稻田中性昆虫对群落食物网的调控作用

本文把稻田既非害虫也非天敌的一类昆虫称为中性昆虫,应用选择性控制法（扑虱灵和杀蚊幼剂＾－ＢＳ）、挤压法、脉冲试验法及通径分析研究了稻田中性昆虫的调控作用;中性昆虫与天敌、害虫的直接和间接作用规律,结果证明中性昆早虫数量增加,中必一昆虫与害虫呈显著的负相关,与天敌呈显著的正相关,中性昆虫对害虫的调控主要是通过影响捕食性天敌而实现的。     

群落食物网间的相似性测度

群落是指一定地段或生境里各种生物种群构成的结构单元。群落内各物种不是孤立存在的,它们之间存在着极为复杂的营养联系。一种植物常有多种害虫取食,一种害虫可取食多种植物,同时又被多种天敌捕食或寄     

丹参田花期昆虫群落结构及多样性研究

为明确丹参田花期昆虫群落结构,本文采用马氏网对丹参花期的昆虫进行收集,分类鉴定后开展群落结构及多样性分析。结果表明,丹参花期共收集到昆虫5 438头,隶属于膜翅目Hymenoptera、双翅目Diptera、半翅目Hemiptera、鳞翅目Lepidoptera、鞘翅目Coleoptera、直翅目Orthoptera、脉翅目Neuroptera 7目52科,双翅目、膜翅目昆虫为优势类群,群落丰盛度、丰富度指数较高,Shannon-Wiener多样性指数、Pielou均匀度指数较为稳定,Simpson优势度指数较低,可见丹参田花期昆虫种群结构较为稳定。     

盐碱旱地转基因抗虫棉田昆虫群落多样性

棉花是耐干旱和耐盐碱的经济作物。随着土壤的盐碱化和干旱化, 在人口数量和植棉成本剧增的背景下, 我国黄河流域和长江流域棉花种植面积锐减, 棉花种植被迫向滨海盐碱地和内陆及西北干旱地区转移。本文于2013年和2014年在山东东营滨海盐碱地和河北枣强半干旱轻度盐碱地以非转基因棉(‘中棉所49’)为对照, 以转Bt基因棉(‘中棉所79’)为试验材料, 分别作施农药和不施农药处理, 于每年5月初到9月中旬, 调查取样点棉株及地面上害虫及其天敌的种类和数量, 并分析不同施药处理下转基因和非转基因棉田昆虫群落的生物多样性参数差异。结果表明, 施药和不施药转Bt基因棉田昆虫群落和害虫亚群落昆虫的个体总数均低于非转基因棉田, 其中昆虫群落和害虫亚群落个体数在二者之间差异显著; 转Bt基因棉田昆虫群落和害虫亚群落昆虫的多样性指数和均匀度指数均高于非转基因棉田, 而优势集中性指数均低于非转基因棉田, 但差异均不显著。施药条件下两种棉田的昆虫群落和害虫亚群落昆虫个体总数、多样性指数和均匀度指数均低于不施药棉田, 优势集中性指数均高于不施药棉田, 但转基因棉田和非转基因棉田之间无显著差异。表明转基因抗虫棉在盐碱旱地对棉田靶标害虫具有较好的控制作用, 棉田昆虫群落稳定性较高, 昆虫群落对外界的入侵和干扰缓冲能力强, 而化学农药的使用对昆虫群落杀伤力较大, 容易导致某种昆虫的抗性产生和昆虫群落的不稳定, 但比非盐碱旱地棉田昆虫群落生物多样性低, 棉田生态系统更简单。     

中川机场及其周边生境昆虫群落组成

采用网捕法和徒手捕捉法对中川机场及其周边生境中的昆虫进行了调查研究,探究中川机场及其周边生境昆虫群落组成。结果表明:采集到的昆虫分属于9目56科,其中鞘翅目、双翅目和鳞翅目为优势类群;聚类分析结果显示,机场控制区与混合类型生境中的昆虫群落组成相似,农田与水库区生境中的昆虫群落组成相似。     

武汉市湿地公园昆虫群落多样性及季节动态研究

本文系统调查了武汉市解放公园和月湖公园人工湿地区不同季节、不同植物类群昆虫群落多样性,共采集昆虫标本7313头,隶属于13目、81科、198种。群落特征研究结果显示9月为昆虫多样性最高的月份,Shan-non-Wiener指数分别为解放公园4.7949,月湖公园4.4611;昆虫群落的季节变化情况是温度升高,多样性指数升高,但温度过高会抑制昆虫多样性;不同植物种类间昆虫多样性差别很大,种类极不相似,昆虫群落多样性最高的植物群落是千屈菜。     

茶园蜘蛛、昆虫群落动态的研究

该文研究报道了皖南地区茶园蜘蛛、昆虫的种类和群落结构,结果如下:1.茶园中昆虫、蜘蛛种类有28个,其中5、6月群落中动物种类多,多样性指数大。调查期内,品种园内动物优势种是天敌。2.主成分分析(PCA)表明:在无人为干扰的品种园内,节肢动物群落结构稳定;进行化学防治的采摘茶园群落结构不稳定。此研究对于在茶园内合理使用农药、繁荣生物群落,提高茶叶品质有重要意义。     

不同林分类型对昆虫群落多样性的影响

为研究近自然森林经营下的华北落叶松人工林不同林分类型对昆虫群落多样性的影响,以塞罕坝自然保护区内的华北落叶松纯林和混交林作为研究对象,对6种不同林分类型中的昆虫群落结构进行了研究。共获得昆虫标本9542头,隶属于7目,68科,187种,以双翅目、半翅目和鞘翅目为优势类群。研究结果表明:6种林分类型中的昆虫在物种和个体数上存在差异,相似性分析显示群落结构均不相似;群落多样性指数分析表明华北落叶松纯林和其它类型的混交林均具有较高的丰富度指数和多样性指数;主成分分析表明各林分类型中捕食性类群和寄生性类群是影响昆虫群落结构的主要因素,且捕食性类群和寄生性类群对植食性类群的控制作用较强;稳定性分析显示6种林分类型昆虫群落结构均具有较高的稳定性。     

苹果园昆虫群落时间结构的研究

<正> 苹果园昆虫群落时间结构的研究,国内尚未见公开报道。本文将苹果园昆虫群落视为一个整体,根据群落内物种的组成和数量,采用群落的几个参数和聚类分析方法,把群落的时间变化划分为几个有序阶段,以期为害虫、天敌的预测预报和苹果园害虫综合治理提供依据。     

麦田昆虫群落的结构与时序动态

采用目测法和网捕法 ,通过对小麦整个生长季节内昆虫群落的系统调查 ,共查得昆虫11目 2 3科 36种 ,其中捕食性昆虫有 4目 5科 12种、寄生性昆虫有 2目 3科 4种、植食性昆虫有 5目 12科 15种、粪食性等其他类昆虫有 1目 3科 5种。在捕食性天敌昆虫中 ,瓢虫的种类和数量最多 ,其次为草蛉和食蚜蝇 ;在寄生性天敌昆虫中 ,蚜茧蜂为优势种 ,其次为寄蝇 ;在植食性昆虫中 ,麦长管蚜为绝对的优势种 ,其次为赤须盲蝽、灰飞虱和麦蓟马。天敌昆虫对害虫具有明显的跟随现象 ,不能有效地控制麦长管蚜的发生与危害。依据昆虫群落的组成与结构 ,结合小麦生育期 ,采用最优分割法将麦田昆虫群落动态划分为 5个阶段 ,并指出不同阶段昆虫群落特点及相应的害虫防治策略。     

烟田中静电喷雾和电动喷雾下噻虫嗪的防效及对昆虫群落的影响

【目的】探明静电喷雾与电动喷雾对噻虫嗪防治害虫效果及烟田昆虫群落的影响,为静电喷雾在烟草上的推广应用提供理论依据。【方法】利用静电喷雾与电动喷雾法喷施0.66 g·L~(-1)25%噻虫嗪水分散粒剂,施药1、3、7 d后,测定2种方法对烟蚜与斜纹夜蛾的防治效果、在烟株与土壤中的沉积以及对昆虫群落的影响。【结果】喷施25%噻虫嗪水分散粒剂1、3、7 d后,静电喷雾对烟蚜和斜纹夜蛾的防治效果均显著高于电动喷雾的防治效果,且防治效果均随时间的推移而升高。噻虫嗪在静电喷雾处理区烟叶上的沉积量高于电动喷雾处理区烟叶上的沉积量,而在静电喷雾处理区土壤中的沉积量低于电动喷雾处理区土壤中的沉积量,且都随时间的推移而降低。静电喷雾与电动喷雾均引起烟田昆虫群落的变化,静电喷雾引起的害虫和中性昆虫的数量变化大于电动喷雾,但天敌昆虫的数量变化小于电动喷雾,且静电喷雾区烟田的物种丰富度明显高于电动喷雾区,可见静电喷雾施药对烟田昆虫群落的影响小于电动喷雾施药。静电喷雾的S_t/S_i与S_n/S_p比值明显高于电动喷雾,说明静电喷雾烟田中昆虫群落稳定性高于电动喷雾烟田中昆虫群落的稳定性。【结论】相比电动喷雾,静电喷雾能够提高噻虫嗪在烟叶上的沉积量,从而提高噻虫嗪对害虫的防治效果,同时减少噻虫嗪在土壤中的沉积量,提高噻虫嗪的生态安全性,因此,静电喷雾在烟草病虫害防治上具有较好的应用前景。     

贵州烟贮害虫发生危害的初步调查与防治

介绍了贵阳烟贮主要害虫烟草粉螟EphesiaelutellaH櫣ｂｎｅｒ、烟草甲虫ＬａｓｉｏｄｅｒｍａｓｅｒｒｉｃｏｒｎｅFabricius的发生危害与防治 ,并对其影响发生的因素进行了初析。     

麦田昆虫群落结构及多样性的季节动态

通过2年对麦田昆虫群落的系统调查,共查得昆虫11目、62科1、13种,其中植食类51种、捕食类23种、寄生类24种、腐食和食血类15种,种类数和个体数分别占群落总数的45.13,20.35,21.24,13.27%和92.89,2.19,3.63,1.35%。麦田昆虫群落可划分为4个营养层、6个功能团和19个类群,麦长管蚜Macrosiphum avenae(Fabricius)是绝对的优势种,其数量变动决定着总群落结构和多样性的季节动态。麦田昆虫群落多样性表现为前期和后期高、中期低的时间格局,类群多样性与物种多样性的变化趋势最为相似,可用类群多样性代替物种多样性进行群落分析。     

Local grassland restoration affects insect communities

1. It is hypothesised that ecological restoration in grasslands can induce an alternative stable state shift in vegetation. The change in vegetation influences insect community assemblages and allows for greater functional redundancy in pollination and refuge for native insect species. 2. Insect community assemblages at eight coastal California grassland sites were evaluated. Half of these sites had undergone restoration through active revegetation of native grassland flora and half were non‐restored. Insects were collected from Lupinus bicolor (Fabaceae) within 2 × 2‐m² plots in spring 2017. Lupinus bicolor is a common native species that is used in California restoration projects, and home and state landscaping projects. 3. Ordination demonstrated that insect community assemblages were different between restored and non‐restored sites. These differences were seen in insect functional groups as well as taxa‐specific differences and were found to be driven by environmental characteristics such as non‐native forb cover. 4. Functional redundancy of herbivores decreased at restored sites, while pollinators became more redundant compared with non‐restored sites. The assemblages of the common species found at restoration sites contained more native insects than those found at non‐restored sites, including species such as Bombus vosnesenskii. 5. Local grassland restoration has the potential to induce an alternative stable state change and affect insect community assemblages. Additionally, it was found that grassland restoration can be a potential conservation tool to provide refugia for bumblebees (Bombus), but additional studies are required to fully understand its broader applicability.     

Seasonality and vertical structure of light-attracted insect communities in a dipterocarp forest in Sarawak

Nocturnal flying insects were collected monthly for 13 months using ultra violet light-traps set at various vertical levels in a weakly-seasonal, tropical lowland dipterocarp forest in Sarawak, Malaysia. Abundance, faunal composition, size distribution and guild structure of these samples were analyzed with respect to temperal and vertical distributions. The nocturnal flying insect community in the canopy level was highly dominated by fig wasps (84%) in individual number, and by scarabaeid beetles (28%) in weight. A principal component analysis on monthly catches detected non-random, seasonal trends of insect abundance. The first two principal trends were an alternation of wetter (September to January) and less wet seasons (February to August) and an alternation between the least wet (January to March) and the other seasons. Many insect groups were less abundant in the least wet season than the other seasons, whilst inverse patterns were found in Scarabaeidae and Tenebrionidae. Significantly positive and negative correlations between monthly catch and rainfall were detected only in ovule-feeders and in phloem-feeders, respectively. Delayed, significant negative correlations between monthly catch and 1–3 month preceding rainfall were more frequently detected in phytophages, phloem-feeders, seed-feeders, wood-borers and scavengers. The peak in abundance along vertical levels were found at the canopy level (35 m) for phloem-, ovule-, seed-, root-, fungal-feeders and nectar collectors, at an upper subcanopy level (25 m) for scavengers and aquatic predators, and at a middle subcanopy level (17 m) for ants. Catches at the emergent level (45 m) did not exceed those at the canopy level.     

合肥郊区春季菜园和茶园昆虫群落的组成及差异

20 0 0年春对合肥郊区菜园和茶园进行了 5天 1次的系统调查 ,共发现菜园有 3 7科 49种昆虫和蜘蛛 ,主要害虫为小菜蛾、菜粉蝶、几种蚜虫和潜叶蝇 ;茶园有 3 1科 44种。重要害虫是茶蚜和黑刺粉虱等。菜园和茶园中主要天敌是黑带食蚜蝇、七星瓢虫、蚜茧蜂和斜纹猫蛛。自 4月中旬 ,菜园物种数、个体数和多样性指数明显增大。茶园物种数、个体数和多样性指数波动性稍小。菜园害虫种数较多 ,个体数波动较大。茶园中益害物种数之比是 1 0 0 ,菜园中则为 0 5 8。主成分分析显示茶园群落的稳定性稍强。     

Do diet and taxonomy influence insect gut bacterial communities?

Many insects contain diverse gut microbial communities. While several studies have focused on a single or small group of species, comparative studies of phylogenetically diverse hosts can illuminate general patterns of host–microbiota associations. In this study, we tested the hypotheses that (i) host diet and (ii) host taxonomy structure intestinal bacterial community composition among insects. We used published 16S rRNA gene sequence data for 58 insect species in addition to four beetle species sampled from the Sevilleta National Wildlife Refuge to test these hypotheses. Overall, gut bacterial species richness in these insects was low. Decaying wood xylophagous insects harboured the richest bacterial gut flora (102.8 species level operational taxonomic units (OTUs)/sample ± 71.7, 11.8 ± 5.9 phylogenetic diversity (PD)/sample), while bees and wasps harboured the least rich bacterial communities (11.0 species level OTUs/sample ± 5.4, 2.6 ± 0.8 PD/sample). We found evidence to support our hypotheses that host diet and taxonomy structure insect gut bacterial communities (P < 0.001 for both). However, while host taxonomy was important in hymenopteran and termite gut community structure, diet was an important community structuring factor particularly for insect hosts that ingest lignocellulose‐derived substances. Our analysis provides a baseline comparison of insect gut bacterial communities from which to test further hypotheses concerning proximate and ultimate causes of these associations.     

Accumulation of a chymotrypsin inhibitor in transgenic tobacco can affect the growth of insect pests

A member of the potato proteinase inhibitor II (PPI II) gene family that encodes for a chymotrypsin iso-inhibitor has been introduced into tobacco (Nicotiana tabacum) usingAgrobacterium tumefaciens-mediated T-DNA transfer. Analysis of the primary transgenic plants (designated R₀) confirmed that the introduced gene is being expressed and the inhibitor accumulates as an intact and fully functional protein. For insect feeding trials, progeny from the self-fertilization of R₀ plants (designated R₁) were used. Leaf tissue, either from transgenic or from control (non-transgenic) plants, was fed to larvae ofChrysodeixis eriosoma (Lepidoptera: Noctuidae, green looper),Spodoptera litura (F.) (Lepidoptera: Noctuidae) andThysanoplusia orichalcea (F.) (Lepidoptera: Noctuidae) and insect weight gain (increase in fresh weight) measured. Consistently,C. eriosoma larvae fed leaf tissue from transgenic plants expressing thePPI II gene grew slower than insects fed leaf tissue from non-transgenic plants or transgenic plants with no detectablePPI II protein accumulation. However, larvae of bothS. litura andT. orichalcea consistently demonstrated similar or faster growth when fed leaf tissue from transgenic plants compared with those fed non-transgenic plants. In agreement with the feeding trials, the chymotrypsin iso-inhibitor extracted from transgenic tobacco effectively retarded chymotrypsin-like activity measured inC. eriosoma digestive tract extracts, but not in extracts fromS. litura. We conclude, therefore, that for certain insects the use of chymotrypsin inhibitors should now be evaluated as an effective strategy to provide field resistance against insect pests in transgenic plants, but further, that a single proteinase inhibitor gene may not be universally effective against a range of insect pests. The significance of these observations is discussed with respect to the inclusion of chymotrypsin inhibitors in the composite of insect pest resistance factors that have been proposed for introduction into crop plants.