• Korean journal of applied entomology
• /
• v.47 no.4
• /
• pp.413-419
• /
• 2008

The susceptibility of five stink bugs species collected soybean fields in Milyang in 2006 to seven insecticides was evaluated using electric auto-sprayer. The insecticide deltamethirn had the lowest median lethal concentration ($LC_{50}$) of 0.4 to 2.3 ppm regardless of stink bugs species while phenthoate had the highest concentration for one-banded stink bug (Piezodorus hybneri), green stink bug (Nezara antennata), sloe bug (Dolycoris baccarum), and brown marmorated stink bug, (Halyomorpha halys); and fenthion for bean bug (Riptortus clavatus). The average $LC_{50}$ for stink bugs to seven insecticides was lowest at 7.5 ppm for R. clavatus, followed by 16.6 ppm for H. halys, 17.6 ppm for D. baccarum, 19.1 ppm for N. antennata, and 28.4 ppm for P. hybneri. The relative tolerance ratio (TR), which is the TR of 90 percent lethal concentration ($LC_{90}$) of stink bugs to the recommended concentration, was the lowest in fipronil for R. clavatus, P. hybneri and D. baccarum; fenitrothion for N. antennata; and fenthion for H. halys. The relative average TR was lowest at 0.09 for R. clavatus, followed by 0.26 for D. baccarum, 0.30 for N. antennata, 0.37 for P. hybneri, and 0.39 for H. halys. Therefore, insecticides susceptibility was highest for R. clavatus and lowest for P. hybneri while the relative average TR was lowest for R. clavatus and highest for H. halys. Accordingly, it is expected that stink bugs can be effectively controlled with by spraying insecticides in soybean field because the relative average TR value of stink bugs was below 1.0, indicating high susceptibility of stink bugs to insecticides.

• The Korean Journal of Mycology
• /
• v.49 no.4
• /
• pp.477-486
• /
• 2021

A survey of insect-associated fungi in Korea revealed a novel fungal strain isolated from the bean bug Riptortus clavatus (Heteroptera: Alydidae). Culturally and morphologically, the fungal strain designated KNUF-20-INY03, shares features with members of the genus Acaulium. Phylogenetic analyses based on the concatenated nucleotide sequences of the internal transcribed spacer regions (ITS) regions and partial sequences of the translation elongation factor 1-alpha (TEF1-α), and β-tubulin (β-TUB), and large subunit of the nuclear ribosomal RNA (LSU) genes showed that the isolate is part of a clade that includes other Acaulium species, but it occupies a distinct phylogenetic position. Based on the shape, size, and color of its conidia and conidiogenous cells, strain KNUF-20-INY03 is readily distinguishable from the closely related A. acremonium, A. albonigrescens, A. caviariformis, A. pannemaniae, and A. retardatum. The conidial length-to-width ratio (1.6) of the novel isolate is significantly lower than that of A. acremonium (1.9), A. albonigrescens (2.4), and A. pannemaniae (2.4), and KNUF-20-INY03 produces hyaline conidia and elliptical conidiogenous cells while A. caviariformis forms brown conidia and A. retardatum produces flask-shaped conidiogenous cells. Thus, both phylogenetic and morphological analyses indicate that this strain is a novel species in the genus Acaulium, and we propose the name Acaulium microspora sp. nov.

• Korean journal of applied entomology
• /
• v.49 no.4
• /
• pp.325-331
• /
• 2010

Attractiveness of stink bugs to various colors, heights and locations of fish-net traps incorporated with aggregation pheromones was determined. Bean bug, Riptortus pedestris Fabricius, was most attracted to yellow color trap, followed by white, black, green, blue and brown. R. pedestris and one-banded stink bug, Piezodorus hybneri Gmelin, were most attracted to fish-net traps placed 80 cm above the ground regardless of sexes of two species of stink bugs. Between the sexes, however, R. pedestris females were more attracted to 40 and 80 cm above the ground than the males at those heights although the attraction was not significantly different at 120 and 160 cm heights. P. hybneri females tended to be attracted to 40 and 80 cm height traps but the attraction was the opposite at 120 and 160 cm heights. The highest attraction of R. pedestris was observed in a perilla field with no significant difference in the soybean field and border area in which no crop were cultivated between the perilla and soybean fields. R. pedestris was also more attracted to the sweet persimmon orchard than the soybean and medicinal crops fields, which was a significant difference between the two fields.

• Journal of Crop Science and Biotechnology
• /
• v.11 no.4
• /
• pp.243-248
• /
• 2008

The bean bug Riptortus clavatus Thunberg (Heteroptera: Alydidae) is an important pest, causing serious yield loss in soybean. But the information on mechanism of resistance to R. clavatus is limited. The objective of this study was to identify QTLs for R. clavatus resistance using simple sequence repeat (SSR) markers in a soybean population of recombinant inbred lines (RILs) developed from the cross PI 171451 ${\times}$ Hwaeomputkong. A genetic map from this population was constructed with a total of 136 SSR markers covering 1073.9 cM on 20 linkage groups (LGs). With 126 $F_5$ RILs, two independent QTLs for resistance to R. clavatus were mapped on LGs B1 and C2. The amount of phenotypic variation explained by these QTLs ranged from 12 to 16%. PI 171451 showed an escape response to R. clavatus. Under feeding conditions, 14.4% of RILs showed greater resistance to R. clavatus than the resistant parent. The resistance to R. clavatus in soybean from PI 171451 was incomplete and quantitatively inherited and the QTLs for resistance to R. clavatus detected in the RIL population were not significantly affected by epistatic interactions.

• Korean journal of applied entomology
• /
• v.31 no.4
• /
• pp.480-485
• /
• 1992

Laboratory studies were done to evaluate the effects of diflubenzuron on embryonic and postembryonic development of Riptortus clavatus Thunberg. Diflubenzuron prevented egg hatch; younger eggs(O-12 h old) were 2 times as susceptible as older(48-60 h old) eggs, but embryos of both younger and older eggs developed normally. Susceptibility of nymphs to diflubenzuron decreased with each successive molt. Compared with the first instar, relative tolerance to diflubenzuron was 1.5 times for the second instar, 18.2 times for the third instar, 39. 4 times for the fourth ins tar and 42.4 times for the fifth instar. Even as low concentrations, diflubenzuron prevented significant numbers of third instar nymphs from developing to fourth and fifth instar nymphs or adults. Weight, longevity and fecundity of adults surviving treatment in the final (fifth) instar were also adversely affected.

• Korean journal of applied entomology
• /
• v.44 no.4 s.141
• /
• pp.325-330
• /
• 2005

This study was conducted to determine the effect of temperatures on the egg and nymphal development, adult longevity and oviposition of bean bug, Riptortus clavatus Thunberg, using Saealkong seed as food sources in fibrous nylon-tube at four different temperatures (20, 24, 28 and $32^{\circ}C$). Hatchability showed the highest value of 100% at $28^{\circ}C$ and decreased with increasing temperature. Egg duration ranged from 7 days at $32^{\circ}$ to 16.7 days at $20^{\circ}C$. Instar duration was longer with increasing instar stage. Nymphal duration was 38 days at $20^{\circ}C$, 30 days at $24^{\circ}C$, 23 days at $28^{\circ}C$, and 18 days at $32^{\circ}C$ Emergence rates to adult were 16, 41, 72 and 68% at 20, 24, 28 and $32^{\circ}C$, respectively. Female adult longelity ranged from a minimum 20 days at $20^{\circ}C$ to a maximum 63 days at $28^{\circ}C$, while the longevity of male ranged from 19 days at $20^{\circ}C$ to 60 days at $28^{\circ}C$. Preoviposition duration was shorter with increasing temperature and ranged from 11 days at $20^{\circ}C$ to 5 days at $32^{\circ}C$. Total number of eggs laid per female ranged from a minimum 21 eggs at $20^{\circ}C$ to a maximum 67 eggs at $28^{\circ}C$. Consequently, the estimated lower threshold tempeatures of each developmental stage were $10.3^{\circ}C$ for egg, and 9.3, 12.7, 10.0, 11.0 and 8.7 for the 1st, 2nd, 3rd, 4th and 5th instar, respectively.

• The Korean Journal of Pesticide Science
• /
• v.17 no.3
• /
• pp.206-212
• /
• 2013

This study was examined for activity of aggregation pheromone fish net trap with residual effect of insecticides against Riptortus pedestris. Time of escape was from aggregation pheromone fish net trap researched 49.74 min ($ET_{99}$) and 65.01 min ($ET_{99}$) with 1st and 2nd instar nymph respectively. Six insecticides for the stink bugs were treated to 3 different materials (wood, metal and plastic). Bifenthrin and fenitrothion were showed 100% insecticidal activity at 48 h to all developmental stage of R. pedestris. Residual effect of bifenthrin and fenitrothion on plastic material were showed 100% insecticidal activity over 15 day after treatment with 1st, 3rd instar nymphs and adults except 5th instar nymph. In field test using plastic material trap with two pesticides, 1st instar nymphs and adults were showed 100% mortality until 10 day after treatment. These results indicate that R. pedestris might be managed using aggregation pheromone trap with insecticides.

• Korean journal of applied entomology
• /
• v.51 no.4
• /
• pp.411-419
• /
• 2012

The lure-distance of Riptortus pedestris aggregation pheromone was elucidated and the damage mitigation effect by mass trapping of R. pedestris was examined in commercial soybean fields. The recaptured ratio showed that 76.1% of total recaptured individuals were lured within 40 m and 89.0% of total recaptured adults were arrested in the lower 80 m. There is not much difference in the number of recaptured individuals according to the location of installed traps in the experiment. There was linear correlation between the total installed number of traps and the total number of trapped individuals in commercial soybean fields. and the highest yield (261.8 g/10 stems) was investigated in the field that had installed a pheromone trap per $770m^2$. No relationship wasf found between the covered areas of a pheromone trap for mass trapping and yield loss. The ratio of type A seed (healthy) was higher in the field that installed a trap per $385m^2$ and $770m^2$ (around 62%) and type B seed (showing distinct injury marks) was lower in the same fields (around 27%). From this result, we could reduce slightly the damage of soybean seeds by the mass trapping of Riptortus pedestris adults with an aggregation pheromone trap per $385{\sim}770m^2$ area range.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.231-236
• /
• 2021

The Aphid, Myzus persicae, and the bean bug, Riptortus clavatus, are major insects in crops. This study examined the insecticide susceptibility and phytotoxicity of insecticides dispersed using an Unmanned Aerial Vehicle (UAV, multi-copter) against the insects. Sulfoxaflor suspension concentrate (SC, 16X) on potato fields and etofenprox, methoxyfenzide suspo-emulsion(SE, 8X) on soybean fields were dispersed after deploying water-sensitive paper within the field to measure the distribution pattern and coverage index of the falling insecticide. Both insecticides showed a controlled mortality of 76.4% against aphids and 97.5% and 94.4% against the 2nd nymphal, and 5th nymphal stage of the bugs, respectively. The droplet distribution was less than 0.5mm, and coverage analysis revealed an inside and outside coverage of 3.1 and 1.6, respectively. The surrounding area was affected by insecticide spraying using a multi-copter. This study is expected to help expand UAV control and use it safely in the future.

• Korean journal of applied entomology
• /
• v.55 no.4
• /
• pp.319-327
• /
• 2016

Chemical pesticides have been used to control persimmon pests, however the overuse of the pesticides caused insect resistance, followed by failure in pest management and residual problems. Herein we investigate the potential of eco-friendly organic pesticides (EFOP) on the control persimmon pests, Stathmopoda masinissa (persimmon fruit moth) and Riptortus pedestris (bean bug). Ten commercially available plant-derived organic pesticides and one microbial pesticide were sprayed on the target insects in laboratory conditions. The chemical pesticide, buprofezin+dinotefuran wettable powder served as a positive control. In the first bioassay against persimmon fruit moth, alternatively Plutella xylostella larvae were used due to the lack of persimmon fruit moth population from fields, and three organic pesticides showed high control efficacy, such as pyroligneous liquor (EFOP-1), the mixture of Chinese scholar tree extract, goosefoot and subtripinnata extracts (EFOP-2) and Bacillus thuringiensis subsp. aizawai NT0423 (EFOP-11). When the three selected organic pesticides were treated on the persimmon fruit moths, the EFOP-2 treatment showed the highest control efficacy: 27.7% (5 days), 13.3% (7 days) and 6.7% (10 days) of survival rates. In the bioassay against bean bugs, the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2 and EFOP-9) and the extracts of sophora and derris (EFOP-10) showed high control efficacy, particularly the highest in the treatment of EFOP-2: 20.0% (5 days) and 16.7% (10 days) of survival rates. These results suggest that the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2) has high and multiple potential in the management of the persimmon pests.