the current year and previous year growths and the average number of nymphs contained in a mass was significantly greater than unity throughout the season. The nymphs dispersed among the branches, resulting in changes in their vertical distribution in June. Density of the nymphs per branch was evaluated by stratifying the branches in relation to their height (and age as well): the weighted average density was 10.5 and 14.0 per branch, or 290 and 328 per tree, for P. densiflora and P. thunbergii, respectively. Daily survival rate was estimated to be 0.990 and 0.970 on P. densiflora and P. thunbergii, respectively. No predation of the nymphs by any arthropod predators coexisting on the pine trees could be observed.View full abstractDownload PDF (1153K) -
Kazuo NOZATO1986 Volume 30 Issue 2 Pages 142-143
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (244K) -
VIII. Fauna of the Blackflies in Tokyo MetropolisKatsumi SAITO, Akihiro KANAYAMA, Hideki SATO, Kazuki OGATA1986 Volume 30 Issue 2 Pages 144-146
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe fauna and distributions of the blackflies in Tokyo Metropolis were investigated by collecting the early stages of flies at 22 sites in winter seasons of 1983 and 1984. A total number of 1, 036 larvae and 79 pupae belonging to 2 genera and 9 species was collected at 14 sites, which are located exclusively in highlands of the western part of Tokyo Metropolis. Simulium (odagmia) iwatense was newly recorded from Metropolis. Predominant species was S. (Simulium) japonicum (44%) followed by S. (Eusimulium) uchidai (43%) and S. (Gnus) bidentatum (7%).View full abstractDownload PDF (402K) -
II. Habitat and Key Host PlantRyoh-ichi OHGUSHI1986 Volume 30 Issue 2 Pages 147-149
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (405K) -
Yasushi WASHIZUKA, Shigemi HIMAKI, Toshio KUSUMI1986 Volume 30 Issue 2 Pages 150-152
Published: May 25, 1986
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESS
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