Publications by authors named "Chae-Hoon Paik"

Fab. is a polyphagous pest causing damage to many agriculture crops leading to yield loss. Recurrent usage of synthetic pesticides to control this pest has resulted in resistance development.

View Article and Find Full Text PDF

Botanical insecticides may provide alternatives to synthetic insecticides for controlling Spodoptera litura (F.) and they are target specific, biodegradable, and harmless to mammals. Eight natural chemical compounds with larvicidal activity were identified from fraction F6 of C.

View Article and Find Full Text PDF

The sex pheromone system of Scrobipalpa salinella (Zeller), an important pest of the halophyte Salicornia europaea in the tidal salt marshes, was studied. Z3-12:OAc and Z5-12:OAc were identified from both female pheromone glands and female emissions, but in quite different ratios. Field trapping tests demonstrated that Z3-12:OAc and Z5-12:OAc are essential for optimal attraction of male moths, and a 100:5 blend found in gland extracts is significantly more attractive to males than a 100:50 ratio similar to that found in SPME samples.

View Article and Find Full Text PDF

The effects of two different neem products (Parker Oil and Neema) on mortality, food consumption and survival of the brown planthopper, Nilaparvata lugens Stål (BPH) (Homoptera: Delphacidae) were investigated. The LC(50) (3.45 ml/L for nymph and 4.

View Article and Find Full Text PDF

Efficacy of Goniothalamin a styryl-pyrone isolated from Goniothalamus wightii Hook.f. and Thoms, against beet armyworm, Spodoptera exigua (Hübner), populations was determined under laboratory condition.

View Article and Find Full Text PDF

Treatment of Dysoxylum pure triterpenes 3beta,24,25-trihydroxycycloartane and beddomei lactone to the rice leaffolder (RLF), Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), resulted in prolonged larval duration and reduced larval weight. In leaf cut choice assay and topical application experiments, beddomei lactone and 3beta,24,25-trihydroxycycloartaneto showed strong antifeedant and growth inhibitor activity against fourth instar larvae of C. medinalis.

View Article and Find Full Text PDF

The effect of azadirachtin (AZA), a tetranortriterpene from neem, on the mortality, acetylcholinesterase (AChE) activity, and the development of the ovaries of female brown planthopper (BPH), Nilaparvata lugens (Stål) was tested in laboratory experiments. The lethal concentrations were determined and applied topically to the adult female BPH (LC(50)=0.47 ppm and LC(90)=0.

View Article and Find Full Text PDF

Extracts of neem (Azadirachta indica A. Juss) are used in the developing world for many purposes including management of agricultural insect pests. The effects of different neem extracts (aqueous (NSKEaq), ethanol (NSKEeth) and hexane (NSKEhex)) on mortality, survival and weight of the brown planthopper, Nilaparvata lugens (Stål) (BPH) (Homoptera: Delphacidae) third and fourth nymphal instars were investigated.

View Article and Find Full Text PDF