살충제 저항성 목화진딧물 집단(완주, 춘천, 고성)에 대한 3종(afidopyropen, chlorfenapyr, cyantraniliprole) 약제별 감수성과 혼용에 따른 방제 효과를 평가하였다. 3개 야외집단에 대해서 3약제 모두100배 이상의 저항성비를 보였다. 혼합제의 협력작용을 평가하기 위해 반수치사농도(LC50) 을 이용한 조합지수(CI), %M(synergism), 연합독성계수(CTC), 와들리 비율(WR), 상승비율(SR)와 사충률을 이용한 아보트 비율(AR)로 비교하였 다. Afidopyropen + chlorfenapyr은 모든 야외집단에 대해서 살충활성의 증가를 보였고, chlorfenapyr + cyantraniliprole, afidopyropen + cayntraniliprole은 완주, 춘천 집단에 대해서 살충활성의 증가를 보였다. 그러나 chlorfenapyr + cyantraniliprole (CI, 1.63; %M(synergism), 30; CTC, 64.0; WR, 0.6, AR, 0.54)과 afidopyropen + cyantraniliprole (CI, 6.7; %M(synergism), 1; CTC, 19.8; WR, 0.2, AR ≤ 0.55)은 고성 집단에 서 길항작용을 나타내었다. 포장조건에서도 afidopyropen + chlorfenapyr, chlorfenapyr + cyantraniliprole, afidopyropen + cyantraniliprole 은 99% 이상의 높은 방제가를 보여 향후 살충제 저항성 목화진딧물 방제용 혼합제 개발에 유용하게 활용될 것이다.
This study compared the development, reproduction, and DNA damage in insecticide (acequinocyl, bifenazate, and etoxazole)-resistant (AR, BR, and ER) and -susceptible (S) strains of Tetranychus urticae by electron beam irradiation. When eggs were irradiated with 150 Gy, the egg hatching was completely inhibited in all strains. When nymphs were irradiated, their emergence rate was decreased with increasing doses of electron beam irradiation. When adults were irradiated, the longevity and the number of eggs was not affected at all target dose in all strains. However, hatchability of F1 generation was perfectly inhibited at 400 Gy in all strains. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. These results suggest that electron beam irradiation induced abnormal development and reproduction in S, AR, BR, and ER strains of T. urticae.
The green peach aphid, Myzus persicae (Sulzer), is one of the most serious pests in cabbage cultivation. Field survey was carried out to know the insecticide resistance levels and to develop the applicable insecticide resistant markers in five main cabbage cultivation regions (Pyeong-chang, Hong-cheon, Bong-wha, Mu-ju and Je-ju) during 2009 to 2011. M. persicae can resist a wide range of insecticides in five surveyed local populations. Therefore multi resistant (MR) strain was selected from these five local populations and esterase over-expression, modified AChE (MACE) and mutation(s) in para-type sodium channel were analyzed using native IEF and quantitative sequencing with five local populations. Esterase over-expression and MACE (StoF mutation) were observed in all populations including MR strain. LtoF mutation is well known as a kdr mutation in para-type sodium channel. However, even though LC50 values of MR strain noted over 2,000 times higher than that of susceptible strain against bifenthrin, LtoF mutation was not detected in para type sodium channel and also local populations. We found another mutation (MtoL) in para and that mutation highly correlated between mutation ratio and bioassay data. For preliminary resistance monitoring, we developed quantitative sequencing (QS) to detect the frequencies of point mutation as a population genotyping. These methods can apply to manage M. persicae resistant populations in field.
The toxicity of imperatorin (1) and osthol (2) identified in Cnidium monnieri seed and four structurally related compounds to third instar larvae of insecticidesusceptible (KS-CP strain) and field-collected (DJ-CP colony) of Culex pipiens pallens was examined. Results were compared with those of to conventional mosquito larvicide, fenitrothion and temephos. Based on 24-h LC50 values, imperatorin was 1.9, 3.7, 4.2, 12.4, and 15.1 times more toxic than isopimpinellin, isoimperatorin, osthole, xanthotoxin, and bergapten against KS-CP larvae, respectively. Overall, these compounds were less toxic than either fenitrothion or temephos. However, these compounds did not differ in toxicity against larvae from the two Culex strains, even though the DJ-CP larvae exhibited high levels of resistance α-cypermethrin, deltamethrin, chlorpyrifos, fenthion, and chlorfenapyr (resistance ratio, 94-1179). This finding indicates that the isolated compounds and the pyrethroid, organophosphorus, and pyrrole insecticides do not share a common mode of action or elicit cross-resistance.
The toxicity of Cyperus rotundus rhizome steam distillate constituents and their related compounds to adult females and males of the susceptible KS-BG strain and field-collected SR-BG and DR-BG colonies of Blattella germanica (L.) was examined using residual contact + fumigant and vapor-phase mortality bioassays. Results were compared with those of three organophosphorus (chlorpyrifos, dichlorvos, and fenitrothion), three carbamate (bendiocarb, dioxacarb, and propoxur), and three pyrethroid insecticides (bifenthrin, cypermethrin, and deltamethrin). In contact + fumigant mortality bioassay, p-cymene (LC50, 0.33 mg/cm2) was the most toxic terpenoid, followed by o-cymene, m-cymene, β-pinene, 1,8-cineole, and α-pinene, (LC50, 0.44–0.92 mg/cm2) against female B. germanica. These terpenoids were less toxic than the insecticides tested. Females were 3.1–3.6 times more tolerant than males to three cymene compounds. The toxicity of these monoterpenoids were almost identical against females from either of the three strains, even though the SR-BG and DR-BG females exhibited resistance to bifenthrin [resistance ratio (RR), 96 and 17], cypermethrin (RR, 67), deltamethrin (97 and 66), dioxacarb (19 and 22), and propoxur (24 and 32). In vapor-phase mortality bioassay, these monoterpenoids were effective in closed but not in open containers, indicating that the effect of these compounds was largely a result of vapor action. C. rotundus rhizome steam distillate and its constituents merit further study as potential insecticides for the control of insecticide-resistant B. germanica populations as fumigants with contact action.
Fenvalerate, cypermethrin, furathiocarb 및 prothiofos에 대해 각각 581, 18, 19, 11배의 저항성을 보인 진주계통과 fenvalerate와 furathiocarb에 대해 각각 38배와 9배의 저항성을 나타내고 있는 함양.서상계동을 bifenthrin과 prothiofos의 혼합조합으로 방제하기 위해 실내 엽침지법과 포장방제시험을 수행하였다. Bifenthrin 1EC와 prothiofos 50EC을 1:50으로 혼합하여 실내엽침지법으로 처리하였을 때 공력계수가 273.2로 최고점에 도달한 후 급격히 감소하는 양상을 보였다. 침지법에서 가장 효과적이었던 혼용비율의 조합을 함양.서상현지 농가에서 실증시험을 수행한 결과, 처리구에서 처리약량을 절반으로 줄였음에도 배추좀나방의 방제효과가 농가관행구와 마찬가지로 우수하였다. 또한 이 조합은 여러가지 대표적인 살충제에 대해 높은 저항성을 나타내고 있는 진주지역계통에 대해서도 합리적인 농약혼합으로 저항성문제에 적절히 대처할 수 있음을 보여주었다.
바퀴(Blattella germanica L.)를 chlorpyrifos와 permthrin 살충제로 누대도태하여 얻어진 저항성 바퀴를 대상으로 저항성 유발 및 교차저항성에 대해서 조사한 결과는 다음과 같다. chlorpyrifos와 permethrin으로 6세대 도태 한 결과 감수성 계통 보다 도태계통의 반수치사농도가 각각 3.23배, 2.10배 증가하였다. chlorpyrifos도태계통에 있어서 propoxur, fenvalerate 및 permethrin의 반수치사농도가 각각 2.97배, 3.89배 및 1.31배로써 fenvalerate 와 proposur가 permethrin보다 비교적 높은 교차저항성을 보였으며, permethrin 도태계통에 있어서 chorpyrifos, propoxur 및 fenvalerate의 반수치사농도가 각각 1.42배, 1.08배 및 5.23배로써 fenvalerate가 다른 살충제에 비하여 비교적 높은 교차저항성을 보였다.