Soon-Sung Hong

Occurrence of Sweet-potato Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) and Its Response to Insecticide in Gyeonggi Area

This study investigated the occurrence of sweet potato whitefly, Bemisia tabaci affecting cucumber, eggplant and red pepper, as well as sweet potato species, and its response to insecticides in Gyeonggi province from 2010 to 2011. Sweet potato whitefly is widespread throughout the southern part of Gyeonggi province. Most regional populations of B. tabaci belong to biotype Q having been reported in the south Korea since 2005, but in Goyang mixed populations of two biotypes (B and Q) were found. Survey results of Tomato Yellow Leaf Curl Virus (TYLCV) disease that was vectored by B. tabaci indicated that this virus disease was not spread throughout the Gyeonggi province. Biotype Q of B. tabaci was found to be resistant to neonicotinoid insecticides, whereas biotype B was highly susceptible to them.

Comparative exposure of operators to fenthion during treatment in paddy field

Operator exposure was evaluated to find out any possible risk during fenthion application in paddy. Hand exposure during mixing/loading was 0.04–33.06 mg, whereas those for spraying were 20.3–288.3 mg. Highest exposure was observed on legs (54%) followed by hand (28%). Inhalation exposure accounted for only 0.001–0.2% of dermal exposure. High variations of exposure levels were observed between repetitions and operators, indicating that lager number of repetitions are strictly required to establish comprehensive exposure database and predicting models. Margin of safety indicated that application works were safe when extreme cases were not considered.