CDNA cloning and characterization of S6 kinase and its effect on yolk protein gene expression in the oriental fruit fly Bactrocera dorsalis (Hendel)

p70 S6 kinase (S6K), a serine/threonine protein kinase, is a downstream target of target of rapamycin (TOR) gene and an important regulator of protein synthesis responsible for cell growth and reproduction. In this study, a S6K gene, named BdS6K (GenBank Accession No. GQ203802), was isolated from the oriental fruit fly Bactrocera dorsalis (Hendel). Quantitative RT-PCR showed that BdS6K mRNA is expressed at a higher level in egg than in other developmental stages, as well as in ovary than in fat body. Downregulation of BdS6K activity by rapamycin treatment in larval stage resulted in the developmental defects of larvae, pupae, and adults, with a reduced yolk protein (YP) expression in the fat body throughout the first reproductive cycle with a substantial reduction in ovary size, and also repressed the egg development in female fruit fly. Knockdown of BdS6K gene by RNA interference in the adult significantly decreased the YP expression. These observations support the involvement of BdS6K signaling in the regulation of the YP synthesis and egg development in B. dorsalis.     

中国果实蝇属种类的DNA条形码鉴定(双翅目,实蝇科)

将实验获得的25种果实蝇的155条COⅠ条形码序列,利用MEGA4.1的Kimura-2-Parameter模型进行了遗传距离分析和构建系统发育树,来检验线粒体COⅠ基因条形码序列对果实蝇属种类鉴定的有效性。研究表明COⅠ条形码序列能够对除桔小实蝇复合体外的中国果实蝇属种类进行准确鉴定。     

中国云南果实蝇属两新种和一新纪录记述(双翅目,实蝇科)(英文)

记述了我国果实蝇属2新纪录亚属,爪哇果实蝇亚属Javadacus和巴布亚果实蝇亚属Papuodacus;1新纪录种,三条果实蝇B.(J.)trilineata(Hardy);及2新种,端黄果实蝇Bactrocera(Javadacus)apiciflava Yu,HeetChen,sp.nov.和中华果实蝇Bactrocera(Papuodacus)sinensisYu,BaietChen,sp.nov.。新种模式标本保存于中国检验检疫科学研究院动植物检疫所,北京。端黄果实蝇,新种Bactrocera(Javadacus)apiciflavaYu,HeetChen,sp.nov.(图1~6)背侧片全黄;前股外侧黑亮,内侧黄;翅端扩大成斑。正模♂,云南河口,2008-09,和万忠采。副模3♂♂,同正模。词源:新种种名据其特征小盾片端部黄而定名。中华果实蝇,新种Bactrocera(Papuodacus)sinensisYu,BaietChen,sp.nov.(图12~16)小盾片黄,端部具黑斑;股节端部具黑斑;翅前缘带达R2+3;腹部3~5背板具黑中纵条。正模♂,云南勐腊,2009-08,白永华采。副模:1♂,同正模;1♂,2010-08-15,其他数据同正模。词源:新种种名据其分布地中国而定名。     

中国果实蝇属一新记录种及云南镞果实蝇亚属记述

Nine species in the subgenus Zeugodacus Hendel were known to occur in Yunnan. We add seven more species to the fauna of Yunnan. Among them, one species, Bactrocera (Zeugodacus) vultus Hardy, 1973, is reported from China for the first time. This species is redescribed in detail and its male genitalia are illustrated and described for the first time. A key to the species of the subgenus Zeugodacus from Yunnan is provided.     

Sexual selection in a tropical fruit fly: role of a plant derived chemical in mate choice

The specific mechanisms by which selective pressures affect individuals are often difficult to resolve. In tephritid fruit flies, males respond strongly and positively to certain plant derived chemicals. Sexual selection by female choice has been hypothesized as the mechanism driving this behaviour in certain species, as females preferentially mate with males that have fed on these chemicals. This hypothesis is, to date, based on studies of only very few species and its generality is largely untested. We tested the hypothesis on different spatial scales (small cage and seminatural field‐cage) using the monophagous fruit fly, Bactrocera cacuminata. This species is known to respond to methyl eugenol (ME), a chemical found in many plant species and one upon which previous studies have focused. Contrary to expectation, no obvious female choice was apparent in selecting ME‐fed males over unfed males as measured by the number of matings achieved over time, copulation duration, or time of copulation initiation. However, the number of matings achieved by ME‐fed males was significantly greater than unfed males 16 and 32 days after exposure to ME in small cages (but not in a field‐cage). This delayed advantage suggests that ME may not influence the pheromone system of B. cacuminata but may have other consequences, acting on some other fitness consequence (e.g., enhancement of physiology or survival) of male exposure to these chemicals. We discuss the ecological and evolutionary implications of our findings to explore alternate hypotheses to explain the patterns of response of dacine fruit flies to specific plant‐derived chemicals.     

Sperm storage and utilization in female Queensland fruit flies (Bactrocera tryoni)

Abstract.  Female animals that use sperm from a single mating to fertilize eggs over an extended period require efficient mechanisms for sperm storage and use. There have been few studies of these mechanisms in tephritid flies. Mating, copula duration, sperm storage and sperm usage patterns are assessed in an Australian tephritid, the Queensland fruit fly ( Bactrocera tryoni ; a.k.a. 'Q-fly'). In particular, the present study investigates whether each of these aspects of mating varies in relation to female size or male size, whether sperm storage patterns change over time after mating (1, 5, 10 and 15 days), and the relative roles of the ventral receptacle and the two spermathecae as sperm storage organs. Large females are more likely to mate than are small females, and are also more fecund in the first 5 days after mating. Females are more likely to store some sperm and, among those that store some sperm, store more sperm if their mate is large. Most sperm are stored in the spermathecae (median = 97%), often with high levels of asymmetry between the two spermathecae. Asymmetry of sperm storage is related to number of sperm stored, but not to male or female size. Total number of stored sperm declines over the 15 days after mating, but this decrease in sperm numbers only reflects changes in the spermathecae; numbers of sperm in the ventral receptacle remain unchanged over this period. As a consequence, the proportion of total sperm stored in the spermathecae declines relative to the ventral receptacle. These results are consistent with a system in which small numbers of sperm are maintained in the ventral receptacle for fertilizations, and are replenished by sperm from the spermathecae as required. Sperm distribution and usage patterns in Q-flies are comparable with recent findings in medflies, Ceratitis capitata , but differ markedly from patterns found in several Anastrepha species.     

重庆地区柑桔大实蝇系统监测研究

柑桔大实蝇Bactrocera minax是柑桔类植物果实的重要害虫,以往对该虫的发生监测仅局限于通过果园诱集和室内外养蛹监测成虫的发生期。本研究综合应用室外养蛹、桔园系统调查、成虫诱集和蛆果解剖等技术手段,以期了解柑桔大实蝇的产卵进度、幼虫发育进度、蛆果落地进度、幼虫化蛹进度以及蛹的羽化进度。研究结果表明,重庆地区柑桔大实蝇产卵盛期为6月下旬-7月上旬,高峰期为6月下旬末-7月初;一龄、二龄和三龄幼虫的发生盛期分别为9月中旬-10月初、10月上旬-下旬和10月中旬-11月初;受害蛆果落地盛期为10月上旬-下旬,与二龄和三龄幼虫的发生盛期吻合;室外养蛹的成虫羽化盛期为5月上旬-中旬末,但果园成虫诱集的盛期为6月中旬-下旬,较室外养蛹的成虫发生盛期推迟30 d左右,对出现此种情况的原因作者做了初步分析。研究结果还表明,各虫态的累计发生进度均可用逻辑斯缔方程拟合,从而可计算出各虫态发生进度为16%、50%和84%的始盛期、高峰期和盛末期。研究结果对于柑桔大实蝇的发生期预测和防治具有重要指导意义。     

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。     

蝇蛹金小蜂对桔小实蝇蛹的寄生功能反应

在温度25±1℃、相对湿度70±5%、光照周期（L∶D）14 h∶10 h条件下,研究了蝇蛹金小蜂对桔小实蝇蛹的寄生功能反应及干扰效应。结果表明,寄主密度、寄主日龄均影响寄生蜂的寄生效能。蝇蛹金小蜂对桔小实蝇2日龄（N=2）、4日龄（N=4）蛹的寄生功能反应均符合HollingⅡ模型,其方程分别为Na= 0.4494N2/ (1+ 0.0294N2)、Na= 0.5586N4/ (1+ 0.0253N4)。24h内单头雌成蜂最多可寄生2日龄、4日龄蝇蛹数量分别为15.29、22.08头。自身密度对蝇蛹金小蜂寄生产生一定的干扰效应,其干扰效应符合Hassell－Varley模型（a= 0.0719P－0.2526）,表明蝇蛹金小蜂雌蜂的发现域随着自身密度的增加而逐渐变小,雌蜂个体间干扰效应降低了寄生效能。     

柑桔大实蝇老熟幼虫和蛹过冷却点和结冰点的测定

为明确柑桔大实蝇Bactrocera minax (Enderlein)老熟幼虫和蛹的抗寒能力,对柑桔大实蝇老熟幼虫、滞育蛹和滞育解除蛹的过冷却点和结冰点进行了测定。结果显示,同一虫态不同个体间其过冷却点和结冰点具有不同程度的变异,但其变异范围均符合正态分布。柑桔大实蝇不同发育状态间的过冷却点和结冰点均具有显著差异,其中,已解除滞育进入发育状态的蛹的过冷却点和结冰点最低,分别为-11.15℃和-9.76℃;其次为滞育蛹,分别为-8.93℃和-7.63℃;而老熟幼虫最高,分别为-7.09℃和-3.43℃。此外,老熟幼虫的结冰点和过冷却点之间的差值最大为3.24℃,显著高于滞育蛹（1.30℃）和滞育解除蛹（1.39℃）。表明,倒春寒对已进入发育状态的柑桔大实蝇蛹不会造成不利影响。