白蛾周氏啮小蜂滞育诱导及滞育后发育

本研究针对人工繁育白蛾周氏啮小蜂Chouioia cunea Yang过程中出现的小蜂滞育现象, 对其滞育诱导的光周期反应及敏感光照虫态进行了调查。结果表明: 沈阳地区的白蛾周氏啮小蜂属长日照型昆虫, 以老熟幼虫进入滞育状态, 但在不同的温度条件下诱导滞育的临界光周期不同, 在18℃时诱导滞育的临界光周期处于13L∶11D和14L∶10D之间; 在21℃和24℃时诱导滞育的临界光周期变短, 处于12L∶12D和13L∶11D之间。白蛾周氏啮小蜂滞育诱导的敏感光照虫态为幼虫期, 且以幼虫的后期最为敏感, 但整个幼虫期接受短光照对滞育的形成更为有利。通过观察白蛾周氏啮小蜂滞育后在18℃, 21℃, 24℃和30℃的恒温条件下的发育历期, 由最小二乘法计算出白蛾周氏啮小蜂老熟幼虫滞育后发育起点温度和有效积温分别为14.60±0.31℃和209.38±8.72日·度。这些结果可为进一步研究白蛾周氏啮小蜂的种蜂长期保存技术和指导商品蜂生产, 正确把握放蜂时机提供理论依据。     

茧蜂滞育的研究进展

滞育现象在多种茧蜂类天敌昆虫中存在, 通过调控茧蜂滞育, 可达到延长产品货架期、延长防控作用时间、提高产品的抗逆性和繁殖力的目标, 对茧蜂的扩繁和应用具有重要意义。本文通过总结1910年以来的2 545篇国内外滞育文献, 统计得出有明确滞育诱导或滞育解除报道的茧蜂有37种, 分属7亚科16属, 其中对滞育特征有详细描述的有23种。茧蜂大多以预蛹进入滞育, 其次为幼虫滞育, 少数为成虫滞育, 其滞育敏感阶段因种不同而异。滞育持续期相对较长, 大多可维持数月, 最长的可达14个月。光周期、温度和寄主是影响茧蜂滞育的主要因子, 湿度、亲代和寄主植物也可在一定程度上影响滞育进程。目前, 茧蜂滞育的研究仅限于生物学观察阶段, 对茧蜂滞育的生理学特征、激素调控和分子调控等尚未有研究报道, 有许多问题有待进一步探讨。     

光周期与温度对广州地区三化螟滞育的影响

尹汝湛(1988)报道短的光周期是诱发广州地区三化螟Scirpophaga incertnlas(Walkef)滞育的主要因子。作者进一步就该地区三化螟进行了两项试验:(一)光周期反应的感应虫期的测定;(二)温度对光周期诱发滞育的影响。     

环境因素诱导昆虫滞育发生的分子机制研究进展

滞育是生物体为了渡过恶劣环境而进行的一种停滞生长发育的生理状态,主要受遗传和环境因素的影响。研究发现光周期、温度、食物营养和体内激素水平等都能诱导昆虫滞育发生,然而滞育诱导是一个复杂的调控过程,对其分子机制的研究仍不清楚。本文对近年来在滞育诱导相关分子和分子信号通路方面取得的研究进展进行梳理,重点介绍了光周期和温度诱导昆虫滞育发生的分子级联系统,包括生物钟Per/Tim和Clk反馈回路、温度敏感型瞬时受体电位通道、γ-氨基丁酸GABA信号通路、珊瑚青素Corazonin信号通路和胰岛素信号途径等,该综述内容将为昆虫滞育研究提供帮助,同时为利用昆虫滞育进行农林害虫的防治及天敌保护提供理论参考。     

烟蚜茧蜂滞育诱导的温光周期反应

烟蚜茧蜂Aphidius gifuensis Ashmead是可持续防控蚜虫的优良内寄生蜂,在害虫生防中具有重要作用,研究其滞育对探索发育调控机制、延长产品货架期、提高防治效果意义重大。本文采用梯度变温法和光周期反应曲线法,系统研究了温度和光周期对烟蚜茧蜂滞育诱导的影响,研究结果表明:烟蚜茧蜂以老熟幼虫滞育,滞育类型属冬滞育型。低温、短光照是诱导烟蚜茧蜂滞育的主要环境因子,二者相互配合能诱导更多个体滞育。短光照(L∶D=8∶16)条件下,温度低于12℃可诱导烟蚜茧蜂进入滞育,8℃时滞育率可达54.35%。长光照(L∶D=14∶10)下,高温不能诱导烟蚜茧蜂滞育,低温下的滞育率较低,仅为1.79%。低温(10℃)下,短光照(8 h)可诱导50.70%的高滞育率,光照为14 h和6 h其滞育率均显著下降。25℃时,不同光照下滞育率均为0,光周期作用不显著。综合而言,温度和光周期均能显著影响烟蚜茧蜂的滞育,温度较光周期的滞育诱导效能更显著,二者互作配合能极显著的诱导烟蚜茧蜂进入滞育态。     

亚洲玉米螟滞育诱导外源性因子研究

研究了食料、温度、光周期等外源性因子对亚洲螟滞育的影响,试验证明,食料性质对其滞育诱导影响显著,取食玉米雌的幼虫以滞育诱导光周反应的敏感性强于取食棉铃的幼虫,在一定范围内,食料中可溶性糖含量增加可促进幼虫的滞育诱导,而粗蛋白含量的增加则具有抑制滞育诱导的作用,两者的互作效应不显著。高温抑制滞育诱导,你 促进滞育诱导。短光周对幼虫的滞育诱导无特定的敏感龄期,但以３龄与２龄对短光周刺激敏感性较强,包光     

二斑叶螨滞育特性的初步研究

诱导滞育实验表明 :短日照和低温是诱导二斑叶螨发生滞育的主要因子。测定我国天水种群 ,在 15℃条件下 ,诱导其滞育的临界日照长度为 9小时 4 2分 ,在每日 8小时光照条件下 ,诱导其滞育的临界温度为 15.5℃。解除滞育实验表明 :在每日 13小时的光照条件下 ,温度越高 ,解除越冬雌成螨滞育的速度越快 ;低温处理滞育雌成螨的时间越长 ,解除其滞育的速度也越快。     

昆虫滞育光周期理论的再思考

任何地方一年中的每一天都有一个特定的光照长度,日期和光周期变化存在固定的对应关系。昆虫在一定的日子滞育,自然也就是在特定的光照长度下滞育,但是并不意味着光周期必然就是滞育的主要诱因。分析光周期的几个重要特点,笔者认为光周期不一定是所有昆虫滞育开始及结束的最主要的或实质性的诱因。     

光周期和温度对亚洲玉米螟滞育形成的影响

短光照是引起玉米螟滞育的信息,处在北纬35°—36°,东经112°—113°的山西沁水玉米螟种群,在太原控制温度25℃,人工饲料饲养下测定,其临界界光周期为14小时30分钟。当光照少于此临界期,诱发滞育;而多于此临界期,则回避滞育。对于玉米螟幼虫任一单独龄期给予短光照处理,不能或几乎不能引起滞育;而相邻虫龄连续接受短光照处理,则可导致滞育。连续接受短光照处理的时间愈长,滞育率也愈高。幼虫对光照刺激反应的敏感期为自孵化后至5龄末进入滞育前的整个阶段,而非仅为3—4龄。高温在一定程度上抑制短光照诱发滞育的作用;低温在一定程度上抑制长光照回避滞育的作用。以长光照累代处理人工饲料饲养的亚洲玉米螟至三,四十代以上、如经短光照处理则照常发生滞育,其滞育特性仍未改变。     

Effect of daylength and temperature on the larval diapause of the sunflower moth, Homoeosoma electellum

The effect of daylength and temperature on the regulation of the larval diapause of a central Missouri population of the sunflower moth, Homoeosoma electellum, was examined. Fully grown fourth-instar larvae exhibit a facultative diapause. Measurements of the effect of photoperiod on diapause induction revealed critical photoperiods of about 13 h 30 min light/day at 20°C, and between 11 h 45 min and 12 h light/day at 23°C. Third and fourth-instar larvae were shown to be the main sensitive stages for diapause determination. Daylength was also shown to be an important regulator of the rate of diapause development. A short day of LD 10:14 h permitted only a low rate of diapause development, whereas long days of LD 14:10 h and LD 16:8 h accelerated diapause development at 25 and 30°C. When long days were alternated with short days at 30°C the accelerating effect of long days on diapause development was not found. Systematic transfers of chilled diapausing larvae revealed an accelerated diapause development in groups transferred from 10 to 30°C LD 10:14 h, but diapause development was not accelerated in groups transferred from 10 to 30°C LD 16:8 h.     

Host plant mediation of diapause induction in the cabbage beetle, Colaphellus bowringi Baly （Coleoptera： Chrysomelidae）

The cabbage beetle, Colaphellus bowringiBaly （Coleoptera： Chrysomelidae）, is a serious pest of crucifers in China, undergoing an imaginal summer and winter diapause in the soil. The effects of host plants on diapause incidence were tested in the beetle. The ratio of adults entering diapause was significantly low when they fed on the mature leaves of Chinese cabbage Shanghaiqin （Brassica chinesis var communis） than those feeding on Chinese cabbage Suzhouqin （Brassica chinesis var communis）, radish （Raphanus sativus var longipinnatus） and stem mustard （Brassicajuncea vat tumida） at 25℃ combined with 13：11 （L： D） h. Fewer adults entered diapause on young leaves compared to physiologically aged and mature radish leaves at 25℃ combined with 13：11 （L： D） h. The effect of host plant species on diapause induction was also evident under continuously dark rearing conditions or at different photoperiods. These experimental results demonstrate that host plant mediation of diapause induction exists in the cabbage beetle. However, at temperatures ≤20℃ or photoperiods of 16：8 （L： D） h combined with 25℃, all individuals entered diapause regardless of the host plants, indicating that the effects of host plants on diapause induction could be expressed only within a limited range of temperatures and photoperiods.     

Effects of photoperiod and temperature on the development and diapause of the bark beetle Ips typographus

Abstract:  Diapause was induced in a Central European population of Ips typographus grown at 20°C when the day length decreased below 16 h [50% diapause incidence occurred in the 14.7:9.3 h L:D (light:dark) regime]. The non-diapausing adults fed on days 2–6 and 10–14 after the ecdysis and swarmed after the second feeding bout with chorionated eggs in the ovaries and sperm in the spermiducts. Neither gonads nor the flight muscles matured and no swarming occurred in the diapausing adults. The development from egg to adult took about 34 days in both 18:6 h (no diapause) and 12:12 h L:D (diapause) regimes, but it was extended by up to 30% without diapause induction when only larvae or pupae were exposed to L:D 12:12 h. Diapause was induced in insects reared at L:D 12:12 h through the last larval and the pupal instars and/or in the adult stage. Temperature ≥ 23°C prevented diapause induction at L:D 12:12 h but diapause occurred at L:D 14:10 h associated with 26:6°C thermoperiod. The effect of thermoperiods on the developmental rate requires further research. Exposure of the non-diapausing adults to 5°C for several days blocked feeding and evoked a diapause-like state, whereas diapausing adults fed and their gonads slowly developed at this temperature. Diapausing adults exposed in forest to low night temperatures and transferred in October to 20°C readily reproduced at 18:6, but not 12:12 h L:D photoperiods. After 2-months at 5°C and darkness, they became insensitive to the photoperiod, matured and most of them also swarmed at 20°C in the 12:12 h L:D regime. In a Scandinavian population, diapause occurred at 18:6 h L:D and was terminated either by exposure to 5°C or by very long photoperiod (L:D 20:4 h) combined with high temperature (23°C).     

Multiple role of temperature during insect diapause: a review

The review emphasizes that there are multiple pathways to diapause completion. The programmed course of events is modified by environmental cues. Often chilling is not a prerequisite for the completion of hibernation diapause (examples tabulated). Diapause completion progresses well at intermediate or high temperatures, sometimes it is even stimulated by high or increasing temperature. Low temperatures are important, as they (1) conserve metabolic reserves, (2) prevent resumption of post-diapause morphogenesis and thus synchronize the life-cycle, (3) represent contrast to the later increase in temperature. Diapause consists of phases with different prerequisites. There is a principal difference between diapause development and photoperiodic activation as indicated by the subsequent physiological condition of insects.     

Seasonal diapause development and diapause termination in the European skipper, Thymelicus lineola (Ochs.)

Eggs of the European skipper, Thymelicus lineola, containing pharate first-instar larvae were brought into the laboratory at the beginning of each month from September to May and maintained at 20°C, 14L:10D. No emergence was observed within 40 days of collection before December. From that time on, while total emergence was similar, the duration of the emergence period decreased over the season from > 120 days in December to < 14 days in May. There was however no marked change in the seasonal supercooling point values of diapausing larvae.The rate of emergence from eggs collected in March was influenced by photoperiod, being slower under short-day conditions. However for any given photoperiod tested, the rate of emergence increased with an increase in temperature. The possible adaptive significance of a two-phase diapause, where diapause termination is photoperiodically controlled in species that overwinter as an egg or as a pharate first-instar larva within the egg chorion in exposed habitats, is discussed.     

光周期和温度对亚洲玉米螟滞育诱导的影响

亚洲玉米螟Ostrinia furnacalis (Guenée)属兼性滞育昆虫, 其滞育特性与种群利用适生境的最大化和季节性活动密切相关。解析季节性因素如光周期和温度对其滞育的诱导作用可为预测种群发生动态提供科学依据。本实验在HPS 500型和HPG-320H型自动控制环境气候箱中, 测定了RH 80%下温度20℃, 27℃和30℃与11个光周期组合对吉林农安（NA）、 河北衡水（HS）、 广东惠州（HZ）和海南海口（HK）等4个地理种群的滞育诱导作用。结果表明： 光周期、 温度及其交互作用均对亚洲玉米螟滞育诱导具有重要影响, 其中光周期在滞育诱导中起主导作用。在20℃条件下, 其光周期反应曲线属典型的长日照反应型, 临界光周期随种群分布的地理纬度降低而缩短, 4个地理种群NA, HS, HZ和HK的临界日昼长依次为14 h 3 min, 13 h 59 min, 13 h 32 min和13 h 7 min, 最有效的滞育诱导光周期是日昼长12 h。另一方面, 随种群分布纬度升高, 其对光周期诱导滞育的敏感性降低。温度为27℃时, 其光周期反应曲线为短日照 长日照反应型, 各种群有两个临界光周期, 临界日昼长依次为12 h 50 min和13 h 32 min, 11 h 35 min和13 h 8 min, 12 h 58 min和13 h 1 min, 以及11 h 50 min和12 h 26 min, 且最有效的滞育诱导光周期范围的滞育率明显低于20℃。一定温度范围内（20℃～27℃）, 随温度升高, 临界光周期缩短; 温度达到30℃时则滞育显著被抑制, 滞育率仅为4.3%或更低。这些结果说明温度对亚洲玉米螟滞育的光周期诱导具有很强的补偿作用。因此, 在自然界亚洲玉米螟的滞育属具有温度补偿作用的长日照反应型昆虫, 临界光周期随地理纬度北移而增长; 种群滞育的短日照 长日照反应型特性可能是产生局部世代种群的重要内因。     

温度和光周期对管侧沟茧蜂滞育诱导及滞育茧的低温冷藏

【目的】为明确诱导管侧沟茧蜂Microplitis tuberculifer 滞育的主要因子,在田间和室内研究了不同温度和光周期下管侧沟茧蜂的滞育率和滞育茧的最佳冷藏温度。【方法】田间实验分别从8月31日到9月25日每隔5 d在室外罩笼内释放管侧沟茧蜂寄生的粘虫幼虫,待寄生蜂结茧后统计子代蜂的滞育率。室内实验共设5个不同温度（16℃, 18℃, 20℃, 22℃和24℃）和7个不同光周期（6L:18D, 8L:16D, 10L:14D, 12L:12D, 14L:10D, 16L:8D和18L:6D）,分别统计寄生蜂在各个处理条件下的滞育率。【结果】在河北中部地区秋季自然条件下,8月底当日平均气温为24.4℃,日平均光照时间为12 h 51 min 时,少数蛹（5.08%）开始进入滞育;9月25日,当日平均气温为17.2℃,日平均光照时间为11 h 36 min以下时,几乎所有蛹个体进入滞育,滞育率达到99.70%。在室内人工控制条件下,当温度为22℃以上,无论光周期如何变化,管侧沟茧蜂不能进入滞育,所结茧全部为非滞育茧。温度为22℃以下存在光周期反应,在温度16℃, 18℃和20℃,光周期10L:14D时形成滞育茧数量最多,滞育率分别为100%, 89.75% 和 29.58%。可见温度和光周期二者共同影响管侧沟茧蜂的滞育。滞育茧在0℃左右条件下冷藏 240 d 和5℃左右环境条件下冷藏180 d, 成虫的羽化率和寄生能力与发育茧差异不显著(P>0.05);0℃条件下冷藏300 d,滞育茧仍有79%可以正常羽化。【结论】该寄生蜂在秋季进入滞育主要是低温条件和短光照反应相互作用的结果,滞育茧在0℃和5℃温度下至少可以保存240 d。这些结果对管侧沟茧蜂的大规模繁殖和滞育茧的保存具有重要参考价值。