桔小实蝇自然种群蛹和越冬成虫的耐寒性

本文通过过冷却点和低温耐寒能力的测定,研究了我国桔小实蝇Boctrocera dorsalis (Hendel)不同季节种群和地理种群蛹的耐寒性规律。结果表明：桔小实蝇自然种群蛹的低温存活力有明显的季节规律,冬前种群的耐寒性显著强于夏季种群。如在0℃低温下暴露2天,夏季种群基本全部死亡,而冬前种群存活率仍为61.4%。2005-2006年不同月份桔小实蝇1日龄蛹过冷却点差异明显,以2月份均值最高,为-9.26℃,8月份最低,为-15.20℃;且2月份桔小实蝇蛹个体过冷却点值出现明显的分化现象,分别在-15℃左右和-6℃左右出现两个明显的聚集区。所研究的5个桔小实蝇地理区域种群没有出现明显的耐寒性分化。结合本文结果,文中还就桔小实蝇自然种群耐寒性影响因素进行了讨论。     

Purification and biochemical characterization of glutathione S-transferases from four field populations of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Glutathione S-transferases (GSTs) are a group of detoxification enzymes that catalyze the nucleophilic addition of glutathione to a wide variety of endogenous and xenobiotic compounds. In this study, GSTs were purified from four field populations of Bactrocera dorsalis with different insecticide susceptibilities by glutathione-agarose affinity chromatography. The populations were collected from Dongguan (DG) and Guangzhou (GZ) of the Guangdong Province, Haikou of the Hainan province (HN), and Kunming of the Yunnan province (YN), China. Differences in GST characteristics among the four populations were studied using purified enzyme samples through comparative SDS-PAGE, kinetic, and inhibition experiments. The specific activities of the purified enzymes were similar, but the purification yield of the GZ population (31.54%) was the lowest. SDS-PAGE analysis showed only one band at approximately 23 kDa for these four populations. Kinetic analyses showed that the affinities of the purified GSTs from the GZ and YN populations for 1-chloro-2.4-dinitrobenzene (CDNB) were much higher than those of GSTs from the other two populations, whereas the HN population had the highest catalytic capability in terms of V(max) value. The optimum temperature for CDNB conjugation was 37 °C and the optimum pH was 7.5 in all four populations. Inhibition kinetics showed that ethacrynic acid, diethyl maleate, tetraethylthiuram disulfide, curcumin, bromosulfalein, and β-cypermethrin had excellent inhibitory effects on GSTs in the four populations of B. dorsalis, but the low inhibitory effects of malathion and avermectin did not differ between populations. These results suggest that GSTs may have a role in detoxification of β-cypermethrin in B. dorsalis.     

应用微卫星标记分析不同桔小实蝇种群的遗传多样性

为探究不同桔小实蝇Bactrocera dorsalis (Hendel)地理种群的遗传变异、入侵来源和扩散情况,利用13对引物对中国南方10省区、泰国、夏威夷、菲律宾和老挝的30个桔小实蝇种群共180个个体的遗传多样性水平进行了研究。 Popgene32和NTSYS-pc2.10e软件分析结果表明：30个不同桔小实蝇种群的遗传相似度在0.3599~0.9153范围内。种群的Nei氏基因多样性指数平均为0.6464±0.1026,Shannon信息指数I平均为1.2845±0.2632, 提示桔小实蝇种群具有较丰富的遗传多样性。UPGMA聚类分析显示,福建地区和海南地区分别独立一支,广东地区和台湾地区种群聚成一支,而广西、泰国、湖南、云南、老挝、四川、 重庆和贵州地区聚为一大支系。据此提出泰国种群和老挝种群是最早入侵我国的种群,云南地区是最早的入侵地,广西地区可能为又一较早入侵地。     

Population dynamics of Bactrocera dorsalis (Diptera: Tephritidae) and analysis of factors influencing populations in Baoshanba, Yunnan, China

Population dynamics of the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), were monitored year‐round using methyl eugenol‐baited traps in 2003, 2004, 2005 and 2006 in Baoshanba, Yunnan Province, China. Environmental factors including air temperature, rainfall and host‐plant species were analyzed with respect to the population dynamics. This species occurred only during April–November, with one yearly peak in August. The population fluctuation patterns with respect to season were identical in all study years. Correlation analysis and stepwise regression analysis indicated that air temperature, rainfall, sunlight hours and relative humidity were the major climatic factors that correlated with changes in the size of the fly population, and that monthly mean temperature, monthly sunlight hours and monthly relative humidity were most important. The seasonal increase in population size coincided with the fruiting period of the fly's host plants, but host fruit availability influenced the population size only when temperatures were sufficiently high. Cold temperatures may explain why there was no trap capture in the winter months. We believe that air temperature is the key factor explaining the seasonal occurrence of the fly population at Baoshanba.     

Population structure and colonization of Bactrocera dorsalis (Diptera: Tephritidae) in China,inferred from mtDNA COI sequences

The oriental fruit fly, Bactrocera dorsalis, is a serious pest of fruits and vegetables in South‐east Asia, and, because of quarantine restrictions, impedes international trade and economic development in the region. Revealing genetic variation in oriental fruit fly populations will provide a better understanding of the colonization process and facilitate the quarantine and management of this species. The genetic structure in 15 populations of oriental fruit fly from southern China, Laos and Myanmar in South‐east Asia was examined with a 640‐bp sequence of the mitochondrial cytochrome oxidase subunit I (COI) gene. The highest levels of genetic diversity were found in Laos and Myanmar. Low to medium levels of genetic differentiation (F_ST ≤ 0.134) were observed among populations. Pooled populations from mainland China differed from those in Laos and Myanmar (F_ST = 0.024). Genetic structure across the region did not follow the isolation‐by‐distance model. The high genetic diversity observed in Laos and Myanmar supports the South‐east Asian origin of B. dorsalis. High genetic diversity and significant differentiation between some populations within mainland China indicate B. dorsalis populations have been established in the region for an extended period of time. High levels of genetic diversity observed among the five populations from Hainan Island and similarity between the Island and Chinese mainland populations indicate that B. dorsalis was introduced to Hainan from the mainland and has been on the island for many years. High genetic diversity in the recently established population in Shanghai (Pudong) suggests multiple introductions or a larger number of founders.     

Improvement of protein bait produced from beer yeast waste for controlling Bactrocera dorsalis (Diptera: Tephritidae) in China

In the present study, preservatives and antibiotics were applied in a variety of doses to assess their effects on the beer waste-based protein bait, a product widely used to control populations of Bactrocera dorsalis (Diptera: Tephritidae). Screening was performed using the inhibition zone method against the dominant bacteria in deteriorated protein bait. Additionally, the attractiveness of the bait was assessed after respectively adding different doses of methyl eugenol, brown sugar solution, ammonium acetate, and guava essence, as determined by bio-cage tests. The results showed that the four selected preservatives had different inhibition effects at different dose levels, and that the level of inhibition increased with dose: at the highest dose of 1:1 (v:v), sodium benzoate can significantly inhibit Staphylococcus spp., potassium sorbate can significantly inhibit Lactobacillus spp., sodium nitrite can significantly inhibit Escherichia spp. and ethyl p-hydroxybenzoate can significantly inhibit Staphylococcus spp. and Xanthomonas spp. Among three antibiotics, kanamycin was the most effective in suppressing a mix of all four bacteria for all tested doses. In terms of lure performance, the addition of four substances in various ratios into the protein bait were found to have varying effects on its attractiveness to B. dorsalis females and males. Specifically, the addition of a high-dose of guava essence could significantly enhance the attractiveness of the bait. Our findings will help to enhance the effectiveness of protein bait applications by prolonging the quality guarantee period and improving its attractiveness toward both female and male B. dorsalis.     

温度对桔小实蝇种群发育的影响

采用室内人工饲养,研究了温度对外来入侵无锡地区的桔小实蝇(Bactrocera dorsalis)发育的影响。结果表明：17℃～33℃桔小实蝇各虫态发育速率逐渐增加;通过直线回归模型与直接最优法,得出桔小实蝇从卵期到成虫期的发育起点温度为9.9 ℃,卵、幼虫和蛹发育所需温度分别为10.5 ℃、9.6 ℃和10.3 ℃;卵期发育到成虫期的有效积温为381.0 d·℃,卵期、幼虫期和蛹期分别为24.1、178.6和176.7 d·℃。此外,温度影响桔小实蝇各虫态的存活率;25 ℃下卵期的存活率最高,而17 ℃下蛹期的存活率最低。温度对桔小实蝇雌雄性比也有一定影响,以25 ℃下雌虫比率最高。     

Juvenile hormone regulation on the flight capability of Bactrocera dorsalis (Diptera: Tephritidae)

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is considered a major economic threat in many regions worldwide. In order to better understand the flight capacity of B. dorsalis and its physiological basis, the functions and regulatory roles of juvenile hormone (JH) in the flight muscle of B. dorsalis were studied under a controlled environment. JH titer of B. dorsalis varied with age and sex. Females have higher JH titers and better flight capabilities than males, given that the increase in JH also corresponded to the ovarian development and maturation in females. The flight duration and distance of both males and females increased with the gradual increase of JH titer after adult emergences. Both JH titer and flight capability peaked in 15-d-old adult and declined subsequently with age. Flight activity stimulated the production of JH as adults flown for 24 h on the flight mills have the highest JH titers compare to adults flown on shorter flight durations. Adults treated with 0.5 µg and 5 µg of JH III were able to fly long durations and long distances, nevertheless when JH titer was too low or too high, it would restrict the flight ability of the fly. The mutual reinforcement of JH and flight activity provides fundamental understanding on the physiological aspects of the flight capability and dispersal, which facilitates strategies for the long-term control of this destructive pest.     

Resistance and synergistic effects of insecticides in Bactrocera dorsalis (Diptera: Tephritidae) in Taiwan

Oriental fruit flies, Bactrocera dorsalis (Hendel), were treated with 10 insecticides, including six organophosphates (naled, trichlorfon, fenitrothion, fenthion, formothion, and malathion), one carbamate (methomyl), and three pyrethroids (cyfluthrin, cypermethrin, and fenvalerate), by a topical application assay under laboratory conditions. Subparental lines of each generation treated with the same insecticide were selected for 30 generations and were designated as x-r lines (x, insecticide; r, resistant). The parent colony was maintained as the susceptible colony. The line treated with naled exhibited the lowest increase in resistance (4.7-fold), whereas the line treated with formothion exhibited the highest increase in resistance (up to 594-fold) compared with the susceptible colony. Synergism bioassays also were carried out. Based on this, S,S,S-tributyl phosphorotrithioate displayed a synergistic effect for naled, trichlorfon, and malathion resistance, whereas piperonyl butoxide displayed a synergistic effect for pyrethroid resistance. All 10 resistant lines also exhibited some cross-resistance to other insecticides, not only to the same chemical class of insecticides but also to other classes. However, none of the organophosphate-resistant or the methomyl-resistant lines exhibited cross-resistance to two of the pyrethroids (cypermethrin and fenvalerate). Overall, the laboratory resistance and cross-resistance data developed here should provide useful tools and information for designing an insecticide management strategy for controlling this fruit fly in the field.     

Characteristics of protein variants in trichlorphon-resistant Bactrocera dorsalis (Diptera; Tephritidae) larvae

Functional proteins in larvae of Bactrocera dorsalis, a major fruit pest, play a central role in their resistance to organophosphorus insecticides. Changes in proteins in B. dorsalis larvae after trichlorphon treatment may have a role in the resistance response to trichlorphon. We analyzed 14 protein spots of crude proteins from B. dorsalis larvae post-treatment with trichlorphon in two-dimensional gel electrophoresis through mass spectrometry and protein sequencing. We found functional proteins that are responsible for signal transduction (pkaap and dual specificity tyrosine-phosphorylation-regulated kinase), immunity (hemolectin), synthesis and decomposition (twinstar, cathepsin B, RE66325p), oxidative stress metabolism (glutathione S transferase and CG7320), energy metabolism (Act57B), and cytoskeleton formation (actin). These proteins appear to be involved in the resistance response to trichlorphon.     

Sublethal and transgenerational effects of six insecticides on Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

To clarify the effects of sublethal concentration of insecticide on the growth, development and reproduction of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), the sublethal and transgenerational effects of the LC₃₀ of six insecticides on adults and progeny (F₁ and F₂ generations) were studied using age-stage, two-sex life tables. Exposure to six insecticides had significant negative impacts on the life-history traits of B. dorsalis and led to reduced adult longevity and fecundity in F₀, a longer larval stage duration in F₁, and reduced fertility and survival. The intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R₀) were reduced in F₁, with the greatest reduction observed in the chlorpyrifos treatment. In the F₂ generation, the adverse effects were weakened, only the cyantraniliprole treatment had lower values than the control, and the fecundity of other treatments returned to normal. Obvious “hormesis” phenomena were not observed in any of the generations. Based on the population hazard index, chlorpyrifos had the best control effect in the early stage, and cyantraniliprole had the best control effect in the long term. These results indicate that the LC₃₀ of the six insecticides exert different transgenerational effects on the B. dorsalis population.     

橘小实蝇和番石榴实蝇重复利用寄主的产卵选择性

检疫性害虫橘小实蝇Bactrocera dorsalis和番石榴实蝇Bactrocera correcta是近缘种。本研究显示,两种实蝇对已被产卵寄主的识别与产卵选择性极相似。当寄主中至少含有600粒新鲜卵时,橘小实蝇或番石榴实蝇的雌成虫在其上继续产卵的数量才被抑制,而对同种实蝇卵和异种实蝇卵的反应几乎没有差异;两种实蝇在已被产卵的寄主中再次产卵,并没有刻意回避原产卵孔;寄主中的卵孵化为幼虫对后续实蝇的产卵行为产生了显著的抑制作用,随着幼虫数量的增多与龄期的增长,便不再有雌蝇选择该寄主产卵。因此,寄主中幼虫的存在是驱避橘小实蝇和番石榴实蝇在其上继续产卵的重要因素。两种实蝇幼虫寄主标记信息素的鉴定与利用将是今后研究的重点,利用其进行有害实蝇的种群控制将有很大的应用前景。     

云南西双版纳桔小实蝇种群动态

于1997年、2000年和2003年在云南西双版纳通过性诱剂诱捕对桔小实蝇种群动态进行了全年监测,并就气候因子及寄主种类对该种群变动的影响进行了系统分析.结果表明,桔小实蝇在西双版纳常年发生.当年11月至次年2月,桔小实蝇种群处于较低水平,3月以后种群数量逐渐上升,至6～7月形成一个种群增长高峰,此后至10月种群数量迅速下降.分析表明,影响桔小实蝇种群变化的重要因子是温度、降雨量和寄主种类.西双版纳各月均温位于桔小实蝇适温范围内,但12～2月的月平均最低温度低于桔小实蝇的适温范围,对桔小实蝇种群数量有一定抑制作用.降雨量是影响桔小实蝇种群数量变动的另一重要因子.月降雨量低于50 mm以下对桔小实蝇种群不利,而100～200 mm的月降雨量有助于桔小实蝇种群的增长.月降雨量大于250 mm以上将导致桔小实蝇种群数量下降.6～7月强降雨过程被认为是桔小实蝇在该时期种群数量下降的主要原因.芒果、番石榴、桃、梨、柑桔、龙眼和荔枝是桔小实蝇在该地区的主要寄主水果.其中,芒果和龙眼是当地桔小实蝇最喜好的寄主水果,其种植面积、挂果期和产量对桔小实蝇种群数量变动影响较大,被认为是影响该地区桔小实蝇种群变动的又一主要因素.     

延迟交配对橘小实蝇繁殖适度的影响

橘小实蝇Bactrocera dorsalis Hendel是一种世界性的入侵害虫,严重为害多种经济果蔬。本文通过响应面分析方法,研究了延迟交配对橘小实蝇交配率、产卵量、孵化率和寿命的影响。结果表明,交配率随雌虫交配日龄的延迟先增后减,雌、雄成虫均为35日龄处理组中的交配率最高,为81.00%±2.00%;而雄虫交配日龄的延迟则对其卵孵化率有明显的负面作用,在56日龄雄虫与35日龄雌虫处理组中,其卵孵化率最低,仅为27.56%±4.55%。雌成虫产卵量和寿命受到雌、雄虫双方交配日龄的的影响,产卵量（y）与雄虫日龄（x1）和雌虫日龄（x2）的回归方程为y=514.36+3.08x1-11.05x2,雌成虫寿命（y）与雄虫日龄（x1）和雌虫日龄（x2）的回归方程为y=35.85+0.23x1+0.40x2。研究结果为田间使用性信息素迷向法防治橘小实蝇提供了理论依据。     

基于CLIMEX的桔小实蝇在中国适生区的预测

桔小实蝇Bactroceradorsalis(Hendel),属双翅目Diptera,果实蝇科Tetriphitidae,主要分布在热带和亚热带地区。温度和湿度是影响桔小实蝇分布的重要气候因子。根据桔小实蝇对温湿度等气候因子的反应,采用CLIMEX软件对桔小实蝇在中国大陆的适生区进行了预测。设置了CLIMEX中的相应参数17个:发育起点温度DV0、生长最适宜温度范围DV1～DV2、致死高温DV3、有效发育积温PDD。生长发育所需最低土壤湿度临界SM0、最适宜湿度范围SM1～SM2、最高土壤湿度临界SM3。冷胁迫日度临界DTCS及其积累速率DHCS,热胁迫临界温度TTHS及其积累速率THHS,干旱胁迫临界SMDS及其积累速率HDS,湿胁迫SMWS及其积累速率HWS。以印度和夏威夷为已知适生分布区,反复调试修正上述这些参数值,使之与已知广泛分布的地区达到最大程度的吻合。然后用优化后的参数和中国大陆85个气象站点的气象资料模拟桔小实蝇在中国大陆的适生分布,结果显示:广东、海南、香港、广西、四川、云南、湖南、湖北、福建、江西、浙江等11个省(区)是桔小实蝇的适生分布区。主要分布在我国的华南和西南大部分地区,以及华中和华东的部分地区。根据CLIMEX模拟结果的EI值大小,将桔小实蝇在我国大陆的适生分布情况进一步划分为最适宜、次适宜、适宜和非适宜4个气候区,即华南地区全部以及广西省全境是桔小实蝇的最适宜分布区,除桂林(EI=17)外,其余气象点的EI值均大于40;西南地区的四川、云南两省及福建沿海地区是桔小实蝇的次适宜分布区,平均EI值为29.7;适宜分布区包括湖南、湖北、江西、浙江的少数地区,除赣州(EI=17)外,其余点的EI值均小于10;长江以北的广大地区是桔小实蝇的非适宜区,这些地区不适合桔小实蝇生存。     

桔小实蝇超氧化物歧化酶基因SOD3的克隆及表达分析

采用反转录聚合酶链式反应(RT-PCR)和快速扩增c DNA末端(RACE)技术克隆桔小实蝇SOD3基因,并命名为Bdor SOD3。Bdor SOD3阅读框全长531 bp,编码176个氨基酸,第1-20位氨基酸为其信号肽区域;该蛋白序列与桔小实蝇的另外一种SOD蛋白AGE89778.1序列的一致性最高,达98.7%;采用Swiss-model在线软件模拟构建Bdor SOD3蛋白的三维结构;采用半定量PCR方法,研究Bdor SOD3基因大肠杆菌诱导后的表达情况,结果表明,Bdor SOD3在处理与对照的24 h、48 h都有表达,但Bdor SOD3在处理后48 h表达量明显升高,结果暗示Bdor SOD3与桔小实蝇蛹对大肠杆菌的免疫机制有关。     

桔小实蝇不同发育阶段过冷却点的测定

对桔小实蝇Bactrocera dorsalis (Hendel)不同发育阶段的过冷却点进行了测定。结果表明：同一虫期个体间的过冷却点出现不同程度的变异,但均服从正态分布。不同虫期的过冷却点差异显著,其中蛹的过冷却点最低（-12.2℃～-15.0℃）。老熟幼虫的过冷却点为-8.1℃。成虫的过冷却点最低值为7日龄雄虫（-10.5℃）和雌虫（-10.1℃）,最高值为60日龄雄虫（-5.9℃）和雌虫（-6.4℃）,但同一发育时期的雌、雄成虫之间的过冷却点没有差异。测定结果提示蛹期最有可能是该虫在温带地区越冬的虫态。     

Global distribution and invasion pattern of oriental fruit fly,Bactrocera dorsalis (Diptera: Tephritidae)

Since the start of the 20th century, many invasive alien species (IAS) have spread rapidly around the world, causing serious threats to economies, societies and the environment. Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is an important quarantine insect species in many countries that spread around the world over the last century. This review collected information on the distribution of B. dorsalis to explore the patterns of its invasion expansion. We found B. dorsalis to be distributed in 75 countries (comprised of 124 geographical distribution regions: provinces or states) in Asia, Africa, North America, South America and Oceania up to 2017. Asia and Africa were the most represented regions, accounting for 86.3% of the total number of countries. From 1910 to 1990, B. dorsalis was only found in five countries, but in the last three decades, it has experienced a sharp increase in its rate of spread, invading 70 more countries. Global temperature anomaly has significantly positive correlation with the spread of B. dorsalis. The results of this review provide a theoretical basis for understanding and predicting the continued spread of B. dorsalis under global changes.     

橘小实蝇交配行为观察

在实验室内对橘小实蝇Bactrocera dorsalis（Hendel）的交配行为进行了观察。描述了橘小实蝇交配中雄虫的“求偶场”,雄雄相遇、雌雌相遇、雌雄相遇时的相互反应,雌雄虫的交配行为与交配后行为。