All issues
Volume 41 (1997)
- Issue 4 Pages 187-
- Issue 3 Pages 115-
- Issue 2 Pages 75-
- Issue 1 Pages 1-
Volume 41, Issue 4
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
-
(1) Evaluation Based on Larval MortalityShoji ASANO, Tomoko IWASA, Akihiro SEKI1997 Volume 41 Issue 4 Pages 187-194
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn bioassays for quality control of Bacillus thuringiensis (BT) formulations, the diet-incorporation method using silkworm (Bombyx mori) has been generally used since 1973. To make the silkworm assay simpler, we attempted a new procedure for preparing the incorporated diet; a powdery diet, BT solution and 2% agar solution were mixed in liquid form at 55°C and then allowed to soldify. The present study showed that the diet water content affected the larval development and BT susceptibility. An appropriate water content with no adverse effects was about 75%. Larval susceptibility to BT formulations differed between instars, and was high in the 2nd, 3rd and 4th instars, and low in the 1st and 5th instars. It decreased with days after ecdysis in the same instar. Larval mortality occurred after 2 days and then increased, but differed with exposure period and types of BT formulations.View full abstractDownload PDF (985K) -
Mikio IGA1997 Volume 41 Issue 4 Pages 195-199
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDiadegma semiclausum was introduced from Taiwan to Japan for the first time in 1989 and was released into an experimental farm from 1991 to 1993. Each release consisted of 100 females. The single release experiment in 1991 produced 30% parasitism of the Diamondback Moth in 1 month. In 1992, four releases were made at intervals of 10 days, and the parasitism reached 50% after 30 days and 70% after 50 days. In 1993, a similar experiment was repeated by increasing the number of releases from four to eight, and starting 1 month earlier. The resultant parasitism was 70%. In 1991, the sex ratio of the D. semiclausum was close to 1.0 during the first 10 days, falling to 0.25. In the 1993 experiment, the populations of the four indigenous natural enemies of the Diamondback Moth decreased as the parasitism by D. semiclausum increased.View full abstractDownload PDF (578K) -
Keiji YASUDA1997 Volume 41 Issue 4 Pages 201-207
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSTo obtain the control threshold for the West-Indian Sweet Potato Weevil, the relationship between the occurrence of sweet-potato stems injured by the larvae and the proportion of damaged tubers at harvest was studied in both insecticide-treated and untreated plots. The ratio of damaged tubers at harvest was high in plots where injured stems occurred early and/or the proportion of injured stems was high. The regression equation, Y=20.83+0.95X (r=0.639*) expresses the relationship between the proportion of damaged tubers at harvest (Y) and the percentage of injured stems on day 75 day after planting (X). Based on this modified equation, the control threshold level of stems injured during the growing period for a tolerable injury level (13.6% of tubers damaged at harvest) was estimated to be 5%. The insecticide application for this control threshold was as effective as the conventional application; three applications could be reduced to two.View full abstractDownload PDF (844K) -
I: Oviposition Site Selection, Nymph Development and Walking Ability of NymphsAyako WADA, Koji HORI1997 Volume 41 Issue 4 Pages 209-216
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSOviposition site preference in Palomena angulosa MOTSCHULSKY (Hemiptera: Pentatomidae) was investigated. The preference of females caught in the field was examined in laboratory cages and outdoor screen cages. Specific preference for plants on which parasitism has been demonstrated in the field was not observed and a lot of oviposition was found on the nets of laboratory cages and net rooms. The nymphs were reared on five species of plants on which oviposition has been previously observed, or on green beans as a control. All the nymphs reared on willow twigs died at a young age. The growth periods until adult emergence differed between plants. The difference was 60 days between the longest-period plant (red clover) and the shortest-period plant (mountain ash). The body weight at emergence was ca. 100mg for mountain ash and ca. 90mg for red clover. The walking abilities of the nymphs (instars 2-5) were compared and the younger instars were found to walk more actively. These results suggest that female oviposition site selection is not necessarily made, and if nymphs hatch on an unsuitable plant for growth, they could walk to a suitable plant host.View full abstractDownload PDF (1017K) -
Hideo UEMATSU, Ryoichi MORIKAWA1997 Volume 41 Issue 4 Pages 217-223
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThis study was carried out to clarify protogyny in the Diamondback Moth, Plutella xylostella. Pupae were collected from cabbage fields in Miyazaki, southern Japan, from 23 January to 7 July 1990. They were kept in chambers controlled at 20°C, 14L-10D, to measure the number of days until adult emergence (NDAE). The NDAE ranged from 1 to 8 days. Median NDAE in females were 1 or 2 days shorter than in males. Females always developed faster than males in rearing experiments at three constant temperatures and two fluctuating ambient temperatures. The results suggest the occurrence of seasonal protogyny in the Diamondback Moth. The significance of protogyny is discussed.View full abstractDownload PDF (749K) -
Haruki KATAYAMA1997 Volume 41 Issue 4 Pages 225-231
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe effect of temperature on the development and fecundity of Frankliniella occidentalis PERGANDE was examined by rearing experiments at constant temperatures on florets and leaves of chrysanthemum (Chrysanthemum morrifolium). The developmental periods on florets were 34.2, 19.2, 12.1 and 9.5 days at 15, 20, 25 and 30°C, respectively. The lower threshold temperature for development and the thermal constant for pre-adult stage were estimated to be 9.5°C and 194 degree-days, respectively. Adult longevity on florets was over 3 months at 15°C, and shortened with increasing rearing temperature. The fecundity on florets was 230-250 eggs per female at temperatures between 15-25°C. The intrinsic rate of natural increase (r) was higher at higher rearing temperatures. The value was 0.198 at 30°C and the reproductive rate per month was 377 on florets. However, adult longevity was shorter, and fecundity was lower on leaves. Consequently, chrysanthemum leaves seem unsuitable for reproduction of the Western Flower Thrips.View full abstractDownload PDF (907K) -
Nobuhiro NYUMURA, Hiroaki ASAGA1997 Volume 41 Issue 4 Pages 233-236
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (1966K) -
Takashi SHINOKAWA1997 Volume 41 Issue 4 Pages 237-239
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSSoil desiccation increases egg floating and floating eggs have a higher hatching rate than sinking eggsView full abstractDownload PDF (431K) -
Ken FUNAYAMA1997 Volume 41 Issue 4 Pages 240-242
Published: November 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSComparative chlorpyrifos susceptibilities were examined in male adults and 5th-instar larvae between resistant and susceptible populations of the Summer Fruit Tortrix, Adoxophyes orana fasciata. The susceptibilities were similar and parallel in both stages in each population. Monitoring of chlorpyrifos resistance is possible by treating male adults captured in sex-pheromone traps using a bodydipping method.View full abstractDownload PDF (394K)
- |<
- <
- 1
- >
- >|