Nysius is one of the most common and widely distributed species in the world. It is one of the emerging pests of perilla crop in the field in Korea. In this study, we investigated the oviposition preference and development of Nysius plebeius and N. hidakai. on five crops seed (Perilla, Sesame, Proso-millet, Sorghum, and Fox-tail millet) using both multiple choice and no-choice tests. Both results found perilla seeds to be the most suitable seeds for oviposition and development. Total developmental period was shortest on perilla seed, and the longest was on rest of crops seeds. The highest of adult emergence, longevity, and adult weight were occurred on the perilla seed. This results suggest that the higher preference and performance of Nysius spp on the perilla seed. The information may facilitate the exploration of resistant genetic materials chemical associated with seeds for successful breeding program in Korea.
Nysius Dallas, 1852, is one of the most common and widely distributed genera under the superfamily Lygaeoidae. Species under this genus are hard to identify due to similarity of the species and variability of the coloration. The Nysius species were collected with the help of aspirator and plastic vile in the perilla crop fields in RDA, Miryang, Korea. Korean species of the Nysius were identified, and three species including a newly reported species N. inconspicuus were recognized. Morphological and genetic characteristics of species were illustrated, and a key to species of Korean Nysius was provided. The DNA barcoding information of N. plebeius and N. inconspicuus were recorded.
Callosobruchus chinensis (Coleoptera: Bruchidae) is a cosmopolitan pest of stored grain legumes. This study assessed the effects of short-term exposure to low-temperatures (4, 0, and -4℃) and seven durations of storage (1, 5, 10, 15, 20, 25, and 30 days) on the survival, development, and adult performance of C. chinensis in laboratory. The effects were studied on three life stages (egg, larva [2-3 instar], and pupa) of C. chinensis. The results showed that low-temperature have significant effects on the life variables of C. chinensis. Among the stages, egg and pupa stages were most sensitive to low-temperature. The very low survival rates of eggs and no pupa survived at –4℃ after 10 days storage. Cold exposure at -4℃ not only increased egg and pupa mortality, but the negative effects also transmitted to the larvae and pupa developed from these eggs. Increasing the duration of cold exposure further reduced survival rates. Low-temperature treatments have also affected on the adult performances such as adult weight. However, there were not any negative effects of low-temperatures on the seed germination. The life variables of C. chinensis are discussed in terms of targeting particular susceptibilities to low-temperatures in different storage duration as an alternative to chemical treatments.