Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper （Cu） ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied. Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time, the analysis of the extracts from the soil was carded out using gas chromatography （GC）. The photodegradation of pyrethroids in water system was conducted under UV irradiation. The effect of Cu^2＋ on the pesticides degradation was measured with half life 00.5） of degradation. It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed. But Cu^2＋ could accelerate photodegradation of the pyrethroids in water. The t0.5 for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil. As for photodegradation, t0.5 for cyhalothrin reduced from 173.3 to 115.5 min and for cypermethrin from 115.5 to 99.0 min. The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms. However, it had catalyst tendency for photodegradation in water system. The difference for the degradation efficiency of pyrethroid isomers in soil was also observed. Copper could obviously accelerate the degradation of some special isomers.

Sensitive determination of fenpropathrin,cyhalothrin and deltamethrin in environmental water samples using multiwalled carbon nanotubes cartridge prior to HPLC

This paper described a new method for the trace determination of fenpropathrin, cyhalothrin and deltamethrin using multiwalled carbon nanotubes （MWCNTs） cartridge. Important parameters, such as the sample pH, eluent and its volume, sample flow rate and sample volume were investigated in detail. The linear ranges, the detection limits, and precisions （R.S.D.） were in the range of 0.1- 40 μg L^-11, 1.34.3 ng L^-1 and 2.3-2.8%, respectively. The performance of the proposed method was validated with real water samples, and the spiked recoveries were in the range of 91.7-117.8%, respectively. The experimental results demonstrated that the proposed method was an excellent alternative for the routine analysis of such pollutants in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Cytotoxicity of lambda-cyhalothrin on the macrophage cell line RAW 264.7

The wide use and wide-spectrum toxicity of synthetic pyrethroids （SPs） insecticides make them an emerging ecotoxicological concern. Some previous studies showed that SPs possessed cytotoxicity in some immune cells such as human lymphocytes and rat bone marrow. However, the cytotoxicity of SPs to macrophages, which are crucial to innate immunity, has not been explored. In the present report, we investigated a new pyrethroid insecticide, lambda-cyhalothrin （LCT）, which may increase the generation of reactive oxygen species （ROS） and DNA damage levels and cause cytotoxicity in RAW 264.7 cells in dose- and time-dependent manners. The results for the first time implicated increased endogenous ROS and DNA damage as co-mediators of LCT-induced cytotoxicity in macrophages. Our results also suggested that macrophages were involved in synthetic pyrethroid-induced adverse immune effects. Considering the ubiquitous environmental presence of SPs, this study provided new information relative to the potential long-term physiological and immunological effects associated with chronic exposure to SPs. Hence, the potential immunotoxicity of SPs should be considered in assessing the safety of these compounds in sensitive environmental compartments.

绿茶中联苯菊酯和氯氟氰菊酯残留检测质量控制基体标准物质的研制

目的:制备一批绿茶中联苯菊酯和氯氟氰菊酯基体标准物质。方法:以绿茶为研究对象,通过喷洒联苯菊酯和氯氟氰菊酯,样品经粉碎、过筛、均质、装瓶,通过均匀性、稳定性检验后,由3家实验室联合定值确定量值,并进行不确定度评估。结果:绿茶中联苯菊酯和氯氟氰菊酯的量值分别为(0.185±0.0197),(0.207±0.0466)mg/kg,k=2,置信区间为95%。结论:研制出的绿茶中联苯菊酯和氯氟氰菊酯基体标准物质足够均匀,足够稳定,定值结果可靠。

基于高光谱成像技术烟叶田间高效氯氟氰菊酯用量的快速检测技术研究

为了能够有效预防烟叶田间用药过量所产生的农药残留危害,加强烟叶生产过程中的农药用量管控,研究了不同用量高效氯氟氰菊酯处理下的田间鲜烟叶高光谱曲线特征并构建了预测模型。应用可见—近红外高光谱成像系统(400~900 nm)采集不同浓度(CK、1∶2000,1∶1000,1∶350)的高效氯氟氰菊酯处理24 h后的鲜烟叶样本的高光谱图像。使用4种常用的光谱预处理方法进行数据预处理,分别采用连续投影法(SPA)、竞争性自适应重加权采样法(CARS)进行数据降维,最后分别构建了最小二乘支持向量机(LSSVM)和随机森林(RF)模型预测模型。结果表明:(1)光谱数据经二阶导数(D2)预处理后,LSSVM和RF模型的准确率均达到100%,经一阶导数(D1)预处理后,RF测试集准确率也达到100%;(2)SPA特征选择数量少于CARS,其中D1预处理后经SPA特征选择的波长数量最少;(3)综合考虑模型复杂度和稳定性,最终选择D1-SPA-RF为最优预测模型,选择11个特征波长,测试集准确率为97.70%。基于高光谱图像的D1-SPA-RF模型预测性能优异,可用于烟叶田间高效氯氟氰菊酯用量的快速检测。

高效液相色谱法测定高效氯氟氰菊酯微囊悬浮剂的优化研究

在现有检测方法的基础上,研究了不同溶剂的破囊效果,建立了高效液相色谱法测定高效氯氟氰菊酯微囊悬浮剂中有效成分含量的方法。方法以乙醇为破囊溶剂,正己烷+乙醇为流动相,使用ZORBAX RX-SIL色谱柱和可变波长紫外检测器,在278 nm波长下对高效氯氟氰菊酯微囊悬浮剂进行分离和定量分析。结果表明,在质量浓度0.05~1.0 mg/mL时,方法线性关系良好,相关系数为0.9999;方法标准偏差为0.06,相对标准偏差为0.55%,平均回收率为100.81%。该分析方法操作简易、安全、准确,分离效果好,可用于高效氯氟氰菊酯微囊悬浮剂有效成分的分析检测。

Effects of cyhalothrin on the transient outward potassium current in central neurons of Helicoverpa armigera

The effects of cyhalothrin on the transient outward potassium current in central neurons of Helicoverpa armigera were studied by using the patch clamp techniques. The results showed that before using cyhalothrin （10.5 mmol/L）, activation potential was approximately -40 mV, after application of the drug, the activation potential shifted roughly 10 mV to the negative potential direction, so channels can be activated more easily. Before and after cyhalothrin application, the change of current amplitude was insignificant. The value of V1/2 and k of activation curves did not change significantly, however, the V1/2 of the inactivation curves changed significantly. Inactivation curves significantly shifted to a negative direction, so that inactivation of the channels was hastened. It is indicated that there may exit a primary way in which cyhalothrin provides neurotoxicity to the nervous system through the regulation of activation potentials and inactivation state of IA channels.

INHERITANCE OF RESISTANCE TO CYHALOTHRIN IN THE HOUSEFLY(DIPTERA:MUSCIDAE)

The genetic inheritance of resistance to cyhalothrin in housefly, Musca domestica (L) was investigated. Reciprocal crosses between susceptible (S) and resistant (R) strains were used to determine the characteristics of resistance. Analysis of probit line from the F 1 generation and F 2 generation obtained by inbreeding the F 1 hybrids indicated that cyhalothrin resistance was controlled by more than one factors and degree of resistance dominance to cyhalothrin was -0.10, indicating cyhalothrin resistance is conferred by incompletely recessive gene(s). The realized heritability of resistance to cyhalothrin cyhalothrin calculated from data collected routinely from laboratory selection was 0 12.

Effect of an eco-friendly o/w emulsion stabilized with amphiphilic sodium alginate derivatives on lambda-cyhalothrin adsorption-desorption on natural soil minerals

The effects of amphiphilic O/W emulsions,stabilized by the alkyl polyglycoside(APG)or cholesterol-grafted sodium alginate(CSAD)/APG systems,on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minerals(i.e.,illite and kaolinite)were investigated.Sorption and desorption of lambda-cyhalothrin onto soil minerals was studied via batch equilibration to give insight into the adsorption equilibrium,kinetics,and thermodynamics of lambda-cyhalothrin adsorption onto minerals.The results indicate the following:(i)The adsorption processes for the APG system and CSAD/APG system include:rapid adsorption,slow adsorption,and adsorption equilibrium.The adsorption kinetics of pesticide on illite and kaolinite are in accordance with the Ho and McKay model,and the adsorption isotherm conforms to the Freundlich model.In addition,the adsorption processes of pesticide for the two systems on minerals were spontaneous and feasible(ΔG^0<0),endothermic(ΔH^0>0),and mainly involved chemical bonding(ΔH^0>60).(ii)The equilibrium adsorption percentages of the pesticide on illite for the APG system and CSAD/APG system were 42.4%and 64.8%,and the corresponding equilibrium adsorption percentages on kaolinite were 40.8%and 61.8%,respectively.Moreover,the pesticide adsorption rate K_(2-CSAD/APG)was faster than K_(2-APG),and its adsorption capacity K_(f-CSAD/APG )was greater than K_(f-APG).Meanwhile,the pesticide desorption K_(fd)in the CSAD/APG system was smaller than that in the APG system.As a result,this eco-friendly O/W emulsion based on amphiphilic sodium alginate derivatives might provide a green pesticide formulation,since it could reduce the amount of lambda-cyhalothrin entering aquatic systems to threaten non-target fish and invertebrate species.

Mutagenic and cytotoxic potential of Endosulfan and Lambda-cyhalothrin—In vitro study describing individual and combined effects of pesticides

Excessive use of pesticides poses increased risks to non target species including humans. In the developing countries, lack of proper awareness about the toxic potential of pesticides makes the farmer more vulnerable to pesticide linked toxicities, which could lead to diverse pathological conditions. The toxic potential of a pesticide could be determined by their ability to induce genetic mutations and cytotoxicity. Hence, determination of genetic mutation and cytotoxicity of each pesticide is unavoidable to legislate health and safety appraisal about pesticides. The objective of current investigation was to determine the genotoxic and cytotoxic potential of Endosulfan（EN） and Lambda-cyhalothrin（LC）; individually and in combination. 3-（4,5-Dimethylthiazol-2-yl）-2,5-Diphenyltetrazolium Bromide（MTT） assay was utilized to determine cytotoxicity, while two mutant histidine dependent Salmonella strains（TA98, TA100） were used to determine the mutagenicity of EN and LC.Moreover, mutagenicity assay was conducted with and without S9 to evaluate the effects of metabolic activation on mutagenicity. Even though a dose dependent increase in the number of revertant colonies was detected with EN against both bacterial strains, a highly significant（p 〈 0.05） increase in the mutagenicity was detected in TA98 with S9. In comparison, data obtained from LC revealed less mutagenic potential than EN. Surprisingly,the non-mutagenic individual-concentrations of EN and LC showed dose dependent mutagenicity when combined. Combination of EN and LC synergistically induced mutagenicity both in TA98 and TA100. MTT assay spotlighted comparable dose dependent cytotoxicity effects of both pesticides. Interestingly, the combination of EN and LC produced increased reversion and cytotoxicity at lower doses as compared to each pesticide, concluding that pesticide exposure even at sub-lethal doses can produce cytotoxicity and genetic mutations, which could lead to carcinogenicity.

土壤中辛硫磷和高效氯氟氰菊酯残留量的高效液相色谱分析

从土壤中超声提取辛硫磷和高效氯氟氰菊酯,并采用高效液相色谱法检测其残留量.用乙腈-水(体积比4∶1)作为提取剂,对土壤样品进行超声萃取,提取液经弗罗里硅土小柱净化后,采用反相高效液相色谱法进行残留量测定.使用SynergiTMPolar-RP 80?(250 mm×4.6 mm, 4μm)色谱柱,以乙腈-水(体积比80∶20)为流动相,紫外检测波长为225 nm.结果表明:辛硫磷与高效氯氟氰菊酯的萃取率均高于92%.辛硫磷浓度在0.6~5.4μg/mL范围内和峰面积线性关系良好,线性回归方程A=25.108ρ+45.008,r=0.998 9;高效氯氟氰菊酯浓度在0.4~3.6μg/mL范围内与峰面积呈良好线性关系,线性回归方程A=48.835ρ+56.574,r=0.999 0.该方法简单、快速、准确度高、精密度好,能满足土壤中辛硫磷和高效氯氟氰菊酯残留量的检测要求.

高效氯氟氰菊酯与烯啶虫胺增效混配剂的筛选及其对小麦蚜虫的田间防治效果

为了延缓麦蚜抗药性和降低杀虫剂使用量,本研究筛选了具有增效作用的高效氯氟氰菊酯和烯啶虫胺的复配比例,并研究了增效复配剂对麦蚜的田间防治效果。浸叶法测定结果表明,高效氯氟氰菊酯对麦蚜的LC_(50)为25.01 mg/L,烯啶虫胺对麦蚜的LC_(50)为28.21 mg/L。通过最佳增效配比的筛选,发现高效氯氟氰菊酯和烯啶虫胺的有效成分比为1.3∶1、1∶1.1、1∶1.7、1∶10.2时,对麦蚜的毒效比分别为1.28、1.49、1.64、1.50,表现为增效作用。深入研究发现高效氯氟氰菊酯和烯啶虫胺的有效成分为1∶4.5、1∶7.5和1∶10.2的混配组合的共毒系数均显示了显著增效作用,其中,当高效氯氟氰菊酯与烯啶虫胺有效成分比为1∶7.5时,混配剂的LC_(50)为5.22 mg/L,共毒系数达到532.61。按有效成分比1∶7.5,将10%高效氯氟氰菊酯水乳剂与20%烯啶虫胺可溶液剂混用后,进行田间试验,结果表明,在药后1、3 d和7 d,混配剂的防效与高效氯氟氰菊酯单剂的防效无显著性差异,在药后1 d,混配剂的防效高于烯啶虫胺单剂的防效,在药后3 d及7 d,混剂与烯啶虫胺单剂的防效没有显著差异。混配剂的防效在药后7 d内不断上升,其中药后7 d防效达到92.98%。混配剂的使用可以达到对高效氯氟氰菊酯减量的目的,同时保证了对麦蚜的防效。

Lambda-cyhalothrin disrupts the up-regulation effect of 17β-estradiol on post-synaptic density 95 protein expression via estrogen receptor α-dependent Akt pathway

Lambda-cyhalothrin（LCT）,one of the type II pyrethroids,has been widely used throughout the world.The estrogenic effect of LCT to increase cell proliferation has been well established.However,whether the estrogenic effect of LCT will influence neurodevelopment has not been investigated.In addition,17β-Estradiol（E2）plays a crucial role in neurodevelopment and induces an increase in synaptic proteins.The post-synaptic density 95（PSD95）protein,which is involved in the development of the structure and function of new spines and localized with estrogen receptor α（ERα）at the post-synaptic density（PSD）,was detected in our study by using hippocampal neuron cell line HT22.We found that LCT up-regulated PSD95 and ERα expression,estrogen receptor（ER）antagonist ICI182,780 and phosphatidylinositol-4;5-bisphosphate 3-kinase（PI3K）inhibitor LY294,002 blocked this effect.In addition,LCT disrupted the promotion effect of E2 on PSD95.To investigate whether the observed changes are caused by ERα-dependent signaling activation,we next detected the effects of LCT on the ERα-mediated PI3K-Protein kinase B（PKB/Akt）-eukaryotic initiation factor（e IF）4E-binding protein 1（4E-BP1）pathway.There existed an activation of Akt and the downstream factor 4E-BP1 after LCT treatment.In addition,LCT could disrupt the activation effect of E2 on the Akt pathway.However,no changes in c AMP response element-binding protein（CREB）activation and PSD95 messenger ribonucleic acid（m RNA）were observed.Our findings demonstrated that LCT could increase the PSD95 protein level via the ERα-dependent Akt pathway,and LCT might disrupt the up-regulation effect of E2 on PSD95 protein expression via this signaling pathway.

Pertussis toxin modulation of sodium channels in the central neurons of cyhalothrin-resistant and cyhalothrinsusceptible cotton bollworm, Helicoverpa armigera

Pertussis toxin （FIX） inhibits the activation of the α-subunit of the inhibitory heterotrimeric G-proteins （Cαi/o） and modulates voltage-gated sodium channels, which may be one of the primary targets of pyrethroids. To investigate the potential mechanisms of agricultural pests resistance to pyrethroid insecticides, we examined the modulations by PTX on sodium channels in the central neurons of the 3rd-4th instar larvae of cyhalothrin-resistant （Cy-R） and cyhaiothrin-susceptible （Cy-S） Helicoverpa armigera by the whole-cell patch-clamp technique. The isolated neurons were cultured for 12-16 h in an improved L15 insect culture medium with or without PTX （400 ng/mL）. The results showed that both the Cy-R and Cy-S sodium channels exhibited fast kinetics and tetrodotoxin （TTX） sensitivity. The Cy-R sodium channels exhibited not only altered gating properties, including a 8.88-mV right shift in voltage-dependent activation （V0.5act） and a 6.54-mV right shift in voltage-dependent inactivation （V0.5inact）, but also a reduced peak in sodium channel density （Ⅰdensity） （55.2% of that in Cy-S neurons）. Cy-R sodium channels also showed low excitability, as evidenced by right shift of activation potential （Ⅴacti） by 5-10 mV and peak potential （Ⅴpcak） by 20 mV. FIX exerted significant effects on Cy-S sodium channels, reducing sodium channel density by 70.04%, right shifting V0.5act by 14.41 mV and V0.5inact by 9. 38 mV. It did not cause any significant changes of the parameters mentioned above in the Cy-R sodium channels. The activation time （Tpeak） from latency to peak at peak voltage and the fast inactivation time constant （τinact） in both Cy-S and Cy-R neurons were not affected. The results suggest that cotton bollworm resistant to pyrethroid insecticides involves not only mutations and allosteric alterations of voltage-gated sodium channels, but also might implicate perturbation of PTX-sensitive Gαi/o-COupled signaling Wansduction pathways.

不同因素对高效氯氟氰菊酯水乳剂物理稳定性的影响

通过测定粒径、跨距、乳液稳定性、冷贮稳定性、热贮稳定性等性能指标,研究不同加工方法、加工设备、剪切速率、剪切时间及水质对高效氯氟氰菊酯水乳剂物理稳定性的影响。结果表明:转相法和直接乳化法均可制备出物理稳定性符合要求的高效氯氟氰菊酯水乳剂,但转相法制备的水乳剂具有更小的中位粒径和跨距;相比磁力搅拌器和超声波,采用高速分散机剪切制备的水乳剂中位粒径更小,稳定性更好;剪切速率为3 000 r/min、剪切时间为5 min,水乳剂具有最小的中位粒径和跨距;不同水质对高效氯氟氰菊酯水乳剂的稳定性具有一定影响,应选择去离子水或自来水制备。

三氟氯氰菊酯对鸡胚的发育毒性及雏鸡生长发育的评价

目的:探讨三氟氯氰菊酯(Lambda-cyhalothrin,LCT)对鸡胚的发育毒性及其出壳后21 d内生长发育的影响。方法:选择已孵化7胚龄的草鸡胚蛋160枚,随机分为5组,每组32枚。Ⅰ组(对照组)向每枚鸡胚的卵黄囊注射0.1 mL生理盐水,Ⅱ~Ⅴ组(处理组)分别向每枚鸡胚的卵黄囊注射0.1 mL 2.5、25、250、2500μg/mL LCT,灭菌石蜡封口,继续孵化至雏鸡出壳,期间分别测定孵化第10、18天的死胎数、生存率以及孵化率、弱雏率、出壳重与第18天胚蛋重的比值等指标;雏鸡出壳后饲喂21 d分别测定体质量、胸肌质量、腿肌质量、部分内脏器官指数、血清生化指标及肝肾氧化应激指标。结果:Ⅴ组的死胚数、死胚率、弱雏率明显高于对照组和Ⅱ~Ⅳ组;Ⅱ~Ⅳ组雏鸡21日龄的体质量、胸肌和腿肌质量低于对照组,血清CREA与UREA-N含量、AST和ALT活性,与对照组相比无显著变化;21日龄时,Ⅲ组肝组织和Ⅱ组肾组织的GSH含量明显升高(P<0.01或P<0.05),Ⅲ组肝组织MDA含量显著增加(P<0.05),各试验组肝、肾组织的SOD活性有增加趋势,但与对照组相比无显著变化(P>0.05)。结论:高剂量LCT暴露对鸡胚具有明显的发育毒性,胚胎期中低剂量LCT暴露抑制出壳后雏鸡的早期生长发育,氧化应激损伤是其毒性机制之一。

茶叶和土壤中cis-联苯菊酯、高效氯氟氰菊酯手性对映体残留分析

为了满足茶叶和土壤中手性农药cis-联苯菊酯和高效氯氟氰菊酯对映异构体残留检测的需要,本试验首次对比研究了正相液相色谱条件下,Daicel ChiralPak®AS-H、Phenomenex®Cellulose-1和Cellulose-3柱对两组手性对映体的拆分效果,以及气相色谱条件下BGB-172柱的分离测定效果,并建立了基于手性气相色谱分离的茶叶和土壤中cis-联苯菊酯和高效氯氟氰菊酯对映体残留分析方法。样品采用正己烷和丙酮提取,Florisil与GCB混合柱净化,气相色谱手性柱BGB-172程序升温分离,电子捕获检测器(ECD)外标法定性定量测定。结果表明,在2.5~800μg·L^(-1)浓度范围内,cis-联苯菊酯对映体色谱峰面积(Y)与浓度(x)之间分别满足线性方程Y=15381.1x-279657.5(r=0.9967)和Y=17387.6x-399048.0(r=0.9937),对映体分数(EF值)=0.489±0.017;在2.5~200μg·L^(-1)浓度范围内,高效氯氟氰菊酯对映体分别满足线性方程Y=22083.8x-161004.3(r=0.9923)和Y=23001.1x-167694.8(r=0.9922),EF=0.492±0.008。在0.005、0.050和0.50 mg·kg^(-1)3个添加浓度水平下,cis-联苯菊酯和高效氯氟氰菊酯对映体在不同茶叶、土壤样品中的平均添加回收率为61.6%~123.4%,相对标准偏差(RSD)为2.5%~14.6%,检测限低于0.001 mg·L^(-1),方法定量限低于0.005 mg·kg^(-1),不同样品中未见到明显基质效应。综上,该方法能够满足cis-联苯菊酯和高效氯氟氰菊酯对映体残留分析的需要,用于研究茶鲜叶中cis-联苯菊酯和高效氯氟氰菊酯对映体残留消解,且无明显对映体选择性差异。本研究结果为进一步开展2种手性农药在茶叶生长和加工过程中的残留和消解规律研究提供了技术支持。

10%高效氯氟氰菊酯水乳剂和21%辛硫·高氯氟乳油杀灭白纹伊蚊的现场效果

目的 观察10%高效氯氟氰菊酯水乳剂和21%辛硫·高氯氟乳油(1%高效氯氟氰菊酯、20%辛硫磷)空间喷雾对白纹伊蚊的杀灭效果,为蚊虫防治的药剂选择提供参考。方法 参照(GB/T 27781—2011)空间喷雾效果的评价方法,采用超低容量喷雾对10%高效氯氟氰菊酯水乳剂(按1∶200稀释)和21%辛硫·高氯氟乳油(1%高效氯氟氰菊酯、20%辛硫磷,按1∶150稀释)进行杀灭白纹伊蚊的现场实验。结果 0.07%高效氯氟氰菊酯对白纹伊蚊2 min击倒率为76%,24 h死亡率为14%,该白纹伊蚊种群为抗性种群。10%高效氯氟氰菊酯水乳剂稀释200倍对距离10、30、50 m挂笼内白纹伊蚊24 h死亡率分别为84.19%、78.65%、36.26%。21%辛硫·高氯氟乳油稀释150倍对距离10、30、50 m挂笼内白纹伊蚊24 h死亡率分别为37.94%、20.17%、10.83%。不同距离死亡率差异有统计学意义(χ^(2)=19.679,P<0.01;χ^(2)=48.202,P<0.01)。结论 2种杀虫剂对现场白纹伊蚊均有一定的杀灭作用,在试验设置的稀释浓度下,10%高效氯氟氰菊酯水乳剂空间喷雾效果显著优于21%辛硫·高氯氟乳油。

氯虫苯甲酰胺对荔枝蒂蛀虫不同虫态的室内毒力测定

荔枝蒂蛀虫Conopomorpha sinensis Bradley是为害荔枝和龙眼的重要害虫,其为害的隐蔽性增加了防治难度。为了探索安全、有效的药剂防治手段和明确氯虫苯甲酰胺的适合施药时期,本研究在室内条件下,以防控荔枝蒂蛀虫常用药剂高效氯氟氰菊酯为对照药,采用喷雾法和药膜法,分别测定了100、10、1、0.1和0.01 mg/L的5个浓度梯度下,氯虫苯甲酰胺对荔枝蒂蛀虫卵、初孵幼虫的毒杀作用以及对成虫的触杀作用。研究结果表明,氯虫苯甲酰胺的5个浓度梯度对产后24 h、48 h和72 h蒂蛀虫卵孵化抑制率均显著高于高效氯氟氰菊酯;氯虫苯甲酰胺对蒂蛀虫初孵幼虫的毒力是高效氯氟氰菊酯的10倍,对荔枝蒂蛀虫初孵幼虫的LC_(50)分别为3.32 mg/L和38.78 mg/L。而在100 mg/L浓度下氯虫苯甲酰胺和高效氯氟氰菊酯对成虫触杀的校正死亡百分率最高分别为34.36%和77.35%。综上所述,氯虫苯甲酰胺对荔枝蒂蛀虫具有较强的杀卵活性和杀初孵幼虫活性,在荔枝生产上具有潜在的应用价值;鉴于其对成虫的触杀作用不强,故建议在荔枝蒂蛀虫的产卵高峰期和初孵幼虫期使用,以期将荔枝蒂蛀虫于发生为害之前进行有效控制。

22%噻虫嗪·高效氯氟氰菊酯悬浮剂对环境非靶标生物的急性毒性与风险评估

建立了基于UPLC-MS/MS法测定曝气自来水和BG11培养基中噻虫嗪、高效氯氟氰菊酯的定性定量分析方法,测定了22%噻虫嗪·高效氯氟氰菊酯悬浮剂对环境5种非靶标生物的毒性并分级。结果表明,22%噻虫嗪·高效氯氟氰菊酯悬浮剂对斑马鱼、大型溞和家蚕的毒性为剧毒;对蜜蜂的毒性为高毒;分别以生长率抑制率和生物量增长抑制率为毒性终点计时,对羊角月牙藻的毒性分别为低毒和中毒。22%噻虫嗪·高效氯氟氰菊酯悬浮剂对蜜蜂和家蚕均存在潜在风险。建议实际施用过程注意周围开花植物花期,蚕室及桑园附近禁用。