In general, hemipteran insects transmit either obligate or facultative symbionts to their offspring using various transmission mechanisms. Riptortus pedestris (Hemiptera: Alydidae) also have facultative symbiosis with Burkholderia sp. which is acquired from the soil every generation especially during 2nd instar nymphal period. This environmental symbiont transmission makes R. pedestris face a great risk of missing their symbionts, however, previous studies showed that they have intimate associations with their symbionts. Therefore, we suspected that R. pedestris 2nd instar nymphs may have a preference toward Burkholderia sp. to achieve an efficient symbiont acquisition during the limited time of window. In order to identify the preference of 2nd instar nymph, we first conducted dual-choice experiments varying with the number of 2nd instar nymphs (a nymph and 100 nymphs) in plastic cages. Furthermore, Y-tube olfactometer experiments varying with the presence of soil as medium of Burkholderia sp. were performed to determine if the insects respond to bacterial volatile induced from the symbiont. Based on our results, we observed that R. pedestris 2nd instar nymphs may not show any specific behavioral preference or response to chemical volatile from Burkholderia sp. in laboratory conditions (P >0.24). Therefore, we will further conduct a dual-choice experiment in a semi-field condition to investigate if such patterns can be detected in a larger arena simulating a more natural environment.

Modern technique development provides a new opportunity to expand entomological researches. Aerial insect sampling has been conducted with fixed-wing unmanned aerial vehicles (UAVs). With improved maneuverability, rotary-wing UAVs can serve as more convenient and feasible tools with lower cost. A rotary-wing UAV with remotely controlled insect nets was developed to collect insects at designated altitudes above the rice field (ca. 80 × 240 meter (width × length)) in Boryeong, South Korea. From 21 flights in June, July, and August 2017, 235, 7, 6, and 3 insects were caught at 5, 10, 50, and 100 meters above the rice field, respectively. The collected insects were identified to family level. Diptera (Phoridae and Chironomidae), Hemiptera (Aphididae and Delphacidae), and Thysanoptera were found from the sample, some of which may contain possible insect pests on rice. Therefore, UAVs have potential as an alternative aerial insect sampling method.

Seasonal distribution of disease vector species including mosquitoes and ticks plays a key role in establishing risk managementof vector-borne disease. However, environmental factors affecting abundance and distribution of vector species are notcurrently well understood. Therefore, we conducted a two-year field sampling to address the population dynamics of mosquitoesand ticks in Gyeonggi-do in 2015 and 2016. In 2015, the population density was highest in May for ticks (e.g. Haemaphysalislongicornis) and June for mosquitoes (e.g. Aedes vexans), whereas both pest groups peaked in August in 2016. Culexpipens (82.3% Species Ratio), Ae. vexans (77.3% SR), and Anopheles sinesis sp. (45.3% SR) were the most dominantspecies in urban area, cow shed and wild bird refuge, respectively. For ticks, H. longicornis (47.7% SR) was the mostdominant throughout four potential habitats.

Different types of insect-borne plant viruses can modify their hosts and vectors in distinct manners. Therefore, interactionsbetween two types of viruses co-existing in a field are known to be complex to predict. Obtaining empirical data byconducting field experiments, however, requires numerous biotic and abiotic factors to be controlled, and is therefore hardto execute. Thus, we designed an individual based model to simulate the transmission pattern of two viruses, using potatoes(Solanum tuberosum) for host plant, aphids (Myzus persicae) for virus vector, potato leafroll virus and potato virus Yfor different types of plant viruses. More specifically, we aimed to investigate the effect of the following on the spreadof the plant viruses: dispersal by winged-form aphids, initial number of virus-infected seed potatoes, and indirect interactionsbetween two viruses by affecting life traits of the vectors.

Vertical transmission of symbiont is known as the most effective way to deliver their offspring. However, it has beenreported that the bean bug, Riptortus pedestris, acquires its gut symbiont, Burkholderia sp., from its environment (e.g.soil) during the 2nd instar nymphal stage. Nevertheless, it is not unknown how they locate their symbiont. For this reason,dual-choice experiments were conducted in both solitary (a nymph) and group conditions (100 nymphs) to investigatewhether or not R. pedestris has preference on Burkholderia sp. treated or untreated solution in laboratory conditions. Inthese experiments, there was no significant difference in the preference between the two treatments. We are testing inthe Y-tube olfactometer system to evaluate the response of R. pedestris on possible chemical cues from Burkholderia sp..