二点叶螨对甲氰菊酯、氧乐果和四螨嗪抗药性的选育、衰退和恢复

以兰州吐鲁沟公园的二点叶螨Tetranychus urticae 为敏感品系,分别用氧乐果、甲氰菊酯、四螨嗪喷雾处理15次,其抗性水平分别为38.5、479.8和67.3倍。将抗性品系分别与敏感品系进行杂交和回交的结果表明：抗氧乐果品系的显性系数DRS（R♀×S♂）为0.4700、D_SR（S♀×R♂）为0.4749;抗甲氰菊酯品系的DRS（R♀×S♂）为0.5155, DSR为0.5237;抗四螨嗪品系的DRS为0.3134, DSR为0.2466。表明二点叶螨对这3种药剂的抗性均是由单个不完全显性基因所控制。在连续10个月不接触药剂的情况下,3个抗性品系的抗药性都有下降,抗氧乐果品系的抗性下降最快,只有敏感品系的抗性倍数的3.6倍;抗甲氰菊酯种群的抗性下降较慢,为敏感品系的95.9倍。再经甲氰菊酯、氧乐果、四螨嗪分别连续15次喷雾处理后,3个抗性种群的抗性水平又再度回升,抗甲氰菊酯品系回升较快,抗性为敏感品系的523.5倍,抗四螨嗪品系次之,抗氧乐果的品系抗性恢复最慢。     

尼氏钝绥螨抗亚胺硫磷品系的筛选及遗传分析

尼氏钝绥螨Amblyseius nicholsi Ehara et Lee是桔全爪螨Panonychus citri(McGregor)的有效天敌之一.为了筛选抗有机磷农药品系, 经实验室内用亚胺硫磷33次处理后, 抗性提高18.9倍, LC₅₀从最初的52.5ppm提高到995ppm, 为大田常用浓度的两倍.S(敏感型)与R(抗性型)的LD-P线近于平行, 表明两者已成为纯系.正交与反交之F₁代雌性个体的LD—P线介于S与R之间略偏向R方, F₁显性度(D)大于0而小于1, 说明抗性为半显性.F₁(杂合子)与敏感亲本的回交结果, 其LD—P线在50%.死亡率处出现一平坡, SR(杂合子)与SS(敏感个体)的分配比例接近于1:1的理论值.以上结果说明尼氏钝绥螨对亚胺硫磷的抗性为半显性的单基因所控制.正、反交F₁代雄性个体的抗性检测结果表明, F₁代的雄性个体具有其遗传性来自母系的特征.尼氏钝绥螨抗亚胺硫磷品系对辛硫磷、水胺硫磷、乐果、敌敌畏、敌百虫等有机磷农药具有一定的交互抗性, 抗性分别提高28.5、8.5、5.4、3.8和2.9倍.     

朱砂叶螨不同抗性品系酯酶同工酶研究

在室内模拟田间药剂的选择压力,用3种不同药剂及其组合(轮用和混用)对朱砂叶螨Tetranychus cinnabarinus 进行抗药性选育.经过40余代的筛选,朱砂叶螨对甲氰菊酯、阿维菌素和哒螨·阿维混剂分别产生了68.5、8.7和6.7倍的抗性;甲氰菊酯和阿维菌素混用和轮用分别对甲氰菊酯产生了5.6倍和28.7倍抗性.朱砂叶螨各品系酯酶同工酶电泳结果和同工酶谱谱带密度扫描表明,与敏感品系相比,各抗性筛选品系的酯酶活性均有不同程度增加;阿维菌素抗性品系活性最强,酯酶带迁移距离明显远于其他抗性品系,表明该品系酯酶体系中存在变构酯酶.     

巴氏新小绥螨甲氰菊酯抗性品系生物学特性及其对常用药剂的交互抗性

【目的】明确橘园常用药剂对巴氏新小绥螨Neoseiulus barkeri成螨的致死效应,弄清巴氏新小绥螨甲氰菊酯抗性品系对柑橘园常用药剂的交互抗性水平及生态适合度变化,为巴氏新小绥螨抗性品系的田间应用提供科学理论依据。【方法】在对巴氏新小绥螨进行致死效应和交互抗性测定的基础上,运用生态学方法对其生物学特性进行评价。【结果】不同药剂对巴氏新小绥螨成螨致死效应存在显著差异。高效氯氟氰菊酯和毒死蜱的致死率最高,校正死亡率分别为97.62%和92.57%;巴氏新小绥螨甲氰菊酯抗性品系螺螨酯、噻虫嗪、乙螨唑、毒死蜱和高效氯氟氰菊酯均存在显著交互抗性,其抗性倍数分别为7.56、10.32、11.45、19.10和45.89倍。生物学特性研究结果表明,与敏感品系相比,甲氰菊酯抗性的获得使其发育历期显著延长,但对捕食量和孵化率影响不显著。哒螨灵、丁氟螨酯和高效氯氟氰菊酯对巴氏新小绥螨抗性品系与敏感品系卵的孵化率具有显著影响,其他常用药剂对巴氏新小绥螨抗性品系与敏感品系卵的孵化率不存在显著影响。【结论】甲氰菊酯抗性获得使巴氏新小绥螨对柑橘园常用药剂表现不同水平的交互抗性;甲氰菊酯抗性获得对巴氏新小绥螨生长、繁殖及捕食均无显著影响,可在田间推广应用。     

朱砂叶螨对甲氰菊酯、阿维菌素,哒螨灵及其混剂抗性遗传力的分析(英文)

采用域性状分析法 ,估算了朱砂叶螨对 5种杀螨剂 (3种单剂和 2种混剂 )的抗性现实遗传力 ,并对 5种药剂的抗性风险进行了评估。把采自重庆北碚田间的朱砂叶螨种群 ,在室内不施药情况下饲养 6 0余代 ,以此作为抗性筛选的敏感品系。分别单一连续汰选近 30代 ,朱砂叶螨对甲氰菊酯、阿维菌素、哒螨灵、哒螨 -阿维 (哒螨灵 :阿维菌素 =7 4 :0 1,m m)和甲氰 -阿维 (甲氰菊酯 :阿维菌素 =8 9:0 1,m m)的抗性分别达 6 5 5 5、5 82、1 2 3、5 2 0和 1 4 2 倍 ;抗性现实遗传力分别为 0 2 16 7、0 0 96 7、0 0 130、0 0 80 0和 0 0 172。在实验室选择条件下 ,预计抗性增长 10倍时 ,甲氰菊酯、阿维菌素、哒螨灵、哒螨 -阿维 (哒螨灵 :阿维菌素 =7 4 :0 1,m m)和甲氰 -阿维 (甲氰菊酯 :阿维菌素 =8 9:0 1,m m)分别需要 15、34、333、4 2和 2 0 0代。甲氰菊酯抗性风险较高 ,其次是阿维菌素、哒螨 -阿维 (哒螨灵 :阿维菌素 =7 4 :0 1,m m)、甲氰 阿维 (甲氰菊酯 :阿维菌素 =8 9:0 1,m m) ,哒螨灵抗性风险较低。混剂哒螨 阿维 (哒螨灵 :阿维菌素 =7 4 :0 1,m m)不能延缓朱砂叶螨对两单剂哒螨灵和阿维菌素的抗性发展 ,而混剂甲氰 阿维 (甲氰菊酯 :阿维菌素 =8 9:0 1,m m)却能有效延缓朱砂叶螨对两单剂     

抗药性叶螨的种群参数和相对适合度

朱砂叶螨对氧化乐果、三氯杀螨醇、双甲脒和哒螨灵产生抗性后（抗药性系数分别为152．83倍、55．59倍、62．61倍和15．67倍）,繁殖力均显著降低,且发育加速。通过组建各品系生命表得知,该螨抗氧化乐果品系、抗三氯杀螨醇品质、抗双甲脒品系和抗哒螨灵品系的相对适合度分别为0．53、0．62、0．59和0．64,均小于1,具有明显的适合度缺陷。抗药性系数和相对适合度呈直线负相关。     

朱砂叶螨对甲氨菊酯、阿维菌素，哒螨灵及其混剂抗性遗传力的分析

采用域性状分析法,估算了朱砂叶螨对5种杀螨剂(3种单剂和2种混剂)的抗性现实遗传力,并对5种药剂的抗性风险进行了评估。把采自重庆北碚田间的朱砂叶螨种群,在室内不施药情况下饲养60余代,以此作为抗性筛选的敏感品系。分别单一连续汰选近30代,朱砂叶螨对甲氰菊酯、阿维菌素、哒螨灵、哒螨—阿维(哒螨灵：阿维菌素＝7．4：0．1,m/m)和甲氰—阿维(甲氰菊酯：阿维菌素＝8．9：0．1,m/m)的抗性分别达65．55、5．82、1．23、5．20和1．42．倍;抗性现实遗传力分别为0．2167、0．0967、0．0130、0．0800和0．0172。在实验室选择条件下,预计抗性增长10倍时,甲氰菊酯、阿维菌素、哒螨灵、哒螨—阿维(哒螨灵：阿维菌素＝7．4：0．1,m/m)和甲氰—阿维(甲氰菊酯：阿维菌素＝8．9：0．1,m/m)分别需要15、34、333、42和200代。甲氰菊酯抗性风险较高,其余是阿维菌素、哒螨—阿维(哒螨灵：阿维菌素＝7．4：0．1,m/m)、甲氰-阿维(甲氰菊酯：阿维菌素＝8．9：0．1,m/m),哒螨灵抗性风险较低。混剂哒螨-阿维(哒螨灵：阿维菌素＝7．4：0．1,m/m)不能延缓朱砂叶螨对两单剂哒螨灵和阿维菌素的抗性发展,而混剂甲氰-阿维(甲氰菊酯：阿维菌素＝8．9：0．1,m/m)却能有效延缓朱砂叶螨对两单剂甲氰菊酯和阿维菌素的抗性发展。     

朱砂叶螨抗性品系不同温度下的相对适合度

为研究朱砂叶螨抗性品系不同温度下的适合度,在抗性选育基础上,通过组建朱砂叶螨相对敏感品系（S）、抗阿维菌素品系（AbR）和抗甲氰菊酯品系（FeR）在不同温度（15 ℃、20 ℃、25 ℃、28 ℃、31 ℃、34 ℃和36 ℃）下的生命表,比较相对敏感品系和抗性品系在不同温度下的发育历期、生殖力和内禀增长率等种群特征参数.结果表明：朱砂叶螨AbR和FeR品系的发育历期在15 ℃时较S品系明显延长,在20 ℃～28 ℃下生殖力较S品系有所下降;两个抗性品系的相对适合度（以r_m值表示）在15 ℃时低于敏感品系,存在一定适合度代价,在20 ℃～31 ℃时,适合度与敏感品系相似,适合度代价不明显,但在高温下（≥34 ℃）,FeR品系适合度代价明显,而AbR品系存在抗性适合度优势.     

柑橘全爪螨两个田间种群抗性监测及羧酸酯酶生化特性研究

采用叶碟浸渍法测定了重庆北碚和万州地区柑橘全爪螨Panonychus citri(McGregor)田间种群对阿维菌素、毒死蜱、甲氰菊酯和哒螨灵的抗性水平。结果表明,同室内敏感品系相比,北碚种群对毒死蜱、甲氰菊酯和哒螨灵的相对抗性水平分别达到3倍、3倍和22倍;万州种群对阿维菌素、毒死蜱、甲氰菊酯和哒螨灵的相对抗性水平分别达到2倍、35倍、10倍和2倍。柑橘全爪螨2个地理种群的羧酸酯酶CarE的生化特性研究发现,CarE酶活的增高和毒死蜱的抗性存在一定的相关性。毒死蜱对不同地理种群柑橘全爪螨CarE的抑制效果不同,对抗性倍数较高的万州种群抑制效果最差。     

二斑叶螨对甲氰菊酯的抗性选育及解毒酶活力变化

为了明确二斑叶螨Tetranychus urticae Koch对甲氰菊酯产生抗性的机理,在室内模拟田间药剂的选择压力, 用甲氰菊酯对二斑叶螨敏感品系（S）进行逐代汰选,选育至38代时, 获得了抗性倍数( resistance ratio, RR)为247.35的抗甲氰菊酯品系（Fe-R）。对S和Fe-R解毒酶活性的分析表明,Fe-R₃₈体内羧酸酯酶（carboxylesterase, CarE）、酸性磷酸酯酶(acid phosphatase, ACP)、 碱性磷酸酯酶(alkaline phosphatase, ALP)、谷胱甘肽-S-转移酶(glutathione s-transferase, GSTs)和多功能氧化酶(mixed function oxidase, MFO)较S体内相应酶的活力显著升高（P< 0.05）,其相对比值（R/S）分别为1.822,13.941,3.789,4.262和17.386。此外,筛选至第9,19,25,32代时,除Fe-R₂₅和Fe-R₃₂的MFO活性与S相比有显著性差异（P< 0.05）外,其余解毒酶（CarE,ACP,ALP,GSTs）的活性与S相比均无显著性差异(P>0.05)。筛选至第38代时, 5种解毒酶的活力与S相比均差异显著(P<0.05)。结果说明二斑叶螨Fe-R随着筛选代数的增加（第25代后）,MFO活性的上升可能是二斑叶螨对甲氰菊酯产生抗性的主要原因。     

棉蚜啶虫脒抗性种群交互抗性和增效剂增效作用的研究

【目的】明确棉蚜Aphis gossypii Glover啶虫脒抗性品系与其它杀虫剂的交互抗性现状以及增效剂的增效作用,为延缓和治理棉蚜对啶虫脒的抗性提供依据。【方法】采用单头反选育和群体汰选的方式,获得了棉蚜啶虫脒敏感和抗性品系;采用叶片药膜法测定了13种杀虫剂对啶虫脒的交互抗性以及增效剂对啶虫脒的增效作用。【结果】经过室内棉蚜敏感和抗性品系的筛选,获得了相对抗性倍数为82.33倍的棉蚜啶虫脒抗性品系。棉蚜啶虫脒抗性品系的交互抗性谱的研究表明,交互抗性倍数小于5的药剂为:吡蚜酮,甲基阿维菌素;交互抗性倍数在5~10倍的药剂为:噻虫嗪,联苯菊酯,毒死蜱,马拉硫磷,丙溴磷,辛硫磷;交互抗性倍数在10~15倍的药剂为:硫丹,阿维菌素,高效氯氰菊酯,三唑磷,氧化乐果;交互抗性倍数大于1 5倍的药剂为:吡虫啉。增效剂实验表明,TPP和PBO在啶虫脒敏感品系中增效作用不明显,但在抗性品系中增效作用显著。在啶虫脒抗性品系中的增效比为1.77、1.61,在啶虫脒敏感品系中的增效比为1.02、1.03。DEM在啶虫脒抗性、敏感品系中的增效作用均不明显,增效比为1.04、1.02。TPP和PBO对啶虫脒有很好的增效作用。以室内棉蚜敏感品系(LC_(50)为0.180 mg/L)为基础,对新疆各主要棉区的棉蚜种群进行了啶虫脒药剂的抗性调查,结果表明新疆各主要棉区棉蚜对啶虫脒的相对抗性倍数为6.1~22.0倍。【结论】由此说明新疆主要棉区棉蚜对啶虫脒具有一定的抗性风险,生产中可以利用无交互抗性的吡蚜酮和甲基阿维菌素来治理抗性棉蚜种群。     

取食不同寄主植物对棉蚜后代抗药性的影响

测定了5种药剂对棉蚜Aphis gossypii抗氰戊菊酯、吡虫啉品系和敏感品系取食棉花、黄瓜和石榴的后代的毒力,并对它们的后代体内乙酰胆碱酯酶和羧酸酯酶的比活力做了初步探索。结果表明,氰戊菊酯抗性品系取食棉花比取食黄瓜的后代对氰戊菊酯的抗性大76.4倍,对灭多威、氧乐果、硫丹和吡虫啉的抗性也大0.5～4.6倍;取食石榴的后代对5种药剂的抗性介于取食棉花和黄瓜的之间。吡虫啉抗性品系的测定结果与氰戊菊酯抗性品系基本一致。敏感品系取食黄瓜比取食棉花的后代对5种药剂的敏感性更高。3个品系取食不同植物的后代相比,其体内乙酰胆碱酯酶的比活力,取食棉花的为取食黄瓜的2.4～2.8倍;羧酸酯酶的比活力,取食棉花的为取食黄瓜的1.8～2.4倍。证明棉蚜的抗性和敏感品系取食的寄主植物不同,可引起对药剂敏感性的变化。乙酰胆碱酯酶和羧酸酯酶活力的变化均是引起这种变化的重要因素。     

Insecticide toxicity, synergism and resistance in the German cockroach (Dictyoptera: Blattellidae)

The toxicity of synergism of and resistance to insecticides in four strains of German cockroach, Blattella germanica (L.), were investigated. Toxicity of nine insecticides by topical application to the susceptible strain varied greater than 2,000-fold, with deltamethrin (LD50 = 0.004 micrograms per cockroach) and malathion (LD50 = 8.4 micrograms per cockroach) being the most and least toxic, respectively. Resistance to pyrethrins (9.5-fold) in the Kenly strain was unaffected by the synergists piperonyl butoxide (PBO) or S,S,S-tributylphosphorotrithioate (DEF), suggesting that the metabolism is not involved in this case. Malathion resistance in the Rutgers strain was suppressible with PBO, implicating oxidative metabolism as a resistance mechanism. The Ectiban-R strain was resistant to all the pyrethroids tested, and cypermethrin resistance was not suppressible with PBO or DEF. These findings support results of previous studies that indicated this train has a kdr-like mechanism. Bendiocarb resistance in both the Kenly and Rutgers strains was partially suppressed by either PBO or DEF, suggesting that oxidative and hydrolytic metabolism are involved in the resistance. Trends between the effects of the synergists on the susceptible versus resistant strains are discussed.     

Inheritance of resistance to flumethrin in the Mexican Aldama strain of the cattle tick Boophilus microplus (Acari: Ixodidae)

The objective of this study was to evaluate the inheritance mode of resistance to flumethrin in the Mexican Aldama Boophilus microplus strain. Two Mexican strains were used, the Chiapas susceptible (SS), and the Aldama flumethrin-resistant from Tamaulipas. Six steers weighing ca. 250 kg were randomly assigned for each of six crosses: the susceptible (SS), resistant (RR), and the F1 (RS, SR) reciprocal crosses and F2 (RS x RS and SR x SR). The reciprocal crosses were made to evaluate maternal and sex linkage effects. Bioassays tested resistant and susceptible larvae along with their hybrid F1 and F2 progeny against a series of concentrations of flumethrin (0, 0.0075, 0.00150, 0.00300, 0.00600 and 0.01200 microg/g). To test the single-gene hypothesis of resistance, a nonparametric line-cross test proposed by Collins was used. The bioassay data were subjected to probit analysis and the resistance factor and effective dominance obtained. Results of this study indicated that inheritance for flumethrin resistance in the Aldama strain was autosomal and controlled for more than one gene. The F1 and F2 larvae had similar lower resistant factor (RF 2.8-4.5) while the resistant Aldama strain was 21-fold higher (RF 81.8) than the mean of the F1 and F2. The extent of flumethrin resistance in the Aldama B. microplus strain depended upon the concentration of the pesticide used. Resistance was almost dominant at the lowest dose while almost completely recessive at the highest dose. Maternal effects were shown for egg-mass. These results shown here indicate more than one gene basis of flumethrin resistance in B. microplus ticks are present. Therefore it is necessary to locate and understand the major loci for elucidate the mechanism of resistance and improve the ability to track and delay the evolution of resistance.     

Different exposure methods to neonicotinoids influenced biochemical characteristics in cotton aphid,Aphis gossypii Glover (Hemiptera:Aphididae)

We measured lipid, carbohydrate and protein content in three strains of cotton aphid, Aphis gossypii (Hemiptera: Aphididae) from very resistant to neonicotinoids up to semi sensitive and sensitive strains in different exposure method of spraying to neonicotinoids. We observed changes in energy source rates at which each substrate was metabolised under starvation, selection and residue stress method spraying that assist in metabolisation of their biochemical parameters. These particular exposure methods influenced some of biochemical parameters in cotton aphid. Results indicated that Sugar, glycogen, total protein and lipid in aphids have significant changes. Studies showed that among three strains called Ag-R, Ag-M and Ag-D which have different susceptibilities to neonicotinoids, strain Ag-R was the most tolerated aphids in counter of imidacloprid and thiametoxam, strain Ag-D was somewhat more tolerated to these insecticides and strain Ag-M was the most sensitive strain which has the resistance factor of nearly 890 in starvation method and was different depending on the method of exposure. Among energy sources, the total lipid in susceptible strain were decreasing more than resistant strain, whereas total proteins were increasing in resistant strain compared with sensitive strain. Total Glycogen was affected significantly in the stress condition which caused an increase and was the most resistant strain.     

Pro-active management of beet armyworm (Lepidoptera: Noctuidae) resistance to tebufenozide and methoxyfenozide: baseline monitoring,risk assessment,and isolation of resistance

Susceptibility to tebufenozide and methoxyfenozide of beet armyworm [Spodoptera exigua (Hübner)] from the southern United States and Thailand was determined through exposure of first and third instars to dipped cotton leaves. Among the field populations evaluated, tebufenozide LC50 values for first and third instars, respectively, ranged from 0.377 to 4.41 and 4.37-46.6 microg (AI) /ml of solution. Methoxyfenozide LC50 values for first and third instars of field populations ranged from 0.058 to 0.487 and 0.601-3.83 microg (AI)/ml of solution. A Thailand field strain exhibiting reduced susceptibility to both compounds was subjected to intense laboratory selection for three nonconsecutive generations. At the LC50 and LC90, selected Thailand strains were 45-68 times and 150-1,500 times less susceptible to tebufenozide and 340-320 times and 120-67 times less susceptible to methoxyfenozide as first and third instars, respectively, when compared with the laboratory reference strain. Among the U.S. field populations evaluated, ones from Belle Glade, FL, and Florence, SC, were generally the most susceptible and ones from Maricopa and Parker, AZ, were the least susceptible. Selection of the Thailand field strain with tebufenozide reduced susceptibility to both compounds, and selection of Thailand strains previously pressured with either compound further reduced susceptibility to both, suggesting at least some commonality of resistance mechanism. Characterization of this resistance will provide information that will be helpful for pro-active management of resistance for this valuable group of insecticides.     

Activation of a stress-induced gene by insecticides in the midge, Chironomus yoshimatsui

Stress proteins (heat shock proteins, HSPs) have been proposed as general biomarkers for environmental monitoring. In the present study, we evaluated the environmental stress-burden on the aquatic midge Chironomus yoshimatsui using hsp70 expression. Larvae collected from streams receiving polluted runoff (field strain) were resistant to the organophosphorus insecticide, fenitrothion (F), and the synthetic pyrethroid, ethofenprox (E), whereas a strain originally collected from an unpolluted area (susceptible strain) showed low resistance to insecticide exposure. To examine the expression of an HSP70 gene in C. yoshimatsui, an hsp70 cDNA probe was prepared using RNA obtained from the field strain larvae and used for Northern blot analyses. The expression of this HSP70 gene in larvae collected from two field sites in May about 1 week after insecticide spraying in the fields was 2.3 (p = 0.018) to 3.3 fold higher than that in the susceptible strain and was also 4.6 and 1.4 (p = 0.033) fold higher than those collected in November 3 months after the cessation of insecticide spraying. In order to identify potential inducers of the HSP70 gene of the field strain, larvae of the susceptible strain were exposed to F or E for 24 h and hsp70 mRNA levels determined. Exposures to F at 0.4 microg/L and E at 1.1 microg/L increased hsp70 mRNA levels 2.7 (p = 0.049) and 4.4 (p = 0.043) fold over controls, respectively. These results suggest that larvae collected from polluted areas are burdened by environmental stressors and the tested insecticides are potential inducers of HSP70. The results also support the suggestion that HSP70 gene expression is a sensitive indicator of low level (nonlethal) exposures to certain insecticides.     

Monitoring pyrethroid resistance in field collected Blattella germanica Linn. (Dictyoptera: Blattellidae) in Indonesia

The German cockroach, Blattella germanica , is a major and the most common pest in public areas in Indonesia. Although intensive control measures have been carried out to control the populations of this pest, results have been far from successful, which is believed to be because of its resistance to insecticides. A standard World Health Organization (WHO) glass jar test was carried out to determine the resistance level of this insect to pyrethroid insecticides, the most commonly used insecticides for cockroach control in Indonesia. A susceptible S1 strain collected from Tembagapura Papua was compared with four strains collected from Bandung, West Java: strain S2, from a local restaurant; strain S3, from the Bandung train station; and strains S4 and S5, from two different hotels. All strains showed low resistance to the pyrethroid, except the S5 strain, which had a Resistance Ratio (RR)₅₀ of 95 for permethrin. The addition of piperonyl butoxide (PBO) suggests that the detoxifying enzyme mixed function oxidases (MFO) played an important role in the development of resistance to permethrin in the S5 strain, suggested by the high Synergist Ratio (SR) of 70.4. However, the low level of resistance to cypermethrin was not affected by PBO, suggesting that other mechanisms of pyrethroid resistance are involved. Our study is the first report of German cockroach resistance to permethrin in Indonesia, and the findings can be used in formulating potential strategies for cockroach resistance management.     

Three anamorphic yeast species Candida sanitii sp. nov., Candida sekii sp. nov. and Candida suwanaritii, three novel yeasts in the Saturnispora clade isolated in Thailand

Nine strains of three novel anamorphic yeast species were obtained from samples collected in Thailand including six strains (RV96, RV152, R14, RS9, RS58 and EA1) obtained from estuarine waters collected from two mangrove forests, one strain (ST84) from insect frass and two strains (SR16 and UB13) from forest soils. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analysis of the D1/D2 domain of the large subunit rRNA gene, the nine strains were found to represent three novel Candida species in the Saturnispora clade. Five strains (RV96, RV152, R14, RS9 and RS58) were assigned as a single novel species, which was named Candida sanitii sp. nov. The type strain is RV152^T (BCC 25967^T=NBRC 103864^T=CBS 10864^T). Strain EA1 was named as Candida suwanaritii sp. nov. The type strain is EA1^T (BCC 29900^T=NBRC 104877^T=CBS 11021^T). Three strains (ST84, SR16 and UB13) represented another novel species, for which Candida sekii sp. nov. is proposed. The type strain is ST84^T (BCC 8320^T=NBRC 105671^T=CBS 10931^T).