• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1150-1157
• /
• 2011

Streptomyces sampsonii KK1024 having strong chitinolytic activity was isolated from crab-shell rich soil at Muan, Jeolanamdo. The KK1024 produced chitinase, protease, gelatinase and lipase. When 50% of KK1024 culture broth was treated to juveniles and eggs of root-knot nematode, juvenile mortality at 3 days was 81.67% and egg hatch rate at 5 days was 2.00%. When $183.7{\mu}g\;mL^{-1}$ of crude enzyme produced by KK1024 was treated, juvenile mortality at 3 days was 96.00% and egg hatch rate at 5 days was 5.33%. At 1% of butanol extract from KK1024, juvenile mortality was highest with 90.00% and egg hatch rate was lowest with 0%. The comparison of the effect of KK1024 culture broth with only medium, synthetic fertilizer, and commercial nematicide on tomato growth and nematode infection was examined in pot trials. KK1024 culture broth showed lower number of egg mass and gall in plant, and population of juveniles in soil compared with only medium and synthetic fertilizer treatment, but not in commercial nematicide. However, the highest shoot weight and length was discovered in KK1024 culture broth. These results suggest that Streptomyces sampsonii KK1024 producing lytic enzymes and nematicidal compounds can be one of candidates for biocontrol agents against root-knot nematodes.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.2
• /
• pp.194-215
• /
• 2021

Termites are important decomposers in the ecosystem. They are also economically significant structural pests. In this study, we reviewed the developments of termite control and recent research on termite management to provide information on the prevention and control of termites. In Korea, most of the damage to wooden historical buildings is caused by subterranean termites. Reticulitermes speratus kyushuensis is the main species, which is widely found throughout the country. In the early 1900s, inorganic insecticides, such as arsenic dust, were used for termite control. After the synthesis of chlorinated hydrocarbon pesticide in the 1940s, it was widely utilized and demonstrated high termite control efficacy. However, chlorinated hydrocarbon insecticides were later banned, disappearing from markets after reports emerged concerning environmental contamination and toxicity to humans. Therefore, the termite control industry sought a new termiticide; hence many pesticides were utilized for termite control. Organophosphate (1960s), carbamate (1970s), pyrethroid, and insect growth inhibitor (1980s) were newly synthesized and adopted. In the 1990s, the first commercial baits using chitin synthesis inhibitors (CSI) were developed, providing a means to eliminate an entire colony of subterranean termites around a structure. Many studies have been carried out on soil termiticides (liquid termiticides) and CSI baits to increase their efficacy, and different baits such as aboveground bait stations, fluid bait, and high-durability bait were also developed in the 2000s. In addition, the paradigm of termite control has shifted from localized treatments using soil termiticides to area-wide pest management using CSI baits to create termite-free zones and protect buildings over time. Termite infestations in wooden historical buildings in Korea have been reported since 1980, and considerable attention was drawn in the 1990s when several UNESCO world heritages such as the Jongmyo Shrine and the Janggyeong Panjeon Depositories of Haeinsa Temple were infested by subterranean termites. Since then, a survey of termite infestation in wooden architectural heritage has been conducted, and the National Research Institute of Cultural Heritage and Heritage Care Program regularly monitors those properties. Finally, we suggest termite management using primarily CSI baits, selective application of various soil treatments applied to the object, foundation soil treatment, research and development of durable termite baits, application of area-wide programs for wooden-building complexes, application of integrated termite management (ITM), and regular education for owners and managers to prevent and reduce termite damage.