姜黄素类化合物对朱砂叶螨的生物活性

分别用玻片浸渍法和叶片浸渍法测定了从姜黄中分离的姜黄素(curcumin,CCM)、去甲氧基姜黄素(demethoxycurcumin,DMC)和双去甲氧基姜黄素(bisdemethoxycurcumin,BDMC) 3种天然姜黄素类化合物对朱砂叶螨Tetranychus cinnabarinus Boisduval的成螨、若螨、卵的触杀活性以及对成螨产卵的抑制作用。结果表明：3种化合物对朱砂叶螨的生物活性大小依次为BDMC>DMC>CCM。3种化合物对朱砂叶螨成螨触杀活性最高者为BDMC,处理24 h和48 h其LC₅₀分别为1.18和0.51 mg/mL。对若螨触杀活性的大体趋势与对成螨的相同,其中处理48 h,BDMC对若螨的LC₅₀最小,为2.48 mg/mL。3种化合物对朱砂叶螨卵的触杀毒力也同样表现为BDMC>DMC>CCM。3种单体化合物都表现出一定的对朱砂叶螨雌成螨的产卵抑制作用。对姜黄素类化合物构效关系的初步研究,明确了甲氧基在姜黄素模板上对杀螨活性的贡献,对于开发具经济价值的叶螨类杀螨剂或者筛选先导化合物模板,具有一定的参考价值。     

Optimization of the microemulsion formulation of curcuma oil and evaluation of its acaricidal efficacy against Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae)

The microemulsion formulation (hereafter formulation) of curcuma oil and its acaricidal efficacy against Tetranychus cinnabarinus Boisduval (Acari: Tetranychidae) were optimized in the laboratory to evaluate their spray effectiveness of oviposition inhibition and repellence. Ethovision XT6 was used to analyse the effects of the sublethal concentrations (LC₂₀) of curcuma oil and the formulation on the behaviors of T. cinnabarinus. The results showed that Tween-80 was the best surfactant, Isopropanol was the best co-surfactant and K_m = 2:1 was the best condition for the formulation. The prepared microemulsions are stable under conditions of centrifugation and incubation for extended periods. The results showed that the effect of the spray bioassays of the formulation against T. cinnabarinus continuously increased during the experiment, but for curcuma oil almost no longer increase observed when the exposure time went beyond 24 h. Moreover, compared with curcuma oil (LC₅₀ = 0.716%), the spray bioassay of the formulation (LC₅₀ = 0.035%) was stronger against T. cinnabarinus. The repellency of the formulation to T. cinnabarinus was stronger with increasing exposure time, but that of curcuma oil declined after 12 h of exposure. The mobile distance of T. cinnabarinus treated with the formulation continuously declined during the experiment but that due to the curcuma oil almost no longer declined when the treatment time reached 12 h. The maximum mobile frequency of T. cinnabarinus treated by curcuma oil and the formulation was recorded at 6 h and 12 h, respectively. Thus, the formulation is a promising candidate as a botanical acaricide of green vegetables.     

共生菌Cardinium对朱砂叶螨的生殖调控作用

为了了解共生菌Cardinium对朱砂叶螨Tetranychus cinnabarinus (Boisduval)的生殖调控作用,从检测到感染Cardinium的种群中选取山西运城和甘肃兰州2个感染率较高的种群作为实验材料,对Cardinium在寄主生殖调控方面的作用进行研究。通过人工培养100%感染Cardinium的种群和100%不感染的种群,并从中挑取不同感染类型的雌雄螨单独进行杂交实验,设立感染Cardinium(♀)×感染Cardinium(♂),感染Cardinium(♀)×不感染(♂),不感染(♀)×感染Cardinium(♂),不感染(♀)×不感染(♂) 4种杂交组合。结果发现,抗生素处理后不感染的雌螨和受感染雄螨的交配表现出了单向的胞质不亲和,而且2个种群表现出了2种类型：在山西种群不亲和的组合中,CI表现为卵孵化率显著降低,多数雌螨都产生出F₁雌螨后代,但是F₁代雌螨数量相对于其他3种组合明显减少; 而在甘肃种群不亲和的组合中则表现为卵全部孵化且幼螨100%存活,但全部为雄螨后代。2个种群中Cardinium的亲缘关系非常相近,而它们却能够在不同的地理种群中表现出不同的CI表型,这提示亲缘关系非常接近的品系也可以产生不同的表型。研究结果为深入揭示Cardinium的感染机制和生殖调控作用提供重要基础。     

东莨菪内酯对朱砂叶螨实验种群的亚致死效应

为明确东莨菪内酯对朱砂叶螨Tetranychus cinnabarinus (Boisduval) 实验种群的亚致死效应, 为其作为植物源杀螨剂的进一步开发及应用提供理论依据, 在室内采用叶碟饲养的方法, 并利用生命表技术研究了东莨菪内酯亚致死剂量对朱砂叶螨F₀代和F₁代种群生长发育和繁殖的影响。结果表明： 东莨菪内酯LC₄₀, LC₃₀和LC₂₀剂量处理朱砂叶螨雌成螨后, 可刺激F₀代雌成螨产卵, 使产卵量分别增加了73.82%, 186.97%和70.18%, 而对成螨寿命、 产卵期和雌雄性比没有影响; F₁代的卵期、 幼螨期和若螨期与对照没有显著性差异 (P>0.05), 而成螨期和雌成螨寿命均低于对照; 对F₁代繁殖力的影响主要表现为产卵期缩短、 产卵量减少和雌性比下降; 子代种群的净生殖率(R₀)由50.5976最低降至33.9910, 世代平均历期(T)和种群倍增时间(Dt)均低于对照, 各处理后的朱砂叶螨种群均存在适合度缺陷。这些结果表明, 在亚致死剂量下, 东莨菪内酯能够降低朱砂叶螨种群的发育和繁殖速率, 这对东莨菪内酯在有害生物防治上的应用具有积极意义。     

东莨菪内酯与双脱甲氧基姜黄素对朱砂叶螨毒力的温度效应

为明确植物性杀螨活性物质东莨菪内酯与双脱甲氧基姜黄素对朱砂叶螨Tetranychus cinnabarinus雌成螨毒力的温度效应, 采用玻片浸渍法测定了两者不同温度下的杀螨活性。结果表明： 在8～26℃的温度范围内, 东莨菪内酯和双脱甲氧基姜黄素对朱砂叶螨雌成螨的毒力呈正温度系数; 在26～34℃的温度范围内两者对朱砂叶螨雌成螨的毒力呈负温度系数。其中26℃下东莨菪内酯和双脱甲氧基姜黄素表现出较好杀螨活性, 处理后48 h的致死中浓度(LC₅₀)分别为0.1884和0.3376 mg/mL; 23℃下的毒力次之。致死中浓度(y)与温度(x)关系的拟合方程为： 东莨菪内酯: y₁= 0.006x₁²-0.278x₁+3.403; 双脱甲氧基姜黄素: y₂=0.007x₂²-0.354x₂+4.826。对y求最小值得出, 东莨菪内酯和双脱甲氧基姜黄素对朱砂叶螨雌成螨的最高毒力温度分别为23.2℃和25.3℃, LC₅₀分别为0.1828和0.3504 mg/mL。据此认为, 在一定的温度范围内, 随着温度的升高, 这两种植物性杀螨活性物质对朱砂叶螨的毒力与温度先呈正相关, 到达最佳毒力温度后再呈负相关。     

Antioxidant responses of the pest natural enemy Hylyphantes graminicola (Araneae: Linyphiidae) exposed to short-term heat stress

Temperature is a critical abiotic factor that causes physiological changes in arthropods. However, little is known about the effect of heat stress on the antioxidant responses of Araneae species. Hylyphantes graminicola is a dominant predator in many cropping systems in China. In the present study, the effect of short-term heat stress (36, 38, 40 or 42 °C) on the reactive oxygen species (ROS) levels, the activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], peroxidases [POD] and glutathione-S-transferases GST]), total antioxidant capacity (TAC), malondialdehyde (MDA) concentrations and survival of H. graminicola spiderlings and adults were investigated. The results showed that H. graminicola adults had a significantly higher survival rate compared to spiderlings at 40 °C. The heat stress increased ROS contents in H. graminicola. The SOD, CAT, POD and GST activities increased in spiderlings and adults under heat stress. These data suggest a defensive function for these enzymes in alleviating oxidative damage. Specifically, SOD plays a key role in reducing the high level of superoxide radicals in spiderlings and adults. Moreover, the POD and CAT capabilities for scavenging H₂O₂ in spiderlings were similar, and CAT may play a more important role than POD in scavenging H₂O₂ in adults at 42 °C. The spiderling TAC increased significantly at 40 and 42 °C, and the adult TAC was stable at 36–40 °C but decreased at 42 °C. These data suggest that TAC was insufficient in H. graminicola adults under more severe stress conditions. These results further our understanding of the physiological response of Araneae species exposed to heat stress.     

Biological parameters of the predatory mite Cheletomimus bakeri (Acari: Cheyletidae) feeding on Tetranychus cinnabarinus (Acari: Tetranychidae)

Developmental periods of egg, larva and nymphal stages and fecundity as well as predation of Cheletomimus bakeri (Acari: Cheyletidae) feeding on Tetranychus cinnabarinus (Acari: Tetranychidae) were evaluated at different temperatures (15, 20, 25, 30 and 35°C) at 65 ± 10% relative humidity and 16 L: 8D in the laboratory. The development periods of C. bakeri from egg through adult decreased significantly when the temperature was increased from 20°C to 35°C. Egg and total development periods of C. bakeri at 20, 25, 30 and 35°C were 13.86, 7.98, 5.07, 4.08 days and 58.66, 41.51, 21.21, 22.92 days, respectively. The highest numbers of total and daily egg production were found at 20°C and 30°C, respectively. Net reproductive rate (R₀ = 13.29), mean generation time (T = 88.30), gross reproductive rate (GRR = 17.46) and doubling time (DT = 23.66) were the highest at 20°C. The intrinsic rate of increase (r_m = 0.0592) and finite capacity for increase (λ = 1.061) for C. bakeri were the highest at 30°C. Predation of C. bakeri increased throughout the range of prey densities. The highest consumption number of C. bakeri feeding on T. cinnabarinus males per day was 4.63, 4.70 and 4.60 when confined to 40, 80 and 160 individuals, respectively. Our data suggest that C. bakeri does not appear to have much promise for the control of spider mites because of the characteristics of the predator such as slow development period, poor searching capacity and low intrinsic rate of increase.     

Effects of simulated acid rain on the physiology of carmine spider mite, Tetranychus cinnabarinus (Boisduvals) (Acari: Tetranychidae)

Abstract:  The physiological effect of simulated acid rain sprayed on carmine spider mite Tetranychus cinnabarinus (Boisduvals) and host plant, were measured in a series of laboratory trials. We examined potential changes in three kinds of protective enzymes [peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT)] and three hydrolases [acid phosphatase (ACP), alkaline phosphatase (ALP) and carboxylesterase (CarE)] in response to changes in pH values of simulated acid rain at different time of exposure. POD, SOD and CAT activities increased significantly with the increase in the acidity of the acid rain, reaching the highest levels at pH 4.0 or 3.0, and then declined. Changes in ACP activity were similar to those observed in the protective enzymes. The increasing extent of the activities of these four enzymes after 30 and 45 days treatment became smaller than that after 15 days treatment . ALP activities decreased as pH value declined. There were no significant changes in CarE activities after 15 and 45 days, but that in pH 4.0 and 3.0 decreased after 30 days. The enhanced anti-oxidation enzyme levels (POD, SOD and CAT) and ACP activities in pH 4.0 and 3.0 reduced the effects of these toxic products on mites, resulting in the strengthening of the defensive power, and increase in survival and reproductive power of the mites, thus leading to an increase in the density of mites on host plant. From these results, we inferred that POD, SOD, CAT and ACP might be relevant to population changes of mites under acid rain pressure.     

Lethal and sublethal effects of synthetic insecticides on the locomotory and feeding behavior of Riptortus pedestris (Hemiptera: Alydidae) under laboratory conditions

The bean bug, Riptortus pedestris (Hemiptera: Alydidae) is a polyphagous insect pest and has a wide range of hosts including leguminous plants and tree fruits. Currently, the management of R. pedestris mainly relies on the use of insecticides, and most studies have focused on the lethal effects of insecticides. However, insecticides can not only kill insects directly, but can also affect behavioral changes of survivors when exposed to sub-lethal doses. In this study, we investigated locomotory behaviors (vertical movement, horizontal movement, and flight ability) and feeding behaviors (frequency of insects approaching dried soybean seeds and number of stylet sheaths left on the dried soybean seeds by insects) of surviving R. pedestris pre-exposed to five insecticide residues for 4 h. None of the three insecticides (bifenthrin, etofenprox, and acetamiprid) tested had significant effects on the locomotory behaviors of R. pedestris adults compared to the water-treated control group. Fenitrothion- and dinotefuran-treated groups showed a significant decrease in the vertical movement compared to the water-treated control, but the insects recovered mobility 24 h after the initial exposure. The frequency of R. pedestris approaching to dried soybean seeds was affected by four insecticides (fenitrothion, etofenprox, bifenthrin, and dinotefuran), but the actual feeding activity of R. pedestris determined by the stylet sheaths remaining on the dried soybean seed was only affected by fenitrothion treatment. Given the relatively low toxic effects of five insecticides tested, a better understanding of the impact of insecticides on the behavior of target species is needed for a more robust pest control strategy and a more effective use of insecticides in IPM programs.     

Effects of reproductive status on behavioral and endocrine responses to acute stress in a biparental rodent, the California mouse (Peromyscus californicus)

In several mammalian species, lactating females show blunted neural, hormonal, and behavioral responses to stressors. It is not known whether new fathers also show stress hyporesponsiveness in species in which males provide infant care. To test this possibility, we determined the effects of male and female reproductive status on stress responsiveness in the biparental, monogamous California mouse (Peromyscus californicus). Breeding (N = 8 females, 8 males), nonbreeding (N = 10 females, 10 males) and virgin mice (N = 12 females, 9 males) were exposed to a 5-min predator-urine stressor at two time points, corresponding to the early postpartum (5-7 days postpartum) and mid/late postpartum (19-21 days postpartum) phases, and blood samples were collected immediately afterwards. Baseline blood samples were obtained 2 days prior to each stress test. Baseline plasma corticosterone (CORT) concentrations did not differ among male or female groups. CORT responses to the stressor did not differ among female reproductive groups, and all three groups showed distinct behavioral responses to predator urine. Virgin males tended to increase their CORT response from the first to the second stress test, while breeding and nonbreeding males did not. Moreover, virgin and nonbreeding males showed significant behavioral changes in response to predator urine, whereas breeding males did not. These results suggest that adrenocortical responses to a repeated stressor in male California mice may be modulated by cohabitation with a female, whereas behavioral responses to stress may be blunted by parental status.     

The calming effect of stimuli presentation on infant Japanese Macaques (Macaca fuscata) under stress situation: a preliminary study

In human newborns, presentation of sounds and odors under stress situations had a calming effect on behavioral and cortisol responses (Kawakami et al., 1996, 1997). These calming effects were examined with 10-day- and 15-day-old Japanese macaques. In Study 1, white noise presentation (Experimental conditions) at the blood sampling was compared with no sound presentation (Control conditions) at the blood sampling. White noise presentation has a calming effect on coded behavioral responses. In Study 2, lavender scent presentation (Experimental conditions) at the blood sampling was compared with no odor presentation (Control conditions) at the blood sampling. Lavender presentation has a calming effect on cortisol responses in the marginal level. From the data of these studies, the salivary cortisol levels were related to the cortisol levels in plasma. Our results may suggest the different effects of sound and odor on infant Japanese macaques.     

不同环境温度下大草蛉对黄精主要害虫二斑叶螨的控害潜能评估

以重要中草药黄精Polygonattum sibiricium的主要害虫二斑叶螨Tetranychus urticae为研究对象,在5个温度(15℃、20℃、25℃、30℃及35℃)条件下,测定了大草蛉Chrysopa pallens雌成虫对二斑叶螨的捕食功能反应及搜索效应。试验结果表明,在温度处理设置范围内,各温度下大草蛉对二斑叶螨的捕食功能反应均拟合HollingII功能反应模型。大草蛉对二斑叶螨的捕食,受温度及猎物密度影响显著。而在各温度处理间,以25℃下的瞬间攻击率最大为0.664,而猎物处理时间最短为0.025d。瞬间攻击率在高温及低温条件下均低于25℃。但猎物处理时间则呈显出相反的趋势。基于捕食功能反应结果计算的搜索效应表明,大草蛉对二斑叶螨的搜索效应在各温度处理内随猎物密度增加而线性上升,其中以25℃下的捕食效应最高,而在15℃下的最低。本研究结果表明,大草蛉雌成虫作为一种捕食性天敌,对黄精上的二斑叶螨具有一定的控害潜能,并且其取食能力受环境温度影响显著。     

Enhanced lysosomal activity is involved in Bax inhibitor-1-induced regulation of the endoplasmic reticulum (ER) stress response and cell death against ER stress: involvement of vacuolar H+-ATPase (V-ATPase)

Bax inhibitor-1 (BI-1) is an evolutionarily conserved protein that protects cells against endoplasmic reticulum (ER) stress while also affecting the ER stress response. In this study, we examined BI-1-induced regulation of the ER stress response as well as the control of the protein over cell death under ER stress. In BI-1-overexpressing cells (BI-1 cells), proteasome activity was similar to that of control cells; however, the lysosomal fraction of BI-1 cells showed sensitivity to degradation of BSA. In addition, areas and polygonal lengths of lysosomes were greater in BI-1 cells than in control cells, as assessed by fluorescence and electron microscopy. In BI-1 cells, lysosomal pH was lower than in control cells and lysosomal vacuolar H(+)-ATPase(V-ATPase), a proton pump, was activated, suggesting high H(+) uptake into lysosomes. Even when exposed to ER stress, BI-1 cells maintained high levels of lysosomal activities, including V-ATPase activity. Bafilomycin, a V-ATPase inhibitor, leads to the reversal of BI-1-induced regulation of ER stress response and cell death due to ER stress. In BI-1 knock-out mouse embryo fibroblasts, lysosomal activity and number per cell were relatively lower than in BI-1 wild-type cells. This study suggests that highly maintained lysosomal activity may be one of the mechanisms by which BI-1 exerts its regulatory effects on the ER stress response and cell death.     

A review towards finding a simplified approach for modelling the kinetics of the soluble microbial products (SMP) in an integrated mathematical model of membrane bioreactor (MBR)

Soluble microbial products (SMPs) tend to accumulate in the membrane bioreactor (MBR) systems as a consequence of high membrane rejection and apparently low biodegradability within the wastewater treatment system. The extension of the activated sludge models (ASMs) with SMPs, therefore, has received crucial importance in recent days, particularly considering their potential use as indicators of the membrane fouling propensity. This paper presents a critical review of the formation and degradation kinetics of SMP subdivisions that have so far been used for the mathematical modelling of MBR. The paper identified a simplified approach to incorporate the kinetics of the SMP formation and degradation in the general mathematical models of MBR. It suggested that the inclusion of only four additional linear differential equations in the ASM1-SMP integrated mathematical model could simulate well the effluent quality and membrane fouling prediction. The model would also serve as a useful tool in optimizing operation conditions for better treatability and fouling control.     

Activity of conventional and reduced-risk insecticides for protection of grapevines against the rose chafer, Macrodactylus subspinosus (Coleoptera: Scarabaeidae)

Abstract:  Bioassays were conducted to compare the residual toxicity and leaf protection activity of conventional broad-spectrum and reduced-risk insecticides against the rose chafer, Macrodactylus subspinosus . Insecticides were applied to a Vitis labrusca (F.) vineyard and residues were aged for 1, 3 or 7 days before leaves were collected and exposed to beetles in no-choice tests. Azinphosmethyl caused rapid knockdown and mortality for up to 1 week after application, with 1-day-old residues providing 95.6% protection against feeding, dropping to 51.6% when residues were a week old. Fenpropathrin caused mortality and knockdown after beetles had been exposed to fresh residues for 72 h. Although these effects diminished as residues aged, this compound provided the best protection of leaves against beetle feeding, with 77.9% reduction in feeding compared with the control after 7 days of aging in the vineyard. Of the reduced-risk insecticides, imidacloprid caused the greatest initial mortality and knockdown of beetles, providing protection against feeding that was equivalent to azinphosmethyl. Exposure to azadirachtin caused a low level of knockdown and mortality when residues were 1- and 3-days old. Protection against feeding was also low, lasting for only 3 days. Beetles were minimally affected by capsaicin and kaolin, with mortality and knockdown seen only when beetles were exposed to 1-day-old residues for 72 h. Foliage protection from these compounds was minimal, with between 10 and 15% reduction in feeding injury. Results are discussed in relation to development of semi-field bioassay methods for evaluating reduced-risk insecticides, and the management of M. subspinosus within grape pest management programs.     

Differential Effects of Plant Species on a Mite Pest (Tetranychus Urticae) and its Predator (Phytoseiulus Persimilis): Implications for Biological Control

The influence of plant species on the population dynamics of the spider mite pest, Tetranychus urticae, and its predator, Phytoseiulus persimilis, was examined as a prerequisite to effective biological control on ornamental nursery stock. Experiments have been done to investigate how the development, fecundity and movement of T. urticae, and the movement of P. persimilis were affected by plant species. A novel experimental method, which incorporates plant structure, was used to investigate the functional response of P. persimilis. Development times for T. urticae were consistent with published data and did not differ with plant species in a biologically meaningful way. Plant species was shown to have a major influence on fecundity (P < 0.001) and movement of the pest mite (P < 0.01), but no influence on the movement of the predator. The movement of both pest and predator was shown to be related to the density of the adult pest mites on the plant (P < 0.001). Plant structure affected the functional response, particularly in relation to the ability of the predator to locate prey at low densities. The impact of these findings on the effective use of biological control on ornamental nursery stock is discussed.     

Selection responses for the number of fertile eggs of the Brown Tsaiya duck (Anas platyrhynchos) after a single artificial insemination with pooled Muscovy (Cairina moschata) semen

A seven-generation selection experiment comprising a selected (S) and a control (C) line was conducted with the objective of increasing the number of fertile eggs (F) of the Brown Tsaiya duck after a single artificial insemination (AI) with pooled Muscovy semen. Both lines consisted of about 20 males and 60 females since parents in each generation and each female duck was tested 3 times, at 26, 29 and 32 weeks of age. The fertile eggs were measured by candling at day 7 of incubation. The selection criterion in the S line was the BLUP animal model value for F. On average, 24.7% of the females and 15% of the males were selected. The direct responses to the selection for F, and correlated responses for the number of eggs set (Ie), the number of total dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) were measured by studying the differences across the generations of selection between the phenotypic value averages in the S and C lines. The predicted genetic responses were calculated by studying the differences between the S and C lines in averaged values of five traits of the BLUP animal model. The selection responses and the predicted responses showed similar trends. There was no genetic change for Ie. After seven generations of selection, the average selection responses per generation were 0.40, 0.33, 0.42, 0.41 genetic standard deviation units for F, M, Dm, and H respectively. Embryo viability was not impaired by this selection. For days 2–8 after AI, the fertility rates (F/Ie) were 89.2% and 63.8%, the hatchability rates (H/F) were 72.5% and 70.6%, and (H/Ie) were 64.7% and 45.1% in the S and C lines respectively. It was concluded that upward selection on the number of fertile eggs after a single AI with pooled Muscovy semen may be effective in ducks to increase the duration of the fertile period and the fertility and hatchability rates with AI once a week instead of twice a week.