Polymorphic microsatellite DNA markers in Bactrocera cacuminata (Hering) (Diptera: Tephritidae)

Bactrocera cacuminata (Hering) is a nonpest member of the Bactrocera dorsalis complex offering a platform to check hypotheses extrapolated from the more studied pest species. Six polymorphic microsatellite loci were isolated from enriched genomic libraries constructed using a biotin/streptavidin capture protocol. Allele number varied between three and nine; the expected heterozygosity ranged between 0.29 and 0.81. No significant deviations from Hardy–Weinberg equilibrium or linkage disequilibrium were found. These microsatellite markers have potential to be used to examine population structure and mating systems in this tropical fruit fly.     

应用种特异性PCR技术快速鉴定辣椒实蝇

【目的】辣椒实蝇 Bactrocera latifrons (Hendel)为我国重要的检疫性有害生物,其寄主范围广泛,危害严重。由于传统鉴定方法受到饲养周期、饲养条件、虫态等因素的限制,使得果蔬进出口贸易通关速度、疫情快速鉴定受到较大的影响,因此迫切需要开发关于实蝇的快速鉴定识别的技术。【方法】本研究基于mtDNA COI序列设计了一对能够准确鉴定辣椒实蝇的种特异性引物FL680和RL1057,选用辣椒实蝇作为阳性对照,选用番石榴实蝇B. correcta (Bezzi)、桔小实蝇 B. dorsalis (Hendel)和颜带实蝇 B. cilifer (Hendel)等20种实蝇作为阴性对照,进行PCR扩增并将PCR产物进行电泳检测。【结果】仅目标种辣椒实蝇能够扩增出清晰且单一的约378 bp的条带,其余实蝇种类均未出现条带。将本实验建立的种特异性PCR（SS-PCR）鉴定方法应用于实际检疫工作中并得到了验证,表明该方法具有强的种特异性。【结论】本文提出辣椒实蝇快速鉴定识别技术可应用于实蝇的疫情监测和口岸的检疫检测工作。     

基于mtDNA Cytb 的六种果实蝇的分子鉴定

本研究首次对果实蝇属的桔小实蝇Bactrocera dorsalis、瓜实蝇B. cucurbitae、南瓜实蝇B. tau、番石榴实蝇B. correcta、具条实蝇B. scutellata、黑漆实蝇B. scutellaris等6种实蝇mtDNA Cytb基因进行了测序。对这6种实蝇72个个体mtDNA Cytb基因中段420 bp的碱基序列进行分析,得到38种单倍型,发现了116个变异位点,其中30个位点较为稳定。对这6种实蝇与其各自鉴别位点的对应关系研究表明,mtDNA Cytb基因可以作为这6种实蝇种类鉴别的分子标记。     

Establishment and application of DNA barcoding technology for identification of the immatures and adult debris of Bactrocera dorsalis (Hendel) ( Diptera: Tephritidae)

实蝇类害虫多为国内外检疫对象,其鉴定识别方法主要依据成虫的外部形态特征,而传统的形态学识别法对口岸经常截获的幼体及残缺的虫体,则无能为力.本研究以桔小实蝇Bactrocera dorsalis的幼体(卵、幼虫、蛹)以及成虫残体(足、翅、头部、胸部、腹部)为对象,利用DNA条形码技术,构建实蝇类害虫快速鉴定技术体系,并以其他4种常见实蝇(包括番石榴实蝇B.correcta、瓜实蝇B.cucurbitae、南亚果实蝇B.tau、柑桔大实蝇B.minax)为对象对该技术体系进行应用验证.结果显示,桔小实蝇幼体以及成虫残体的碱基序列与数据库中靶标种CO Ⅰ基因碱基序列的一致性为99.51％～99.84％,其他4种实蝇相应序列与数据库中靶标种CO Ⅰ基因序列的一致性分别为100％,100％,99.81％～ 99.83％和100％;以邻接法(NJ法)构建系统发育树,靶标种实蝇均与数据库中对应种实蝇聚为一支,且置信度均为100％.以K2-P模型计算种内及种间遗传距离得出,5种实蝇的种间遗传距离为0.0597～0.2363,平均为0.1693;种内遗传距离为0.0000 ～0.0041,平均为0.0019.这些结果表明,基于DNA条形码的物种识别技术完全可用于口岸截获的实蝇类害虫幼体及残体的准确鉴定.     

Population structure,population history and DNA barcoding of fruit fly Bactrocera latifrons (Hendel) (Diptera: Tephritidae)

The fruit fly Bactrocera latifrons (Hendel) is an important pest of commercially significant plants such as chili, tomato and eggplant. The species is native to South and Southeast Asia, but has now invaded Japan, Hawaii and Africa. In this study, mitochondrial DNA sequences were used to infer genetic structure and demographic history of B. latifrons. The efficiency of DNA barcodes for identification of B. latifrons was also tested. Ninety‐three specimens infesting four host‐plant species were obtained from 11 sampling locations in Thailand. The mitochondrial haplotype network revealed no major divergent lineage, which was consistent with a phylogenetic analysis that found strong support for the monophyly of B. latifrons. Population pairwise F_ST revealed that most (65%) comparisons were not significantly different, suggesting a high rate of gene flow. Analysis of molecular variance (amova ) found no significant genetic differentiation among populations from different host‐plant species. Sharing of several haplotypes among flies from different host‐plants indicates that the flies were moved freely across the plant species. Demographic history analysis revealed that the population has undergone recent expansion dating back to the end of the last glaciation. Thus, the results indicate that both ongoing and historical factors have played important roles in determining the genetic structure and diversity of B. latifrons. DNA barcoding analysis revealed that B. latifrons specimens were clearly differentiated from other species with 100% correct identification. Therefore, cytochrome oxidase I (COI) barcoding sequences could be effectively used to identify this important pest species, which could encourage monitoring and control efforts for this species.     

桔小实蝇幼体及成虫残体DNA条形码识别技术的建立与应用

实蝇类害虫多为国内外检疫对象, 其鉴定识别方法主要依据成虫的外部形态特征, 而传统的形态学识别法对口岸经常截获的幼体及残缺的虫体, 则无能为力。本研究以桔小实蝇Bactrocera dorsalis的幼体（卵、 幼虫、 蛹）以及成虫残体（足、 翅、 头部、 胸部、 腹部）为对象, 利用 DNA 条形码技术, 构建实蝇类害虫快速鉴定技术体系, 并以其他4种常见实蝇（包括番石榴实蝇B. correcta、 瓜实蝇B. cucurbitae、 南亚果实蝇B. tau、 柑桔大实蝇B. minax）为对象对该技术体系进行应用验证。结果显示, 桔小实蝇幼体以及成虫残体的碱基序列与数据库中靶标种COⅠ基因碱基序列的一致性为99.51%~99.84%, 其他4种实蝇相应序列与数据库中靶标种COⅠ基因序列的一致性分别为100%, 100%, 99.81%~99.83%和100%; 以邻接法（NJ法）构建系统发育树, 靶标种实蝇均与数据库中对应种实蝇聚为一支, 且置信度均为100%。以K2-P模型计算种内及种间遗传距离得出, 5种实蝇的种间遗传距离为0.0597~0.2363, 平均为0.1693; 种内遗传距离为0.0000~0.0041, 平均为0.0019。这些结果表明, 基于DNA条形码的物种识别技术完全可用于口岸截获的实蝇类害虫幼体及残体的准确鉴定。     

Development of internal COI primers to improve and extend barcoding of fruit flies (Diptera: Tephritidae: Dacini)

Accurate species-level identifications underpin many aspects of basic and applied biology;however,identifications can be hampered by a lack of discriminating morphological characters,taxonomic expertise or time.Molecular approaches,such as DNA"barcoding"of the cytochrome c oxidase(COI)gene,are argued to overcome these issues.However,nuclear encoding of mitochondrial genes(numts)and poor amplification success of suboptimally preserved specimens can lead to erroneous identifications.One insect group for which these molecular and morphological problems are significant are the dacine fruit flies(Diptera:Tephritidae:Dacini).We addressed these issues associated with COI barcoding in the dacines by first assessing several"universal"COI primers against public mitochondrial genome and numt sequences for dacine taxa.We then modified a set of four primers that more closely matched true dacine COI sequence and amplified two overlapping portions of the COI barcode region.Our new primers were tested alongside universal primers on a selection of dacine species,including both fresh preserved and decades-old dry specimens.Additionally,Bactrocera tiyoni mitochondrial and nuclear genomes were compared to identify putative numts.Four numt clades were identified,three of which were amplified using existing universal primers.In contrast,our new primers preferentially amplified the"true"mitochondrial COI barcode in all dacine species tested.The new primers also successfully amplified partial barcodes from dry specimens for which full length barcodes were unobtainable.Thus we recommend these new primers be incorporated into the suites of primers used by diagnosticians and quarantine labs for the accurate identification of dacine species.     

Polymorphic microsatellite markers in the Melon Fruit Fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae)

Bactrocera cucurbitae (Coquillett) is an important insect pest of melon fruit causing extensive losses of production in Asia and Pacific areas. Twelve polymorphic microsatellite loci were isolated from an enriched DNA library of this species and their amplification characteristics are described. Genetic parameters were estimated on 80 individual flies from four natural populations. Allele numbers per locus ranged from three to 20. These microsatellite markers have potential utility in population structure and gene flow studies of B. cucurbitae.     

基于mtDNA COI基因的离腹寡毛实蝇属常见种DNA条形码识别和系统发育分析

【目的】离腹寡毛实蝇属Bactrocera昆虫是最具经济重要性的实蝇类害虫,本研究依据mtDNA COI基因碱基序列对离腹寡毛实蝇属常见实蝇种类进行识别鉴定与系统发育分析。【方法】以口岸经常截获的离腹寡毛实蝇属8个亚属21种实蝇为对象,采用DNA条形码技术,通过对mtDNA COI基因片段 (约650 bp)的测序和比对,以MEGA软件的K2-P双参数模型计算种内及种间遗传距离,以邻接法(NJ) 构建系统发育树。【结果】聚类分析与形态学鉴定结果一致,除11种单一序列实蝇外,其他10种实蝇均各自形成一个单系,节点支持率为99%以上。种内（10种）遗传距离为0.0003~0.0068,平均为0.0043;种间（21种）遗传距离为0.0154~0.2395,平均为0.1540;种间遗传距离为种内遗传距离的35.8倍,而且种内、种间遗传距离没有重叠区域。【结论】基于mtDNA COI基因的DNA条形码技术可以用于离腹寡毛实蝇属昆虫的快速鉴定识别,该技术体系的建立对实蝇类害虫的检测监测具有重要意义。     

云南边境地区果实蝇属种类DNA条形码鉴定

【目的】果实蝇属Bactrocera中有国际上重要的检疫性害虫, 基于形态的物种鉴定有一定的局限性。另一方面, 云南边境地区为东南亚地区实蝇入侵我国的重要通道。因此, 对该地区实蝇分子鉴定方法的研究对于该属物种的快速准确鉴定具有重要意义。本研究旨在探讨DNA条形码技术在果实蝇属物种鉴定中的有效性。【方法】使用线粒体基因COI和COII序列的通用引物对果实蝇属20个物种60份样品进行PCR扩增、测序和序列分析; 采取距离方法和建树方法评价2种序列的鉴别能力。【结果】COI和COII序列平均长度分别为682 bp和339 bp, 种内和种间遗传差异较大, 有较明显的遗传距离间隔（barcoding gap）, 鉴定成功率分别为91.2%和90.7%。另外, 分子系统树表明华实蝇亚属Sinodacus不是单系群。【结论】COI和COII序列均能够将绝大多数果实蝇属物种进行准确鉴别, 应用COI或COII序列进行果实蝇属物种鉴定具有一定的可行性。     

Real‐time PCR assays for rapid detection of Zeugodacus cucumis and Bactrocera jarvisi (Diptera: Tephritidae) for quarantine application

Zeugodacus cucumis and Bactrocera jarvisi are pests of fruit and vegetable crops and cause damage to horticulture industries. Immature stages of these two fruit fly species have been intercepted in New Zealand a number of times. Identification to species was not possible using morphological characters; thus, it is important to develop an assay for their species‐level identification. Here, the real‐time PCR assays for rapid identification of Z. cucumis and B. jarvisi were developed and validated. The PCR protocols demonstrated their specificity by amplifying the two target species successfully, with no cross‐reactions observed in the tested tephritid species. The in silico test of the primer and probe binding sites of the two assays also demonstrated the assays’ specificity by no mismatches present in the binding regions of the target species, but 1–4 mismatches in the binding regions of the non‐target fruit fly species. The thresholds of detection for the two assays are as low as 10 copies/µl of the target DNA, indicating that the assays have a very high sensitivity. The application of the real‐time PCR assays has greatly assisted in routine pest identifications at the New Zealand border and surveillance programme. Therefore, the assays have the potential to be used by diagnostic agencies and research organizations worldwide.     

菲律宾实蝇生物学特性研究

菲律宾实蝇Bactrocera (Bactrocera) philippinensis (Drew & Hancock)是重要的检疫性有害生物, 严重危害芒果Mangifera indica L.、木瓜Carica papaya L.和菠萝蜜Artocarpus heterophyllus Lam.等水果。本文在室内实验条件下对菲律宾实蝇生物学特性进行了较为系统的研究。结果表明: 菲律宾实蝇在6~18 h羽化率达93.93%。成虫活动、寿命、交配和产卵与温度、光照密切相关。补充营养能显著延长成虫寿命。菲律宾实蝇生长、发育和繁殖的适宜温度为25~30℃。25℃和30℃时平均产卵量分别为627.35粒和652.57粒。发育起点温度和世代有效积温分别为14.31℃和450.43日·度。温度与发育历期呈显著的负相关（r=-0.9005）。本研究为菲律宾实蝇的检疫处理和田间防治技术研究提供了重要的基础资料。     

Phylogenetic relationships among Bactrocera species (Diptera: Tephritidae) inferred from mitochondrial DNA sequences

Several members of the dipteran family Tephritdae are serious pests because females lay eggs in ripening fruit. The genus Bactrocera is one of the largest within the family with over 500 described species arranged in 28 subgenera. The phylogenetic relationships among the various species and subgenera, and the monophyly of specific groups have not been examined using a rigorous phylogenetic analysis. Therefore, phylogenetic relationships among 24 Bactrocera species belonging to 9 subgenera were inferred from DNA sequence of portions of the mitochondrial 16S rRNA, cytochrome oxidase II, tRNA(Lys), and tRNA(Asp) genes. Two morphological characters that traditionally have been used to define the four groups within the subgenus Bactrocera were evaluated in a phylogenetic context by mapping the character states onto the parsimony tree. In addition, the evolutionary trend in male-lure response was evaluated in a phylogenetic context. Maximum parsimony analyses suggested the following relationships: (1) the genus Bactrocera is monophyletic, (2) the subgenus B. (Zeugodacus) is paraphyletic, (3) the subgenus B. (Daculus) is a sister group to subgenus B. (Bactrocera), and (4) the subgenus B. (Bactrocera) is monophyletic. The mapping analyses suggested that the morphological characters exhibit a simple evolutionary transition from one character state to another. Male-lure response was identified as being a labile behavior that has been lost on multiple occasions. Cue-lure response was plesiomorphic to methyl-eugenol response, and the latter has evolved independently within the Bactrocera and Zeugodacus groups of subgenera. The implications of our results for devising a coherent, consolidated classification for Bactrocera is discussed.     

On the complementarity of DNA barcoding and morphology to distinguish benign endemic insects from possible pests: the case of Dirioxa pornia and the tribe Acanthonevrini (Diptera: Tephritidae: Phytalmiinae) in Australia

Fruit flies are considered economically important insects due to some species being agricultural pests. However, morphological identification of fruit fly adults and larvae can be difficult requiring a high level of taxonomic expertise, with misidentifications causing problematic false-positive/negative results. While destructive molecular techniques can assist with the identification process, these often cannot be applied where it is mandatory to retain a voucher reference specimen. In this work, we non-destructively (and partial-destructively) processed larvae and adults mostly belonging to the species Dirioxa pornia (Walker, 1849), of the poorly studied nonpest fruit fly tribe Acanthonevrini (Tephritidae) from Australia, to enable molecular identifications whilst retaining morphological vouchers. By retaining the morphological features of specimens, we confirmed useful characters for genus/species-level identification, contributing to improved accuracy for future diagnostics using both molecular and morphological approaches. We provide DNA barcode information for three species of Acanthonevrini known from Australia, which prior to our study was only available for a single species, D. pornia. Our specimen examinations provide new distribution records for three nonpest species: Acanthonevroides variegatus Permkam and Hancock, 1995 in South Australia, Acanthonevroides basalis (Walker, 1853) and D. pornia in Victoria, Australia; as well as new host plant records for D. pornia, from kangaroo apple, apricot and loquat.     

DNA barcoding for identification of sand flies (Diptera: Psychodidae) in India

About 50 species of sand flies have been reported to be prevalent in India. We explored the utility of the DNA barcode approach towards species identification of these medically important insects. A total of 62 specimens belonging to seven morphologically identified species of two genera, Phlebotomus and Sergentomyia, collected from Puducherry Union Territory, Maharashtra and Rajasthan states of India were subjected to the analysis. Neighbor‐joining (NJ) analysis of DNA barcode sequences identified the individuals of seven morphological species into eight distinct species, as presented in the designed NJ tree. This methodology delineated morphologically identified species, S. bailyi, into two genetically isolated groups. Also, this study characterizes DNA barcodes of P. argentipes and P. papatasi, the vector species of leishmaniasis in India, for the first time.     

Biology of Bactrocera (Zeugodacus) tau (Walker) (Diptera: Tephritidae)

The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.     

DNA microsatellite analysis of naturally occurring colour intermediates between Bactrocera tryoni (Froggatt) and Bactrocera neohumeralis (Hardy) (Diptera: Tephritidae)

Abstract  The sympatric tephritid fruit flies Bactrocera tryoni (Froggatt) (Queensland fruit fly) and B. neohumeralis (Hardy) differ in time of mating and for the colour of the humeral callus ('shoulder pad'), which is typically entirely yellow in B. tryoni and typically entirely brown in B. neohumeralis . Field collections in sympatric regions usually include at least 1% of individuals whose humeral calli show mixed patches of yellow and brown ('intermediates'). Over 40 years, a number of studies have debated the possibility that these intermediates are interspecific hybrids. In the present study, we have used microsatellites to show that few if any of these intermediates are hybrids. Instead, most variation humeral callus appears to be confined to one species, B. tryoni . We discuss these results in the context of geneflow between the two species and suggest directions for future research.     

柑橘大实蝇产卵器的超微结构观察(双翅目：实蝇科)

柑橘大实蝇Bactrocera minax(Enderlein),是柑橘的重要害虫。本文基于光学显微镜、扫描电镜、石蜡切片和透射电镜观察,对柑橘大实蝇的产卵器形态结构进行研究。结果表明,柑橘大实蝇产卵器由产卵器基节、翻缩膜和产卵针3部分组成,翻缩膜是浅黄色的柔软的细长管状结构,又分为骨化带、骨化环和膜质部3部分。骨化带表面有4条褐色的、纵向的、柔软的离散带。骨化环和膜质部表面存在小齿和无齿两种角质化鳞片,鳞片的一端与表皮连接,另外一端处于自由状态,鳞片以覆瓦状包围在骨化环和膜质部表面。骨化带和骨化环弯曲程度极低,而膜质部弯曲程度较大。产卵针由1块背片和2块腹片组成,2块腹片之间、背片与腹片之间与可折叠弯曲的柔性角质层连接。其背片两内侧均存在1个未封闭的圆环,其内部有肌肉(背腹肌)、气管、输卵管和直肠等组织或器官。产卵器上有毛形、腔锥形和钟形3种类型感受器。在产卵器收缩时,首先产卵针折叠在翻缩膜内,然后再一起折叠在基节内。因此,在成虫休息时,产卵器形成了产卵针(内层)、翻缩膜(中间层)和基节(外层)3个腹节的套叠。柑橘大实蝇的产卵器是伪产卵器,其结构或组织经过进化,从而适应其伪产卵器的外...     

云南六种实蝇的RAPD快速鉴定

采用RAPD技术构建了果实蝇属（Bactrocera）的南瓜实蝇(B. tau)、黑漆实蝇(B.scutellaris)、具条实蝇(B. scutellata)、瓜实蝇(B. cucurbitae)、桔小实蝇(B. dorsalis)和番石榴实蝇(B. correcta)6种实蝇的指纹图谱.从131个引物中筛选出5个重复性好、多态性高的引物,共扩增出302条谱带,其中111条谱带具有遗传多态性.引物OPC-01、OPI-17、OPL-07、OPL-08以及OPL-16可以用于6种实蝇的分类鉴定.