Seok-Jo Hwang

Incidence of Wolbachia and Cardinium endosymbionts in the Osmia community in Korea.

Sex ratio distorting endosymbionts induce reproductive anomalies in their arthropod hosts. They have recently been paid much attention as firstly texts of evolution of host-symbiont relationships and secondly potential biological control agents to control arthropod pests. Among such organisms, Wolbachia and Cardinium bacteria are well characterized. This study aims at probing such bacteria in the Osmia community to evaluate their potential utilization to control arthropod pests. Among 17 PCR tested species, Osmia cornifrons and a parasitic fly are infected with Wolbachia and a mite species is infected with Cardinium. Phylogenetic tree analyses suggest that horizontal transfer of the bacteria occurred between phylogenetically distant hosts.

Cold storage effect on the biological characteristics of Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae).

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, , RH , in dark condition. Overall, an appropriate temperature for cold storage was for O. laevigatus and for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at . The O. laevigatus stored at for days laid eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was of normal fecundity. P. persimilis stored at for days with (food eggs of Tetranychus urticae) laid eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was of normal fecundity.

Biological Identity of Hwangchung and History on the Control of Hwangchung Outbreaks in Joseon Dynasty Analyzed through the Database Program on the Annals of the Joseon Dynasty and the Enrollment of Haegoeje

We tried to establish the history of outbreaks and control methods of `hwangchung` in Joseon Dynasty, uncovering the biological reality of the `hwangchung` (called hwang or bihwang) analyzed through the Database program on `the Annals of the Joseon Dynasty` and `the Emollment of Haegoeje`, two of the finest examples of classical historical records. The total number of articles on the outbreak of the hwangchung is 261 in the Annals of the Joseon Dynasty and 65 in the Emollment of Haegoeje. There were four peaks by hwangchung throughout the Joseon Era. Among them, the periods of King Taejo to King Sejong had the highest incidence. By comparing the number of records of the hwangchung from the Annals of the Joseon Dynasty with that in the Emollment of Haegoeje during the same period, results show the former was less than the latter, 35 vs 65. However, both records were relatively inconsistent with each other. Insect pests in forests as well as in agriculture were included in the biological identities of the hwangchung in the Joseon Dynasty periods, which is in accordance with those of Saigo`s. The taxonomic identity could be confirmed in only 25 cases (9.5%) among the articles on hwangchung. It largely coincided with Paik`s opinion: II in armyworm, nine in moth larva, one in rice stem borer, two in migratory locust, one in planthopper and one in rice-plant weevil. Therefore, it is not reasonable to regard hwangchung as a migratory locust or grasshopper only. The number of reports on the occurrence of hwangchung in the Annals of the Joseon Dynasty was 173 (66% of the total) and 47% of them were just simple reports, which means the report itself on the appearance of hwangchung was very significant. The reports on controlling insect pests were of low frequency, in 20% (34 cases) of the total reports, capturing insect pests or holding traditional ceremony called `Poje`. Among them, only one case related to the treatment of seeds to prevent the damage by hwangchung was published in the King Sejong period. There were 37 discussions about changes and management of government policies due to disasters by hwangchung. They were mostly about relief or tax cut to the people who suffered damage and about cancellation of recruiting people to military training, constructing castles, and so on. It seems that not only the people but also the king was influenced by the hwangchung. In the case of King Seongjong, he referred to the stress of the prevention measure of locusts in 10 articles. The damage also had an effect on abdication in the reign of King Jeongjong.

Survey on insect fauna and role of insect gardens for ecotourism.

This study was conducted to investigate insect fauna in the four insect garden sites of Suwon, Yeongyang, Buyeo and Yecheon from 2005 to 2007. Seasonal population size of insects was largest from June to August in all the four sites. In the four sites, Coleopteran insects were dominant followed by Hemiptera and Orthoptera. Unique education/learning programs are successfully run at the insect gardens based on the three geographic types (i.e. urban, mountainous and rural). These activities will help preserve insect biodiversity in the area and visitors better understand life forms such as insects found in the areas.

Effect on the Pollinating Activities of Honeybee, Apis mellierfa L.(Hymenoptera: Apidae) and Bumblebee, Bombus terrestris L. in Paprika Vinyl-Houses

This study was surveyed the effects by pollinating activity of Apis mellifera and Bombus terrestris released in the paprika vinyl-houses. The foraging activity and behaviour of A. mellifera and B. terrestris visited on the paprika flowers were nearly alike. The pick times of pollinating activity by A. mellifera and B. terrestris were showed the hightest at 11:00 and 15:00, and 09:00 to 11:00, respectively. The rate of fruit set by A. mellifera and B. terrestris released for pollinating paprika were same level with 94%, and these rate were higher than the fruit setting rate which was 92% by fan operated. The qualities of paprika produced by pollinators released were higher than those by fan operated. And weight per fruit, number of seeds per fruit and economical profit per 2,310 were over 10% higher than those by fan operated. Therefore the economical effects by the pollinating activities of A. mellifera and B. terrestris released in the paprika vinyl-houses were obviously demonstrated.