火红拟孔蜂的生物学特性

首次报道了火红拟孔蜂除雌性成虫以外的各虫态形态特征、生活史、生殖发育及性行为等生物学特性。该蜂在西鄂尔多斯地区一年发生一代。越冬幼虫翌年4月中旬开始化蛹;预蛹约d左右;蛹期约15d。成虫5月上旬陆续羽化出茧;雄蜂早于雌蜂数日出现,雄蜂交尾后不久死去,寿命约为10d左右。雌蜂寿命约30d。卵期约3d左右。老熟幼虫多数在6月中下旬结茧后进入滞育状态,幼虫期长达300d左右。滞育幼虫通过人工控制温度可提前打破滞育或推迟其羽化的时间。     

油茶地蜂生活史及相关生物学习性

油茶地蜂Andrena camellia Wu 是江西、湖南等地油茶花期主要传粉昆虫之一。2006–2007年在江西宜春对油茶地蜂除成虫外各虫态的形态特征、生活史及幼虫和成虫的行为等生物学特性进行了观察研究。结果表明： 该蜂在江西宜春1年发生1代。成虫10月中旬开始出巢活动, 雄蜂早于雌蜂3 d左右出现,完成交尾后数日死亡,雄蜂出巢后寿命18 d左右,雌蜂约38 d。卵期约8 d。幼虫期24 d左右,幼虫取食完花粉球后长成老熟幼虫进入滞育期,滞育期约241 d。翌年9月中旬开始化蛹,蛹期约30 d。出土后的雌蜂当天就可以交配,交配后的雌蜂在羽化地点附近选址筑巢,采集油茶的花粉和花蜜于虫室中制成球形蜂粮并在上面产卵,每粒花粉球上产卵一枚。     

大分舌蜂主要生物学特性研究

大分舌蜂Colleles gigas Cockerell是江西、湖南、广东等地油茶Camellia oleifera Abel花期主要传粉昆虫之一,广泛分布于我国南方油茶林区及周边林区。2011-2014年在江西新余等中国南方地区对该蜂的形态特征、生活史、行为等生物学特性进行了观察研究。结果表明:该蜂在我国南方地区1年1代。成虫11月中旬开始出巢活动,雄蜂早于雌蜂5 d左右出现,完成交尾后数日死亡,雄蜂寿命25 d左右,雌蜂约45 d,卵期约9 d。幼虫期35 d左右,幼虫将花粉球消耗完后变成老熟幼虫并进入滞育期,滞育期约230 d。翌年10月中旬开始化蛹,蛹期约35 d。出土后的雌蜂当天就可以交配,交配后的雌蜂在羽化地点附近选址筑巢,采集油茶的花粉和花蜜于虫室中预先做好的玻璃纸状包膜中并制成糊状蜂粮,每个包膜中的蜂粮上产卵1粒,偶有2粒。     

中华食蜂郭公虫的生物学特性和行为观察

中华食蜂郭公虫Trichodes sinae Chevrolat是西鄂尔多斯地区重要传粉昆虫火红拟孔蜂Hoplitis pyrrhosoma Wu的寄生性天敌。文章报道中华食蜂郭公虫除成虫外各虫态的形态特征、生活史及幼虫和成虫的行为等生物学特性。该虫在西鄂尔多斯地区1年发生1代,越冬幼虫于4月上旬开始化蛹,5月中旬陆续羽化出巢,成虫取食植物补充营养后,开始交尾、产卵。1龄幼虫能够寻找并钻入火红拟孔蜂的巢室,取食火红拟孔蜂幼虫,直至结茧化蛹。室温条件下,卵期约6~8d,幼虫期约260~280d,蛹期约40~50d;雄虫寿命约28~30d,雌虫寿命约35~40d。     

巨型褶翅小蜂的生活史和产卵行为

巨型褶翅小蜂Leucospis gigas Fabricius是小蜂总科中体型最大的物种之一,对野生传粉蜜蜂中的一些种类为害很大。在西鄂尔多斯地区首次发现其寄生当地多种植物的重要传粉昆虫沙漠石蜂Megachile(Chalicodoma)desertorum Cockerell后,对其在当地的生活史、成蜂的活动规律、寄主范围以及产卵行为进行了研究。结果表明:巨型褶翅小蜂在西鄂尔多斯地区1年发生1代,当地没有雄性个体,营孤雌生殖。雌蜂寿命30d左右,每年的6月中旬为成蜂活动高峰期。在当地只发现其寄生沙漠石蜂的老熟幼虫,其产卵行为分为3个阶段,即寻找寄主巢室、选择产卵位点与产卵、拉出产卵针。     

条纹小斑蛾的生物学特性

条纹小斑蛾Thyrassia penangae(Moor)是乌蔹莓(Japanese cayratia)的重要害虫,在南昌1年发生4～5代,以老熟幼虫结茧越冬。由于该虫各世代总有极少部分个体进入滞育,少数进入越夏的个体1年只发生2代或3代。羽化时间多出现在上午7～10时,羽化后当日或次日下午交配,交配时间集中在下午3～6时,交配一般可持续12个h左右。成虫羽化后需取食花蜜做补充营养才能充分产卵。产配后次日即可产卵。第1代成虫常将卵数十粒聚产于幼嫩叶片的背面,以后各代主要聚产于花蕾上,平均每雌产卵量为43粒。幼虫为4龄。第1代主要取食叶芽、幼枝及嫩叶,以后各代主要取食花蕾。在自然条件下各虫态发育历期:卵为4～7d;幼虫为10～14d;非滞育的茧期(指幼虫结茧后的预蛹至成虫羽化的日期)为8～11d,越夏茧期为32～40d,越冬茧期为205～224d。成虫寿命为3～13d。     

苹果绵蚜蚜小蜂发育历期、发育起点温度和有效积温的研究

本文以苹果绵蚜为繁殖寄主,研究了苹果绵蚜蚜小蜂在不同温度下的发育历期、发育起点温度和有效积温。结果显示:苹果绵蚜蚜小蜂的发育历期随温度的升高而缩短,最适发育温度为21℃-27℃。山东地区越冬代苹果绵蚜蚜小蜂打破滞育的发育起点温度为雌蜂8.58℃,雄蜂8.22℃;有效积温为雌蜂148.72日度,雄蜂154.68日度。非越冬代苹果绵蚜蚜小蜂在卵-羽化阶段发育起点温度为雌蜂5.62℃,雄蜂5.55℃;有效积温为雌蜂284.40日度,雄蜂为295.61日度。并推测了2008年济南地区苹果绵蚜蚜小蜂发生代数和越冬代羽化时间,与实测情况基本相符。     

灰钝额斑螟的生物学特性

灰钝额斑螟Bazaria turensis Ragonot是柴达木盆地白刺(Nitraria sp.)灌丛的主要害虫,为了有效控制该害虫对白刺的危害,采用室内饲养和田间定点观察,对灰钝额斑螟进行了生物学特性观察。结果表明灰钝额斑螟在柴达木盆地1年发生1代,有卵、幼虫、蛹和成虫4种虫态,通过头壳宽确定了幼虫为5个虫龄,以滞育蛹越冬。翌年5月中旬开始羽化,5月下旬为羽化高峰期,6月中旬孵化,6月下旬为孵化盛期,8月上旬开始结茧化蛹,8月中旬结茧化蛹高峰期,随后蛹进入滞育越冬。6月下旬初龄幼虫发生盛期是该害虫防治的最佳时期。     

凹唇壁蜂滞育后阶段过冷却能力及生化物质动态变化

【目的】凹唇壁蜂Osmia excavata Alfken是我国北方果树的主要授粉昆虫,发挥着重要的传粉增产生态服务功能。掌握其滞育后阶段抗寒性特点,并从生理生化水平上探讨耐寒机制,对于凹唇壁蜂的保护与利用具有重要意义。【方法】本文系统测定了滞育后阶段及出茧后凹唇壁蜂雌蜂、雄蜂的过冷却点、冰点,自由水、脂肪、蛋白质、海藻糖含量,过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、乙酰胆碱酯酶(AchE)的活性。【结果】凹唇壁蜂雌蜂、雄蜂的抗寒性差异不大,滞育后阶段过冷却点和冰点在出茧前逐渐升高、出茧后降低。其中,出茧日凹唇壁蜂雌蜂、雄蜂的过冷却点、冰点最高(抗寒性最低),分别为﹣12.35℃、﹣9.98℃和﹣12.63℃、﹣8.91℃。在滞育后阶段雄蜂脂肪含量显著高于雌蜂,雌蜂的蛋白质含量显著高于雄蜂,出茧后雄蜂的脂肪含量均迅速下降,雌蜂的蛋白含量迅速下降。出茧前,雄蜂的超氧化物歧化酶、过氧化氢酶、乙酰胆碱酯酶酶活性高于雌蜂;出茧后,雌蜂的酶活显著升高。在滞育后阶段,凹唇壁蜂雌蜂、雄蜂体内的海藻糖均呈显著降低趋势,出茧日雌蜂的海藻糖含量比茧后190 d下降了64.5%。【结论】滞育后阶段凹唇壁蜂有较强的抗寒性。在出茧前抗寒性逐渐降低,出茧后抗寒性升高。海藻糖代谢可能是凹唇壁蜂滞育后阶段能量消耗的重要途径。雄蜂的个体较小,但是有比雌蜂功能更强的抗氧化系统。     

脐腹小蠹形态特征和生物学特性

脐腹小蠹Scolytus schevyrewi Seme.是榆树的一种重要蛀干害虫。本研究在宁夏盐池县通过室内观察和林间调查相结合,研究了脐腹小蠹的形态特征及其生活史、成虫寿命、习性、交尾行为等生物学特性。结果显示:脐腹小蠹虫在宁夏盐池县一年发生2代,以老熟幼虫或蛹越冬,老熟幼虫约占98.2%,蛹约占1.8%。越冬幼虫于5月上旬开始化蛹,5月中旬为化蛹盛期,5月下旬开始羽化,6月上旬为羽化盛期。第2代幼虫于6月底、7月初开始化蛹,7月下旬达羽化盛期,8月上旬羽化结束;脐腹小蠹雌成虫平均寿命为(27.14±3.74)d,雄成虫的平均寿命为(16.86±4.13)d,差异显著(P<0.05);此外,脐腹小蠹无滞育现象;脐腹小蠹的4种天敌,分别是榆小蠹长茧蜂Elachistocontrum sp.、虱形螨Pedieuloids ventricosus Newport、拟截斑郭公虫Thansimus sp.和蠼螋Labidura sp.。     

沙漠石蜂的筑巢习性和行为

2004-2005年在西鄂尔多斯地区,选择巢室数＞300的沙漠石蜂Megachile(Chalicodoma)desertorum Morawitz巢区,通过标记巢室和雌蜂,在整个成蜂活动期连续对沙漠石蜂的筑巢习性和行为进行了观测研究.结果显示:该蜂一生一般能建8～12个巢室,优先利用未被破坏的旧巢.利用旧巢的过程为:...     

沙漠石蜂的筑巢材料和蜂巢结构

沙漠石蜂Megachile(Chalicodoma) desertorum Morawitz为多种植物的传粉昆虫,在西鄂尔多斯地区是多种濒危植物和荒漠建群植物的重要传粉者。在该地区研究沙漠石蜂的筑巢场所、筑巢材料和蜂巢结构。共调查统计5148个蜂巢的筑巢场所和朝向;选择4个土壤表层成分不同的筑巢地,分别测定其筑巢沙土的机械组成、pH值和土壤紧实度;定点连续观察整个筑巢过程。结果表明:沙漠石蜂95.80%的巢建于岩石表面;土墙、灌木枝条、水泥柱及钢窗框上的巢室数均较少。83.1%的巢室建在东向一面;南向14.2%,西向2.4%,北向仅0.3%;筑巢材料为沙土和唾液制成的泥浆,所用沙土的pH值在8.18～9.34之间、紧实度在1.28～1.84g/cm3之间,其中粒径为0.06～0.15mm的沙土比例最高;1个蜂巢一般由4～10个巢室组成。说明该蜂喜欢将巢室建在朝向东方的岩石表面;筑巢材料主要由唾液和以碱性的粒径为0.06～0.15mm左右的沙土构成。也说明是对干旱炎热的荒漠环境的适应。     

Effects of photoperiod and temperature on reproductive diapause in Ophraella communa (Coleoptera: Chrysomelidae), a potential biocontrol agent against Ambrosia artemisiifolia

Abstract To investigate the seasonal adaptation strategies of Ophraella communa to new habitats, the effects and regulation mechanisms of photoperiod and temperature on the reproductive diapause in a population collected from Changsha, Hunan were examined. Adults showed obvious reproductive diapause, which was regulated by photoperiod and temperature. At 30°C, there was no adult diapause occurring under either long‐day or short‐day conditions; at 25°C the pre‐oviposition period was short and fecundity was high in adult females under L : D 16 : 8 h, whereas under L : D 12 : 12 h, a few females entered reproductive diapause; at 20°C under short‐day conditions, all female adults entered diapause. The pre‐oviposition period was significantly prolonged when the pupae and adults were transferred from long‐days to short‐days, but the day length influence was not obvious when they were transferred only in the adult stage. However, the fecundity dropped greatly no matter whether the photoperiod shifted to short‐days only in the adult stage or whether the shift occurred in both the pupal and adult stage. The fecundity was extremely low when photoperiod shifted from long‐days to short‐days in both pupal and adult stages. This was an indication that the pupal and adult stages were the photoperiod‐sensitive stage for adult reproductive diapause. This was especially true for the photoperiod in the pupal stage, which has a distinctly significant regulative effect on reproductive diapause. Additionally, this article also addresses the reason for different photoperiodic response patterns in reproductive diapause induction between the Changsha strain and the Tsukuba strain (Japan) of O. communa.     

Presence of three diapauses in a subtropical cockroach: control mechanisms and adaptive significance

Abstract.  Diapause is common among insects and is regarded as an adaptive response to periodic occurrence of adverse conditions. It occurs at a particular developmental stage, typically only once in a lifetime. However, little is known about the details of the control mechanism of life cycles with multiple diapauses in insects. In this study, a complex 2-year life cycle with three types of diapause is reported in a subtropical cockroach, Symploce japonica : a winter diapause in mid-nymphal instars, a summer diapause in later nymphal instars, and a reproductive diapause is reported in the adult stage. Nymphal development was extremely slow either at short days (winter diapause) or long days (summer diapause). Nymphs in summer diapause matured rapidly when transferred from long days to short days, indicating that seasonal changes in day-length are the pivotal factor in the control of this life cycle. It is proposed that the main significance of winter diapause in this subtropical species is to enable the nymphs to survive the mild winter successfully with reduced energy demand, and that of summer diapause is to delay adult emergence until late in the autumn for successful induction of the following adult diapause. Adults do not emerge until shortly before winter, yet the presence of diapause in the adult stage does not simply appear to be a response to cope with the winter conditions but, instead, ensures that reproduction will occur early the next year, before summer, because reproduction is greatly hampered at high temperature.     

Diapause‐inducing signals prolong nymphal development in the two‐spotted spider mite Tetranychus urticae

Female two‐spotted spider mite Tetranychus urticae are grown under different photoperiods and the photoperiodic regulation of diapause is examined. The photoperiodic response curve for diapause induction was of the long day–short day type, with critical day lengths (CDLs) of 2 and 12.5 h; diapause was induced between these CDLs. The preimaginal period is significantly longer in diapausing females than in non‐diapausing females; moreover, a significant positive correlation is detected between diapause incidence and deutonymphal period. Diapause incidence is high when long‐night photoperiods are applied against a background of continuous darkness in the stages including the deutonymph; this stage appears to be the most sensitive to photoperiod. These observations suggest that diapause‐inducing conditions inhibit nymphal development, particularly in the deutonymphal stage when photoperiodic time measurement for determination of reproduction or diapause is carried out.     

Prothoracicotropic Hormone Acts as a Neuroendocrine Switch between Pupal Diapause and Adult Development

Diapause is a programmed developmental arrest that has evolved in a wide variety of organisms and allows them survive unfavorable seasons. This developmental state is particularly common in insects. Based on circumstantial evidence, pupal diapause has been hypothesized to result from a cessation of prothoracicotropic hormone (PTTH) secretion from the brain. Here, we provide direct evidence for this classical hypothesis by determining both the PTTH titer in the hemolymph and the PTTH content in the brain of diapause pupae in the cabbage army moth Mamestra brassicae. For this purpose, we cloned the PTTH gene, produced PTTH-specific antibodies, and developed a highly sensitive immunoassay for PTTH. While the hemolymph PTTH titer in non-diapause pupae was maintained at high levels after pupation, the titer in diapause pupae dropped to an undetectable level. In contrast, the PTTH content of the post-pupation brain was higher in diapause animals than in non-diapause animals. These results clearly demonstrate that diapause pupae have sufficient PTTH in their brain, but they do not release it into the hemolymph. Injecting PTTH into diapause pupae immediately after pupation induced adult development, showing that a lack of PTTH is a necessary and sufficient condition for inducing pupal diapause. Most interestingly, in diapause-destined larvae, lower hemolymph titers of PTTH and reduced PTTH gene expression were observed for 4 and 2 days, respectively, prior to pupation. This discovery demonstrates that the diapause program is already manifested in the PTTH neurons as early as the mid final instar stage.     

Life history strategies of annual killifish <Emphasis Type="Italic">Millerichthys robustus</Emphasis> (Cyprinodontiformes:Cynolebiidae) in a seasonally ephemeral water body in Veracruz,México

The annual life cycle of Millerichthys robustus is described from an ephemeral pool in Veracruz, Mexico. The state of the pool can be divided into three periods: a flood period lasting from September to March when the pool was filled with water, a drought period from April to June when the pool was dry, and a humid period in July and August when the pool was intermittently filled. Soil substrate was examined in each of these three periods (flood, drought and humid), embryos were found, and the stage of embryonic diapause was determined. During the flood period embryos were in diapause I; during the drought period in diapause II; and during the humid period mainly in diapause III with a small subset in diapause II (an example of a bet-hedging strategy). Two hatching periods (separated by two weeks) were documented during the beginning of the flood period. Fish growth was analyzed in both males and females, with females showing an overall slower growth rate and smaller adult size. In females, ovarian maturity was characterized histologically to understand the reproductive cycle. The onset of sexual maturity began during the third week after hatching (21 days) with the presence of secondary sexual characteristics in females and the beginning of Secondary Growth Stage in some ovarian follicles. All stages of oogenesis, postovulatory follicles and ovulated oocytes were observed from the fourth week post hatching (28 days) until death. M. robustus appears to exhibit similar patterns of embryonic diapause compared to other annual killifish living in seasonal water bodies closer to the equator. This study characterizes (for the first time) the adaptations and life cycle of M. robustus. This information could be useful to evaluate the potential risk of these populations and, if necessary, to develop plans for their conservation.