The cotton aphid, Aphis gossypii (Glover) (Hemiptera:Aphididae), is a highly polyphagous pest that directly or indirectly damages cultivated plants. Six field-collected populations of cotton aphid, A. gossypii (BY-A, BY-B, YJ-A, YJ-B, CJ-A, and CJ-B) were tested for susceptibility to 14 different insecticides. Most population exhibited high to very high levels of resistance to neonicotinoid. Among them, a strain showing resistance to imidacloprid were selected and showed 1,543-fold in resistance as compared with susceptible strain. Piperonyl butoxide (PBO), diethyl maleate (DEM), and S,S,S tributyl-phosphorothiolate (DEF) failed to synergize imidacloprid in this resistant population. In addition, the activity of detoxification enzymes (P450, EST, GST) were no differences between susceptibility and imidalcoprid resistance strain. However, by analyzing the nicotinic acetylcholine receptor β1 subunit loop D, R81T point mutation was detected in BY-A, BY-B, YJ-A, and YJ-B strain.
Insecticidal susceptibilities of 16 registered insecticides on each developmental stages of Phthorimaea operculella were investigated and further examined the contact, oral and residual toxicities after chosen from insecticides showing good effect. Mortality, longevity and effect on reproduction of 16 insecticides to P. operculella adults were also investigated. To the eggs and pupae, only spinosad showed 71.1% inhibition rate of egg hatch and 66.7% inhibition rate of emergence. To the 3rd nymphs, fenitrothion (LC50 336.6 ppm), esfenvalerate (LC50 8.6 ppm), ethofenprox (LC50 35.7 ppm), and emamectin benzoate (LC50 0.05 ppm) showed oral toxicity over 90% and esfenvalerate (LC50 0.87 ppm), ethofenprox (LC50 16.5 ppm), emamectin benzoate (LC50 0.53 ppm), and spinosad (LC50 2.48 ppm) showed the contact toxicity over 90%. To the adults, mortalities of insecticides were showed as below: deltamethrin and spinosad showed perfect mortality 48 h after treatment; esfenvalerate, ethofenprox, and thiamethoxam showed 40 - 60% mortalities; but the others are not showed any effect. Fecundities of female adults were inhibited by esfenvalerate, emamectin benzoate, and dinotefuran, compare to that of the control, but there were no statistical differences to that of ethofenprox, benfuracarb, thiamethoxam, clothianidin, and diflubenzuron. Adult longevity was showed no difference compare to that of the control. Residual effect of emamectin benzoate showed perfect insecticidal activity at 14 days after treatment and the next ethofenprox showed over 90% at 7 days after treatment.
From April 2010 to the present, seasonal occurrence of Riptortus pedestris was investigated. Five locations for population density and migration route tracking were the same as last year (two sites of Mt. Yangseong, Jujung-dong, O-Chang, and the campus of Chungbuk National University(CBNU)). In Mt. Yangseong, separated the farmland (80m) and forest (200 and 300m) by altitude, population density in 2010 was showed high density at mid-June, mid-Aug., and late-Oct., but population density in 2011 was showed high density at late-April, late-July and mid-Aug. In O-Chang and Jujung-dong, population density in 2010 was captured the adult from June to Aug. in the farmland, and from Sept. to Nov. in the forest. Total captured number of R. pedestris were high in farmland than forest. In campus of CBNU, the adult was captured from mid-Jul. to late-Aug. It showed the difference in the population density by its environmental conditions. Attraction effect of pheromone lure trap with soybeans were good than that of pheromone lure trap only. To track the migration of R. pedestris, we painted the fluorescent paint with different color. Being painted 500 R. pedestris were released and recaptured 10 and 20 days after release. Among released 500 R. pedestris at asl 300m on Yangseong site A and B in 25 Apr. were recaptured one at 300 and 80 m at site A, and site B was recaptured one marked R. pedestris adult at 200 m. In 25 May, release at 200 m in site A was recaptured only 80 m with 2 and site B was recaptured 200m with 8 and 80m with 1. Released in 17 Jul. at 80 m, marked R. pedestris adults were recaptured only 80 m with 5 and 2, respectively. It means that R. pedestris adults seem to migrate from the forest to the farmland in this season, but the data from Aug. to Oct. in 2010 was different.
원자력 발전소에서 발생하는 고체 방사성 폐기물인 이온교환수지, 제올라이트, 활성탄 및 슬러지 에 포함된 성분 원소 분석을 위한 산분해 조건을 확립하였다. 방사성 폐기물의 분해 에는 흔합산을 이용한 밀폐형 극초단파 산분해법을 사용하였으며, 제안한 방법에 따른 산분해 후의 용액은 맑고 색이 없는 투명한 상태임을 확인할 수 있었다. 또한, 산분해 과정을 거친 각각의 용액 시료는 ICP-AES와 AAS를 사용하여 분석하였고, 모의 방사성 폐기물에 첨가한 5종의 금속 원소들은 이상의 높은 회수율을 보여주었다. 화학적 특성을 고려하여 제안된 산분해 조건에 의해 용액화된 중저준위 방사성 폐기물의 성분 원소 분석은 최적의 유리화 기술 개발을 위한 기초 자료로 유용하게 사용될 수 있을 것으로 판단된다.