用ElISA研究稻田节肢类捕食者对稻飞虱的捕食作用

应用酶联免疫吸附试验(ELlSA)来研究捕食作用能较准确地评价捕食性天敌对害虫的控制作用。ELlSA检测表明,不同种类的捕食性天敌对稻飞虱的捕食作用有较大差别,其中以优势种食虫沟瘤蛛和拟水狼蛛的捕食作用最大,阳性反应率与稻飞虱的种群密度有一定的相关关系,但在稻飞虱密度较低的情况下也表现出较高的阳性反应率。     

一种捕食螨饲养观察装置

【目的】为在室内防止捕食螨逃逸,设计一种防止逃逸行为的饲养观察装置。【方法】对比研究了传统隔水式饲养装置和改进型装置在防止逃逸行为中的效果,及改进型装置对捕食螨发育及繁殖能力有无影响。【结果】改进型装置通过添加瓶塞、棉线、盖玻片组成密闭小室,可有效防止捕食螨的逃逸,逃逸率仅为3.3%。另外,使用该装置后的捕食螨生长发育及繁殖等能力与隔水式饲养法相比未受到显著影响。【结论】本文设计的饲养观察装置可在捕食螨生物学、生态学及农药抗性等基础研究中应用。     

人工饲料饲养的叉角厉蝽对昆虫的捕食能力评价

叉角厉蝽Eocanthecona furcellate(Wolff)是广泛分布于热带亚热带地区的一种重要捕食性天敌昆虫。为评估人工饲料饲养的叉角厉蝽的捕食能力,在实验室采用捕食功能反应的方法,以黄粉虫作为中介猎物饲养的叉角厉蝽为对照,评价了人工饲料饲养的叉角厉蝽3龄若虫、5龄若虫以及雌成虫对黄粉虫Tenebriomolitor(L.)幼虫及斜纹夜蛾Spodoptera litura(Fabricius)3龄幼虫、5龄幼虫的捕食效能。结果表明,两种饲料饲养的不同虫态叉角厉蝽的捕食量均随着猎物密度的增加而上升,当猎物密度增加到一定水平,捕食量趋于稳定,其捕食功能反应均符合HollingII模型。人工饲料组饲养的各虫态叉角厉蝽与对照组的对黄粉虫幼虫的捕食量没有明显差异;在饱和猎物密度条件下,人工饲料饲养的叉角厉蝽3龄若虫、5龄若虫以及雌成虫对斜纹夜蛾3龄幼虫的日最大捕食量分别为7.20、9.20、14.60头,对斜纹夜蛾5龄幼虫的日最大捕食量分别4.20、5.80、6.20头,均略低于对照组,但从取食猎物数量上来看,仍保持较强的捕食能力。     

Application of DNA metabarcoding on faeces to identify European catfish Silurus glanis diet

In this study, the results of conventional stomach‐content analysis are compared with the recent DNA metabarcoding approach on faeces to identify fish species consumed by non‐native European catfish Silurus glanis in the Garonne River (south‐western France), with a special emphasis on anadromous prey. Fourteen prey species were identified in the stomach contents or faeces, including four anadromous fish species. Despite higher intestine than stomach emptiness, more species were identified through faecal analysis (11 of 14) than through stomach‐content analysis (five of 14) suggesting that DNA metabarcoding on faeces is an efficient, non‐intrusive technique to study the diet of predatory fishes.     

多杀菌素和氟虫睛对瓢虫、寄生蜂和菜缢管蚜选择性的研究

采用药膜法研究了多杀菌素和氟虫睛对3种瓢虫、2种寄生蜂和菜缢管蚜的选择性。与菜缢管蚜相比,2种杀虫剂对3种瓢虫的毒性较低(LC50比值=1.73-41.9),尤其是氟虫睛对3种瓢虫以及多杀菌素对稻红瓢虫均具有较好的选择性(LC50比值大于5)。菜蚜茧蜂和蚜虫宽缘金小蜂对2种杀虫剂的敏感性远高于3种瓢虫和菜缢管蚜,2种杀虫剂对菜蚜茧蜂和蚜虫宽缘金小蜂均是高毒的(LC50比值=0.006-0.05)。3种瓢虫对多杀菌素和氟虫睛具有较高的耐药性,这将有助于其在生物防治中的应用。     

山楂叶螨、苹果全爪螨及其捕食性天敌生态位的研究Ⅰ——时间与空间生态位

统计分析表明两种叶螨间生态位重叠值较大、各自生态位宽度较大。两种叶螨的时动空间生态位与各自种群消长曲线相一致,显示了它们对资源有相似要求以及“逐步扩散整树危害”的取食危害方式。它们的生态位分离表现在叶片正、反面及叶片反面的某些小“领域”上。苹果全爪螨更喜欢分布在树冠上层和外层。统计和模糊分析都表明草蛉和小花螨与两种叶螨的时间同步和空间同域性较强,捕食螨与叶螨的时间生态位重叠较小,而空间生态位重叠较大。天敌与叶螨间的时空生态位重叠以及天敌食谱生态位宽度结合分析有助于合理评价天敌的控制作用。     

杀虫双对梭毒隐翅虫捕食功能的影响

梭毒隐翅虫Paederus fuscipes Curtis是一种重要的天敌昆虫.在室内条件下,采用浸渍法测定了18%高效杀虫双在田间常用最低浓度时,对梭毒隐翅虫成虫死亡率和捕食功能的影响.试验结果表明,18%高效杀虫双对梭毒隐翅虫的致死作用及捕食功能影响均较小,但对残存个体捕食功能的影响超过致死作用.     

Two new species of Abernessia Arlé (Pompilidae,?Ctenocerinae)

Two new species are added to the rare pompilid genus Abernessia Arlé. Abernessia capixaba sp. n. and A. giga sp. n. are described and illustrated. This is the first record of the genus from the states of Espírito Santo and Minas Gerais, Brazil. The genus now contains four species. A brief discussion of generic characters, illustrations, and a key to the known species of Abernessia are provided.     

Distribution,dispersal and spread of the invasive social wasp (Vespula germanica) in Argentina

We studied the distribution and spread of the invasive social wasp Vespula germanica in Argentina, focusing on the contribution of queen dispersal to territorial expansion. Vespula germanica is native to Eurasia and has invaded several regions of the world, including Southern Argentina. Flight potential of field‐collected queens was measured using flight mills. Also, by means of an extensive survey we estimated the rate of spread by analysing the relationship between years since arrival and distance from the introduction locality. The mean distance flown by wasp queens in flight mills was 404.7 ± 140.8 m (mean ± SE, n = 59), while the rate of spread of V. germanica was estimated at 37.2 ± 2.1 km year^?1 (mean ± SE, n = 67), although faster towards the south. The observed spread rate of V. germanica wasps in Argentina confirms the invasive potential shown by several Hymenoptera species worldwide. Still, a stratified geographical expansion pattern does not match observed queen dispersal abilities, suggesting that human‐aided transport of hibernating queens is the central driver of the current distribution of these wasps. We suggest that despite several life‐history traits known for social insects that contribute to successful invasion, wasp spread must still rely strongly on human mediated pathways. This observation sheds light on those factors that are crucial for managing invasions of this and related pestiferous wasps.     

Timing alters how a heat shock affects a host-parasitoid interaction

Abiotic factors' effects on species are now well-studied, yet they are still often difficult to predict, especially for strongly interacting species. If these altered abiotic factors and species interactions occur as discrete events in time, such complications may occur because of the events’ relative timing. One such discrete abiotic factor is the short-duration, large magnitude increase in temperature called a heat shock. This study investigates how the timing of heat shocks affects the successful attack and reproduction of a parasitoid wasp (Aphidius ervi) attacking its host, the pea aphid (Acyrthosiphon pisum). We tested three relative timings: 1) heat shock before the wasp attacks hosts, 2) heat shock while the wasp is foraging, and 3) heat shock after the wasp has attacked hosts. In each scenario we compared wasp mummy production (pupal stage) with and without a heat shock. Our results showed that a heat shock had the largest effect when it occurred while wasps actively foraged, with fewer mummies produced when exposed to a heat shock compared to the no heat shock control. Follow-up behavioral tests suggest this was caused by wasps becoming inactive during heat shocks. In contrast, when heat shocks were applied three days before or after foraging, we found no difference in mummy production between the heat shock treatment and no heat shock control. These results show the potential importance of timing when considering the ramifications of an altered abiotic factor, especially with relatively discrete abiotic events and interactions.