临海柑橘园橘小实蝇种群数量消长规律

【背景】近年来,随着种植结构的改变以及南方携虫水果的频繁调运,橘小实蝇逐渐向北扩散危害,对水果生产造成严重威胁。【方法】2008～2010年应用性诱剂的监测方法对柑橘园橘小实蝇种群数量进行了定点、系统的跟踪监测;并结合气象资料和田间调查情况,通过对当旬成虫数量与当旬及其前延逐句气象要素的筛选来建模,进而确定影响橘小实蝇种群数量的主要气象因子。【结果】临海柑橘园橘小实蝇种群数量时序变化呈单峰型曲线,其性诱成虫初见期在6月下旬至8月初,高峰期在9月上旬至11月上旬,11月中旬后成虫数量逐渐下降,到12月下旬未诱集到成虫。气象因子筛选和建模结果表明,柑橘园橘小实蝇成虫种群数量年度变动以旬平均温度为决定要素,季节性变化以旬降雨量为决定要素。【结论与意义】临海柑橘园橘小实蝇种群数量随温度和土壤湿度的增大而增长。本研究对提高橘小实蝇监测预警水平、有效控制橘小实蝇危害具有重要意义。     

几种物质对橘小实蝇的引诱力测定

分别以3种果泥、4种人工合成水果味香精、发酵面粉、蜂蜜、甲基丁香酚、月罗香植物粗提取液为引诱物,测定11种引诱物对橘小实蝇的田间引诱能力。结果表明,水果香精、蜂蜜对橘小实蝇的引诱效果很差;香蕉果泥具有极强的引诱能力,诱虫数达到354只,雌雄比达1∶1;发酵面粉具有较好的诱雌性,诱虫总量达287只,雌雄比为8∶1;甲基丁香酚具有最强的诱雄能力,共引诱了763只橘小实蝇;月罗香粗提取液引诱了429只雄橘小实蝇,具有较强的引诱力。     

福州实蝇监测初报

自2005年5月29日至2006年5月28日在福州金山福建农林大学校园内进行了实蝇监测。采用甲基丁香酚(M e)、诱蝇酮(Cue)和地中海实蝇诱芯(T),诱集到橘小实蝇[Bactrocera(Bactrocera)dorsalis]、瓜实蝇[B.(Zeugodacus)cucurbi-tae]、南瓜实蝇[B.(Zeugodacus)tau]和具条实蝇(B.scutellata)4种实蝇,但未诱到地中海实蝇(Ceratitis capitata)。其中,橘小实蝇诱集量最大,8月中下旬达到高峰。本研究为掌握福州地区实蝇发生动态提供了基础资料。     

海南儋州地区橘小实蝇成虫数量动态

【背景】橘小实蝇是热带、亚热带水果的重要害虫,在海南发生严重。【方法】利用橘小实蝇性诱剂进行田间诱捕,以诱到的雄成虫为指标,通过定期调查,获得了海南儋州地区4种样地橘小实蝇成虫的种群动态,并进一步通过相关分析,研究了芒果园橘小实蝇种群动态与温度和降雨量的相关性。【结果】儋州地区橘小实蝇种群周年发生,冬季种群数量较低,夏季种群数量较高。橘小实蝇种群高峰期发生于6月,其中芒果园达327.6头,蔬菜地为182.8头,办公区为150.0头,植物园为209.6头。在芒果园中,随着温度的升高,橘小实蝇的种群数量呈指数增长,其相关系数R=0.799;而与降雨量的相关系数较低,为0.367。【结论与意义】本研究可为儋州地区制定橘小实蝇综合防治策略提供理论依据。     

柑桔大实蝇辐照成虫对两种引诱剂的敏感性

为了明确柑桔大实蝇Bactrocera minax (Enderlein)辐照成虫和田间自然发生的成虫对引诱剂的敏感性差异,指导柑桔大实蝇辐照不育技术的有效利用,在田间释放柑桔大实蝇辐照成虫,以常用引诱剂桔丰和果瑞特同期进行诱集监测。监测结果显示,辐照显著降低了柑桔大实蝇成虫对桔丰和果瑞特的敏感性。在柑桔大实蝇成虫发生高峰期桔丰诱集到辐照成虫的数量仅为诱集总虫量的2.6%-11.6%,果瑞特为5.0%-50.0%;桔丰诱集到的辐照雌性成虫的数量仅为诱集的所有雌性成虫数量的4.4%-11.8%,果瑞特为33.7%-50.0%;桔丰诱集到的辐照雄性成虫的数量仅为诱集的所有雄性成虫的5.3%-11.4%,而果瑞特始终未能诱集到辐照雄性成虫。此外,辐照缩短了柑桔大实蝇成虫对常用引诱剂趋向性的持续时间。研究结果对柑桔大实蝇辐照不育技术与诱集诱杀技术的协调应用具有重要指导意义。     

广东橘园生境实蝇多样性及优势种的季节动态

为明确广东橘园生境的实蝇种类及优势种的季节动态,2016年在肇庆市怀集县、韶关市始兴县和潮州市潮安区各选择一处橘园开展实蝇监测并分析实蝇昆虫的多样性特征及优势种的季节动态。本次监测共诱集到7属15种实蝇。其中,怀集县橘园的物种丰富度最高,所获得的15种实蝇在该地均有发现,橘小实蝇Bactrocera dorsalis为怀集县橘园的优势种。此外,值得关注的是,怀集县橘园还监测到柑橘专性害虫蜜柑大实蝇B.tsuneonis,蜜柑大实蝇的此次发现在广东省为首次报道。始兴县橘园监测到实蝇7种,其多样性、优势度和均匀度指数在3个橘园中最高,南瓜实蝇Bactrocera tau和橘小实蝇是该橘园的优势种。潮安区橘园监测到5种,其所有多样性指数在3个橘园中最低,橘小实蝇占绝对优势。监测结果表明橘小实蝇、南瓜实蝇、瓜实蝇和具条实蝇是广东橘园生境的常见种。橘小实蝇与南瓜实蝇是橘园生境的优势种,橘小实蝇与南瓜实蝇的成虫全年均可发生。     

柑橘大实蝇羽化出土及橘园成虫诱集动态研究

【背景】柑橘大实蝇是柑橘类果树上的重要害虫。预测该虫的羽化出土进度、掌握成虫发生动态是指导橘同成虫期防治的重要依据。【方法】本研究通过在25℃恒温、室内常温和室外网室3种条件下饲养柑橘大实蝇的蛹,以逐日观察成虫羽化出土数量;在重庆武隆、四川江油等5个地区共设置240个麦克菲尔（MePhail）诱集器,以糖酒醋液和水解蛋白为诱饵诱集成虫,得到柑橘大实蝇成虫羽化出土的逐日数量和橘园成虫诱集的逐期数量。【结果】用逻辑斯带模型拟合成虫羽化出土和橘园成虫诱集动态,结果表明,成虫的始盛期、高峰期和盛末期在25℃恒温条件下分别为4月25日、28日和30日,盛期的持续时间为6d;在室内常温条件下分别为5月3日、7日和10日,盛期的持续时间为8d;在室外网室条件下分别为5月8日、14日和18日,盛期的持续时间为11d;橘园诱集成虫分别为6月2日、14日和26日,盛期的持续时间为25d。【结论与意义】随着羽化期温度的提高,柑橘大实蝇羽化出土期提前,历期缩短,羽化整齐。虽然网室成虫羽化和橘园成虫诱集都处于室外条件,但后者的始盛期、盛期和盛末期比前者分别迟了36、30和22d。因此,建议采用室外网室饲养蛹的方法监测柑橘大实蝇成虫的发生期,若仅凭橘园诱集成虫的数据,因其滞后性十分明显,对指导柑橘大实蝇成虫防治的意义不大。     

橘小实蝇神经肽sulfakinin的分子生物学特性及其表达模式

【目的】分析橘小实蝇sulfakinin的时空表达模式及其对饥饿的响应,初步明确sulfakinin在调节橘小实蝇行为和生理方面的功能。【方法】利用RT-PCR技术克隆橘小实蝇神经肽sulfakinin的c DNA序列,采用实时定量PCR技术分析该基因在橘小实蝇不同发育阶段、成虫不同组织、幼虫不同组织及其在饥饿胁迫下的表达模式,并运用半定量RT-PCR技术进一步验证。【结果】实时定量PCR分析结果表明,sulfakinin在橘小实蝇的幼虫期和成虫期显著性高表达,卵期和蛹期几乎不表达。其中早期成虫表达量最高,约为晚期成虫的2倍,幼虫期表达量位于两者之间。在橘小实蝇幼虫、成虫不同组织中,sulfakinin在中枢神经系统的表达量显著高于其他组织,在触角的表达量仅次于中枢神经系统。此外,橘小实蝇在经饥饿处理24 h的过程中,sulfakinin的表达量均出现下调,其中从饥饿处理结果可知在6 h下降幅度最大,12 h和24 h表达量下降幅度减少。半定量RT-PCR技术进一步检测结果与实时定量PCR技术检测结果一致。【结论】sulfakinin在橘小实蝇中枢神经系统可能调节橘小实蝇成虫对饥饿胁迫的响应。其在触角中的高表达可能与橘小实蝇嗅觉的敏感性相关。本研究为进一步研究橘小实蝇sulfakinin的生理功能、评估其药靶潜力奠定了理论基础。     

橘小实蝇田间消长动态及对柑橘果实危害研究

【目的】找出橘小食蝇Bactrocera dorsalis(Hendel)在桂林东郊柑橘果园的消长规律,掌握橘小实蝇对不同柑橘品种的危害程度。【方法】2012-2013年,利用橘小实蝇性诱器对桂林东郊柑橘果园的橘小实蝇田间动态进行监测,收集逐旬诱虫数量,并制作周年诱虫消长曲线,分析橘小实蝇消长规律。选取果园内18个早中晚熟柑橘品种进行橘小实蝇危害调查,从果实受害前到果实成熟采收,统计各个品种的逐旬虫果数量,分析各品种受害情况。【结果】田间橘小实蝇成虫5月开始出现,9月下旬-10月上旬达到高峰期,12月中下旬活动减弱或停止。早中熟柑橘品种受橘小实蝇的危害率多在26.72%-73.19%,而晚熟品种多在16.08%以下。宽皮柑橘类受橘小实蝇的危害率多在15.23%以上,而橙类和杂柑类低于10.81%。早熟品种从7-8月开始受橘小实蝇危害,一直持续到果实成熟,受害程度逐步加重。中晚熟品种10月中下旬后开始受害,在11月上旬到12月上旬之间有1-2个受害高峰期,12月中下旬受害减轻。同一品种在不同年份的受害开始时间、高峰期、低谷期不完全相同。【结论】橘小实蝇成虫在春季条件适合时开始活动,在秋季达到活动高峰期,在冬季气温下降等不利条件下活动减弱或停止。橘小实蝇对柑橘早中熟品种的危害率高于晚熟品种,对宽皮柑橘类的危害率高于橙类。在果实生长成熟过程中,早熟品种随果实成熟度增高受害程度加重,中晚熟品种受害高峰期出现在果实成熟中、前期,同年内成熟期相同品种的受害消长走势基本相同,同一品种在不同年份的受害消长走势不同。     

不育胺对橘小实蝇的化学不育效果

【目的】为了解不育胺对橘小实蝇Bactrocera dorsalis(Hendel)的化学不育效果。【方法】通过喂食橘小实蝇不同浓度不育胺食料,测定了其对橘小实蝇的卵量及孵化率的影响。【结果】结果表明:喂食0.08%-0.3%不育胺食料的橘小实蝇成虫交配始见期和产卵始见期与正常对照相比推迟1-2d,均为9-10日龄开始交配,11-12日龄开始产卵;橘小实蝇取食不同浓度不育胺食料后,卵量和孵化率随浓度增加而降低。当取食0.3%不育胺食料时,♀处理×♂处理未见产卵,♀正常×♂处理和♀处理×♂正常均见产卵但卵量与对照相比显著降低且卵不孵化。取食0.3%不育胺的橘小实蝇雄虫相对不育系数为0.48,表明其交配竞争能力与正常雄虫相当。【结论】0.3%浓度的不育胺可作为橘小实蝇的化学不育剂。     

Attractiveness to Anastrepha ludens (Diptera: Tephritidae) of plant essential oils and a synthetic food-odour lure

Abstract:  Experiments were conducted in a citrus orchard to investigate the attractiveness of 26 plant essential oils individually and in combination with a synthetic food odour lure to the Mexican fruit fly, Anastrepha ludens Loew. Anise, rose/grape seed, and tea tree oils were more attractive than unbaited traps but none approached the attractiveness of Advanced Pheromone Technologies' AFF lure, a synthetic food-odour lure that emits several nitrogenous chemicals attractive to this fly. Traps baited with most of the oils were less attractive than unbaited traps. Rose/grape seed oil and pure-rose oil enhanced attractiveness of AFF lures to both males and females by about 68%. Grape seed oil did not enhance the attractiveness of AFF lures demonstrating that rose oil was the active component of the rose/grape seed oil. No other oil enhanced attractiveness of AFF lures and most decreased attraction to AFF lures. The possibility that highly attractive chemicals may be present in rose oil as minor components is discussed. Traps baited with the combination of clove bud oil and the AFF lure captured only 3% as many flies as traps baited only with the AFF lure indicating that clove bud oil is highly repellent to Mexican fruit flies.     

Behavioral responses of female oriental fruit flies to the odor of papayas at three ripeness stages in a laboratory flight tunnel (Diptera: Tephritidae)

Behavioral responses of adult female oriental fruit flies, Dacus dorsalisHendel, to the odor of papayas from three ripeness classes were studied using a threechoice flight tunnel bioassay. Laboratoryreared flies were allowed to respond freely to any of three papaya odors (mature green, colorbreak to one-fourth ripe, and one-half to full ripe) emanating from identical (spherical) fruit models. Five behaviors were measured in assessing the fly's relative attraction to the odors (number of landings), arrestment (total fly seconds on sphere), fly-fly interactions on the fruit model (maximum and modal fly density), and acceptance for oviposition (total eggs laid). Females showed no significant difference in total fly landings based on all age classes combined. Significant differences were noted among age classes. Females spent more total time on the sphere and showed a higher maximum density and modal fly density to ripe fruit than to green fruit odors. Ovipositional acceptance of fruit models based on the total number of eggs laid in a sphere was greater in response to the ripefruit odor than to the other two odor classes. Olfactorystimulated behavioral responses of females to the odor of ripe papayas were significantly different from the other ripeness classes for all behaviors at 8 days postemergence and then declined in 11-day-old flies. Behavioral responses were greater during the afternoon than in the morning. Observations of wild oriental fruit flies to papayas in the field indicated a preference for residing on riper fruit. The results of this study are discussed with regard to the role of olfactory inputs generated by the odor of ripening fruit on female attraction and oviposition behavior resulting in infestation of papayas by oriental fruit fly.     

A potential field suppression system for Bactrocera dorsalis Hendel

Development of an effective and safe detection or control system is important for pest management. Attractants for male fruit flies, e.g., methyl eugenol (ME), are currently being used in fruit fly control in combination with insecticides. A single formulation that possesses both attraction and killing properties would improve control methods and cost effectiveness. We previously observed the attraction of oriental fruit flies to a basil plant in a yard and confirmed the attraction of male fruit flies to basil oil (BO) in the laboratory. Subsequently, we identified insecticidal compounds from BO that killed three species of tephritid fruit flies in the laboratory, and we also discovered physiological interactions between BO constituents and male attractants. Based on these observations, we developed a single package of basil oil and methyl eugenol (BO + ME) formulation that possesses “attract and kill” properties in combination with a modified AWPM standard trap for field application. The effectiveness of this system is dependent on the type of trap and weather conditions (sunny or not sunny). Any attracted flies were killed within 2 h after entering the BO + ME trap. The combination of BO, ME, and a clear bucket trap may be a novel alternative for a cost effective and environmentally friendly fruit fly management system.     

Differences in body size and egg loads of Rhagoletis indifferens (Diptera: Tephritidae) from introduced and native cherries

The western cherry fruit fly, Rhagoletis indifferens Curran, infests introduced, domesticated sweet [Prunus avium (L.) L.], and tart cherries (Prunus cerasus L.) as well as native bitter cherry, Prunus emarginata (Douglas) Eaton. Bitter cherries are smaller than sweet and tart cherries and this could affect various life history traits of flies. The objectives of the current study were to determine 1) if body size and egg loads of flies infesting sweet, tart, and bitter cherries differ from one another; and 2) if any observed body size differences are genetically based or caused by the host fruit environment. Pupae and adults of both sexes reared from larval-infested sweet and tart cherries collected in Washington and Montana were larger than those reared from bitter cherries. In addition, flies of both sexes caught on traps in sweet and tart cherry trees were larger than those caught in bitter cherry trees and females trapped from sweet and tart cherry trees had 54.0-98.8% more eggs. The progeny of flies from naturally-infested sweet and bitter cherries reared for one generation in the laboratory on sweet cherry did not differ in size. The same also was true for progeny of sweet and bitter cherry flies reared in the field on bitter cherry. The results suggest that the larger body sizes of flies from sweet and tart cherries than bitter cherries in the field are caused by host fruit and not genetic factors.     

梨小食心虫成虫性比、日羽化节律及活动规律

梨小食心虫Grapholitha molesta(Busck)是我国重要的果树害虫,本文利用室内饲养观察、室外田间模拟、果园采集饲养等方法系统研究了梨小食心虫成虫的性比及日羽化节律;并利用性诱剂、糖醋液、黑光灯等诱集梨小食心虫成虫,研究了梨小食心虫成虫的活动规律。结果表明:1、田间采集调查表明,梨小食心虫成虫雌雄比例为1∶1.143,室内饲养雌雄比例为1∶1.708。2、梨小食心虫成虫羽化时间主要集中在4:00—10:00,其中以6:00—8:00羽化率最高;梨小食心虫在室外羽化时间比室内推迟2 h左右,室外梨小食心虫比室内普遍晚4 d羽化,这可能与室外温度和光照条件有关;雌虫羽化较雄虫早1² d;3、性诱剂和糖醋液诱集成虫高峰时间均为晚上20:00—22:00,说明梨小食心虫无论雄虫还是雌虫都在此期间活动;夜间各个时间段利用黑光灯都能诱到梨小食心虫成虫,说明梨小食心虫具有趋光性。结论:梨小食心虫雌雄比例为1∶1.12 d;3、性诱剂和糖醋液诱集成虫高峰时间均为晚上20:00—22:00,说明梨小食心虫无论雄虫还是雌虫都在此期间活动;夜间各个时间段利用黑光灯都能诱到梨小食心虫成虫,说明梨小食心虫具有趋光性。结论:梨小食心虫雌雄比例为1∶1.1¹.7,主要在早晨及上午羽化,雌虫较雄虫先羽化;在果园活动时间主要为晚上20:00—22:00。本结果可为梨小食心虫的田间性诱剂监测和诱捕、迷向防治提供指导。     

Volatile host fruit odors as attractants for the oriental fruit fly (Diptera: Tephritidae)

We examined the responses of oriental fruit flies, Bactrocera dorsalis Hendel, to the odors of different stages and types of fruit presented on potted trees in a field cage. Females were most attracted to odors of soft, ripe fruit. Odors of common guava were more attractive to females than papaya and starfruit, and equally as attractive as strawberry guava, orange, and mango. In field tests, McPhail traps baited with mango, common guava, and orange captured equal numbers of females. Traps baited with mango were compared with 2 commercially available fruit fly traps. McPhail traps baited with mango captured more females than visual fruit-mimicking sticky traps (Ladd traps) and equal numbers of females as McPhail traps baited with protein odors. Results from this study indicate that host fruit volatiles could be used as lures for capturing oriental fruit flies in orchards.     

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.     

Visual and olfactory stimuli and fruit maturity affect trap captures of Oriental fruit flies (Diptera: Tephritidae)

An effective lure-and-kill trap is a potentially important instrument in monitoring and controlling oriental fruit flies, Bactrocera dorsalis (Hendel). A number of experiments were performed in an orchard of commercial guava, Psydium guajava L., to determine how fly captures are affected by combining visual and olfactory stimuli, and by the timing of trap deployment relative to host phenology. Baiting sticky Ladd traps with hydrolyzed liquid protein significantly increased the number of captured flies. Mostly male flies were caught in the absence of mature guava fruit, whereas mostly female flies were caught when ripe fruit was abundant. These results suggest that an effective oriental fruit fly trap should include both visual and olfactory lures, and that proper timing of trap deployment can be an important factor in monitoring female abundance in oriental fruit fly populations.     

Essential oils of citrus fruit stimulate oviposition in the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae)

Female Mediterranean fruit flies (medfly) Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) perceive both qualitative and quantitative aspects of citrus fruit chemistry. However, the behavioural and biological adjustments of this response remain largely unknown. In the present study, the ovipositional responses of gravid female medflies to essential oils (i.e. the most critical resistance factor to medfly infestation) of various citrus fruits are investigated. In dual‐choice (treatment versus distilled water control) experiments, females lay significantly more eggs into pre‐punctured hollow oviposition hemispheres (domes) provided with 1 µL of citrus peel oil from sweet orange, satsuma mandarin, bitter orange, grapefruit and lemon compared with odourless domes. No‐choice tests show a weak effect of lemon essential oils in stimulating oviposition. The female ovipositional response to sweet orange oil (the most active in eliciting oviposition) is dose‐dependent. Additionally, limonene, the most abundant chemical in all citrus oils, stimulates oviposition, whereas linalool, a representative compound of immature citrus fruit associated with high toxicity against immature stages of fruit flies, has a significant deterrent effect. In further no‐choice tests, females lay approximately 23% fewer eggs in limonene (93%) (amount found in orange oil) and 60% fewer eggs in limonene 93% plus linalool 3% (approximately 10‐fold the amount found in orange oil) mixtures, relative to sweet orange oil. The results suggest that the limonene content accounts largely (but not completely) for the ovipositional responses observed in sweet orange oil, whereas high linalool proportions are capable of significantly masking and/or disrupting its stimulatory effects in citrus oils. The importance and practical implications of these findings with respect to understanding how citrus fruit chemistry influences the ovipositional responses of medfly is discussed.     

Captures of pest fruit flies (Diptera: Tephritidae) and nontarget insects in BioLure and torula yeast traps in Hawaii

MultiLure traps were deployed in a Hawaiian orchard to compare the attraction of economically important fruit flies and nontarget insects to the three-component BioLure and torula yeast food lures. Either water or a 20% propylene glycol solution was used to dissolve the torula yeast or as capture fluid in BioLure traps. Torula yeast in water was more attractive than BioLure for male and female Bactrocera cucurbitae (Coquillett) and Bactrocera dorsalis (Hendel) and as attractive for Ceratitis capitata (Wiedemann), and the addition of propylene glycol significantly inhibited the attractiveness of torula yeast. The known synergistic effect of propylene glycol with BioLure, resulting in increased captures of Anastrepha flies, was not observed with Bactrocera. Nontarget Drosophilidae, Neriidae, Phoridae, Calliphoridae, Sarcophagidae, and Muscidae were more strongly attracted to BioLure, and both lures collected Chloropidae equally. As with fruit flies, propylene glycol in torula yeast significantly decreased nontarget captures. The results therefore suggest that torula yeast in water is a more effective attractant than BioLure for pest Bactrocera while minimizing nontarget captures.