Tin dioxide nanoparticles are prepared using a newly developed synthesis method of plasma-assisted electrolysis. A high voltage is applied to the tin metal plate to apply a high pressure and temperature to the synthesized oxide layer on the metal surface, producing nanoparticles in a low concentration of sulfuric acid. The particle size, morphology, and size distribution is controlled by the concentration of electrolytes and frequency of the power supply. The as-prepared powder of tin dioxide nanoparticles is used to fabricate a gas sensor to investigate the potential application. The particle-based gas sensor exhibits a short response and recovery time. There is sensitivity to the reduction gas for the gas flowing at rates of 50, 250, and 500 ppm of H2S gas.

Amblyseius eharai is a native predatory mite in Korea and a candidate of biological control agent to control spidermites. To evaluate the predation ability of A. eharai, its functional response was tested at 10, 30, 50, 70 and 130 larvaeof Tetranychus urticae. A. eharai showed the Type 2 functional response. The attack rate of female and male A. eharaiwas 0.109 and 0.019, respectively. The handling time of female and male was 0.164 h and 0.234 h, respectively. Theattack rate was significantly different between male and females at 95% confidence interval. However, handling time wasnot statistically different. In comparison with Neoseiulus californicus, attack rate and handling time of A. eharai werebetter than N. californicus. These result should be helpful for evaluation of A. eharai for a biological agent against T.urticae.

The confused taxonomy of the east Palaearctic pear psyllids, serious pests on cultivated pear, is reviewed. Fifty-sixnominal species have been reported from Pyrus, 25 of which we consider valid and ten as not being associated withPyrus. Our taxonomic revision suggests that, in Korea, four Cacopsylla species develop on pear. Three species occuralso in Japan. New synonyms are suggested and seasonal dimorphism are critically discussed.Key words : Psyllidae, Cacopsylla, taxonomy, host plant, Pyrus, Rosaceae, Manchrian pear, Asian pear, European pear, China,Japan, South Korea, Russian Far East

The diamondback moth, Plutella xylostella is one of the world’s major pests. Economic cost to control this pest wasestimated between US$1.3 billion and US$2.3 billion based on management costs. Conservative estimate included yieldloss caused by 5% diamondback moth was estimated US$4 billion-US$5 billion. P. xylostella was managed by chemicalinsecticide such as organophosphates, carbamates and pyrethroids. But insecticide resistance which is caused by repeatedapplication makes it difficult to control this pest. For environmental friendly control of diamondback moth, entomopathogenicfungi could be used as alternative. We conducted bioassay to select high virulent isolate to larva of diamondback mothwith forty six entomopathogenic fungi which were isolated from soil samples by insect-bait method. As a result of bioassaytwelve isolates was selected as candidate. We investigated control efficacy of these twelve isolates with potted Chinesecabbage at laboratory and greenhouse.

The migratory locust, Locusta migratoria, is one of the famous insect pests in the world. Although the species revealsseveral morphological variations, it is largely divided into two lineages, Southern (Africa, Southern Europe, Southern Asia,and Australian) and Northern (East Asia, Eurasian continent). In 2014, a large number of L. migratoria nymphs withred-brown color were suddenly occurred in the southern region (Haenam-gun, Jeollanam-do) of Korea. In this study, mitochondrialCOI sequences were analyzed to recognize the genetic identity of L. migratoria with nymph or adult samples collectedfrom 15 localities in Korea. The analysis results reveal that most of all samples are belonging to the Nothern lineage,and the Southern lineage was discovered only in Iksan and Chunju of Korea.

The spotted wing drosophila (SWD), Drosophila suzukii, is classified exotic quarantine pest in Australia and EU, soSWD-free must be supported by evidence of surveys and phytosanitary measures in exported host agricultural commoditiesin Korea. From a quarantine control point of view, SWD is importantly considered as model insect pest for exotic fruitflies (Bactrocera dorsalis) in Korea as well because of similarity in ecological cycles. In evaluations of ethyl formate(EF) only and combined cold treatment to kill eggs and larvae of SWD, the combined EF fumigation applied at LCt50%(50% killed lethal concentration X time) and cold treatement (5℃) for > 5 days showed the promise to new conceptfor eradicating quarantine pest and these could be helpful to pre-develop exotic fruit fly management in Korea.

Among two different acetylcholinesterase (AmAChE1 and AmAChE2) of the western honey bee, the soluble AmAChE1might be related with a stress response as judged from its over-expression in honey bee workers when brood rearingwas suppressed. In this study, to ensure the nature of AmAChE1 responding to stress factors, the expression patternsof AmAChE1 were investigated following various treatments, including varroa mite infestation, bacterial challenge, broodrearing suppression, thermal stresses, chemical treatments, ultraviolet B irradiation, starvation, water restriction and crowdingstress. In addition, transcription profiles of four heat shock protein genes known as general stress markers and vitellogeningene, which is induced in several stress conditions, were tested as positive references. In every tested condition, onlybrood rearing suppression and heat shock were related with the expression of AmAChE1.