Microsatellite markers for the pest fruit fly,Bactrocera papayae (Diptera: Tephritidae) and other Bactrocera species

The dorsalis complex contains some of the most economically important fruit fly pests of the Asia–Pacific regions, including Bactrocera dorsalis, Bactrocera papayae and Bactrocera carambolae. These species are morphologically indistinct and genetically very similar. We describe the development of 12 microsatellite markers isolated from a representative of the dorsalis complex, B. papayae. We show the potential utility of the B. papayae microsatellites and a set of microsatellites isolated from Bactrocera tryoni as population and species markers for the dorsalis complex.     

Polymorphic microsatellite DNA markers from the Oriental Fruit Fly Bactrocera dorsalis (Hendel)

Six polymorphic microsatellite loci are isolated from the Oriental fruit fly Bactrocera dorsalis (Hendel), an agricultural pest in Asia, including Taiwan. To assess their potential utility as high‐resolution genetic markers, polymerase chain reaction (PCR) primers, amplification conditions, and an automated fluorescence detection protocol were developed. In analyses of 71 individual flies from six different areas of Taiwan, allele numbers ranged from five to 25 were detected for each locus. The observed heterozygosity ranged between 0.268 and 0.737 among these loci. No linkage disequilibrium was found. These microsatellite markers have potential utility to population structure and gene flow studies of B. dorsalis (Hendel).     

Fruit fly (Diptera: Tephritidae) diversity in cucurbit fields and surrounding forest areas of Himachal Pradesh,a north-western Himalayan state of India

During the course of studies, Bactrocera (Bactrocera) latifrons (Hendel), B. (B.) nigrofemoralis White and Tsuruta, Dacus (Callantra) longicornis Wiedemann, Dacus (Callantra) sphaeroidalis (Bezzi), Cyrtostola limbata (Hendel) and Pliomelaena udhampurensis Agarwal and Kapoor were recorded for the first time in Himachal Pradesh in a cucurbit ecosystem. Apart from these, other species viz. Bactrocera tau, Bactrocera cucurbitae, Bactrocera dorsalis, Bactrocera zonata, Bactrocera scutellaris, Bactrocera diversa and Dioxyna sororcula (Wiedemann) were also identified. Distribution records of B. (B.) dorsalis (Hendel), B. (B.) zonata (Saunders), Bactrocera (Hemigymnodacus) diversa (Coquillett), B. (Zeugodacus) cucurbitae (Coquillett), B. (Z.) scutellaris (Bezzi) and B. (Z.) tau (Walker) has been described.     

Polymorphic microsatellite markers in the guava fruit fly, Bactrocera correcta (Diptera: Tephritidae)

Bactrocera correcta (Bezzi) is one of the most destructive insect pests of fruits and vegetables in tropical and subtropical regions. At present, this fly is primarily distributed in Southeast Asia. Twelve microsatellite loci were isolated from an enriched genomic library based on a biotin/streptavidin capture protocol. The polymorphism of these loci was tested on 74 individual flies from two natural populations. Allele number ranged from 6 to 14 and 10 loci demonstrated a polymorphic information content (PIC) greater than 0.5. The pairwise F _ST value between the two populations was 0.0048 (P > 0.05). These microsatellite loci have potential utility for studies of population genetic structure in this species.     

Microsatellite analysis revealed a different approach of control of olive fly population (Bactrocera oleae) in Slovenia

The olive fruit fly (Bactrocera oleae Gmelin) is the most important olive pest in the north‐eastern Adriatic coast region. Despite the importance of olive production in the region, and the significance of the olive fruit fly, no information with respect to genetic diversity, population structure or dispersion patterns of this pest is available. The aims of this study were to investigate the genetic structure of the olive fly population in the Slovenian Istria region using microsatellite markers to determine olive fruit fly migration between locations and to establish an appropriate and effective strategy for controlling the pest population. Analysis was performed on a sample of 117 flies, collected from attacked olive fruits at three different locations. Olive fruit flies were genotyped using eight microsatellite loci. Sixty‐six alleles were identified over all microsatellite loci with an average of 8.25 alleles per locus. The population structure was determined with methods based on Bayesian principles using the BAPS 6.0 and STRUCTURE 2.3 programs. Genetic analysis confirmed unlimited migration and random mating between individuals of different microlocations, which suggests time‐coordinated first treatment in the region would be the best solution.     

Impact of habitat modification on the distribution and abundance of fruit flies (Diptera: Tephritidae) in Southeast Queensland

Loss of rainforest because of agricultural and urban development may impact the abundance and diversity of species that are rainforest natives. Tropical fruit flies are one group of such organisms indigenous to rainforests. In southeast Queensland, a region subject to rapid urbanization, we assessed the impact of habitat disturbance on the distribution and abundance of native fruit flies. Data on four species (Bactrocera tryoni, Bactrocera neohumeralis, Bactrocera chorista, and Dacus aequalis) were gathered and analyzed over 6 months in three habitat types: suburbia, open sclerophyll forest, and rainforest. We also analyzed the data at a combined "dacine fruit fly" level incorporating all fruit fly species trapped over the period of study (as might occur in a biodiversity assessment): these included the four species already named and Bactrocera melas, Bactrocera bryoniae, Bactrocera newmani, and Dacus absonifacies. Analysis at the species level showed that the polyphagous pest species responded differently to the monophagous species. Bactrocera tryoni, which has more exotic than native hosts, was positively affected by transformation of natural habitat into suburbia whereas B. neohumeralis, which has nearly identical numbers of native and exotic hosts, was found equally across habitat types. Bactrocera chorista and Dacus aequalis, each monophagous on a species-specific rainforest host plant, were most abundant in rainforest. The analysis based on the combined data suggests that replacing rainforest with suburbia has a neutral, or even positive, effect on the abundance of fruit flies as a whole. At the species level, however, it can be seen that this is an erroneous conclusion biased by the abundance of a single pest species. Our discussion raises the issue of analyses at supraspecific levels in biodiversity and impact assessment studies. Received: March 6, 2000 / Accepted: June 19, 2000     

~(137)Cs辐照对橘小实蝇雄虫肠道菌群多样性的影响

【目的】为研究137Cs辐照前后橘小实蝇雄虫肠道菌群多样性和丰度的变化及其肠道菌群在不同分类阶元上的显著差异物种。【方法】本研究利用IlluminaHiSeq高通量测序技术对辐照组和对照组共6个样品进行测序分析。【结果】变形菌门和厚壁菌门分别以60.38%、24.33%的比例作为橘小实蝇肠道中的优势菌门和次优势菌门,肠杆菌科和肠球菌科分别以60.38%和15.69%作为优势菌科和次优势菌科。米勒氏菌属(Moellerella)、摩根氏菌属(Morganella)、Cosenzaea属、链球菌科未知属和酸热菌属(Acidothermus)是组间显著差异的菌属。【结论】本研究发现橘小实蝇在辐照后的肠道菌群多样性和丰度均有显著性降低,并在目至属等3个分类阶元上找到辐照后具有显著差异的物种,为后期利用差异菌群来改善辐照对橘小实蝇的消极影响及修复辐照损伤提供理论基础。     

Host specificity of the egg pupal parasitoid Fopius arisanus (Hymenoptera: Braconidae) in La Reunion

Fopius arisanus is a polyphagous parasitoid of Tephritidae, which has been recently introduced to La Réunion Island as part of a classical biological control programme. We carried out laboratory experiments to assess the host specificity of this parasitoid, initially reared on Bactrocera zonata, and then offered for parasitization the eight local tephritid pest species. Naive or experienced parasitoid females were given tephritid eggs in no choice tests. Fopius arisanus females parasitize all fly species but parasitism varies with host species. No adult wasps emerge from Bactrocera cucurbitae and the survival of this species is only slightly affected by parasitism. Dissections show that the late instars of this fly may eliminate the parasitoid by encapsulation. When developing on Ceratitis capitata, Ceratitis rosa, Dacus ciliatus, Dacus demmerezi, and Neoceratitis cyanescens, parasitoid survival rate ranges from 10 to 25%. Bactrocera zonata and Ceratitis catoirii are the best hosts, yielding parasitoid survival rates of more than 70% with no premature mortality. The egg-larval mortality of C. capitata, C. rosa, D. ciliatus, and N. cyanescens, and the pupal mortality of D. demmerezi, are significantly increased by parasitism. The size of emerging adults is affected by host species and is correlated to pupal weight. Bactrocera zonata would be a favorable host to support routine colonization of F. arisanus for mass production of this parasitoid.     

Polymorphic tetranucleotide microsatellite loci in the Hwamei (Garrulax canorus canorus) (Timaliidae)

Eight polymorphic tetrarepeat (GATA)_n, microsatellite loci were isolated from a babbler, Hwamei (Garrulax canorus canorus). We evaluated the polymorphism of these microsatellite loci by genotyping 36–48 individuals from the Asian mainland. The number of alleles for each locus ranged from eight to 29. The heterozygosity was between 0.587 and 0.978. Except for one locus, genotype frequencies of these microsatellites did not significantly deviate from the Hardy–Weinberg expectation. These markers should be useful for monitoring potential hybridization between different Hwamei subspecies and provide new insights into the mating system and geographical differentiation of these birds.     

A Simple Method for Developing Microsatellite Markers using Amplified Fragments of Inter-simple Sequence Repeat (ISSR)

10 A primer IP1 designed from the sequenced region at one end of the microsatellite and for nested PCR another primer IP2 based on the sequence between IP1 and the microsatellite were prepared. These two primers were used to determine the other sequence flanking the microsatellite by a “walking” method. With this approach, we developed several microsatellite markers from Salix reinii, Pinus densiflora and Robinia pseudoacacia, respectively. The absence of enrichment processes and screening procedures makes it easier to develop microsatellite markers, and this approach provides an alternative for the development of microsatellite markers in any organism. Received 23 April 2001/ Accepted in revised form 11 June 2001     

Twelve polymorphic microsatellite loci from a dinucleotide-enriched genomic library of Japanese Spanish mackerel (Scomberomorus niphonius)

In the study, 34 microsatellite loci were isolated from a dinucleotide-enriched genomic library of Japanese Spanish mackerel (Scomberomorus niphonius). And 12 microsatellite loci were found to be polymorphic between 3 and 8 alleles. The number of observed and expected heterozygosity per locus in 23 individuals ranged from 0.6087 to 1.0000 and 0.8908 to 0.9773, respectively. Two loci significantly deviated from Hardy–Weinberg equilibrium after Bonferroni correction analysis and there was no significant linkage disequilibrium found between pairs of loci. As a result, 12 microsatellite loci probably located on different chromosome pairs and these polymorphic microsatellite loci should provide sufficient level of genetic diversity to investigate the fine-scale population structure and evaluate the breeding strategy in S. niphonius. The authors Shi-Chao Xing and Gen-Bo Xu contributed equally.     

Macrogeographic population structuring in the cosmopolitan agricultural pest Bactrocera cucurbitae (Diptera: Tephritidae)

The macrogeographic population structure of the agricultural pest Bactrocera cucurbitae (Diptera: Tephritidae) was investigated in order to identify the geographic origin of the species and reconstruct its range expansion. Individuals of B. cucurbitae were collected from 25 worldwide‐distributed localities (n = 570) and genotyped at 13 microsatellite loci. The Bayesian clustering reveals that B. cucurbitae can be subdivided into five main groups corresponding to populations from (i) the African continent, (ii) La Réunion, (iii) Central Asia, (iv) East Asia and (v) Hawaii. The proportions of inter‐regional assignments and the higher values of genetic diversity in populations from Pakistan, India and Bangladesh suggest that B. cucurbitae originated in Central Asia and expanded its range to East Asia and Hawaii on one hand and to Africa and the islands of the Indian Ocean on the other. A number of outliers (10–19 specimens according to different clustering algorithms) show high levels of admixture (Q > 0.70) with populations from different regions and reveal complex patterns of inter‐regional gene flow. Anthropogenic transport is the most plausible promoter of this large‐scale dispersal. The introduction of individuals from geographically distant sources did not have a relevant role in the most recent African invasions, which originated from the expansion of local populations. These results could provide a useful background to better evaluate invasion risks and establish priorities for the management of this cosmopolitan agricultural pest.     

Characterization of expressed sequence tag (EST)-derived microsatellite loci in the fire ant Solenopsis invicta (Hymenoptera: Formicidae)

The fire ant Solenopsis invicta has received considerable attention as a damaging invasive pest. In the present study, 12 polymorphic microsatellite loci were developed from publicly available expressed sequence tags (ESTs) of S. invicta. The number of alleles varied between 3 and 12, with an average of 6.42 per locus. The observed and expected heterozygosities ranged from 0.4167 to 1.0000 and from 0.3446 to 0.8543, respectively. These informative EST-derived microsatellite loci provide a powerful complementary tool for genetic studies of S. invicta.     

One and the same: integrative taxonomic evidence that Bactrocera invadens (Diptera: Tephritidae) is the same species as the Oriental fruit fly Bactrocera dorsalis

The invasive fruit fly Bactrocera invadens Drew, Tsuruta & White, and the Oriental fruit fly Bactrocera dorsalis (Hendel) are highly destructive horticultural pests of global significance. Bactrocera invadens originates from the Indian subcontinent and has recently invaded all of sub‐Saharan Africa, while B. dorsalis principally occurs from the Indian subcontinent towards southern China and South‐east Asia. High morphological and genetic similarity has cast doubt over whether B. invadens is a distinct species from B. dorsalis. Addressing this issue within an integrative taxonomic framework, we sampled from across the geographic distribution of both taxa and: (i) analysed morphological variation, including those characters considered diagnostic (scutum colour, length of aedeagus, width of postsutural lateral vittae, wing size, and wing shape); (ii) sequenced four loci (ITS1, ITS2, cox1 and nad4) for phylogenetic inference; and (iii) generated a cox1 haplotype network to examine population structure. Molecular analyses included the closely related species, Bactrocera kandiensis Drew & Hancock. Scutum colour varies from red‐brown to fully black for individuals from Africa and the Indian subcontinent. All individuals east of the Indian subcontinent are black except for a few red‐brown individuals from China. The postsutural lateral vittae width of B. invadens is narrower than B. dorsalis from eastern Asia, but the variation is clinal, with subcontinent B. dorsalis populations intermediate in size. Aedeagus length, wing shape and wing size cannot discriminate between the two taxa. Phylogenetic analyses failed to resolve B. invadens from B. dorsalis, but did resolve B. kandiensis. Bactrocera dorsalis and B. invadens shared cox1 haplotypes, yet the haplotype network pattern does not reflect current taxonomy or patterns in thoracic colour. Some individuals of B. dorsalis/B. invadens possessed haplotypes more closely related to B. kandiensis than to conspecifics, suggestive of mitochondrial introgression between these species. The combined evidence fails to support the delimitation of B. dorsalis and B. invadens as separate biological species. Consequently, existing biological data for B. dorsalis may be applied to the invasive population in Africa. Our recommendation, in line with other recent publications, is that B. invadens be synonymized with B. dorsalis.     

Analysis of mitochondrial COI sequences of the Diachasmimorpha longicaudata (Hymenoptera: Braconidae) species complex in Thailand

Diachasmimorpha longicaudata is an Opiinae parasitoid used to control tephritid fruit flies, which cause tremendous economic losses of fruits worldwide. In Thailand, D. longicaudata is classified as three sibling species, DLA, DLB and DLBB, based on the morphological and biological species concepts but their genetic variation has not been studied. Therefore, we investigated the genetic differentiation of the mitochondrial COI gene to clarify the ambiguous taxonomy of this species complex. The 603‐bp COI region was sequenced from laboratory‐bred colonies and field‐collected specimens from seven locations representing five geographical regions in Thailand. DLA was associated with the host Bactrocera correcta while DLB and DLBB were associated with Bactrocera dorsalis. The interspecific nucleotide differences of COI sequences among the three groups ranged from 6.70% to 7.62% (Kimura 2‐parameter distance), which adequately separates species complexes within the order Hymenoptera and supports the current sibling species classification. The neighbor joining, maximum likelihood and consensus Bayesian phylogenetic trees constructed from COI sequences revealed that the three sibling species of laboratory and field‐collected D. longicaudata are monophyletic with 100% support. The high genetic variation and molecular phylogeny of the COI sequences were shown to discriminate between the D. longicaudata species examined in this study.     

Characterisation and analysis of microsatellite loci in a mangrove species, Avicennia marina (Forsk.) Vierh. (Avicenniaceae)

An enriched microsatellite library of the mangrove species Avicennia marina was constructed, in which 85.8% of the clones contained microsatellite sequences. Of the microsatellite repeat sequences isolated, 55.0% were di-nucleotides, 34.2% were tri-nucleotides, 50.0% were perfect, 24.2% were imperfect, and 15.0% were compound. Four different di-nucleotide repeats were isolated with repeat lengths ranging from 5 to 33; ten different tri-nucleotide repeats were isolated with repeat lengths ranging from 3 to 25. The most common di-nucleotide was the AC/TG repeat; the most common tri-nucleotide was the CCG/GGC repeat. Sixteen microsatellite sequences were selected for primer design, and 6 primers were selected to investigate the polymorphism detected among 15 individuals of A. marina from three natural populations in Australia. A total of 40 alleles were detected at 6 microsatellite loci. The number of alleles per microsatellite locus ranged from 5 to 13. On average, 7 alleles were detected per locus. All microsatellite loci showed high levels of gene diversity (heterozygosity), with values ranging from 0.53 to 0.88; the mean value of gene diversity was 0.70. Microsatellite loci were also tested for conservation across Avicennia species. There was a decline in amplification success with increasing divergence between Avicennia species. The results indicate that microsatellites are abundant in the Avicennia genome and can be valuable genetic markers for assessing the effects of deforestation and forest fragmentation in mangrove communities, which is an important issue for mangrove conservation and afforestation schemes. Received: 8 June 1999 / Accepted: 21 September 1999     

Microsatellite markers for the driver ant Dorylus (Anomma) molestus

We report primer sequences for five novel polymorphic microsatellite loci that were developed for the African driver ant Dorylus (Anomma) molestus. The number of alleles in the studied population ranged from three to 10 with observed heterozygosities between 0.458 and 0.806. These microsatellite markers will be useful for the study of mating system evolution and the genetic structure of colonies and populations of army ants.     

Novel tetranucleotide microsatellite markers from the Del Norte salamander (Plethodon elongatus) with application to its sister species the Siskiyou Mountain salamander (P. stormi)

Eleven tetranucleotide microsatellite loci were developed for the Del Norte salamander (Plethodon elongatus). The loci were variably polymorphic, ranging from two to 20 alleles per locus, with expected heterozygosities ranging from 0.07 to 0.86. The loci also amplified in a congener, the Siskiyou Mountain salamander (P. stormi). The microsatellite loci will be used to assess the utility of highly polymorphic markers to assay within‐ and between‐species differentiation between these two closely related species.     

New microsatellite resources for groupers (Serranidae)

We characterized nine microsatellite loci and identified an additional 60 genomic regions containing microsatellites in the red hind grouper, Epinephelus guttatus. The nine loci were highly polymorphic, and primers designed from red hind genomic DNA produced a strong amplification product in a test panel of 16 other groupers in the genera Epinephelus and Mycteroperca collected from across the world. Most of the amplified regions were homologous to the red hind locus and a well‐defined microsatellite repeat was generally evident. The nine loci, together with the 60 uncharacterized microsatellite‐containing regions, provide a powerful tool for ecological and evolutionary studies in groupers.