The Asian corn borer, O. furnacalis (Crambidae) and the old world bollworm, H. armigera (Noctuidae) simultaneously cause ear damage in corn in Suwon area. It has been assumed that the second generation of larvae of both insects is responsible for the damage. We, therefore, studied proper spray timing of insecticide in order to reduce the damage. A waxy corn hybrid cultivar, Ilmichal, was sown directly on four plots of a field at April 10, April 20, May 4, and May 18, 2018, respectively. A sodium channel blocker, indoxacarb, was sprayed eight times at 3- or 4-day intervals around the silking stage of corn in each sowing plot. At ear harvest time of each plot, we investigated damaged ratio and length of ear, and the numbers of both insect species. The significantly effective spray timings on reduction of ear damage were the sprays at June 29 and July 2 in the plot sown at April 10, the sprays from July 2 to 13 in the April 20-sown plot, the sprays from July 2 to 19 in the May 4-sown plot, and the sprays at July 19 in the May 18-sown plot, respectively. The damage level was positively related to the insect number. The result indicated that the spray at the silking stage of corn was effective on reduction of ear damage. It was assumed that occurrence time of neonate larvae of the insects at silking stage cause the damage, based on the experimental results using screened pots inoculated with the two species.
In the present study, Cydia kamijoi Oku is newly recognized in korean insect fauna. This tortricid moth was first found damaging the cones of Abies koreana in Jeju Island 2014. The moth can be a serious insect pest on A. koreana because of high damage rate on the cones, up to 71% average. The genus Cydia now was 11 korean species including C. kamijoi. Regarding this species, some basic information such as collection records, morphological characters, and ecology were provided
A long term monitoring was carried out to compare altitudinal effects on insect community structures on high mountains and evaluate responses the monitoring and changed of insect communities induced by the climate change. These mountains were choose for Mt. Jeombong for northern part, Mt. Ilwol for middle and Mt. Beakun for southern. Each mountain was divided into three altitudinal gradients. They were collected three times a season from spring to autumn, using pitfall traps for ground beetles and UV light trap for moths. The present study presents preliminary results of analysis for the first year monitoring. In total 41beetle species and 326 moths were collected from the monitoring sites in 2012. abundance of ground beetles and moths were the highest in Mt. Baekun followed by Mt. Ilwol and lowest in Mt. Jeombong. Analysis of variance (ANOVA) results showed statistically significant differences among sampling area, species evenness and Shannon’s diversity index with altitude in species abundance as a response variable. Also we found statistically significant differences to three species of ground beetle and six species of moths with altitude. Although we expected a distinct cluster with the difference of altitude at each study site. one of ordination analysis, nonmetric multidimensional scaling (NMS), showed distinct clusters with the ground beetles assemblage at some altitude and moths assemblage at sampling date.
This study was conducted to improve the effect of environment-friendly Tetranychus urticae pesticide through the development of Tetranychus urticae biopesticide using the plant extract. Tested extracts were fig leaf extract, viburnum erosum extract; besides Sophora flavescens Ait extract, Derris root extract, Tobacco leaf extract, and they were proved to be the caricidal effect of two spotted spider mite adults by spraying on the French bean leaf inoculated for Tetranychus urticae with each concentration; 500ppm, 200ppm, 100ppm, 50ppm. In the control treatments, caricidal effect was compared with only ‘Eungsami’ (500ppm, 200ppm, 100ppm, 50ppm), of which the main ingredient as environment-friendly organic material is, and distilled water.
The caricidal effect of tested extracts to the two spotted spider mite adult was the highest in the Sophora flavescens Ait extract and Tobacco leaf extract over 90%, and comparatively low in the Derris root extract. When the caricidal effect of ‘Eungsami’ was compared with two spotted spider mite adults with each concentration, ‘Eungsami’(500ppm) and Tobacco leaf extract(500ppm) were very excellent as each 95.5%, 98.7% in treated concentration. The effect of Sophora flavescens Ait extract was also high as 96.5%. In the low concentration(50ppm), Sophora flavescens Ait extract was 45.8%, Tobacco leaf extract was the most effective as 53.8%.
The turnip aphid is a worldwide pest, damaging mainly to crucifers. In order to understand the life parameters of Lipaphis erysimi for the eventual goal of control, the developmental periods, survival rates, lifespan, and fecundity of the species were investigated under five temperature regimes (15℃ - 35℃). Furthermore, the efficacy of several environment-friendly agricultural materials (EFAMs) that are on the market was subjected to test in order to obtain further accurate information. The developmental period of the turnip aphid nymph was longest at 15ºC as 16.9 days, shortened as temperature goes up to 25ºC (5.4 days), and then somewhat increased at 30ºC (5.9 days), suggesting that the most efficient temperature for nymphal development could be around 25ºC. Mortality of the nymphal turnip aphid was obvious at 35ºC, whereas it was minimal at other temperature schemes. The longevity of adults shortened as temperature goes up to 30ºC. In particular, the maximum lifespan for adults continued for 55 days at 15ºC, but shortened to 21 days at 30ºC. The total fecundity per day was 35.7 at 15ºC, 81 at 20ºC, 64.2 at 25ºC, and 6.6 individuals at 30ºC, showing the highest fecundity at 20ºC. After the turnip aphids were successfully stabilized in indoor environment the insecticidal activity was tested and mortality was determined 12, 24, 36, and 48 hrs after EFAMs are treated. Several on-the-market EFAMs showed more than 90% of insecticidal activity within 24 hrs or 48 hrs, but a few showed less than 90% activity, signifying importance of selection of proper EFAMs.
A reaction of 214 lines and varieties to BB korean race K1, resistance and moderately resistance was 33 varieties which were bred before in 1990, susceptible were 5 varieties (Milyang23, Dongjinbyeo, Sinseonchalbyeo, Changseongbyeo and Cheongmyeongbyeo). Among bred after in 1990 resistance appeared 58 varieties, 18 varieties were susceptible. Bred after in 2000 were 50 varieties appeared resistance and 5 varieties were susceptible (Manho, Goun, Jinbong, Josaengheugchal, and Manna). Accordingly most varieties bred in south korea seemed to possession resistance to BB korean race K1. As a result of whether or not having Xa1 gene of rice varieties by SNP marker appeared that 43 varieties and the other 10 lines and varieties have Xa1 gene. Varieties bred before in 1990 have 18 (62.1%) varieties out of 29 varieties possession Xa1 gene to showed resistance to BB korean race K1, 19 (47.5%) varieties bred in 1990~2000, 6 (12.8%) varieties (Boseogchal, Daepyong, Hanareumbyeo, Hopyeongbyeo, Jongnam, Kuman) bred after in 2000 seemed to possession Xa1 gene.
Research Institute (HARI), NTCS, RDA, in 2004. This cultivar has a short grain shape and about 123 days growth duration from trans-planting to harvesting under the reclaimed saline area of the south-western and the mid-western coastal plain and Honam plai