• Korean journal of applied entomology
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• v.47 no.4
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• pp.379-383
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• 2008

Oviposition preference of the bean bug, Riptortus clavatus to sites on a plant and within a field, to plants at different developmental stages, and to different leguminous germplasms was observed. The insect layed its eggs mainly on the back surface of leaf in the upper half of plant in both observation from oviposition cage and soybean field. The egg number in fields were observed at a statistically-same rate in marginal and inside area, and at a median value of one egg per leaf in oviposited leaves. Full seed stage of soybean hardly affected oviposition preference of the insect. A statistically-significant difference in oviposition to different leguminous germplasms was observed.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.73-79
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• 2009

Male adults of bean bug, Riptortus clavatus Thunberg (Heteroptera: Alydidae), release aggregation pheromone (AP) which consists of (E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), (E)-2-hexenyl (E)-2-hexenoate (E2HE2H), and tetradecyl isobutyrate (TI). Variation in the pheromonal secretion were checked by the factors of age, mating status, seasons, body weight and time in a day. There were no significant differences in the amounts of AP secretion by mating, body weight, and time in a day. Higher amount of AP was detected from older males than younger ones. The amount of AP detected was higher in the males collected from April to September than in those collected during October. No AP was detected in the males of November and December. These phenomena in the AP secretion were discussed in relation to food exploitation and reproductive diapause of the bean bug.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.437-448
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• 2013

Hemipteran bugs, which were previously considered as secondary pests, have currently become important pests of numerous crops. Among them, Riptortus pedestris (Fabricius) is a major species that occurs in Korea, Japan, China, and South Asian countries. Riptortus pedestris infests leguminous crops like soybean, vetches, and red clover; fruit trees like persimmon and yuju; and grains like barley, foxtail millet, broomcorn, and sorghum. Riptortus pedestris causes the greatest damage to soybean, as it is the most suitable host for the bug. Feeding damage during pod formation significantly reduces the yield of soybean. Currently, 17 insecticides, including diazinon and etofenprox, are registered for the control of hemipteran bugs in Korea, and growers apply insecticides two to three times on a regular basis. Aggregation pheromone traps are widely used as a monitoring tool and partial control measure. The aggregation pheromone of R. pedestris attracts conspecific adults and nymphs and is used for food exploitation rather than sexual attraction. In addition, the pheromone serves as a kairomone for egg parasitoids such as Gryon japonicum (Ashmead) and Ooencyrtus nezarae Ishii. As a new method of pest management, nonviable host eggs were included in the pheromone trap to catch R. pedestris and propagate parasitoids. As a part of cultural practices, resistant soybean varieties with specific color and size of pod and control of flowering time through the alteration of planting date can be used. For the effective management of R. pedestris in the near future, development of cultural practices that can support natural control factors and the use of multiple control tactics are needed.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.51-62
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• 2022

Numerous insect pests threaten the Korean orchard industry through feeding on various tissues of fruit trees. Generally, the control of economically important orchard pests is based on the use of chemical insecticides. Owing to growing concerns regarding the environmental and human health effects of insecticides, environment-friendly pest control strategies are urgently needed. Pheromones of orchard pests could lead to an environmentally safe control system based on mating disruption or mass trapping. This review summarizes the functions and compounds of known pheromones from 51 orchard pests in Korea. The pheromones identified to date from 14 species in the families Miridae, Aphididae, Diaspididae, Pseudococcidae, Rutelidae, Cecidomyiidae, and Eurytomidae and 26 species in the order Lepidoptera are female-produced sex pheromones that attract only males. In contrast, all known examples for 11 species in the families Alydidae, Pentatomidae, Thripidae and Cerambycidae are male-produced aggregation pheromones that attract both sexes. Research on pheromones in new pests, kairomones in key orchard pests, mating disruption dispensers to generate prolonged release of the pheromones, and trap design and trap location for mass trapping will be required for the expanded use of pheromones and other semiochemicals in orchard pest management in the future.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.357-362
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• 2010

Soybean seed injury was analyzed in the experiments in which the bean bug, Riptortus pedestris(Hemiptera: Alydidae), was released into screen-caged pots containing full seed stage(R6) of soybean. When the different stages of insects, from the 3rd instar nymphs to adults, were released into pots during 8 days in soybean R6 stage, soybean seeds with injury marks (B-type seeds) increased. The weight reduction ratio in B-type seeds was highest in the injury by the 5th instar nymphs, while the daily-produced number ratio of B-type seeds was small in the treatment. In the injury by the different number of adult released into pots, 4, 8, 16 adults caused a significant increase of B-type seeds, while 16 adults caused the significant increase of the deformed (C-type) seeds. In the injury by the different release period of adults, the total number of pods was not significantly different among treatments, while the total seed number harvested was significantly small in the release for 48 days. The release for 8 and 16 days caused a significant increase of B-type seeds, while the release for 48 days caused the increase of C-type seeds. The results indicated that injury of soybean R6 stage by the bean bug produced soybean seeds with distinct injury marks at relatively low density and during short term attack period, while it produced deformed seeds at high density and during long attack period.