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.     

Apodeme and ovarian development as predictors of physiological status in Bactrocera cacuminata (Hering) (Diptera: Tephritidae)

Abstract Assessing resource-use by different life stages of insects is crucial to our understanding of their ecology. Development of appropriate methods by which different physiological states can be identified is therefore significant. We develop one such method for the dacine fly Bactrocera cacuminata (Hering) (Diptera: Tephritidae). In male flies, the ejaculatory apodeme, a structural part of the reproductive endoskeleton, grows as a function of age of the fly. This growth pattern is sigmoid, reaching a maximum threshold that corresponds with the attainment of sexual maturity, as measured by the incidence of first mating. Similarly, in female flies ovarian development appears to be a reliable indicator of sexual maturity. Assuming that similar growth thresholds occur in wild flies, it is possible to use apodeme and ovarian development as measures of physiological/reproductive status in this species.     

Spatial and temporal partitioning of behaviour by adult dacines: direct evidence for methyl eugenol as a mate rendezvous cue for Bactrocera cacuminata

Abstract. Resource use in adult Dacinae (Diptera: Tephritidae) is believed to be restricted to the host plant (i.e. the plant that provides fruit for oviposition and larval development). However, studies on Bactrocera cacuminata did not support this hypothesis. Thus, it was hypothesized that adult flies partition their diurnal activities between spatially separated resources (host plant, sugar, protein and methyl eugenol) as a function of the physiological status of the fly (immature, mature–unmated, mature–mated). In accordance with a priori predictions, the results of a field‐cage study show that there are significant diurnal patterns in abundance and behaviour, and that flies of different physiological status use resources differently. Immature flies spend most of their time foraging for sugar and protein to facilitate development. Sexually mature flies forage for sugars during the day, and at dusk, responded strongly to methyl eugenol and mate. The fact that polygynous males wait at methyl eugenol at dusk whereas the mated, monandrous females spend their time ovipositing in fruit and are nonresponsive to methyl eugenol, supports Metcalf's hypothesis that such phenylpropanoids serve as mate rendezvous cues.     

Two new species and a new Australian record of Bactrocera Macquart (Diptera: Tephritidae: Dacinae) from northern Queensland, Torres Strait and Papua New Guinea

Abstract  Bactrocera (Bactrocera) speewahensis Fay & Hancock sp. n. is described from northern Queensland and B. (B.) torresiae Huxham & Hancock sp. n. is described from Boigu, Saibai and Dauan islands in Torres Strait and southern Papua New Guinea. Bactrocera (B.) nigrovittata Drew is newly recorded from Australia. All records are of male flies responding to chemical lures.     

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.     

Biology of Bactrocera carambolae (Diptera: Tephritidae) on four hosts

Bactrocera carambolae is a quarantine pest found in Brazil, restricted to the states of Amapá, Pará and Roraima. This fruit fly can potentially cause extensive socioeconomic and environmental damage in the country, if it disperse into areas where fruit is grown for exporting. The objective of this work was to study the biology of B. carambolae on fruits of Averrhoa carambola L. (Oxalidaceae), Psidium guajava L. (Myrtaceae), Spondias mombin L. (Anacardiaceae) and Eugenia stipitata McVaugh (Myrtaceae). The following parameters were investigated: duration of egg-larva, pupal, egg-adult, pre-oviposition, oviposition and post-oviposition periods, pupal weight and viability, sex ratio, fecundity, fertility and longevity. All parameters except pupal weight, oviposition and post-oviposition period, egg fertility and sex ratio were influenced by the host plant on which the larvae were reared. The carambola fruit fly completes its development on all those hosts studied here, with the highest fecundities on A. carambola and P. guajava.     

Influence of fruit traits on oviposition preference and offspring performance of Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) on three tomato (Lycopersicon lycopersicum) cultivars

Abstract  In Queensland, three tomato ( Lycopersicon lycopersicum ) cultivars, Grosse Lisse, Roma and Cherry, are infested by Queensland fruit fly, Bactrocera tryoni (Froggatt). In this study, we examined if there was a correlation between oviposition preference and offspring performance of B. tryoni among the three tomato cultivars. We also investigated host plant traits that may explain any variation in preference and performance. Choice and no-choice experiments were carried out under laboratory conditions. A positive correlation between oviposition preference and offspring performance of B. tryoni was observed in the three tomato cultivars. Grosse Lisse and Roma cultivars were highly preferred by B. tryoni over Cherry cultivar. Performance (measured as proportion of eggs developing to the pupal stage) was significantly higher in Grosse Lisse and Roma cultivars than in Cherry cultivar. The pericarp toughness of Cherry cultivar appears responsible for its low rate of infestation, while the presence of 2-butanol and 1,4-butanediamine in Roma and Grosse Lisse, respectively, may partly be responsible for the high oviposition preference shown by B. tryoni towards these cultivars.     

Mating activity of Bactrocera cacuminata (Hering) (Diptera: Tephritidae) on its larval host plant Solanum mauritianum Scopoli in southeast Queensland

A detailed study was conducted on the mating behaviour of Bactrocera cacuminata (Hering) (Diptera: Tephritidae) in nature. Plant tissues from Solanum mauritianum Scopoli, the primary larval host for B. cacuminata, were also analysed for methyl eugenol content. In the field, over a 15 month period, 44,171 observations of adult B. cacuminata individuals were made including 1109 mating pairs on S. mauritianum. Calling behaviour consisting of wing fanning and anus beating by males was also consistently observed on the underside of leaves of S. mauritianum after sunset. Female flies that arrived into these groups of 10-15 calling males were mated and often remained coupled until dawn. No methyl eugenol was detected from the analysis of leaves, flowers and fruits of S. mauritianum. Thus, B. cacuminata does not need to aggregate at sites where methyl eugenol is present and the hypothesis that this chemical plays a role in the selection of mating sites by B. cacuminata is not supported by the current study. It is concluded that S. mauritianum is the primary site of mating for B. cacuminata in nature and that the concept that the larval host plant is the centre of activity for dacine fruit flies remains robust, being fully supported by the results of this study.     

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is not invasive through Asia: It's been there all along

Oriental fruit fly, Bactrocera dorsalis (Hendel), is a highly polyphagous fruit fly which, in the last 15 years, has invaded (with or without establishment) Africa, Europe and North America. As a direct result of these invasions, there is increasing research interest in the invasion history and spread patterns of this fly. A statement being repeatedly used in the B. dorsalis invasion literature is that the species was first identified from Taiwan in 1912 and that it subsequently spread through South‐East and South Asia during the 20th century. This assumption is incorrect and stems from: (a) an incomplete knowledge of B. dorsalis taxonomic history; and (b) a confounding of first taxonomic record with first invasion record. Rather than being first detected in Taiwan in 1912, the first record of oriental fruit fly was from “East India” (India orientali) under the synonymous name of Musca ferruginea by Fabricius in 1794, and in the 1910s, it was known not only from Taiwan, but widely across tropical Asia with records from India, Burma, Bengal, Sri Lanka (as Ceylon), Singapore and Indonesia (multiple islands). The taxonomic literature is very clear that oriental fruit fly has not invaded the rest of Asia from Taiwan since 1912, and this error should not continue to be repeated in the literature.     

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     

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.     

海南寡鬃实蝇亚科分类研究(双翅目: 实蝇科)

根据2000～2004年间海南省实蝇监测和野外调查的部分研究结果,确认海南寡鬃实蝇亚科Dacinae现知下列14种：桔小实蝇 Bactrocera (Bactrocera) dorsalis (Hendel), 辣椒果实蝇 B. (B.) latifrons (Hendel), 锈红果实蝇B. (B.) rubigina (Wang et Zhao), 五指山果实蝇 B. (B.) wuzhishana Lin et Yang, sp. nov., 何氏华实蝇B. (Sinodacus) hochii (Zia), 短条果实蝇 B. (Zeugodacus) abbreviata (Hardy), 普通果实蝇 B. (Z.) caudata (Fabricius), 两带果实蝇B. (Z.) cilifera (Hendel), 瓜实蝇 B. (Z.) cucurbitae (Coquillett), 黑颜果实蝇 B. (Z.) diaphora (Hendel), 宽带果实蝇 B. (Z.) scutellata (Hendel), 南亚果实蝇 B. (Z.) tau (Walker), 海口棍腹实蝇 Dacus (Callantra) haikouensis Wang et Chen, 海南寡鬃实蝇 Dacus (Dacus) hainanus Wang et Zhao。五指山果实蝇 B. (B.) wuzhishana Lin et Yang, sp. nov. 区别于果实蝇属内其他种的鉴别特征如下：1）颜具2个黑色大斑点;2）中胸盾片的缝后黄色侧条短而窄,后端约与缝后翅上鬃处于同一水平;3）翅前缘带较窄,末端稍加宽;4）足的股节除中股节基部的1/2和后股节基部的3/5呈黄色外,余全黑色;腹部完全黑色。除附新种特征图外,还提供海南寡鬃实蝇亚科的种类修订名录和分种检索表。     

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。     

Odorant receptor co-receptor Orco is upregulated by methyl eugenol in male Bactrocera dorsalis (Diptera: Tephritidae)

Bactrocera dorsalis is a destructive fruit-eating pest that causes severe economic damage to the fruit and vegetable industry. Methyl eugenol (ME) has been widely used as an effective sexual attractant for male fruit flies through olfactory perception. However, the molecular mechanism underlying the olfactory perception of ME remains unknown. Here, we report the characterization and functional analysis of a newly discovered cDNA that encodes a Drosophila melanogaster odorant receptor co-receptor Orco ortholog in B. dorsalis. qRT-PCR analysis revealed that it was abundantly expressed in the antenna of adult B. dorsalis. Notably, Orco was upregulated by ME in the antenna of male flies. Mature males of B. dorsalis showed significant taxis toward ME within 0.5h, and Orco was significantly upregulated in the attracted adults within the same period. Silencing Orco through the ingestion of dsRNA reduced the attractive effects of ME. These data suggest that Orco may play an essential role in ME attraction in the olfactory signal transduction pathway.     

食料对南亚果实蝇解毒酶活力的影响

昆虫解毒酶是一类异质酶系, 对分解大量的内源或外源有毒物质、维持正常生理代谢起着重要作用。本文采用生物化学的方法测定了5种寄主果实对南亚果实蝇Bactrocera tau Walker 3个虫态体内总蛋白含量和5种解毒酶的活力。双因子方差分析显示, 南亚果实蝇种群取食黄瓜Cucumis sativus L.、南瓜Cucurbita moschala L.、丝瓜Luffa cylindrical L.、冬瓜Benincasa hispida (Thunb.) Coqn.和苦瓜Momordica charantia L.后, 体内蛋白含量和解毒酶活性均存在显著差异。以丝瓜为食料时, 南亚果实蝇体内蛋白含量较高; 而以黄瓜和冬瓜为食料时蛋白含量则相对较低。在以上5种寄主果实间, 南亚果实蝇的羧酸酯酶（CarE）活性在黄瓜和南瓜上较高, 细胞色素P450 O-脱甲基和谷胱甘肽S-转移酶（GST）活性在苦瓜上较高, 酸性磷酸酯酶（ACP）和碱性磷酸酯酶（ALP）活性却分别在黄瓜和南瓜上较低。在幼虫、蛹和成虫3个虫态间, 解毒酶活性亦存在显著差异, 成虫具有较高的CarE活性;幼虫具有较高的细胞色素P450 O-脱甲基, GST和ALP活性,但具有较低的ACP活性;除ACP外,蛹期解毒酶活性均较低。据以上结果可以推测,南亚果实蝇解毒酶活力受寄主果实种类以及该种群本身发育阶段的影响。     

Attraction of feral Bactrocera dorsalis males (Diptera: Tephritidae) to natural versus commercial sources of methyl eugenol

Males of Bactrocera dorsalis (Hendel) are strongly attracted to methyl eugenol (ME), which occurs in over 450 plant species. Given this powerful attraction, ME is commonly used in surveillance and eradication programs against this invasive agricultural pest. Preliminary observations revealed that B. dorsalis males visited ME-bearing flowers of the fruit fly orchid (FFO) Bulbophyllum cheiri subsp. cheiri even when these occurred near traps baited with far greater quantities of ME. Based on this evidence, we undertook field experiments to assess the attraction of feral B. dorsalis males to FFO flowers relative to commercial sources of ME. At the edge of a secondary forest, an FFO flower was placed midway between two ME sources located 20 m apart, and attracted flies were collected over an entire day. When the ME sources were unenclosed (not in traps), the relative attractiveness of FFO flowers to B. dorsalis males varied with the amount of ME placed nearby. The FFO flower (i) attracted a similar proportion of males when 1 g ME was placed at the flanking sites but (ii) captured significantly smaller proportions when the nearby sites had 6 or 10 g commercial ME sources. Similar tests with the commercial sources enclosed in traps showed that (i) 6 g ME sources in Steiner traps attracted significantly more B. dorsalis males than FFO flowers but (ii) 10 g sources in Clear traps (1 L buckets with 4 entrance holes) did not outperform the FFO flowers, presumably owing to limited dispersion of volatiles from the trap. Implications of these results for surveillance programs are discussed.     

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。