A rod-shaped, Gram-negative chlorpyrifos-methyl (CM) degrading bacterium (designated strain KR200) was isolated from a Korean rice paddy soil and was further tested for its substrate specificity against 11 insecticides and its sensitivity against eight commercial antibiotics. Based on morphological, biochemical, and molecular characteristics, this bacterium showed greatest similarity to members of the order Flavobacteriales and was shown to be most closely related to members of the Chryseobacterium proteolyticum group. Strain KR200 hydrolyzed CM to 3,5,6-trichloro-2-pyridinol (TCP) but could not degrade TCP further. The isolate was also able to degrade chlorpyrifos, dicrotophpos, monocrotophos, and carbaryl at 300 μg mL–1 but diazinon, dimethoate, and furathiocarb at 100μg mL–1. The ability to degrade CM was found to be encoded on the chromosome. Genes encoding resistance to amphotericin B, polymixin B sulfate, and tetracycline were also located on the chromosome. This bacterium merits further study as a potential biological agent for the remediation of soil, water, or crop contaminated with organophosphorus (OP) compounds because of its greater biodegradation activity and its broad specificity against a range of OP insecticides.

A novel recombinant baculovirus, NeuroBactrus, was constructed to develop an improved baculovirus insecticide with additional beneficial properties, such as a higher insecticidal activity and improved recovery, compared to wild-type baculovirus. For the construction of the NeuroBactrus, the Bacillus thuringiensis cry1-5 crystal protein gene was introduced into the Autographa californica nucleopolyhedrovirus(AcMNPV) genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of the polyhedrin promoter. In the opposite direction, an insect-specific neurotoxin gene, AaIT, from Androctonus australis was introduced under the control of an early promoter from Cotesia plutellae bracovirus by fusion of a partial fragment of orf603. The Polyhedrin-Cry1-5-Polyhedrin fusion protein expressed by the NeuroBactrus was not only occluded into the polyhedra, but it was also activated by treatment with trypsin, resulting in an approximately 65-kDa active toxin. In addition, qPCR revealed that the neurotoxin was expressed from the early phase of infection. The NeuroBactrus showed a high level of insecticidal activity against Plutella xylostella larvae and a significant reduction in the median lethal time(LT50) against Spodoptera exigua larvae compared to those of wild-type AcMNPV. Re-recombinant mutants derived from NeuroBactrus in which AaIT and/or cry1-5 were deleted were generated by serial passages in vitro. Expression of the foreign proteins(Bt toxin and AaIT) was continuously reduced during the serial passage of the NeuroBactrus. Moreover, polyhedra collected from S. exigua larvae infected with the serially passed NeuroBactrus showed insecticidal activity similar to that of wild-type AcMNPV. These results suggested that the NeuroBactrus could be recovered to wild-type AcMNPV through serial passaging.

Potassium hydroxide-activated carbons (CK21, CK11, and CK12) were prepared from pis-tachio nutshells. Physicochemical properties of activated carbons were characterized by TGA, pHpzc, Fourier transform infrared spectroscopy, scanning electron microscopy, and N2-adsorption at -196°C. The examinations showed that activated carbons have high sur-face area ranging between 695-1218 m2/g, total pore volume ranging between 0.527-0.772 mL/g, and a pore radius around 1.4 nm. The presence of acidic and basic surface C-O groups was confirmed.Batch adsorption experiments were carried out to study the effects of adsorbent dosage, temperature, initial concentration of adsorbate, and contact time on deltamethrin adsorption by activated carbons. The kinetic studies showed that the adsorp-tion data followed a pseudo-second order kinetic model. The Langmuir model showed a maximum adsorption capacity of 162.6 mg/g at 35°C on CK12. Thermodynamic studies indicated that adsorption was spontaneous and increased with temperature, suggesting an endothermic process.

Vector mosquitoes are related with various diseases on human, such as malaria (Anopheles sinensis (L.), An. sinensis), Japanese encephalitis (Culex tritaeniorhynchus (L.), Cx. tritaeniorhynchus), yellow fever (Aedes albopictus (L.)), dengue hemorrhagic fever (Ae. albopictus) and filariasis (Ae. albopictus), as well as nuisance insect pests (Culex pipiens pallens Foskal, Cx. p. pallens). Continued and repeated use of conventional insecticides such as organophosphorus and carbamates, pyrethroids has often resulted in the widespread development of resistance and has undesirable effects on non-target organisms and environment. Particularly, widespread insecticide resistance has been a major obstacle in the cost-effective integrated vector management program. In theRepublic of Korea (ROK), studies on mass vector mosquito control using insecticides were mainly carried out until 1970’s such as a fuselage-mounted ULV spray system to C-46 aircraft, effectiveness of ground aerosols ULV premiumsumihtion, a helicopter application of ULV Dibrom and residual toxicity of organophosphates in animal shelters for Japanese Encephalitis (JE) and Plasmodium vivax malaria vector mosquito control. Regional insecticide resistance of vector mosquitoes has been annually evaluated since ,early 1980’s, the first detailed study on susceptibility of seven mosquito species to 13 organophosphorus insecticides revealed the DDT and lindane resistance of Cx. tritaeniorhyunchus. Marked annual and regional variations of insecticide resistance have been observed. In comparative resistance, the resistance ratios of various insecticides were compared among each other using two strains of vector mosquitoes that were collected from same locality. An. sinensis from Koyang-si in 1992 and 1981 demonstrated >100 folds and >3000 folds of higher resistance to DDT and to bio-resmethrin. An. sinensis from Paju-si in 2008 demonstrated 30 folds of higher susceptibility to fenthion than those collected in seven years ago. Cx. tritaeniorhynchus from Gwanju in 2010 and in 1992 showed >100 folds of higher resistance to pyrethroids. In comparative regional resistance monitoring, Cx. p. pallens from six localities in the ROK in 2008 and six geospatially-distant field Cx. tritaeniorhynchus strains in 2011 showed marked regional resistance variations. Field populations of Cx. tritaeniorhynchus from agricultural areas demonstrated extremely higher insecticide resistance to pyrethroids than those from non-agricultural areas. Cx. tritaeniorhynchus populations from rice paddies had been under heavy selection pressure due to pyrethroids, which were used for a long time to control agricultural pests in the localities. These results indicate that careful selection and rotational use of these insecticides may results in continued satisfactory control against field populations of vector mosquitoes

A phase variation has been reported in an entomopathogenic bacterium, Xenorhabdus nematophila. Compared to a wild type primary form, a secondary form usually lose several physiological and biochemical characters. This study showed that the phase variation of X. nematophila caused a significant alteration in its immunosuppressive activity and subsequent entomopathogenicity. A secondary form of X. nematophila was detected in laboratory colonies and exhibited significant differences in dye absorption and entomopathogenicity. In addition, the secondary form was different in production of eicosanoid-biosynthesis inhibitors (EBIs) compared to the primary form of X. nematophila. Production of oxindole and p-hydroxypropionic acid was significantly reduced in the culture broth of the secondary form of X. nematophila. The reduced EBI production resulted in significant suppression in the inhibitory effects on a cellular nodule formation and phenoloxidase activity. Culture broth of the primary form of X. nematophila significantly more enhanced the pathogenicity of Bacillus thuringiensis (Bt) than the culture broth of the secondary form. Furthermore, this study developed a high efficient ‘Dual Bt-Plus’ to control both lepidopteran insect pests of Plutella xylostella and Spodoptera exigua by mixing two effective Bt strains along with the addition of potent bacterial metabolites or 100-fold concentrated X. nematophila culture broth.

곤충병원세균(Bacillus thuringiensis: 비티)의 살충효과를 증가시킨 미생물살충제 “비티플러스”가 개발되었다. 그러나 수화제 형태의 비티플러스는 농가나 산업체에서 높은 단가로 선호하지 않고 있는 실정이다. 이에 본 연구는 액상 제형의 비티플러스를 개발하는 연구 목적을 두었다. 이러한 목적에 따라 먼저 비티플러스 제조에 포함되는 두 세균 배양액의 최적 혼합 비율을 결정하였다. 이 최적 혼합액은 10%의 에탄올을 보존제로 사용되었으며, 비티와 또 다른 곤충병원세균인 Xenorhabdus nematophila (Xn)의 배양액 비율이 5:4 (v/v)로 제조하게 했다. 또한 이 액상제형이 1,000 희석배수에서 효과를 보이기 위해 비티 배양액을 10 배 농축하여 최적 비율로 혼합하였다. 이렇게 해서 얻어진 액상 제형을 발육 후기 유충의 배추좀나방(Plutella xylostella)이 가해를 하는 배추밭에 처리하여 7일 후 약 77%의 방제 효과를 보였는데, 이 처리 효과는 현재 상용화되는 배추좀나방 적용 생물농약들과 비등한 효과를 나타내는 것으로 판명되었다. 저온 및 상온의 저장 분석에서 본 액상 제형은 최소한 한 달 동안 안정된 방제효과를 나타내는 것으로 분석되었다. 이 액상 제형의 안정된 방제 효과를 보장하여 주는 품질관리 기술을 개발하기 위해 제형 내비티 포자 밀도와 Xn 유래 유용물질의 농도를 판별하였다. 본 연구 분석은 최적의 방제 효과를 나타내기 위해서는 비티플러스 액상 제형에 비티 포자 밀도가 최소 5 × 1011 spores/mL 이고, Xn 세균 대사물질들 가운데 8 종 유효물질의 농도가 품질관리 판별 기준으로 제시되었다.

The toxicity of red pine needle hydrodistillate, its constituents, and 12 structurally related compounds to third instar larvae of insecticide-susceptible Aedes aegypti and wild Aedes albopictus was examined using a direct-contact bioassay. Results were compared with those of the currently used larvicides fenthion and temephos. The red pine needle hydrodistillate constituents were identified by GC-MS and co-elution of authenticated samples following co-injection. Based on 24 h LC50 values, 3-carene (8.60–9.33 mg/L), limonene (10.34–10.77 mg/L), and thymol (10.65–11.45 mg/L) were the most toxic constituents. The moderate toxicity was produced by (1S)-(–)-α-pinene, p-cymene, geranyl acetate, myrcene, and β -caryophyllene (LC50, 27.62–38.01 and 28.61–39.52 mg/L). Overall, these compounds were less effective than either fenthion (LC50, 0.012–0.022 mg/L) or temephos (LC50, 0.010–0.015 mg/L). In the light of global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment, red pine needle hydrodistillate and the compounds described merit further study as potential larvicides for the control of mosquito populations.

Crystals of proteinaceous insecticidal proteins, Cry proteins, produced by Bacillus thuringiensis (Bt) have been generally used to control insect pests. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. To construct novel cry genes with enhanced insecticidal activity, we randomly mutated these 23 amino acid sequences by in vitro muti site-directed mutagenesis, resulting in totally 24 mutant cry genes. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella and S. exigua were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, among them Mutant-N16 showed the highest insecticidal activity against to both of P. xylostella and S. exigua. Therefore, Mutant-N16 is considered to have the potential for the efficacious biological insecticide.

Insecticide resistance and activation of the metabolic detoxification enzymes of female Culex pipiens pallens by the blood meal were assessed using a micro-application bioassay and micro-plate enzyme activity assays. Four group of Cx. pipiens pallens were used, a susceptible non-engorging group at seven days after emerging, SNE7 Cp; a resistant non-engorging group at seven days after emerging, RNE7 Cp; a resistant engorged group at one day after blood feeding and a resistant engorged group at seven days after blood feeding, REG7 Cp. Insecticide resistance of Cx. pipiens pallans was increased by the blood feeding. Based on LC50 values, SNE7 Cp demonstrated >50 fold of higher susceptibility to all tested insecticides when compared with RNE7 Cp. RNE7 Cp showed higher susceptibility to all tested insecticides than REG1 Cp and REG7 Cp with a relative susceptibility LC50 (SRLC50) of 25.8 to 50.0 and 25.0 to 48.8. In micro-plate enzyme assays, the metabolic detoxification enzyme activity of Cx. pipiens pallans adult females was increased by the blood feeding. Activation of non-specific esterases (EST), glutathione-S-transferase (GST) and mixed function oxidase (MFO) in RNE7 were higher than in SNE7 and the all tested enzymes in REG1 and REG7 demonstrated significantly higher enzyme activation than RNE7, except for activation of GST in REG1. Activation of MFO in REG1 and REG7 were 209.4- and 74.6- fold higher than in REG7, respectively. Non-specific esterases (EST) and glutathione-S-transferase exhibited < 10 fold of higher Rr values. These results may be significant in terms of the criteria that are used to evaluate resistance, because blood fed female mosquitoes may show enhanced expression of the resistance phenotype, possibly allowing for earlier detection of insecticide resistance.

국내 배추좀나방(Plutella xylostella) 집단은 피레스로이드 농약에 대해서 저항성을 보이며, 이는 이 살충제의 작용점인 소듐이온채널 유전자의 돌연변이에 기인된다. 더욱이 배추좀나방은 대부분 상용화된 살충제에 대해서 저항성을 발달시킬 수 있다. 본 연구는 배추좀나방을 효과적으로 방제하기 위해 내부기생성 천적인 프루텔고치벌(Cotesia plutellae)과 미생물농약인 Bacillus thuringiensis의 혼합처리 기술을 개발하기 위해 수행되었다. 프루텔고치벌이 감수성과 저항성 배추좀나방에 대한 기생 선호성에 차등이 있는 지 조사하기 위해 다섯 개 서로 다른 집단에 대해서 살충제 감수성과 프루텔고치벌 기생성 차이를 비교하였다. 이들 배추좀나방 집단들은 피레스로이드, 유기인계, 네오니코틴계 및 곤충성장조절제를 포함하는 세 종류의 상용 살충제에 대한 약제 감수성에서 뚜렷한 차이를 보였다. 그러나 이들 집단들은 프루텔고치벌에 의한 기생률에서는 차이를 보이지 않았다. 더욱이 기생된 배추좀나방은 B. thuringiensis에 대해서 감수성이 증가되었다. 프루텔고치벌이 갖는 면역억제인자 가운데 바이러스 유래 ankyrin 유전자(vankyrin)를 비기생된 배추좀나방에 발현시켰다. Vankyrin의 발현은 배추좀나방 3령충의 B. thuringiensis에 대한 감수성을 현격하게 증가시켰다. 즉, 프루텔고치벌에 의해 야기된 면역저하가 B. thuringiensis의 살충력을 증가시켰다. 이러한 결과들은 프루텔고치벌과 미생물농약인 B. thuringiensis의 혼합처리가 살충제 저항성 배추좀나방을 효과적으로 방제할 수 있다고 제시하고 있다.

경기지역에서 담배가루이의 발생 및 약제반응을 조사하였다. 담배가루이는 13개 시군에서 발생되었으며, 유전자(16S rRNA, MtCOI) 분석결과, 고양시 일부지역은 biotype B와 Q가 혼재되었으나, 그 밖의 지역에서 2005부터 국내 발생이 보고되었던 biotype Q로 나타났다. 채집곤충 및 기주식물의 total DNA에 대해 PCR을 통한 염기서열 분석과 southern hybridization 분석 결과 모든 지역에서 Tomato Yellow Leaf Curl Virus(TYLCV)는 검출되지 않았다. 5개 지역에서 채집한 6 개체군의 담배가루이를 실내사육하면서 유묘검정법으로 성충에 대한 살충제 감수성을 검정한 결과, 지역별로 다소 차이는 있었지만 네오니코티노이드계 약제의 경우 biotype B에게 높은 살충활성을 나타낸 반면 biotype Q에게는 상대적으로 낮은 살충활성을 나타내었다.

To identify whether higher expression of carboxylesterase (CbE) E4 in Myzus persicae is due to gene duplication, gene copy number was determined by quantitative real-time PCR. In addition, to determine the actual protein concentration of CbE E4 and it activity, Western blotting and activity staining were conducted. CbE gene copy number was highly correlated with carbamate resistance ratio (r2=0.934). However, CbE E4 expression level was little correlated with insecticide resistance ratio (r2<0.046) and no apparent correlation was observed among the gene copy number, protein quantity and total activity of CbE E4. Therefore, it was assumed that not only quantitative changing but also qualitative alteration of CbE E4 occurred in M. persicae. To investigate any potential alteration of CbE E4, mutation survey was conducted by sequencing of CbE E4 from various local strains of M. persicae. G137D and W251L mutations have been known as the main mutations associated with structural change leading to resistance. Interestingly, a new G134C mutation, which is in proximity of G137D mutation, was identified in the oxyanion hole of CbE E4. To predict the functional role of this mutation in resistance, 3-dimensional structure modeling was conducted. In summary, CbE E4 appears to be involved in resistance to both pyrethroids and carbamates as a nonspecific hydrolase or sequestration protein in M. persicae.

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.

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.

Secondary air pollution can be caused by aerosol formation through reactions of ozone and volatile organic compounds (VOCs) emitted from household products used in the indoor environment. In this study, we investigated the potential for aerosol production during the reactions of ozone and VOCs emitted from a home insecticide, a popular commercial product extracted from natural ingredients, in a 1-m³ reaction chamber. The major chemical component of the test product was prallethrin, which has very high efficacy of mosquito and housefly elimination. Toluene, α-pinene, cymene, d-limonene, α-terpinene, and α-thujone were also identified as constituents of the insecticide. Injected ozone concentrations of 50, 100, and 200 ppb generated particle mass concentrations, corrected for wall loss and air exchange loss, of 7.3, 33.1, and 40.0 μg/m³, respectively, after a 4-h reaction time. These concentrations are lower than those generated by an air freshener in a previous study under the same experimental conditions. It was concluded that the home insecticide tested had the potential to initiate secondary aerosol formation under ozone exposure due to the biogenic VOCs it contained.

해충저항성 Bacillus thuringiensis (Bt) 벼의 비표적곤충인 벼물바구미(Lissorhoptrus oryzophilus)에 대한 성충 전용살충제 Clothianidin 액상수화제의 살충제 감수성 시험을 실시한 결과, 72시간-LC50은 0.245 ml/L(95% 신뢰한계는 0.195~0.307 ml/L)이었으며, Bt벼의 모본으로 대조로 사용한 낙동벼의 72시간-LC50은 0.257 ml/L(95% 신뢰한계는 0.199~0.331 ml/L)이었다. 72시간-LC50은 낙동벼에서 다소 높았지만, 해충저항성 Bt벼 72시간-LC50이 낙동벼의 95% 신뢰한계 내에 포함되어, 두 품종의 LC50값에 유의성이 없는 것으로 판단된다.

The green peach aphid, Myzus persicae (Sulzer), is one of the most serious pest in cabbage cultivation. Field survey was carried out to know the insecticide resistance levels in five main cabbage cultivation regions (Pyeong-chang, Hong-cheon, Bong-wha, Mu-ju and Je-ju) in 2009~2011. The green peach aphid can resist a wide range of insecticides in five surveyed local populations. Among the nine tested insecticides, four chemicals (methomyl, bifenthrin, pymetrozine and flonicarmid) showed less than 60% mortality in the recommended concentration in most years of local populations. Multi resistant (MR) strain was selected from these populations and modified AChE (MACE: StoF mutation), MtoL mutation in para-type sodium channel, esterase over-expression were observed in almost of all populations including MR strain. Especially, StoF and MtoL mutations were highly correlated with resistance ratio and population based quantitative sequencing results. Therefore, these results suggested that molecular-biology based resistance monitoring can applied resistance management in M. persicae.

Toxicities of 10 insecticides were examined against late third instars of Culex tritaeniorhynchus using the direct-contact mortality bioassay. Six geospatially distant field mosquitoes were collected from Chuncheon-si (designated CC-CT), Hwaseong (HS-CT), Seosan (SS-CT) Jeonju (JJ-CT), Daegu (DG-CT), and Busan (BS-CT) in the Republic of Korea (ROK). Marked regional variations of insecticide susceptibility were observed. Field populations of SS-CT, JJ-CT and DG-CT from agricultural areas showed higher to extremely higher insecticide susceptibility to pyrethroids than those of CC-CT, HS-CT and BS-CT strains from none agricultural areas. Extremely high to low levels of susceptibility were measured: bifenthrin, susceptible ratio (SR) = 2.7–896.3; β-cyfluthrin, SR = 1.8–633.3; α-cypermethrin, SR = 1.2–1,051.9; deltamethrin, SR = 1.3–711.1; permethrin, SR = 1.5–1,053.4 etofenprox, SR = 2.2–29.3; chlorfenapyr, SR = 5.1–103.6; chlorpyrifos, SR = 2.3–337.0; fenitrothion, SR = 2.0–142.3 and fenthion, SR = 1.4–186.2. Culex tritaeniorhynchus populations from rice paddies had been under heavy selection pressure due to the agricultural insecticides and that’s why the mosquito species demonstrated high resistance to pyrethroids which were used for a long time to control agricultural pests in the localities. These results indicate that careful selection and rotational use of these insecticides mayresult in continued satisfactory control against field populations of Japanese encephalitis vector mosquitoes.

The toxicity of materials derived from the seed of Pongamia pinnata to third instars of insecticide-susceptible Culex pipiens pallens and Aedes aegypti and wild Aedes albopictus was examined using a direct contact bioassay. Results were compared with those of the currently used insecticides fenthion and temephos. The active principles of Pongamia pinnata were identified as the karanjin (1), karanjachromene (2), pongamol (3), pongarotene (4), oleic acid (5), and palmitic acid (6) by spectroscopic analysis. Based on 24 h LC50 values, karanjin (14.61 and 16.13 mg/L) was the most toxic compound, followed by oleic acid (18.07 and 18.45 mg/L) and karanjachromene (18.74 and 20.57 mg/L). These constituents were less toxic than either fenthion (LC50, 0.0031 and 0.0048 mg/L) or temephos (0.021 and 0.050 mg/L) against Ae. aegypti and Cx. p. pallens. Low toxicity was produced by pongamol (LC50, 23.95 and 25.76 mg/L), pongarotene (25.52 and 37.61 mg/L), and palmitic acid (34.50 and 42.96 mg/L). Against A. alpopictus instars, oleic acid (LC50, 18.79 mg/L) was most toxic. Low toxicity was observed with the other five constituents (LC50, 35.26- 85.61 mg/L). P. pinnata seed-derived active principles, particularly karanjin, karanjachromene, and oleic acid, merits further study as potential mosquito larvicides for the control of mosquito populations in light of global efforts to reduce the level of highly toxic synthetic larvicides in the aquatic environment.

Sulfoxaflor, a novel sulfoximine insecticide, discovered by and proprietary to Dow AgroSciences is being developed globally. Sulfoxaflor will be used in all major crop groups, including fruits, vegetables, rice, cereals, soybean, and many other crops. Sulfoxaflor provides excellent efficacy at low use rates through contact and ingestion against important and difficult-to-control sap-feeding insect pests, including certain species of aphids, scales, plant bugs, whiteflies, planthoppers and other sap feeders. Sulfoxaflor’s mode of action is via agonism of the insect nicotinic acetylcholine receptor (nAchR), which is the same target site of neo-nicotinoid insecticides. However, relative to most neonicotinoids, sulfoxaflor is a high efficacy agonist of the nAchR with relatively low affinity for the imidacloprid binding site. Furthermore, sulfoxaflor is less susceptible to metabolism by monooxygenase enzymes and displays a broad lack of metabolism-based cross-resistance with neonicotinoids. This difference as well as its novel chemical structure led to sulfoxaflor being designated as the sole member of Group 4, Subgroup C of the IRAC Mode of Action Classification Scheme. Because of broad lack of crossresistance, sulfoxaflor will be a useful rotational partner with other insecticide chemistries, enhancing Insect Resistance Management strategies. In Korea, sulfoxaflor is being developed for use in fruit and leafy and fruiting vegetable by several companies. Results from several laboratory and field trials revealed that sulfoxaflor at use rate of 35 ppm (7% product, X2,000 dilution rate) provided excellent performance against economically important aphids in several crops compared with current sap-feeding pest control agents. Sulfoxaflor was registered in October 2011 as brandname TRANSFORM® (Sulfoxaflor 7% SC which is produced by Dongbu Hannong) will be launched for apple, pear and red-pepper in 2012.