Laboratory evaluation of interspecific mating between Zeugodacus fruit flies and Bactrocera dorsalis

The increasing number of tephritid pest invasions worldwide highlights the importance of interspecific interactions among tephritid pests. The melon fly [Zeugodacus cucurbitae (Coquillett)], the pumpkin fruit fly [Zeugodacus tau (Walker)], and the oriental fruit fly [Bactrocera dorsalis (Hendel)] (all Diptera: Tephritidae) are neotropical fruit flies with overlapping distributions. Their interactions during mating hours have rarely been observed in nature due to their nocturnal behavior. Here, laboratory studies were conducted under no-choice and choice conditions to quantify interspecific mating. The interactions during mating hours resulted in interspecific mating, which reduced conspecific mating success and interrupted mating activity patterns. Successful interspecific mating pairs of Z. cucurbitae and Z. tau were recorded in no-choice and choice tests. Interspecific mating between male Z. cucurbitae and female Z. tau significantly reduced conspecific mating in Z. tau. Observations of the diel mating activity patterns showed that male Z. cucurbitae initiated calling behaviors earlier than Z. tau males, giving Z. cucurbitae more chances to court Z. tau. Though males of neither Zeugodacus species formed mating pairs with B. dorsalis, Zeugodacus males reduced conspecific mating in B. dorsalis in the choice trials. Thus, interspecific interactions among Z. cucurbitae, Z. tau, and B. dorsalis affected conspecific mating; interrupted conspecific mating activity patterns were recorded in all three species. This information could be used to improve management practices.     

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。     

植物果实、颜色和形状对橘小实蝇产卵选择的影响

橘小实蝇Bactrocera dorsalis(Hendel)是近几年入侵江苏南部地区,严重危害当地水果、蔬菜的重要害虫。为深入了解其在该地区果树、蔬菜上的产卵特性,进行植物果实、颜色和形状对其产卵选择影响的研究。实验室中"纸杯法"的产卵选择试验结果表明,橘小实蝇对不同水果的产卵偏好性由高到低依次为:柑橘、香蕉、芒果、枣、石榴、苹果、桃子、梨、李、葡萄、柿;对不同蔬菜的产卵偏好性由高到低依次为:丝瓜、豇豆、苦瓜、黄瓜、茄子、南瓜、青椒、番茄。对不同寄主颜色和形状的产卵选择特点为,雌虫常选择桔黄色、绿色,以及圆球形的寄主产卵,而较少选择黑色、方形的寄主产卵。从试验结果可以看出,寄主果实散发出的气味,及其颜色和形状对橘小实蝇的产卵选择有影响。     

橘小实蝇的发生特点与综合防治技术

橘小实蝇(Bactrocera dorsalis)在福建省寄主范围很广,并严重为害寄主。它的主要为害期是每年的4-11月。生产实践中采用综合治理与农业防治技术有效地控制其为害。     

Inferences on the population structure and colonization process of the invasive oriental fruit fly, Bactrocera dorsalis (Hendel)

The phytophagous insects of the Tephritidae family offer different case histories of successful invasions. An example is Bactrocera dorsalis sensu stricto, the oriental fruit fly which has been recognized as a key pest of Asia and the Pacific. It is known to have the potential to establish adventive populations in various tropical and subtropical areas. Despite the economic risk associated with a putative stable presence of this fly, the genetic aspects of its invasion process have remained relatively unexplored. Using microsatellite markers we have investigated the population structure and genetic variability in 14 geographical populations across the four areas of the actual species range: Far East Asia, South Asia, Southeast Asia and the Pacific Area. Results of clustering and admixture, associated with phylogenetic and migration analyses, were used to evaluate the changes in population genetic structure that this species underwent during its invasion process and establishment in the different areas. The colonization process of this fly is associated with a relatively stable population demographic structure, especially in an unfragmented habitat, rich in intensive cultivation such as in Southeast Asia. In this area, the results suggest a lively demographic history, characterized by evolutionary recent demographic expansions and no recent bottlenecks. Cases of genetic isolation attributable to geographical factors, fragmented habitats and/or fruit trade restrictions were observed in Bangladesh, Myanmar and Hawaii. Regarding the pattern of invasion, the overall genetic profile of the considered populations suggests a western orientated migration route from China to the West.     

Trimedlure affects mating success and mate attraction in male Mediterranean fruit flies

Male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), are attracted to the synthetic compound trimedlure. Despite the common use of trimedlure in control programs, the underlying basis of male attraction remains unknown. In a series of laboratory trials, we compared the mating success of (treated) males exposed to trimedlure and (control) males not given access to trimedlure. When tested immediately after exposure, treated males mated more frequently than control males. This mating advantage was short-lived, however, and males tested as little as 24 h after exposure had no advantage over control males. When tested immediately after exposure, treated males exhibited higher levels of pheromone calling than control males. Consequently, more females were attracted to treated males than to control males in field tests.     

土壤含水量对桔小实蝇蛹期存活的影响

浸水时间、土壤含水量对桔小实蝇Bactroceradorsalis(Hendel)蛹的存活及成虫羽化的影响的研究结果表明:(1)不同浸水时间对桔小实蝇蛹存活率的影响不同。浸水时间越长,蛹存活率越低;浸水对初期蛹的影响较大,蛹龄越大,浸水作用效果越低。浸水时间(TW)、蛹期(AP)和蛹存活率(SP)之间关系符合以下模型:SP=0.4165-0.00307TW+0.2290AP-0.00004496T2W-0.0002528A2P+0.00008258TWAP。(2)土壤含水量对桔小实蝇成虫羽化影响明显。当土壤含水量较低或较高时,羽化率都明显受到抑制。相对含水量在30%～80%之间,蛹的羽化率较高。相对含水量(Ws)和成虫羽化率(E)之间存在以下关系:E=0.396+0.01985W-0.000181W2。     

利用微卫星标记初步分析橘小实蝇4个地理种群的遗传多态性

橘小实蝇Bactrocera dorsalis(Bactrocera)(Hendel)是我国重要的检疫性害虫,对果蔬生产及其国际贸易造成很大影响。作者运用微卫星分子标记技术,用6对微卫星引物对采自我国福建、广东、云南3个地区及邻近国越南橘小实蝇种群间的遗传关系进行了初步分析,结果显示上述4个橘小实蝇地理种群间存在一定的遗传差异,地理隔离是造成这一差异的主要原因。     

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。     

The mating system of the true fruit fly Bactrocera tryoni and its sister species,Bactrocera neohumeralis

The frugivorous “true” fruit fly, Bactrocera tryoni (Queensland fruit fly), is presumed to have a nonresourced‐based lek mating system. This is largely untested, and contrary data exists to suggest Bactrocera tryoni may have a resource‐based mating system focused on fruiting host plants. We tested the mating system of Bactrocera tryoni, and its close sibling Bactrocera neohumeralis, in large field cages using laboratory reared flies. We used observational experiments that allowed us to determine if: (i) mating pairs were aggregated or nonaggregated; (ii) mating system was resource or nonresource based; (iii) flies utilized possible landmarks (tall trees over short) as mate‐rendezvous sites; and (iv) males called females from male‐dominated leks. We recorded nearly 250 Bactrocera tryoni mating pairs across all experiments, revealing that: (i) mating pairs were aggregated; (ii) mating nearly always occurred in tall trees over short; (iii) mating was nonresource based; and (iv) that males and females arrived at the mate‐rendezvous site together with no evidence that males preceded females. Bactrocera neohumeralis copulations were much more infrequent (only 30 mating pairs in total), but for those pairs there was a similar preference for tall trees and no evidence of a resource‐based mating system. Some aspects of Bactrocera tryoni mating behavior align with theoretical expectations of a lekking system, but others do not. Until evidence for unequivocal female choice can be provided (as predicted under a true lek), the mating system of Bactrocera tryoni is best described as a nonresource based, aggregation system for which we also have evidence that land‐marking may be involved.     

桔小实蝇线粒体基因组全序列及其分析

桔小实蝇Bactrocera dorsalis线粒体基因组全序列对研究实蝇分子系统进化具有重要意义。本研究通过DNA测序和克隆技术,对桔小实蝇mtDNA全序列进行了测定和分析。结果表明：桔小实蝇线粒体基因组全长15 915 bp（GenBank序列号: DQ845759）。基因组碱基组成为39.3%A,16.2%C,10.2%G,34.3%T,由13个蛋白编码基因、22个tRNA基因、2个rRNA基因以及一个非编码的控制区域（A+T-rich区）组成。7个蛋白编码基因和13个tRNA基因从J链编码,其余6个蛋白编码基因和9个tRNA基因从N链编码。位于J链上的蛋白编码基因具有近似的A、T含量,而位于N链上的蛋白编码基因的A的含量明显高于T的含量。以mtDNA COⅠ基因为例,比较了桔小实蝇与其他14种实蝇的亲缘关系,结果显示其与同亚属（果实蝇亚属Bactrocera）内的其他近缘种相互间的同源性很高。     

Inducing and isolation of antibacterial peptides from oriental fruit fly, Bactrocera dorsalis Hendel

One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion‐exchange chromatography, gel filtration chromatography and reverse‐phase high performance liquid chromatography (HPLC). The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram‐positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation.     

病原线虫对桔小实蝇种群的控制作用

通过室内和田间实验研究了昆虫病原线虫对桔小实蝇Bactrocera (Bactrocera) dorsalis (Hendel)的控制作用。室内实验结果表明,供试的3种线虫的4个品系（小卷蛾斯氏线虫Steinernema carpocapsae All品系与A24品系,夜蛾斯氏线虫Steinernema feltiae SN品系和嗜菌异小杆线虫Heterorhabditis bacteriophora H06品系）,以小卷蛾斯氏线虫All品系对桔小实蝇的侵染力最强,其3天的LD₅₀和LD₉₅分别为35.0和257.1条/cm²土壤。按300条/cm²土壤的量施用,小卷蛾斯氏线虫All品系对当代桔小实蝇的控制效果为86.3%。用以虫期作用因子组建的生命表方法评价了小卷蛾斯氏线虫All品系对田间桔小实蝇下代种群的控制作用,结果表明,按300条/cm²土壤的量施用线虫,对照杨桃园的桔小实蝇种群趋势指数为105.9,而处理杨桃园的桔小实蝇种群趋势指数下降为15.5;小卷蛾斯氏线虫All品系对桔小实蝇的干扰控制指数为0.146,即线虫处理果园的下代种群密度仅为对照果园的14.6%。     

Potential for pre-release diet supplements to increase the sexual performance and longevity of male Queensland fruit flies

1 Recent studies have shown that continuous access to a protein source (yeast hydrolysate) can greatly enhance the sexual performance of male Queensland fruit flies ( Bactrocera tryoni ; 'Q-flies'). However, in Sterile Insect Technique programmes used to eradicate or suppress wild populations, mass-reared Q-flies are typically fed only sucrose and water for up to 2 days before release.
2 We investigated whether adding a protein source to the diet of male Q-flies for a 24- or 48-h window after emergence and then removing it is sufficient to enhance mating probability, latency to mate, copula duration, probability of sperm storage, number of sperm stored, female remating tendency and longevity of male Q-flies.
3 Protein-fed males were more likely to mate than males fed only sucrose, especially when young. Protein-fed males also had shorter mating latencies and longer copulations than protein-deprived males.
4 Females mated by protein-fed males were more likely to store sperm, stored more sperm and were less likely to remate than were females mated by protein-deprived males. Females were also less likely to remate if their first mate had been large.
5 Overall, providing male Q-flies access to a protein source for a 24- or 48-h window early on in their adult life was sufficient to greatly enhance all assessed measures of performance. Although 24-h access was sufficient for a notable enhancement, further benefits were evident in males provided 48-h access.
6 The results are discussed in terms of the practical implications for Sterile Insect Technique programs used to eradicate or suppress wild Q-fly populations.     

Re-examining the relationship between sexual maturation and age of response to methyl eugenol in males of the oriental fruit fly

Males of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), are strongly attracted to, and feed voraciously on, methyl eugenol (ME) and use metabolites of this chemical to synthesize their sex pheromone. Previously, Wong et al. (1989 ) proposed that B .  dorsalis males were attracted to ME even before attaining sexual maturity. However, their interpretation is possibly confounded by the fact that, in monitoring age-related mating readiness, males were presented with equal-aged females. As a result, if females mature more slowly than males, the age of male sexual maturation may have been overestimated, which may have accounted for the discrepancy observed between male age of ME responsiveness and mating activity. Here, we re-examined the relationship between male age and mating readiness by comparing male mating activity when presented with same-aged females vs. sexually mature females. In addition, we measured the age-dependent response of B .  dorsalis males to ME by recording (i) capture in ME-baited traps, and (ii) feeding duration on ME-containing paper discs. Our data support the conclusion of Wong et al. (1989 ) that B .  dorsalis males show attraction to, and feed on, ME before attaining sexual maturity, but suggest that a marked difference in ME response and mating activity exists over a shorter age interval than indicated by Wong et al. (1989 ). Early attraction to, but not ingestion of, ME was related to accelerated sexual maturation. Unexpectedly, ingestion of ME by sexually immature males did not boost their mating success in trials conducted 10 days after feeding on the lure.     

橘小实蝇复合体分类学研究进展

橘小实蝇复合体Bactroceradorsaliscomplex是以橘小实蝇命名的实蝇类群,已知75种,广泛分布于亚洲、澳洲及环太平洋周边地区。文章概述基于形态学和遗传学特征基础上的橘小实蝇复合体的分类鉴定及系统发育研究进展,介绍近年来分子生物学技术在橘小实蝇复合体分类及系统发育研究中的应用情况,展望系统发育和行为学研究是橘小实蝇复合体未来研究的重点领域。     

桔小实蝇雄成虫联系性嗅觉学习

【目的】为了探究桔小实蝇 Bactrocera dorsalis (Hendel)雄成虫的嗅觉学习能力。【方法】本研究采用经典性嗅觉条件反射训练法（classical olfactory conditioning）在室内对固定的羽化后14-17日龄的桔小实蝇雄成虫进行气味与食物的联合学习训练, 即薄荷精油和10%蔗糖溶液联合的奖赏性训练（appetitive conditioning）以及甲基丁香酚(methyl eugenol, ME)和饱和盐溶液联合的惩罚性训练（aversive conditioning）,并以伸喙反射行为（proboscis extension reflex, PER）作为学习与否的判定标准。【结果】经过奖赏性训练后,桔小实蝇雄成虫对薄荷精油的伸喙反射率可从0%增加至68%;而经过惩罚性训练后,桔小实蝇对甲基丁香酚的伸喙反射率可从100%降低至36.54%,且这种伸喙反射率的变化是通过气味条件刺激（conditioned stimulus）和食物非条件刺激（unconditioned stimulus）的对称性联合而产生的。【结论】结果表明,桔小实蝇雄性成虫具有较强的联系性嗅觉学习能力,并且两种刺激的联合是形成学习记忆的必要条件。     

桔小实蝇、木瓜实蝇和番石榴实蝇耐热性的热动力学分析

果实蝇属是重要的检疫性有害生物之一, 其中桔小实蝇Bactrocera dorsalis (Hendel)、 木瓜实蝇B. papayae Drew & Hancock和番石榴实蝇B. correcta (Bezzi)近几年在口岸检出率居高。本研究利用热水浸泡处理法比较这3种实蝇的卵、 1龄幼虫和3龄幼虫在44~47℃下的耐热性, 利用热动力学模型和活化能比较每种实蝇的耐热虫态以确定耐热种。结果表明： 在测定温度范围内, 3种实蝇卵、 1龄幼虫和3龄幼虫的死亡率都与处理时间呈正相关。热动力学系数取0.5时, 最适合热动力学模型预测3种实蝇在各实验温度LT_99.9968的致死时间。3种实蝇在44~47℃耐热性均为： 卵>1龄幼虫>3龄幼虫。番石榴实蝇在3种实蝇中最耐热。本研究结果为实蝇热处理指标的制定提供了实验依据。     

橘小实蝇的风险分析

从地理评估和管理标准、传人的可能性、传播途径、定殖、定殖后扩散的可能性及橘小实蝇危害性评估等方面对橘小实蝇传人中国风险进行定性分析,筛选了橘小实蝇传人中国的风险因子。根据我国各气候大区的30a（1961—1990）的平均气温、月最高平均气温、月最低平均气温及年降雨量等气候因子和橘小实蝇的发生规律,将我国地域划分为适生区、次适生区、非适生区,明确了南亚热带湿润大区、边缘热带湿润大区、边缘热带亚湿润大区为橘小实蝇的适生区;暖温带湿润大区、北亚热带湿润大区、南亚热带亚湿润大区、高原亚温带湿润大区为橘小实蝇的次适生区。提出了降低橘小实蝇风险的管理措施,为制定检疫政策提供依据。