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Volume 34 (1990)
- Issue 4 Pages 279-
- Issue 3 Pages 189-
- Issue 2 Pages 89-
- Issue 1 Pages 1-
Volume 34, Issue 1
Displaying 1-14 of 14 articles from this issue
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I. Infection of S1NPV to the Next Generation Larvae through the Male Moths Contaminated with S1NPVToshio MASUDA, Hidenori IWAHANA, Kisaku AKUTU1990 Volume 34 Issue 1 Pages 1-6
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe nuclear polyhedrosis virus of Spodoptera litura (S1NPV) was transmitted by male moths contaminated with polyhedral inclusion bodies (PIBs) of S1NPV to the next generation. The clasper or abdomen of male moths were treated with powder or suspension of PIBs. The treated moths were mated with untreated females. So, the clasper treatment with PIBs powder was most effective in S1NPV infection of the next generation larvae in all treatments. S1NPV was transmitted by the male moths self-contaminated with PIBs powder placed around the sex-pheromone source. PIBs were observed on claspers of self-contaminated male moths and also on the eggs oviposited by females mated with contaminated males using SEMed. Many PIBs were microscopically observed in the feces of the male moths which sucked sucrose solution containing PIBs placed around the sex-pheromone source, and the next generation larvae were infected with S1NPV.View full abstractDownload PDF (1436K) -
I. Investigation of Adult Emergence Holes in Citrus Orchards in Kagawa PrefectureMakoto MITOMI, Eiji KURODA, Hidetosi OKAMOTO1990 Volume 34 Issue 1 Pages 7-13
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn citrus orchards under customary management selected from six regions in Kagawa Prefecture (Nagao, Aji, Shinden, Kinashi, Sakaide, and Nio), 300 trees (50 in each region) were randomly sampled. The number of adult emergence holes in the trees sampled and the distance of the holes from the ground were investigated, dividing them into “new” (produced in 1987) and “old” (pre-1987) groups. Trees with new or old emergence holes were found in every region, ranging from 50% of all trees in Nio to 94% in Shinden (average frequency of trees with emergence holes in all six regions was 66%). The minimum and maximum frequencies of trees with new emergence holes were 10% (Aji) and 52% (Shinden), respectively (average for the six regions, 19.3%). The mean number of emergence holes per tree bearing the holes varied from 2.2 (Nagao and Nio) to 5.9 (Shinden) (average for the six regions, 3.8). Among all trees sampled, the maximum number of emergence holes per tree was 36 (Sakaide). These results indicate frequent emergence, and therefore considerable citrus tree damage, of adult beetles even in orchards with conventional pest control. The vertical distribution of emergence holes was centralized into a zone within 30cm from the ground, independent of hole freshness or the location of the investigated region, though it shifted slightly upward as the number of emergence holes increased. From daily changes in the numbers of new emergence holes investigated in an orchard under uncontrolled management (Maedahigashi region), it was found that the dates of first, last and 50% emergence were June 8, July 14 and June 26, respectively.View full abstractDownload PDF (766K) -
Susumu IZUMI, Toshihide ICHIKAWA, Hidetoshi OKAMOTO1990 Volume 34 Issue 1 Pages 15-19
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSStudies were carried out on the sounds produced by Japanese pine sawyer larvae. The duration of sounds alternating with silent phases, intervals between sound-units, and wave form and intensities of sound-units were studied, and larval sound producing behavior was observed. The duration of one continual sound production did not exceed five min and shortened with the progression of larval development. Intervals between two sound-units were approximately two sec and nearly constant throughout larval development. Sound-units lasted nearly 0.04sec in length and consisted of more than 10 wave trains which were around 0.001sec in length. The intensity of sound pressure exceeded 40dB and the sounds were clearly audible at more than 15m from the sound source in a pine stand during good weather conditions. Larvae were also observed revealed to produce sound from a posture contacting mandibles with gallery walls.View full abstractDownload PDF (569K) -
Yoshio MIYAHARA1990 Volume 34 Issue 1 Pages 21-27
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSMoths of the rice leaf roller, Cnaphalocrocis medinalis GUENÉE, and the Hawaiian beet webworm, Hymenia recurvalis FABRICIUS resting on seashore vegetation (containing no host plants) were periodically collected with an insect net at the coast of Hyuga, Miyazaki Prefecture, in 1987 and 1988. H. recurvalis moths were also collected at two sites. One site was on host plant, Amaranthus lividus L. The other site was on non-host plants, consisting mainly of grassy weeds in vegetable fields where host plants were abundant, in 1988. Both species of moth were counted separately and sexed. Female moths were dissected to examine the number of spermatophore. Both species were found from mid August; C. medinalis was observed until late October. H. recurvalis was observed until early November. There was no difference found in the sex ratios of the two species collected. The mating rate ranged from 8.0% to 20.9% in C. medinalis and from 9.4% to 19.6% in H. recurvalis, indicating a low level of sexual maturity. The movements of both species were observed on August 31, September 1, September 26 and September 27 at the seashore vegetation site. Moths took off within half an hour after sunset. Both species were found on the following day at the same site. In the vegetable fields the mating rate of H. recurvalis on the host plant ranged from 11.4% to 92.3% depending on the date of collection. The mating rate of non-host plants, however, varied from 63.0% to 100%, with an average of 81.5% during the autumn. This indicated that the female moths on non-host plants were more sexually mature and differed markedly from the moths on seashore vegetation. No difference was found in the sex ratio of moths found on non-host plants. These results suggest that both species found on seashore vegetation might be temporarily landed populations in the course of migration flight, and that H. recurvalis might also be a migrant as is C. medinalis.View full abstractDownload PDF (869K) -
Isamu SHIMIZU1990 Volume 34 Issue 1 Pages 29-36
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSPhototactic response of an ommochrome pigment-less mutant (w-1) of the silkworm, Bombyx mori, was investigated. The light intensity response curves varied with light- and dark-adaptive stages of the newly-hatched larvae. After light-adaptation the larvae showed a positive phototaxis at low intensities of the yellow test-light, but a negative phototaxis at high intensities. After dark-adaptation they showed negative phototactic responses to all intensities of test light. The halftimes of the sign reversion in the response by light- or dark-adaptation were 20-30min. Green light (500-560nm) was effective in both positive and negative responses. After light-adaptation, mature w-1 larvae moved toward a light source with a klinotactic behavior, but dark-adapted larvae moved away from it. The results of crosses between w-1 and other positive-phototactic races showed that the genetic factor determining the characteristics of phototactic response of w-1 is completely recessive.View full abstractDownload PDF (1009K) -
II. Variation of Esterase Activity by Host PlantsTsutomu SAITO1990 Volume 34 Issue 1 Pages 37-41
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIndividual esterase activity in 124 field populations of the cotton aphid, Aphis gossypii GLOVER, was examined on 16 hostplants. Frequency distribution of esterase activity in all apterous viviparae (3, 679 adults) examined had two peaks of 1-10 and 40-50nmol of hydrolyzed α-naphtyl acetate per μg protein of the aphid. The populations from each hostplant had different frequency distributions. It is remarkable that aphids with high esterase activity were observed frequently on Cucurbitaceae crops but not Solanaceae, whereas strawberry and chrysanthemum hosts supported aphids with both high and low esterase activity. Frequency distributions remained constant throughout the sampling period. These results show that biotypes differ, at least between aphids occurring on Cucurbitaceae and Solanaceae. It is suggested that insecticide resistance of the aphid is closely associated with its biotype.View full abstractDownload PDF (655K) -
Sadao WAKAMURA1990 Volume 34 Issue 1 Pages 43-48
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSFertilized females of Spodoptera exigua laid 713±154 eggs (mean±S.D.) for 4.8±1.5 days in the laboratory at 25°C and 14L: 10D. They laid ca. 40% of the eggs during the first night after mating, and the daily oviposition diminished exponentially thereafter. In contrast, unmated females laid 371±175 eggs for 5.3±2.2 days. Mating delay for more than 4 days after emergence resulted in fewer eggs and less hatchability. Simulation showed that ca. 97% of daily inhibition of mating would result in a ca. 20% accumulated mating rate of females. This value would be necessary to exceed a 90% reduction of reproduction. This estimation coincided with the population suppression effects observed in a field experiment of communication disruption conducted in 1987 by WAKAMURA et al. (1989).View full abstractDownload PDF (758K) -
Masateru INOUE1990 Volume 34 Issue 1 Pages 49-53
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe efficiency of folded vinyl in preventing dispersal of spider mites was investigated. Mites could not climb over vinyl surfaces with 30 or 45 degree lapels and wandered under them. These “fences” greatly reduced the number of mite immigrants into a spinach field with a vinyl rain cover, and were also very effective in preventing emigration of mites from a box into which post-harvest strawberry plants colonized by many mites were being abandoned.View full abstractDownload PDF (614K) -
IV. Seasonal Trends of Feeding and Oviposition Activities of AdultsTakenari INOUE, Norizumi SHINKAJI1990 Volume 34 Issue 1 Pages 55-62
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSSeasonal trends of feeding and oviposition activities of adults of the fleabeetle Argopistes coccinelliformis were investigated. Under field conditions, newly emerged adults showed a high feeding activity in early summer which soon declined and stayed at a low level during other seasons. These adults, collected in the field from early summer to autumn, needed a long period of time before ovipositing under laboratory conditions. On the other hand, the adults collected in late autumn or early winter showed a high feeding activity and required only a short period of incubation prior to oviposition. Feeding and oviposition activities were influenced by photoperiods, decreasing with short daylength. The overall results suggested that adults of this species were in a state of diapause during the period from summer to autumn, and that this state might be broken in late autumn or early winter in the field. However, the results also indicated that the species does not necessarily require a specific period of ‘late autumn or early winter’ to break the diapause. We speculated that conditions of short daylength and low temperature during the autumn and winter delayed ovarian development until the spring, and that this mechanism enhanced the alignment of the oviposition period to the time of the start of host plant sprouting.View full abstractDownload PDF (1072K) -
Mika SAKAKIBARA, Chitose ORIKASA, Hajime FUGO1990 Volume 34 Issue 1 Pages 63-70
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn order to clarify the regulation mechanism for eclosion hormone synthesis and secretion, fundamental culture conditions for brain-corpora Cardiaca-corpora allata complexes (Br-CC-CA complexes) of the silkworm, Bombyx mori, were established. When 10 brains were placed in 3ml of CSM-2F medium, eclosion hormone activity was detected throughout the cultured periods. On the 6th day of the cultivation, the positive response for Bombyx eclosion hormone assay from the cultured brains was about 60%, and thereafter the activity decreased with the culture. Eclosion hormone activity was first detectable from the cultured medium 6 days after the cultivation. The highest eclosion hormone titer in the cultured medium was 22.5 units. It was concluded that culture conditions were not appropriate for the hormone synthesis since the hormone titer in brains and culture media was extremely low compared with those in vivo. Therefore, the culture conditions were modified for using Br-CC-CA complexes. It seemed suitable to culture 10 Br-CC-CA complexes together in 1ml of CSM-2F medium with a gentle stream of air at 25±1°C in 16 L-8 D. In these conditions, an increase of about 2-fold in eclosion hormone titer was observed in a brain during 12 day culture periods. Although the eclosion hormone activity was not detected in CC-CA and media at the initiation of culture, hormone activity in CC-CA could be detected 4 days after onset of the cultivation. Furthermore, the hormone titer in CC-CA became 2 units after 12 days cultivation. On the other hand, 55 units of hormone titer was detected in 1ml of the medium 12 days after onset of cultivation, indicating that 5.5 units of hormone were released from 1 Br-CC-CA complex. Eclosion hormone titer detected from cultured Br-CC-CA complexes and media and expressed as the titer from a single Br-CC-CA complex coincided well with the hormone titer present in 1 intact animal. Morphological changes of brain and CA were scarcely observed during 16 days culture periods in the CSM-2F medium. These results indicate that the synthesis and secretion of eclosion hormone occurred during the culture periods.View full abstractDownload PDF (2427K) -
Kenji KOYAMA, Jun MITSUHASHI1990 Volume 34 Issue 1 Pages 71-72
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (261K) -
Tsuneo HIRAO, Narihiko ARAI1990 Volume 34 Issue 1 Pages 73-76
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe gustatory and feeding responses to amino acids were investigated in the silkworm, Bombyx mori L. Gustatory responses to L-isoleucine and L-leucine were observed in the sensory hair, Ss-I. The sensory hair, Ss-II, responded to L-arginine-HCl, L-histidine-HCl-H2O, L-leucine, L-lysine and L-tryptophan. The responses of the receptor cells to amino acids, isoleucine and leucine, disagreed with that of any type of the receptor cells in Ss-I. On the other hand, the responses of the receptor cells in Ss-II to amino acids, L-arginine-HCL, L-histidine-HCl-H2O, L-leucine, L-lysine and L-tryptophan, agreed with that of R-cells (the receptor to repellents, such as “bitter substances”). The feeding responses decreased with increasing concentrations of each amino acid, L-arginine-HCl, L-histidine-HCl-H2O, L-lysine or L-tryptophan. These results showed that the feeding responses to amino acids were closely related to the responses of the R-cells.View full abstractDownload PDF (513K) -
Hiroaki NODA, Hai-Bin SUN, Tomotoshi NOSE, Takehiko MATSUI1990 Volume 34 Issue 1 Pages 77-78
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSRhythms of imaginal ecdysis of two rice planthoppers Nilaparvata lugens and Laodelphax striatellus were studied at a constant temperature of 25°C. The two species showed clear rhythms under the influence of diel cycle illuminations. N. lugens usually emerged within the first two hr of the photophase under 16L-8D photoperiod and within the last two hr of the scotophase under 10L-14D photoperiod. The emergence rhythms continued in a clear circadian manner after being transferred to continuous light conditions. The rhythms were well synchronized between males and females.View full abstractDownload PDF (209K) -
Kenichi KANDA, Yoshio HIRAI1990 Volume 34 Issue 1 Pages 79-81
Published: February 25, 1990
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn the early spring of 1989, an outbreak of the winter grain mite, Penthaleus major (DUGÈS), occurred in the forage grasses of the Nasu region in north-central Honshu, Japan. The mites heavily damaged 10ha of Italian ryegrass fields and caused withering of the stubs. The average number of mites per square meter was about 80, 000, with population density fluctuating from 9, 851 to 157, 120. The relationship between population density and orchard grass yields was surveyed. Dry weight of the grass per square meter with densities 32, 454 and 1, 629 were 64.5 and 145.1g, respectively.View full abstractDownload PDF (440K)
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