톱다리개미허리노린재는 콩과작물과 과수에 경제적 피해를 주는 주요해충이다. 본 연구는 톱다리개미허리노린재의 온도에 따른 산란특성을 규명하고 수정란을 이용한 산란모형과 생명표 매개변수를 추정하기 위하여 15.8, 19.7, 24.0, 27.8, 32.6, 34.0, 35.5℃ 정온조건에서 실험을 실시하였다. 15.8℃를 제외하고 조사된 모든 항온온도조건에서 산란이 가능하였다. 암컷 성충 수명은 15.8℃ (110.5일)에서 가장 길었으며 온도 가 올라갈수록 짧아지는 경향을 보였다(19.7℃에서 76.6일, 35.5℃에서 20.6일). 전체 산란수와 수정란수는 24.0℃ (193.5와 151.2)에서 가장 많았으며 부화율은 27.8℃ (84.0%)에서 가장 높았다. 전체 산란수와 수정란수를 이용하여 산란모형과 생명표 매개변수를 비교하였다. 수정란수 를 이용시 온도별 총산란수 모형의 추정된 총산란수(159개)는 전체 산란수(190개)를 이용했을 때보다 적었다. 생명표분석에서 수정란을 이용하였을 때 개체군순증가율과 평균세대기간은 전체 산란수를 이용한 결과보다 작은 값을 나타내었다. 수정란을 이용한 산란모형 작성과 생명표분석은 실질적인 개체군변이를 이해하는데 도움이 될 것이다.

The bean bug, Riptortus pedestris, is one of major hemipteran pests against the soybean, Glycine max in Korea. In previous study, it was suggested that water-taking in the first instar nymphal stage of R. pedestris is certainly necessary for successful ecdysis and their survival. To investigate water-taking behavior of the first instar nymphs of R. pedestris on plant, electrical penetration graphic patterns were analysed while R. pedestris fed on the napa cabbage leaf, Brassica rapa subsp. pekinensis by using EPG system. In the result, a X-waveform was dominantly observed for average 42.0 min out of total recording time (120 min). There was significant positive correlation (r = 0.457, P = 0.000452, n = 55) between body weight increase and cumulative durations of X-waveform. In addition, histological observation of cross-sections indicated that stylet tip in the plant tissue during X-waveform period is located nearby xylem cells, suggesting that X-waveform is closely related to xylem sap feeding behavior of R. pedestris in plant.

Riptortus pedestris is a polyphagous species and an economically important insect pest of soybean. We investigated the development time, survivorship, longevity and fecundity of R. pedestris at five different temperatures. Life table analysis is the prime tool in population dynamics and pest management. We applied the computer programs – TWOSEX-MSChart and TIMING-MSChart - to analyze our data. We obtained the population parameters – adult preoviposition period (APOP), total preoviposition period (TPOP), oviposition days, eggs per reproductive female, first age of survival rate <50%, proportion of male and female individuals and life table parameters (net reproductive rate, intrinsic rate of increase, finite rate of increase, and mean generation time) - and population projection using two computer programs.

The study conducted to understand the annual phenology of hemipteran insect pests including Halyomorpha halys, Nezara antennata, Plautia stali, and Riptortus pedestris in Jeju, Korea, 2017 and 2018. We investigated the population density of them at three locations for two years. The commercial and fish trap were used for monitoring. We compare the seasonal occurrence among species and sampling locations. The repeated measured ANOVA was used to explain the difference of seasonal occurrence among locations and sampling time. There was difference the first adult catch and the peak occurrence of species among sampling sites.

Riptortus pedestris is one of economically important insect pests in soybean fields. The study was conducted at seven constant temperatures of 15.8, 19.7, 24.0, 27.8, 32.6, 34.0 and 35.5℃. We compared the results from life table parameters and oviposition models of R. pedestris between two data sets. One included the total number of eggs and the other used only hatched eggs. When the total number of eggs were included to calculate the parameters the intrinsic rate of increase, net reproductive rate and mean generation time were 0.066, 58.13 and 61.45 at 24℃, respectively. These values were different only when hatched eggs were applied (0.064, 45.46 and 59.41, respectively). The parameters of temperature-dependent total fecundity and age-specific cumulative oviposition rate from each data set were different.

We investigated densities of the bean bug, R. pedestris (Alydidae) and three Pentatomidae stinkbug species, Dolycoris baccarum, Nezera antennata and Halyomorpha halys in an experimental field in Suwon, 2018. Three pheromone traps for R. pedestris adults were installed at distances of more than 50 meters from soybean fields. The adults began to be caught from late March. Its mean number increased from early August, and reached a maximum at early September. The fluctuation aspects of adult number caught, however, were different among trapping sites. Soybean and mungbean were sowed at June 21, and all stages of stinkbugs were scouted from July 18 to late September through direct observation. Adults and eggs of R. pedestris were not observed during the vegetative stage of soybean, but observed first at the flowering stage, mainly early August, of reproductive stage. The results indicated that R. pedestris adults invaded into soybean fields at the flowering stage, despite of inhabitation in the surrounding area during the pre-reproductive stage of soybean. Adults of only D. baccarum in Pentatomid stinkbugs were found at the vegetative stage of soybean. Densities of R. pedestris were compared between two mungbean cultivars, which those seeds have been known to be resistant and susceptible to feeding of the bean bug, respectively. The densities of the third and fifth instar nymphs were higher on the susceptible cultivar than on the resistant cultivar, but densities of egg, adult, and the first and second instar nymphs were not significantly different between the two cultivars.

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.

Riptortus pedestris is one of economically important insect pests in soybean fields. The study was conducted at six constant temperatures of 15.8, 19.7, 24.0, 27.8, 32.6 and 35.5℃. We investigated the biological traits of R. pedestris adults. R. pedestris adults survived at all temperatures tested but female did not oviposit under 15.8℃. The longevity of R. pedestris male was longer than that of female. Oviposition model was constructed using nonlinear functions and the number of eggs produced by a cohort of females was estimated in relation to constant temperature and adult age. The life table parameters in relation to temperature were analyzed.

Riptortus pedestris is a polyphagous species and an economically important insect pest of soybean. We investigated the phenology of R. pedestris at 13 locations - Jeonju, Naju, Goheung, Milyang, Gunwi, Andong and 7 locations of Jeju. Fish trap was used for monitoring R. pedestris. The traps were baited with lures containing a 1:5:1 ratio of myristyl isobutyrate, (E)-2-hexenyl (E)-2 hexenoate and (E)-2-hexenyl (Z)-3-hexenoate. There was difference the first adult catch and local temperatures among sampling sites. To determine spring emergence distribution and annual phenology pattern, we used the monitoring data and ambient temperature from each sampling sites. We compare the seasonal occurrence and spring emergence between 2016 and 2017 in each location.

Riptortus pedestris (Fabricius) has caused severe agricultural damage in Asian regions. To clarify genetic relationships among different populations of R. pedestris in Korea, 294 COI sequences were generated from 294 individual samples collected in 42 local regions. In total, 36 haplotypes were detected from the 294 COI sequences, and the genetic distances among the 42 local populations ranged from 0.00 % to 1.50 %. In the AMOVA results, a variability of more than 98 % was observed within populations, and the median joining (MJ) networks revealed that R. pedestris has expanded by crossing the nine geographical groups. Most of the samples shared one haplotype, H2; however, some samples obtained from the same regions displayed slight genetic differences. These results indicate that R. pedestris have undergone a series of genetic variations.

Both a fluorescent marking system (FMS) and a portable harmonic radar system (PHRS) are effective insect tracking methods. Prior to comparing their efficacies, we tested the viability of FMS in detection of an agricultural pest, Riptortus pedestris (Hemiptera: Alydidae); previous studies showed the harmlessness of PHRS on R. pedestris and its detection distance. Fluorescent marking allowed the detection of marked R. pedestris from > 25 m, when illuminated with a laser in the dark, while affecting only the vertical walking distance of the insect. Then, we assessed the efficacy of the FMS and PHRS as well as combining both methods (BOTH) in detection of R. pedestris in a grass field and a bean field during day and night. PHRS and BOTH showed higher detection rates than FMS in all settings, except for in the bean field at night. Also, although BOTH did not enhance total detection time, it facilitated the retrieval of the sample at night compared to only using PHRS.

The bean bug is one of major hemipteran pests against the soybean, Glycine max in Korea. Gene expression regulation technologies such as RNA interference and gene editing have emerged as a next generation pest control strategy in agriculture. To search genes effective to feeding inhibition with exogenous dsRNA, a total of 26,761 transcripts were obtained from salivary glands of the bean bug and several target gene candidates such as GPCR, OBP, and CSP were profiled in this study. On the other hand, 1st instar nymphs of the bean bug after hatching were highly attracted to water and absorbed about 701.5 ± 137.72 ㎍/individual/day, suggesting that it could be a practical way for RNA interference by feeding exogenous dsRNA dissolved in water. These preliminary results are expected to be helpful to investigate novel pest control strategy of R. pedestris in the future.

Riptortus pedestris (F.) (Hemiptera: Alydidae) is one of major pests of fruit trees and cause economic injury by piercing and sucking fruits. Although growers usually depend on synthetic insecticides to control this pest, demand for using environment-friendly insecticide is increasing. As, in our previous studies, extracts of Nicotiana tabacum L. and Allium sativum L. was effective against Grapholita molesta (Busck), we evaluated them also on the different life stages (< 24 h) of R. pedestris at 2 mg/ml in laboratory by glass scintillation vial assay. The toxicity of N. tabacum, A. sativum, and their mixture to second instar nymph was not different compared to methanol control. But, N. tabacum was more toxic to fourth instar nymph with LT50 of 59.0 h. In adult stage, the toxicity of both N. tabacum and A. sativum was higher compared to the mixture and methanol control. Thus, N. tabacum could be potential botanical insecticide against R. pedestris.