Do larvae of species in macrolepidopteran assemblages share traits that influence susceptibility to parasitism?

Research on how morphology, behavior, and life histories of insects determine their susceptibility to parasitism has primarily focused on the traits of single host species. Very little research has been conducted attempting to determine if similarities or differences in the traits of co-occurring species, on a single plant or in a habitat, influence levels of parasitism imposed on any member of an assemblage. In this study, we use categorical and regression tree analyses to determine which traits of the larvae of macrolepidopteran species are associated with highest levels of parasitism. Of a variety of morphological, behavioral, and ecological traits of 72 species (representing eight families), caterpillar color was the trait that had the greatest influence on susceptibility to parasitism. The highest levels of parasitism were associated primarily with green larvae. These results suggest that the herbivore species composition and, specifically, the traits possessed by the species may influence community or assemblagewide patterns of parasitism. That is, sharing of traits that enhance host finding and successful parasitism may result in associational susceptibility to parasitism, whereas co-occurrence with species that differ morphologically, behaviorally, or ecologically may reduce the likelihood of parasitism and thus result in associational resistance. The concepts of associational resistance and susceptibility have historically been restricted to plant-plant interactions. The extension of these concepts to herbivores is novel. If found to be widespread, these interactions can have significant impacts on our expectations of the effectiveness of biological control agents.     

Insecticide susceptibility and resistance of Blattella germanica (Blattaria: Blattellidae) in Seoul, Republic of Korea, 2007

The susceptibility of Blattella germanica (L.) in the Republic of Korea (ROK) to insecticides was evaluated under laboratory conditions using 12 insecticides currently used by the local public health centers and/or pest control operators in the ROK. The insecticides included seven pyrethroids and five organophosphates. Based on their LD₅₀ values, the order of susceptibility of B. germanica adults to the insecticides was chlorpyrifos-methyl, profenofos and chlorpyrifos with values of 0.07, 0.29 and 0.88 µg/♀, respectively. The least susceptibility was obtained with tetramethrin at LD₅₀ of 7.39 µg/♀. In the comparative resistance test, the resistance ratios (RR) of 12 insecticides were compared to each other using field-collected B. germanica adults in Seoul between 1993 and 2007. Blattella germanica demonstrated higher RRs to pyrethroids such as λ-cyhalothrin, and low RRs among the organophosphates. Among the pyrethroids, λ-cyhalothrin had the highest RRs of 111- and 129-fold differences at LD₅₀ and LD₉₀ values, respectively. Among the organophosphates, profenofos was observed to have the highest RRs of 4- and 15-fold differences at LD₅₀ and LD₉₀ values, respectively. However, there were no significant differences in susceptibility to tetramethrin, chlorpyrifos and fenitrothion. Blattella germanica was more susceptible to pyridafenthion showing a 0.7-fold difference in a resistance ratio (RRLD₅₀= LD₅₀ value of 2007/LD₅₀ value of 1993). Resistance ratio of tetramethrin was low, but susceptibility was also not high.     

Abstracts of the 4th annual meeting of the European society for chronobiology jointly with the 3rd annual meeting of the British society for chronobiology,Birmingham, UK., July 9–12,1988

Abstract

In common voles (Microtus arvalis) and golden hamsters (Mesocricetus auratus) circadian changes in the susceptibility to acute dosing of rodenticides, zinc phosphide and crimidine, were investigated. Animals were dosed at four different times of day (2.00, 8.00, 14.00, 20.00 h) and mortality, convulsive seizure, latency period to first seizure, and running wheel activity were studied. Both voles and hamsters showed the highest susceptibility to zinc phosphide during the light period. In case of crimidine, circadian pattern of susceptibility was noted only in hamsters with the highest mortality during the beginning of the dark period. The data demonstrate that circadian changes in susceptibility to rodenticides have to be taken into account.     

Antimicrobial resistance among urinary tract infection (UTI) isolates in Europe: results from the SENTRY Antimicrobial Surveillance Program 1997

The SENTRY Antimicrobial Surveillance Program was established to monitor the occurrence and antimicrobial susceptibility of bacterial pathogens via an international network of sentinel hospitals. Twenty European hospitals referred a total of 887 urinary tract infection (UTI) isolates to the European SENTRY reference laboratory during the period October–December 1997. Ninety percent of the referred species were represented by Escherichia coli (52%), Enterococcus spp. (12%), Klebsiella spp. (7%), Proteus spp. (7%), Pseudomonas aeruginosa (7%), and Enterobacter spp. (5%). The susceptibility of E. coli isolates to penicillins was less than 60%, while almost all of the isolates were susceptible to piperacillin/tazobactam (98% susceptibility), cephalosporins (98%), and carbapenems (100%). Amikacin was the best aminoglycoside (99.8% susceptibility). The susceptibility to quinolones was only 88–89%, with highest levels of resistance observed for isolates from Portugal, Italy, England, The Netherlands, and some centers in France, Spain, and Poland. The susceptibility of Klebsiella spp. to the newer generations of cephalosporins was 82–95% and to the carbapenems 100%. Amikacin was again the best aminoglycoside (94% susceptibility). The susceptibility of Enterobacter spp. to any ß-lactam antibiotic was poor, except for the carbapenems (100% susceptibility) and cefepime (90% susceptibility), while the susceptibility to aminoglycosides was 80–89%. Proteus spp. showed complete susceptibility to cefepime, ceftriaxone, the carbapenems, and piperacillin/tazobactam, while the susceptibility of P. aeruginosa isolates was poor, with best results for the carbapenems (susceptibility 89%), piperacillin/tazobactam (susceptibility 84%), and amikacin and ticarcillin (susceptibility to both 80%). Enterococcus spp. showed the highest susceptibility to vancomycin (98%), teicoplanin (98%), and ampicillin (94%).     

Serosurveillance of susceptibility to rubella in a Mexican female group.

The susceptibility to rubella of a group of Mexican females of childbearing age was determined. Members of the group were selected based on the highest probability of having been exposed to the virus they were older than 15, and from a low socio-economic urban stratum. Anti-viral antibodies were determined by hemagglutination inhibition. Concentration was expressed as International Units of IgG anti-rubella hemagglutinin (IU). Antibody concentrations lower than 15.6 IU/ml were regarded as non-protective. A 16% susceptibility was found.     

Angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism in Mexican populations

The angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism was determined in 211 Mexican healthy individuals belonging to different Mexican ethnic groups (98 Mestizos, 64 Teenek, and 49 Nahuas). ACE polymorphism differed among Mexicans with a high frequency of the D allele and the D/D genotype in Mexican Mestizos. The D/D genotype was absent in Teenek and present in only one Nahua individual (2.0%). When comparisons were made, we observed that Caucasian, African, and Asian populations presented the highest frequencies of the D allele, whereas Amerindian (Teenek and Pima) and Australian Aboriginals showed the highest frequencies of the I allele. The distribution of I/D genotype was heterogeneous in all populations: Australian Aboriginals presented the lowest frequency (4.9%), whereas Nahuas presented the highest (73.4%). The present study shows the frequencies of a polymorphism not analyzed previously in Mexican populations and establishes that this polymorphism distinguishes the Amerindian populations of other groups. On the other hand, since ACE alleles have been associated with genetic susceptibility to developing cardiovascular diseases and hypertension, knowledge of the distribution of these alleles could help to define the true significance of ACE polymorphism as a genetic susceptibility marker in the Amerindian populations.     

Insecticide susceptibility and resistance of larvae of the Anopheles sinensis Group (Diptera: Culicidae) from Paju, Republic of Korea

The susceptibility of members of the Anopheles sinensis Group in Korea to insecticides was evaluated under laboratory conditions using 15 insecticides currently used by local public health centers in Korea. The insecticides included eight pyrethroids, six organophosphates and a pyrazol analogue. Based on their LC₅₀ values, the order of susceptibility of An. sinensis larvae to the insecticides was bifenthrin, chlorfenapyr, α-cypermethrin and λ-cyhalothrin, with values of 0.009, 0.04, 0.06 and 0.08 p.p.m., respectively. The least susceptibility was obtained with fenitrothion, with an LC₅₀ of 7.7 p.p.m. In the comparative resistance test, the resistance ratios (RR) of 14 insecticides were compared to each other using two strains of members of the An. sinensis Group collected in the locality in 2001 and 2008. Anopheles spp. demonstrated higher RR to organophosphates such as fenthion, and low RR for the pyrethroids. Among the organophosphates, fenthion had the highest RR of 33.3 and 270.0 fold differences for LC₅₀ and LC₉₀ values, respectively. Among the pyrethroids, permethrin was observed to have the highest RR of 3.8 and 1.8 fold differences for LC₅₀ and LC₉₀ values, respectively. However, there were no significant differences in susceptibility to chlorfenapyr, chlorpyrifos, deltamethrin and fenitrothion. An. sinensis s. l. was more susceptible to the six insecticides bifenthrin, λ-cyhalothrin, α-cypermethrin, cypermethrin, cyfluthrin and pyridafenthion, showing 0.03, 0.06, 0.3, 0.3, 0.4 and 0.4 fold differences in resistance rates (RR LC₅₀), respectively.     

小菜蛾对杀虫剂的敏感性与其抗药性的相关性

在开展云南省通海县小菜蛾Plutella xylostella(L.)种群对11种杀虫剂的敏感性的同时,对小菜蛾抗药性进行了测定,并分析二者之间的相关性,结果表明:小菜蛾对杀虫剂的敏感性与其抗药性总体上呈现负相关,即随着抗药性的增加,小菜蛾对杀虫剂的敏感性呈下降趋势,但相关性并不显著。如在无抗性至高抗性的杀虫剂之间,其敏感性并无明显的变化,处理间无差异,只有对其极高抗性的阿维菌素、虫酰肼和高效氯氰菊酯才表现出明显的下降趋势。因此,在实际生产过程中,一种药剂是否因抗药性增加而不能使用,还应该参照田间防治效果。     

Effect of certain cultural practices on susceptibility of potato tubers to soft rot disease caused by Erwinia carotovora pv. carotovora

Erwinia soft rot causes destructive and serious damage to many vegetable crops including potato in the field, transit and storage periods. The effect of certain cultural practices on the susceptibility of potato tubers to soft rot bacteria was studied and the results of this work can be summarised in the following: potato tubers harvested on 1 May first exhibited the highest disease incidence compared with those harvested on 15 May or 30 May. Harvesting on 15 June resulted in the lowest disease infection. The application of high levels of nitrogen fertiliser as urea (46.5%), ammonium nitrate (31%) and ammonium sulphate (20.5%) resulted in an increase of the susceptibility of potato tubers to bacterial soft rot disease. In contrast, the addition of phosphorous as superphosphate (15.5%) fertiliser caused the reverse effect. The addition of potassium as potassium sulphate (48%) alone at any of the tested levels showed no effect. The susceptibility of potato tubers to bacterial soft rotting disease was increased by increasing storage periods at 4°C for 1, 2, 3 and 4 months. Spraying copper sulphate exhibited the highest decrease in soft rot incidence disease followed by manganese, zinc and iron. However, spraying of boron increased susceptibility to the disease. Potato tubers obtained from plants sprayed with copper and stored for different periods showed the lowest susceptibility to disease incidence. Tuber sprayed with zinc, iron, manganese and finally boron came next.     

The influence of visibility and escape ability on sex-specific susceptibility to fish predation in Eudiaptomus gracilis (Copepoda,Crustacea)

The susceptibility to fish predation in males, ovigerous, and non-ovigerous females of the freshwater copepod Eudiaptomus gracilis is investigated in the laboratory by direct observation of the predation sequence of zebrafish, and by studying mortality when confronted with zebrafish or roach. Ovigerous females had the highest encounter rate indicating that the highly visible egg-clutch is a major determinant of their susceptibility. Males were least successful in escaping, the main reason being their inability or disinclination to react fast enough when attacked. This difference in escape reaction may have evolved because of sex-specific requirements in mate encounter and mate location. Ovigerous females and males had higher mortality than non-ovigerous females in all experiments while ovigerous mortality was higher than male mortality only in the zebrafish experiments. Neither experiment showed any difference in male and overall female mortality but as a consequence of the abrupt change in susceptibility between the ovigerous and non-ovigerous condition, it follows that sex-specific mortality rates may be dependent on the reproductive condition within diaptomid populations. A consequence of the sex-specific difference in escape ability is that the sex-specific mortality may be influenced by variation in the attack efficiency within and among predator populations.     

Carcinogen susceptibility is regulated by genome architecture and predicts cancer mutagenesis

The development of many sporadic cancers is directly initiated by carcinogen exposure. Carcinogens induce malignancies by creating DNA lesions (i.e., adducts) that can result in mutations if left unrepaired. Despite this knowledge, there has been remarkably little investigation into the regulation of susceptibility to acquire DNA lesions. In this study, we present the first quantitative human genome‐wide map of DNA lesions induced by ultraviolet (UV) radiation, the ubiquitous carcinogen in sunlight that causes skin cancer. Remarkably, the pattern of carcinogen susceptibility across the genome of primary cells significantly reflects mutation frequency in malignant melanoma. Surprisingly, DNase‐accessible euchromatin is protected from UV, while lamina‐associated heterochromatin at the nuclear periphery is vulnerable. Many cancer driver genes have an intrinsic increase in carcinogen susceptibility, including the BRAF oncogene that has the highest mutation frequency in melanoma. These findings provide a genome‐wide snapshot of DNA injuries at the earliest stage of carcinogenesis. Furthermore, they identify carcinogen susceptibility as an origin of genome instability that is regulated by nuclear architecture and mirrors mutagenesis in cancer.     

346株鲍曼不动杆菌临床分布及耐药率分析

目的了解鲍曼不动杆菌引起医院感染的特点以及对抗菌药物的耐药性的变化趋势。方法应用美国BD公司Phoenix^TM100全自动细菌和药敏系统鉴定仪对所分离的364株鲍曼不动杆菌进行鉴定和药敏试验,并进行统计学分析。结果 346株鲍曼不动杆菌来自痰液、伤口分泌物、中段尿、静脉血及大便,分别占58.96%、30.92%、5.49%、4.34%、0.29%。药敏结果显示鲍曼不动杆菌对多粘菌素和米诺环素敏感性最高,耐药率低于10.4%。结论加强鲍曼不动杆菌的耐药监测,了解其耐药性变迁,可合理指导用药,有效控制鲍曼不动杆菌耐药菌株的产生。     

High susceptibility of Neotricula aperta gamma-strain from Krakor and Sdau in Cambodia to Schistosoma mekongi from Khong Island in Laos

Neotricula aperta gamma-strain snails collected from Krakor and Sdau in Cambodia were found to have the same or higher susceptibility to Schistosoma mekongi as N. aperta originally isolated from Khong in Laos. Infection rates of N. aperta gamma-strain snails exposed to 3 miracidia at week 8 were: Khong gamma-strain, 22.6%; Krakor gamma-strain, 33.3%; and Sdau gamma-strain, 67.4%. At week 10, the Sdau gamma-strain showed the highest infection rate of 83.3%. We thus found significantly high susceptibility of the Sdau gamma-strain to S. mekongi originally isolated from Khong. However, in another experiment, susceptibility of the Sdau gamma-strain was rather comparable to that of Khong and Krakor gamma-strain. We also found no significant differences in infection and survival rates between the Khong and Krakor gamma-strain when the snails were exposed to 3 or 6 miracidia. This is the first report to confirm the high susceptibility in the laboratory of N. aperta gamma-strain snails from endemic areas in Cambodia to S. mekongi originally isolated from Laos. The high susceptibility of N. aperta gamma-strain snails to S. mekongi in distant areas may be an important factor in the endemic transmission of human schistosomiasis.     

大鼠动情周期雌激素水平变化对晕动病易感性的影响

目的：众多的流行病学研究和动物实验表明,晕动病存在明显的性别差异,特别是雌激素对晕动病易感性可能存在某些易化的调节作用,本研究为探讨“异食癖”模型上大鼠动情周期雌激素水平的变化对晕动病易感性的影响。方法：大鼠在不同的动情周期,给予足够的旋转刺激以后,通过摄取高岭土量的变化评价大鼠的晕动病反应,同时测定血浆雌激素（E2和P）水平,观察雌激素水平的变化对晕动病易感性的影响。结果：大鼠体内的雌性激素（E2和P）水平随着动情周期而发生波动,在动情期时,E2水平达到最高,而在动情前期则达到最低。P水平在动情间期和动情前期较高而在动情期与动情后期较低。足够的旋转刺激之后,大鼠的摄取高岭土量显著增加,并且呈现与大鼠动情周期雌激素水平波动的一致性,即动情期时摄取高岭土量最多。结论：大鼠动情周期雌激素水平的升高可能在一定程度上会加重大鼠的晕动病反应。可为进一步探讨雌激素水平与晕动病易感性之间的关系提供参考,从而也可能为发现晕动病新病因的研究打下基础,还可能为晕动病预防策略和措施启发新的应用价值。     

Varietal susceptibility of potatoes to wireworm herbivory

1 Wireworms, the soil dwelling larvae of click beetles, Agriotes spp., have recently become a more prevalent pest of potatoes. The present study investigated whether potato varieties showed variable susceptibility to wireworm herbivory, and also tested whether increased susceptibility was associated with lower concentrations of glycoalkaloids. Twelve varieties were originally screened across a range of experimental scales, including laboratory and tunnel experiments and a large‐scale field trial involving over 2000 tubers. 2 In laboratory no‐choice tests, Maris Peer, Marfona and Rooster varieties were significantly more susceptible to wireworm attack, with 63% of tubers showing damage, compared with just 15% of the less susceptible varieties of King Edward, Nadine and Maris Piper. There was also greater tissue consumption and weight gain when wireworms were reared on the most susceptible varieties. 3 In choice tests, wireworms showed a significant preference for those varieties previously identified as being the most susceptible to wireworm herbivory (4.2 holes per tuber) compared with the least susceptible (1.2 holes per tuber). Similar patterns of susceptibility were seen in the field trial, although there was generally more variation in susceptibility. 4 In a tunnel experiment, Marfona and Maris Peer were significantly more susceptibile to wireworm attack (47% of tubers showing damage) compared with Nadine, King Edward and Maris Piper (27% of tubers showing damage). Although Nadine, in particular, had the highest glycoalkaloid concentrations (309.33 mg/kg) and lowest amounts of wireworm herbivory, the relationship between susceptibility and glycoalkaloid concentrations was weak, suggesting that this is unlikely to be the sole mechanism underpinning varietal susceptibility.     

黄曲条跳甲对毒死蜱敏感性差异的生化机制

采用生物测定方法测定黄曲条跳甲Phyllotreta striolata(F.)2个室内试验种群(蔊菜试验种群、上海青试验种群)和1个田间自然种群对毒死蜱的LC50值。结果表明,蔊菜试验种群对毒死蜱的LC50值最低,为30.3459mg.L-1;田间自然种群对毒死蜱的LC50值最高,为77.8448mg.L-1,与蔊菜试验种群相比的敏感性指数为0.39。对不同种群黄曲条跳甲乙酰胆碱酯酶(AChE)、羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GSTs)的活性测定结果表明,黄曲条跳甲田间自然种群AChE活性最低,与菜试验种群、上海青试验种群相比,差异极显著(P>0.01);田间自然种群GSTs活性最高,与蔊菜试验种群、上海青试验种群相比,差异极显著(P>0.01);黄曲条跳甲蔊菜试验种群CarE活性最低,田间自然种群CarE活性最高,二者差异极显著(P>0.01);说明黄曲条跳甲对毒死蜱的敏感性下降可能与AChE活性的降低,与CarE、GSTs的活性提高有一定的关系。     

Cross-resistance of Cry1Ab-selected Ostrinia nubilalis (Lepidoptera: Crambidae) to Bacillus thuringiensis delta-endotoxins

Corn plants expressing the toxin from Bacillus thuringiensis (Berliner) have proven to be effective in controlling lepidopteran pests such as the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). Several Bt toxins are being tested and incorporated into crop genomes, although tests for cross-resistance among different toxins have been limited by a lack of resistant colonies. Four different colonies of O. nubilalis selected with full-length Cry1Ab incorporated into artificial diet developed significant levels of resistance (2.0- to 10-fold) within 10 generations. Additionally, selection with Cry1Ab resulted in decreased susceptibility to a number of other toxins to which the selected colonies were not previously exposed. Significantly, levels of resistance were highest to Cry1Ac with resistance ratios up to 51.0-fold. Low levels (less than five-fold) of cross-resistance were detected with Cry1F. In contrast, Cry9C susceptibility was unaffected by selection with Cry1Ab. These results indicate that the availability of multiple toxins could improve resistance management strategies, provided cross-resistance among toxins is not a factor.     

5种常用鱼药对黑尾近红鲌鱼种的急性毒性实验

在常温静水条件下,用硫酸铜与硫酸亚铁合剂(比例5∶ 2)、高锰酸钾、晶体敌百虫、强氯精、溴氯菊脂等5种常用水产药物对黑尾近红鲌鱼苗进行急性毒性试验.试验结果表明,安全浓度最高的是高锰酸钾为0.738 mg/L,安全浓度最低的是溴氯菊脂为0.0033 mg/L, 5种常用水产药物对黑尾近红鲌鱼苗都比较敏感,药物的敏感性大小依次为:溴氯菊脂>强氯精>敌百虫>硫酸铜与硫酸亚铁合剂>高锰酸钾.     

金黄色葡萄球菌的耐药性分析及基因分型研究

目的通过分析上海地区院内分离金黄色葡萄球菌的药敏谱型及对耐甲氧西林的金黄色葡萄球菌（MRSA）进行基因谱型的研究,了解金黄色葡萄球菌的院内流行状况。方法对临床分离出的43株金黄色葡萄球菌进行药敏试验和SCCmec基因盒的多重PCR检测,并将结果整合后用MEGA3．1软件分析其进化相关关系。结果药敏结果显示43株金葡菌对青霉素和甲氧西林的耐药率最高。甲氧西林的耐药率达到62．8％。MecA阳性菌株SCCmec的分型显示均为Ⅱ型或Ⅲ型,且所占比例相近,未见Ⅰ型和Ⅳ型。进化树分析发现了在同一医院中亲缘关系相近的菌株,为院内感染流行株。结论MecA基因介导的MRSA在分离菌株中所占比例高,存在院内感染爆发性流行。     

Evidence of Field-Evolved Resistance to Bifenthrin in Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) Populations in Western Nebraska and Kansas

Pyrethroid insecticides have been used to control larvae or adults of the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, a key pest of field corn in the United States. In response to reports of reduced efficacy of pyrethroids in WCR management programs in southwestern areas of Nebraska and Kansas the present research was designed to establish a baseline of susceptibility to the pyrethroid insecticide, bifenthrin, using susceptible laboratory populations and to compare this baseline with susceptibility of field populations. Concentration-response bioassays were performed to estimate the baseline susceptibility. From the baseline data, a diagnostic concentration (LC₉₉) was determined and used to test adults of both laboratory and field populations. Larval susceptibility was also tested using both laboratory and field populations. Significant differences were recorded in adult and larval susceptibility among WCR field and laboratory populations. The highest LC₅₀ for WCR adults was observed in populations from Keith 2 and Chase Counties, NE, with LC₅₀s of 2.2 and 1.38 μg/vial, respectively, and Finney County 1, KS, with 1.43 μg/vial, as compared to a laboratory non-diapause population (0.24 μg/vial). For larvae, significant differences between WCR field and laboratory populations were also recorded. Significant differences in mortalities at the diagnostic bifenthrin concentration (LC₉₉) were observed among WCR adult populations with western Corn Belt populations exhibiting lower susceptibility to bifenthrin, especially in southwestern Nebraska and southwestern Kansas. This study provides evidence that resistance to bifenthrin is evolving in field populations that have been exposed for multiple years to pyrethroid insecticides. Implications to sustainable rootworm management are discussed.