地形对贺兰山步甲群落物种多样性分布格局的影响

【目的】步甲是主要栖息于地表的种类最丰富的昆虫类群之一,它们对生境的变化更为敏感。分析地形因子对贺兰山步甲昆虫群落物种多样性分布格局的影响,以期揭示步甲昆虫物种多样性分布格局形成和稳定的机制。【方法】2015年7-8月选取贺兰山山地针叶林、山地疏林、山地灌丛、山地草原和浅山荒漠5种生境98个样地,用杯诱法对步甲群落物种组成和多样性进行调查,并采用典范对应分析(CCA)分析物种多样性指数和物种分布与地形因子之间的关系,运用广义可加模型(GAM)拟合不同生境步甲群落多样性指数对海拔梯度的响应曲线,探讨贺兰山步甲群落物种多样性的垂直分布格局。【结果】共采集步甲昆虫21属65种10 989头,其中,直角通缘步甲Pterostichus gebleri和径婪步甲Harpalus salinus为优势种,其个体数量分别占总捕获个体数的44.93%和11.33%。山地疏林生境步甲物种丰富度最高,山地针叶林的步甲Shannon-Wiener多样性指数最高,浅山荒漠的步甲均匀度最高。海拔、坡向、坡度、剖面曲率和地形湿度指数的综合作用对步甲物种多样性分布格局有显著影响。其中,海拔对5种生境的步甲分布影响均显著,且解释力度最高;坡向对山地针叶林和浅山荒漠步甲分布影响显著。步甲总体丰富度和个体数量与海拔呈不对称的单峰曲线关系,Shannon-Wiener多样性指数随海拔呈先递增后保持稳定的变化,均匀度指数与海拔呈"V"型变化趋势。【结论】贺兰山山地步甲物种多样性的分布格局受海拔为主的多种地形因子综合作用的影响。     

桃园节肢动物群落相对丰盛度的季节动态研究

以合肥市杏花林果科技示范园为例,研究了桃园节肢动物群落物种的组成和数量,对植食类、捕食类、寄生类和其它类4种功能类群的相对丰盛度作了详尽的阐述。捕食类同植食类的相对丰盛度变化趋势一致,说明捕食类节肢动物是桃树生长期植食类害虫的重要天敌。     

多异瓢虫食物消耗与利用与其猎物棉蚜的寄主植物种类相关

【目的】猎物质量和类型在捕食者食物选择、消耗及营养转化过程中起着重要作用,植物的营养质量影响植食者的营养质量,进而植食者作为捕食者猎物的营养质量。为进一步了解植物-猎物-捕食者三营养层的相互作用,研究了寄主植物对捕食者食物消耗与利用的影响。【方法】在室内评价了多异瓢虫Hippodamia variegata (Goeze) 4龄幼虫和雌成虫取食和利用 5种不同葫芦科植物上的棉蚜 Aphis gossypii Glover的效率。【结果】多异瓢虫4龄幼虫和成虫均对南瓜Cucurbita moschata var. melonaeformis上的蚜虫取食量最高,而对瓢葫芦Lagenaria siceraria var. gourda上的蚜虫取食量最低。4龄幼虫取食哈密瓜 Cucumis melo var. cantalupensis上的蚜虫时,其相对生长率、食物利用率和食物转化率均达到最大,而雌成虫在取食黄瓜Cucumis sativus和搅瓜Cucurbita pepo var. medullosa上的蚜虫时,其相对生长率不存在显著差异,在取食黄瓜、瓢葫芦和搅瓜上的蚜虫时,其食物利用率和食物转化率也不存在显著差异。因此,哈密瓜上的瓜蚜更适宜作为多异瓢虫4龄幼虫的猎物,而黄瓜、瓢葫芦和搅瓜上的瓜蚜更适宜作为成虫的猎物。【结论】寄主植物种类与多异瓢虫对棉蚜的捕食效率相关,该结论为进一步利用昆虫的食性对害虫进行控制奠定理论基础。     

多异瓢虫食物消耗与利用与其猎物棉蚜的寄主植物种类相关（英文）

【目的】猎物质量和类型在捕食者食物选择、消耗及营养转化过程中起着重要作用,植物的营养质量影响植食者的营养质量,进而植食者作为捕食者猎物的营养质量。为进一步了解植物-猎物-捕食者三营养层的相互作用,研究了寄主植物对捕食者食物消耗与利用的影响。【方法】在室内评价了多异瓢虫Hippodamia variegata(Goeze)4龄幼虫和雌成虫取食和利用5种不同葫芦科植物上的棉蚜Aphis gossypii Glover的效率。【结果】多异瓢虫4龄幼虫和成虫均对南瓜Cucurbita moschata var.melonaeformis上的蚜虫取食量最高,而对瓢葫芦Lagenaria siceraria var.gourda上的蚜虫取食量最低。4龄幼虫取食哈密瓜Cucumis melo var.cantalupensis上的蚜虫时,其相对生长率、食物利用率和食物转化率均达到最大,而雌成虫在取食黄瓜Cucumis sativus和搅瓜Cucurbita pepo var.medullosa上的蚜虫时,其相对生长率不存在显著差异,在取食黄瓜、瓢葫芦和搅瓜上的蚜虫时,其食物利用率和食物转化率也不存在显著差异。因此,哈密瓜上的瓜蚜更适宜作为多异瓢虫4龄幼虫的猎物,而黄瓜、瓢葫芦和搅瓜上的瓜蚜更适宜作为成虫的猎物。【结论】寄主植物种类与多异瓢虫对棉蚜的捕食效率相关,该结论为进一步利用昆虫的食性对害虫进行控制奠定理论基础。     

宁夏盐池荒漠草原步甲物种多样性

采用巴氏罐诱法于2009年3月到10月对盐池四墩子3种不同类型荒漠草原的步甲物种组成、数量分布进行了系统调查,共获得步甲标本1318号,分属于9属15种,其中直角通缘步甲Pterostichus gebleri、蒙古伪葬步甲Pseudotaphoxnus mongolicus、径婪步甲Harpalus salinus和短翅伪葬步甲Pseudotaphoxnus brevipennis为优势种,个体数量分别占个体总数的33.08%、19.73%、15.94%和8.04%。多样性分析表明适度干扰荒漠草地的Shannon-Wiener多样性、丰富度和均匀度均高于低干扰和强干扰荒漠草地。群落相似性分析显示猪毛蒿和甘草混交带与围栏放牧带及柠条带有较高的相似性,蒙古冰草带和苜蓿与柠条混种带相似性较高。从时间动态上看,步甲群落的个体数量在8月份达到最高。4种优势种季节性变化分别是直角通缘步甲盛发期为8月,径婪步甲发生的高峰期为8、9月,短翅伪葬步甲在5月和8月,蒙古伪葬步甲7-10月个体数量均多;不同物种在不同类型荒漠草地出现的高峰期是不一致的。典范对应分析(CCA)分析表明土壤含水量是影响步甲分布的最重要环境因子,植物生物量和植被密度次之;土壤含水量与步甲的Shannon-Wiener多样性、均匀度显著负相关,与优势度呈显著正相关。     

互花米草入侵对长江口九段沙湿地昆虫功能群组成特征及季节动态的影响

【目的】揭示互花米草Spartina alterniflora入侵对盐沼湿地昆虫不同功能群组成特征和时间动态的影响。【方法】于2015年的不同季节,在不同的样点沿10 m长的样线,以扫网法对长江口九段沙湿地不同样点的互花米草、芦苇和藨草群落进行昆虫采集。采用非参数检验方法比较不同植物群落中不同昆虫取食功能群物种丰富度、个体多度和季节动态的差异,采用非参数多维度排序方法分析植物生境对各昆虫功能群组成的影响,并用指示种分析方法分析不同昆虫的生境偏好。【结果】共采集昆虫72科,188种,10 338头。互花米草群落昆虫物种丰富度和个体多度显著低于芦苇群落,藨草群落昆虫物种丰富度与互花米草群落差异不显著,但昆虫个体数显著多于互花米草群落。不同昆虫功能群分别比较表明,植食昆虫物种数和个体数在互花米草和芦苇群落间差异不显著,藨草群落植食昆虫物种数最少但个体数量最多。芦苇群落捕食/寄生昆虫物种数和个体数均显著多于互花米草和藨草群落。腐食/菌食昆虫物种数和个体数在不同植物群落无显著差异。季节动态分析显示,不同昆虫功能群物种数和个体数在互花米草群落的峰值均出现在春季,而在芦苇和藨草群落中则具不同趋势。根据非参数多维度排序分析结果,互花米草入侵显著改变了昆虫的群落结构,并对不同昆虫功能群的物种组成均产生了显著影响。指示种分析方法结果进一步表明,偏好互花米草的昆虫物种数最少,主要为广食性植食昆虫。偏好芦苇分布的昆虫物种数最多,主要为捕食/寄生昆虫和专食性植食昆虫。偏好藨草的植食昆虫虽为广食性,但指示值较高。【结论】互花米草入侵降低了盐沼湿地的昆虫多样性,并显著改变了盐沼湿地昆虫功能群组成特征和季节动态。相比植食昆虫,天敌昆虫对互花米草入侵的影响更为敏感。一些广食性的植食昆虫可能已对互花米草产生了适应机制,其可能造成的生态学后果应引起重视。     

桃园生草对桃树节肢动物群落多样性与稳定性的影响

对种植白三叶草的桃园(生草桃园)和非生草桃园的桃树节肢动物群落进行分析比较.结果表明:生草桃园桃树天敌、中性类群和植食类群数量分别是非生草桃园的1.48、1.84和0.64倍,而节肢动物群落个体总数无显著差异;与非生草桃园相比,生草桃园桃树节肢动物群落丰富度(83.733±4.932)、多样性(4.966±0.110)和均匀性指数(0.795±0.014)均显著升高,而优势度指数(0.135±0.012)显著降低.稳定性指数S/N、Sd/Sp与非生草桃园均无显著差异,但Nn/Np、Nd/Np及Sn/Sp均显著高于非生草桃园.生草桃园桃树节肢动物群落多样性与稳定性指数N/Np、Sd/Sp、S/N存在显著的负相关关系,而与Nn/Np、Sn/Sp无相关性;非生草桃园多样性与稳定性指数Nn／Np、Nd/Np存在显著的正相关关系,而与其他稳定性指数无显著相关性.     

千岛湖地区常见木本植物性状和相对多度对幼苗植食作用的影响

植食性动物取食植物(植食作用)一直是生物多样性和生态系统功能研究的热点问题。植食作用能够显著影响植物幼苗的生长,从而决定种群更新动态。以往的研究较少讨论植物的不同性状对幼苗植食作用差异的重要性,也较少将之与物种相对多度对植食作用的影响进行比较。该文以千岛湖地区的16种常见木本被子植物幼苗为研究对象,调查植物的11种功能性状和相对多度,并运用回归模型和方差分解方法,研究植物功能性状和物种相对多度对幼苗叶片受昆虫植食损伤(虫食率)的相对重要性,探讨虫食率对植物功能性状的依赖性以及物种相对多度对虫食率的影响。结果表明叶片功能性状(即叶片碳氮比、叶片厚度)和物种相对多度对虫食率有重要影响,二者共解释了种间虫食率变异的54%。在这些性状中,有更高的防御能力、更低的营养成分和更高相对多度的物种虫食率更低。我们建议在未来的植食作用研究中,应考虑基于个体水平的功能性状和基于群落水平的相对多度。     

区域变动尺度上不同生境类型及环境因子对西双版纳蝴蝶多样性的影响

【目的】生境类型和环境因子对物种分布和维持具有重要的影响。本研究通过分析不同生境类型对蝴蝶群落多样性及其群落结构影响的差异,以及环境因子对蝴蝶物种丰富度和多度的影响,为区域变动尺度蝴蝶多样性维持机制的研究奠定基础。【方法】于2019年8月和10月,在西双版纳地区采用样线法,调查了天然林、次生林、复合生境、人工林和农田5种生境中蝴蝶的物种,分析了蝴蝶群落多样性、群落结构相似性及物种丰富度和多度与环境因子的关系。【结果】2019年从西双版纳共采集蝴蝶2 226头,隶属于11科98属175种,在西双版纳州级尺度上蝴蝶物种丰富度高于县域尺度。在西双版纳州级尺度上,蝴蝶的物种丰富度和多度在5种生境间存在显著差异,而在县域尺度上,物种丰富度、多度和Chao 1物种丰富度估计值没有一致性规律。群落结构相似性结果显示,在西双版纳州级尺度上,蝴蝶群落结构在不同生境类型间存在极显著差异,在县域尺度上,仅勐腊区域蝴蝶群落结构在不同生境类型间存在显著差异。蝴蝶物种丰富度和多度不仅受到生境类型的影响,还受到温度、年均降水和海拔的影响。【结论】本研究结果表明,在区域变动尺度上,生境类型对西双版纳蝴蝶的多样性的影响较大,而温度、年均降水和海拔是维持蝴蝶物种多样性的重要因素。这些发现对当前人类导致的生境丧失和气候变化时代生物多样性的保护具有重要意义。     

转植酸酶基因玉米对步甲群落动态的影响

本研究以陷阱法研究转植酸酶基因玉米及其亲本玉米在整个生长季节对地表步甲类群的影响。每个玉米品系设置6块样地, 两个玉米品系交替排列, 每个样地设置2个采样点, 共设置24个样点, 整个玉米生育期取样8次。本研究共采集步甲标本8 012头, 隶属于11属23种, 其中黄斑青步甲Chlaenius micans个体数量分别占个体总数的87.54%, 为玉米田内的主要常见物种, 蠋步甲Dolichus halensis、 后斑青步甲Chlaenius posticalis和单齿蝼步甲Scarites terricola个体数量分别占除黄斑青步甲之外所有步甲个体总数的34.77%, 31.16%和6.21%, 这些物种组成当地玉米田内的常见物种。步甲物种多样性与常见物种个体数量随季节变化明显, 且转植酸酶基因玉米与其亲本玉米田内步甲物种多样性和常见物种个体数量的季节变化趋势相似度较高。重复测量方差分析（Repeated ANOVA）结果表明, 转植酸酶基因玉米对步甲物种丰富度、 物种多度、 香农威纳多样性指数和均匀度指数均没有显著影响; 转植酸酶基因玉米田内的后斑青步甲个体数量明显增加, 但其他常见物种没有显著变化。基于非度量多维度（NMDS）的群落结构分析表明转植酸酶基因玉米与亲本玉米田内的步甲群落结构非常相似。本文结果表明转植酸酶基因玉米的种植对步甲物种多样性及常见物种没有明显影响。     

非寄主植物间套作对马铃薯甲虫种群及其天敌的影响

农田作物布局作为害虫生态调控的重要内容,一直是保护性生物防治的研究热点。为进一步明确马铃薯田块作物间套作种植模式对马铃薯甲虫种群动态的影响,探索马铃薯甲虫可持续防控的新思路与新方法,本研究在马铃薯甲虫发生期对马铃薯-玉米、马铃薯-向日葵、马铃薯单作3种作物间套作模式进行田间种群数量调查,分析比较不同种植模式下的马铃薯甲虫种群动态差异。结果表明：在马铃薯甲虫发生期,马铃薯单作第二代幼虫为害高峰期出现晚于两种间套作模式,第一代成虫为害高峰期早于两种间套作模式。第二代幼虫为害低峰期（8月26日-9月7日）时,马铃薯-玉米间套作幼虫量显著低于马铃薯单作（P<0.05）,马铃薯-玉米间套作幼虫量显著低于马铃薯-向日葵（P<0.05）,整个调查期间,马铃薯单作虫量要大于两种间套作。此外,天敌昆虫群落调查表明：间套作玉米异色瓢虫量显著高于马铃薯单作（P<0.05）,间套作向日葵的草蛉、食蚜蝇虫量高于马铃薯单作。间套作向日葵或玉米对越冬代马铃薯甲虫的扩散有影响,马铃薯播种初期间套作向日葵或玉米能在一定程度上阻隔马铃薯甲虫的定殖扩散。     

Mitochondrial haplotypic diversity of pine cone beetles (Scolytinae: Conophthorus) collected on food sources

Conophthorus Hopkins attack, oviposit, and feed in immature cones of many pine (Pinus) species. They are a serious pest of pine seed orchards and can destroy up to 100% of the cone crop. Beetles can plague orchards over many years because emerging beetles tend to attack cones of the same or a nearby tree. However, fluctuating pine cone production suggests that beetles may disperse from their natal tree stand to find second-year cones for oviposition. These dispersal behaviors may influence population level genetic diversity, that is, populations may exhibit low or high diversity. In this study, we assess the mitochondrial haplotypic diversity among 10 populations of Conophthorus representing four species. Furthermore, the haplotypic diversities are compared with published haplotypic diversities of other scolytine species to assess the influence of fluctuating food resources on Conophthorus haplotype diversity. Conophthorus haplotypic diversity ranged between 13 and 70%, which was similar to population level haplotypic diversities of other scolytines. The tendency of the emerging brood to reinfest the same tree has little influence on haplotype composition of populations and haplotype diversity is likely more influenced by beetles in search of pine cones.     

Insect taxa with similar habitat requirements may differ in response to the environment in heterogeneous patches of traditional fruit orchards

Semi-natural habitats are currently one of the most important environments for many taxa. The main aim of this study was to discover how diurnal butterflies (Lepidoptera) and flower-visiting beetles (Coleoptera) respond to the environment of traditional fruit orchards. In total, 25 orchards were studied in the rural-agricultural landscape in the Czech Republic. Both study taxa were sampled using timed survey walks in 2010. Seven variables in two environmental categories (patch and geography) were evaluated with respect to the species richness of the studied taxa using partial regression, hierarchical partitioning and generalized linear modeling of the best selected variables. Butterflies were highly influenced at a patch level. An increased number of flowering plants, as a reflection of nectar sources for adults, significantly explained a high level of variability, both alone and via interaction with other studied variables. Beetles were influenced by patch and geography to the same degree, although altitude (as a reflection of geographical heterogeneity) significantly negatively explained the highest level of variability. The results indicate that diurnal butterflies and flower-visiting beetles as insect taxa with similar habitat requirements respond differently in heterogeneous environments of traditional fruit orchards. They also indicate the need for multi-taxa studies, even in marginal ecosystems of recent landscapes.     

Influence of pest control pressure on occurrence of ground beetles (Coleoptera: Carabidae) in apple orchards

Bioindicators that reflect the level of chemical control have not been developed for use in apple orchards in Japan. In Japan, many carabid beetles and spiders are beneficial predators of a wide range of agricultural pest insects. In apple orchards, spider numbers are reflective of the level of control pressure, but there is no information on carabid beetles. To establish whether carabid beetles could indeed be useful bioindicators, the number of carabid beetles and spiders in six apple orchards (A–F) under different levels of control pressure was investigated in Akita prefecture, northern Japan, in 2008 and 2009. The negative impact on beneficial arthropods was assumed to decrease in the order of pyrethroids (A) > organophosphates (B) > neonicotinoids (C) > insect growth regulators (D) > fungicides only (E) > no spraying (F). Sprays were applied at 2-week intervals from mid-May to early August. Twenty species of carabid beetles were found in orchard F; about 50% of adults were Anisodactylus punctatipennis, and 30–40% were Amara chalcites. The number of Am. chalcites significantly decreased with increasing control pressure: (A–C) < (E, F) in 2008, (A–E) < F in 2009, and (A, B) < E in 2009. Most spiders collected were juvenile Tetragnathidae and Araneidae. The numbers of spiders and Am. chalcites adults were significantly highly correlated at each control pressure in both years. Thus, it was considered that only Am. chalcites adults can be used as bioindicators reflecting the control pressure in apple orchards in northern Japan, whereas the main diet of this species is probably C3 plants.     

The impact of maize-bean intercropping on insect biodiversity

Intensive agriculture is one of the main reasons for recent insect declines. This loss of biodiversity has created the need to develop methods of intensive cultivation that combine high yields with biodiversity conservation. One promising method in maize cultivation is intercropping with beans. The objective of this study was to determine whether maize-bean intercropping could increase insect biodiversity. We examined the activity density, species richness and Shannon diversity of bees and carabid beetles in pure and intercropped maize under both organic and conventional management. We collected carabid beetles using pitfall traps and bees by doing transect walks. The study was carried out in an agricultural landscape, on a set of 17 study sites. We found that intercropping leads to significant increases in bumblebee and honeybee activity as well as in bee species richness. Differences between pure and intercropped maize were dependent on the year of data acquisition and the management style. Solitary wild bee species activity was not significantly affected. Carabid activity density and carabid species richness also did not differ significantly between the cropping systems. We conclude that maize-bean intercropping can contribute to insect biodiversity conservation but its contribution is limited to bumblebees. Despite its relatively low contribution per hectare, maize-bean intercropping could have a surprisingly positive impact, as maize now covers large areas of German farmland. Potential exists to increase the biodiversity value of maize intercropping even further by using varied plant mixes. Our results strongly encourage further research in this direction.     

Effect of a cotton intercrop on spider mite populations in jujube trees

In the arid and semi-arid parts of Xinjiang (China), jujube (Zizyphus jujube Mill) orchards are regularly intercropped with cotton. In 2016–2017, a field study was conducted to compare the species composition and infestation pressure of spider mites in local jujube trees under a cotton-jujube intercropping system and a jujube monocrop system. Our results showed that Tetranychus truncatus Ehara accounted for 94.2–98.5% of all spider mites in either cropping systems. Overall abundance of tree-inhabiting spider mites, including T. truncatus, in intercropped orchards was generally higher than in monocrop ones. Combining our work with earlier findings, we demonstrate how intercropping of cotton and jujube trees generally increases population levels of spider mites on either crop.     

Rain forest provides pollinating beetles for atemoya crops

Small beetles, usually species of Nitidulidae, are the natural pollinators of atemoya (Annona squamosa L. x A. cherimola Mill. hybrids; custard apple) flowers but commercial atemoya growers often need to carry out labor-intensive hand pollination to produce enough high-quality fruit. Because Australian rain forest has plant species in the same family as atemoya (Annonaceae) and because many rain forest plants are beetle pollinated, we set out to discover whether tropical rain forest in far north Queensland harbors beetles that could provide this ecosystem service for atemoya crops. Orchards were chosen along a gradient of increasing distance from tropical rain forest (0.1-24 km). We sampled 100 flowers from each of nine atemoya orchards and determined the identity and abundance of insects within each flower. To assess the amount of pollination due to insects, we bagged six flowers per tree and left another six flowers per tree accessible to insects on 10 trees at an orchard near rain forest. Results indicated that atemoya orchards < or = 0.5 km from rain forest were predominantly visited by five previously unrecognized native beetle pollinators that are likely to originate in tropical rain forest. These native beetles occurred reliably enough in crops near rain forest to have a positive effect on the quantity of fruit produced but their contribution was not great enough to satisfy commercial production needs. Management changes, aimed at increasing native beetle abundance in crops, are required before these beetles could eliminate the need for growers to hand pollinate atemoya flowers. Appreciation of the value of this resource is necessary if we are to develop landscapes that both conserve native biodiversity and support agricultural production.     

Species composition of leaf beetle assemblages in the canopies of apple and pear orchards in Hungary and Great Britain (Coleoptera: Chrysomelidae)

The species richness and species composition of Coleoptera assemblages were investigated in the canopies of apple and pear orchards in Hungary and in the apple orchards in Great Britain. The investigations were carried out in Hungary (Nagykovácsi: 3 plots, Kecskemét: 5 plots, Sárospatak: 4 plots) between 1990-94, and in Great Britain in Kent (East Malling, Marden and Robertsbridge) in 2001 and 2002. Former investigations in Hungary revealed that the diversity of Coleoptera assemblages in the canopy of apple and pear orchard were surprisingly high. As a result of our investigations it was found that altogether 324 species, almost 3% of the Hungarian beetle fauna were represented: 253 species in apple orchards and 188 species in pear orchards. Similar results were obtained in the investigations carried out in Great Britain between 2001-2002. In Hungary, the majority of the species belonged to the families Curculionidae, Chrysomelidae and Coccinelidae. The proportion of leaf beetles varied between 15 and 20%. The most common leaf beetle species in the canopy of the commercial orchards were Phyllotreta vittula, Phyllotreta atra, Phyllotreta nigripes, Oulemta melanopus, and Aphthona euphorbiae. In the abandoned orchards the most common species were Luperus xanthopoda, Smaragdina salicina and Orsodacne liieola. In Great Britain 44 leaf beetle species were found in the canopies of the investigated orchards. The species with higher abundance were Aphthona euphorbiae. Chaetocnema concinna and Longitarsus parvulus. We concluded, that leaf beetles give high part of the orchard canopy biodiversity and sometimes occur with high species richness and abundance. However, the reasons of their occurrence and their potential role are poorly known.     

Influence of ground beetles (Carabidae) as biological agent to control of the Mediterranean fruit fly pupae,Ceratitis capitata,in Iranian citrus orchards

Damage by Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in the northern Iranian citrus orchards has been led to spray by different chemical pesticides. The present study was conducted in the citrus orchard in Mazandaran province of Iran where with the exception of mineral oil treatments for scale insects, had not been sprayed with synthetic insecticides for six years. The purpose of this study was initially to investigate faun and seasonal activity of predaceous ground carabid beetles in the citrus orchards. Additionally, their role as predators of Ceratitis capitata (Wiedemann) pupae was evaluated under laboratory and field conditions. Predation in laboratory was evaluated by no choice feeding experiments while predation under field conditions was evaluated by molecular detection of the pest DNA in the gut contents of field-collected Carabids. A total of 3437 beetles of ten carabid species were collected from a non-chemical treatment citrus orchard. The results of the seasonal density fluctuation indicated increasing population in spring reaching the highest in September, simultaneously with the peak of fruit fly damage, and thereafter decreasing during winter when the pest was overwintering. However, three species, Harpalus rufipes, Broscus karelinii and Brachinus brevicollis were most abundant in the field collection but the results of no-choice experiments in the laboratory indicated H. rufipes, B. karelinii and Pterostichus macer were the most voracious predators on pupae. Results of gut content analysis of the voracious species indicated the positive testing for pest DNA in 79.16 % of H. rufipes, 76.92 % of B. karelinii and 75 % of P. macer of analyzed beetles. The results of the study strongly indicated that in citrus orchards where intensive spraying is eliminated, natural enemies such as Carabid beetles could play an important role in reducing pests such as medfly.     

Establishment and management of wildflower areas for insect pollinators in commercial orchards

Sown wildflower areas are increasingly recommended as an agri-environmental intervention measure, but evidence for their success is limited to particular insect groups or hampered by the challenges of establishing seed mixes and maintaining flower abundance over time. We conducted a replicated experiment to establish wildflower areas to support insect pollinators in apple orchards. Over three years, and across 23 commercial UK orchards with and without sown wildflowers, we conducted 828 transect surveys across various non-crop habitats. We found that the abundance of flower-visiting solitary bees, bumblebees, honeybees, and beetles was increased in sown wildflower areas, compared with existing non-crop habitats in control orchards, from the second year following floral establishment. Abundance of hoverflies and other non-syrphid flies was increased in wildflower areas from the first year. Beyond the effect of wildflower areas, solitary bee abundance was also positively related to levels of floral cover in other local habitats within orchards, but neither local nor wider landscape-scale context affected abundance of other studied insect taxa within study orchards. There was a change in plant community composition on the sown wildflower areas between years, and in patterns of flowering within and between years, showing a succession from unsown weedy species towards a dominance of sown species over time. We discuss how the successful establishment of sown wildflower areas and delivery of benefits for different insect taxa relies on appropriate and reactive management practices as a key component of any such agri-environment scheme.