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1.
In an agroecosystem, catches of epigeal invertebrate predators obtained by pitfall traps were compared to absolute population densities estimated by ground photoeclectors in two different habitats, a field and an adjacent set-aside land. In general, abundance of Carabidae and Lycosidae were overestimated by pitfalls, while Staphylinidae and Linyphiidae were underestimated, and beetle larvae showed no obvious trend. The overestimation of Carabidae and Lycosidae by pitfalls had its maximum in spring and summer. Numbers collected by pitfalls did represent actual population densities better in the field than in the set-aside. This is probably caused by the higher vegetation diversity and complexity of the set-aside land which additionally influenced the catches. Pitfalls recovered higher numbers of animals and species, and species composition differed significantly between pitfalls and photoeclectors, in the field as well as in the set-aside. Body size seemed to be the main factor in determining the catch, the relatively larger species being more frequently caught by pitfall traps. In sum, the relationship between pitfall trap catches and actual population densities appeared to be either absent, weak or highly variable among taxa, habitat and time of the season. Thus numbers caught in pitfall traps cannot be considered as reliable indices of “real” abundance nor do they reflect the relative abundance within a given predator community correctly. Therefore, in most cases absolute density estimates should be preferred for the study of epigeal invertebrates in arable land. However, I suggest a combination of both pitfall traps and standardised area samples, because the two approaches possibly provide information of different qualities equally important for the evaluation of epigeal predator species, namely searching activity and population density.  相似文献   

2.
陷阱法调查转Bt棉对棉田地面蜘蛛群落的影响   总被引:1,自引:1,他引:0  
为明确转Bt棉对非靶标节肢动物棉田蜘蛛群落的影响,在棉花全生长期利用陷阱法对转Bt棉(中棉29)和传统棉田(湘杂3号)蜘蛛的群落多样性及数量动态变化进行了系统调查。结果表明:共采集棉田蜘蛛5 020头,隶属13科33种,其中转Bt棉田2 548头,隶属12科27种,传统棉田2 472头,隶属12科27种;转Bt棉田和传统棉田均以狼蛛科Lycosidae、平腹蛛科Gnaphosidae和隐石蛛科Titanoecidae为优势科,优势科的优势种也均为沟渠豹蛛Pardosa laura、蛞平腹蛛Gnaphosa kompirensis和白斑隐石蛛Nurscia albofasciata,2种棉田在地面蜘蛛群落组成上除少部分稀有物种存在差异外,优势科及优势科的优势种均无显著差异;且3种优势种蜘蛛数量、Shannon-Wiener多样性指数以及物种丰富度均无显著差异;2种棉田地面蜘蛛数量动态变化也无显著差异,均有2个高峰期,分别在苗期和铃期。表明转Bt棉对棉田地面蜘蛛群落无显著影响。  相似文献   

3.
The effect of spraying winter rape and winter wheat with deltamethrin on the numbers of epigeal Carabidae, Staphylinidae and Linyphiidae caught in pitfall traps was studied in Northern Germany in 1980 and 1981. Two experiments were performed with each crop, deltamethrin being sprayed at 7.5 g a.i. ha?1 in 300 litres of water in springtime on rape, and in midsummer on wheat. Sprayed plots were rectangles of 2 and 3 ha; unsprayed plots were squares of 0.5 ha each (two replicates). Ten pitfall traps were placed per replicate at least 3 weeks before spraying and were left for at least 3 weeks after spraying, the traps being emptied weekly. Beneficial Carabid species which have been shown already to have an economic significance, were rare during this study, but four other species (three of them were autumn breeders) were not affected by deltamethrin. At the spraying dates the autumn breeders were hidden in the soil as pupae. Three Staphylinid species, studied in only one experiment each, appeared to be strongly reduced in numbers by deltamethrin. The Linyphiid spiders were affected most heavily by deltamethrin sprayed in spring or in midsummer; the initial mortality of more than 92% lasted longer than 4 weeks, and an adverse effect was still significant in winter wheat 6 weeks after spraying. Overall, deltamethrin appears to have a broad spectrum effect concerning the epigeal predatory arthropods.  相似文献   

4.
为研究稻-棉邻作系统稻田和棉田地表捕食性天敌丰富度和多样性,采用陷阱诱捕法对邻作稻田-棉田地表的捕食性天敌进行了系统调查,应用群落特征参数等对陷阱诱集物种群落、物种丰富度和多样性指数进行了比较分析。结果表明:稻-棉邻作系统共诱集3纲11目33科8532头样本。其中,稻田陷阱收集到8目27科35种5878头个体,捕食性天敌物种丰富度、多样性指数和均匀度分别为1.8779、0.7297、0.2576;棉田陷阱收集到3纲9目28科35种2654头个体,捕食性天敌物种丰富度、多样性指数和均匀度分别为2.4771、0.8041、0.4149。稻-棉邻作系统捕食性天敌有3纲3目13科17种5971头,优势种为捕食性天敌狼蛛,泽蛙是次优势天敌功能团,捕食性的鞘翅目天敌瓢虫类、步甲等种类多样性丰富。  相似文献   

5.
In the present study, the effects of spinosad, spinetoram and chlorpyrifos on ground-dwelling arthropod diversity and abundance were compared in a herbaceous field in order to evaluate their relative compatibility with conservation of arthropod densities. Ten different treatments of spinosad, spinetoram, and chlorpyrifos, which was used as a toxic reference, were allocated at random to experimental plots. A total of 101,119 individuals of epigeal arthropods belonging to 18 orders and suborders were captured in pitfall traps, with the most abundant taxa Hymenoptera, Collembola, Araneae, Acari, Coleoptera, Isopoda, Julida and Opiliones. The orders Araneae, Coleoptera, Collembola, Hymenoptera and Opiliones were identified to the family or species level. Gnaphosidae, Carabidae, Entomobryidae, Formicidae and Metaplatybunus grandissimus CL Koch (Phalangiidae) were the most abundant taxa of Araneae, Coleoptera, Collembola, Hymenoptera and Opiliones, respectively. Significant density reduction was observed for Gnaphosidae, Linyphiidae (Araneae), Carabidae, Entomobryidae, Formicidae and M. grandissimus after chlorpyrifos treatment. Formicidae individuals were significantly reduced after spinosad application, while the Entomobryidae and M. grandissimus individuals were reduced after the application of both spinosad and spinetoram. Our results showed no significant differences in diversity level of orders and suborders as well as of Araneae families between the spinetoram-treated plots at both concentrations tested and the control. In contrast, a significant difference in the diversity of Coleoptera was detected between the spinetoram treatments and the control. Our findings showed that spinosad and spinetoram may disrupt the structure and the abundance of surface-active arthropod fauna causing considerable changes in the ground-dwelling biodiversity of this ecosystem.  相似文献   

6.
宁夏麦蚜天敌多样性及种间关系   总被引:1,自引:1,他引:0  
麦蚜是宁夏小麦的主要害虫,为了实现自然天敌对麦蚜的有效控制,采用网捕法和陷阱法等采集手段,通过3年田间调查,共鉴定麦蚜天敌97种,包括寄生性天敌16种和捕食性天敌81种。将麦蚜天敌划分为单食性天敌、寡食性天敌、多食性天敌及杂食性天敌共4类功能团进行分析,结果表明,不同天敌功能团对麦蚜种群的影响存在显著的交互作用;寄生性天敌中蚜茧蜂属的燕麦蚜茧蜂与烟蚜茧蜂是优势种;捕食性天敌种类较为复杂,不同地区麦蚜天敌组成存在显著性差异,复杂的农业景观能够维持更高的天敌多样性。表明在农业生态系统中建立和恢复非作物生境能够明显提高天敌种群数量,进而提高其生物防治作用。  相似文献   

7.
During a 6-year study, effects of two contrasting regimes of pesticide use on pitfall and suction catches of Collembola were monitored in an arable field under a rotation of grass and winter wheat. Current farm practice (CFP) represented conventional fungicide and herbicide use plus applications of organophosphorus (OP) insecticides, whereas reduced input approach (RIA) utilised minimum inputs of fungicides and herbicides and excluded any use of insecticides. Compared with RIA, the CFP regime caused a substantial decline in the abundance and diversity of Collembola in the field, including the local disappearance of one species, without recovery during the study. At the field edge, which was protected during OP applications by a 6-m unsprayed buffer zone, effects of the CFP regime were less severe, and were not persistent in the long term. Some Collembola species occurred only in field-edge samples. Pitfall and suction sampling yielded remarkably similar patterns of catches, indicating that pitfall trapping may be appropriate for detecting long-term changes in collembolan abundance caused by intensive agricultural management practices.  相似文献   

8.
The aim of this investigation was to clarify whether pheromone traps could provide a reliable tool for early detection of aS. littoralis adult population and for indicating infestation by its larvae in the field. The aggregated pattern of distribution of adults is indicated by the fit of data to Taylor’s Power Law or to the negative binomial distribution. However, the relatively high k values obtained indicate thatS. littoralis adults are only slightly aggregated and sometimes almost randomly distributed. Trap position in the field and number of traps per area unit affected size of catches in both female-baited and synthetic-pheromone-baited traps. No relationship between size of catches and temperature, wind velocity or moon phase was detected. Variations in size of catches among traps was not affected much by the baited females. Pheromone traps proved to be a reliable tool for estimating fluctuations in population density and for indicating adult peaks. However, no correlation between male catches and infestation by larvae in the experimental plots was found. Pheromone traps may serve only as a warning device indicating the possibility of potential attack due to an increase in adult population level. Mercury vapor light traps were inferior to pheromone traps in detecting changes inS. littoralis population densities. Synthetic pheromone (“Litlure”) was somewhat less efficient in attracting males than virgin females; however, it is suitable for detecting fluctuations in theS. littoralis adult population.  相似文献   

9.
In the south-west of England, cereal aphids can spread barley yellow dwarf virus and reproduce during winter. Ground-living polyphagous predators may be important in controlling these active cereal aphids. This 2-year study investigated the effect of deltamethrin on predator numbers, using pitfall traps. A randomised block design was used in an area of winter wheat (cv. Aquilla) in which deltamethrin-treated and control plots were surrounded by polyethylene barriers. Pitfall catches of polyphagous predators were reduced by about 30% in the treated plots compared with the control plots.  相似文献   

10.
Temperature is a key factor for the living organisms on earth. It influences weed management practices, either directly or indirectly. Field experiments were conducted to determine the effect of temperature on the postdispersal seed predation of four important weed species (Cuscuta compestris, Stellaria media, Taraxacum officinale and Veronica persica) in two lucerne fields in Mashhad and Chenaran, north‐eastern Iran. These two cities have the same climate: temperate and cold alpine but the temperature varies between them. Wire mesh cages were used to determine the relative importance of birds in predation and pitfall traps were used to detect the species and the activity density of invertebrate predators. The results showed that the predation preference of different weed species was significantly different between and within fields. Seed predation fluctuated widely throughout the sampling periods, matching the periodic forage harvest and regrowth cycle of lucerne. Despite the level of seed predation fluctuating, it declined toward the last sampling periods. Using wire mesh exclusion cages showed no significant effect of birds on weed seed predation in both fields. Ants, crickets and carabid beetles were the invertebrate seed predators that were caught in the pitfall traps. There were significant correlations between the mean temperature and predator activity densities and also between the predated seeds and the mean air temperature in both locations. The results of this study indicate the significant effect of temperature on postdispersal weed seed predation. Therefore, with respect to climate change and increasing global warming, it would be possible to focus on postdispersal seed predation in weed management in the future.  相似文献   

11.
The efficacy and species specifity of two commercial sticky traps (Ekolex-V and Trappit-Lo Line) were compared in field tests in a multistorey restaurant complex in CZ. Traps were tested under high population density ofblatta orientalis L. (BO) andBlattella germanica (L.) (BG). We found species specific differences in trapping efficiency between the two traps. There was a high correlation between visually estimated counts and actual catches of BG and BO in Trappit. The correlation in Ekolex catches was lower (BG: r=0.86, BO: r=0.58). Nymph/adult ratio increased with increasing population density in both Trappit and Ekolex traps. Although both types of traps reflected differences in population density, we found Trappit more efficient than Ekolex especially forBlatta orientalis. Estimated Trappit/Ekolex ratio of BG catches decreased with increasing population density showing Trappit more sensitive. Trapping sensitivity at low cockroach density was proposed as a standard criterion for evaluation of cockroach trap efficiency.  相似文献   

12.
BACKGROUND: Field trapping experiments were carried out to evaluate effective trap characteristics for maximising Ips duplicatus (Sahlberg) catches in pheromone‐baited traps in China. RESULTS: Window‐slot and cross‐barrier traps had significantly higher catches than multiple‐funnel traps. The colour of window‐slot traps showed a significant effect on catches, with dark colours (black and red) being more effective than light colours, especially white and yellow. Window‐slot traps at a 1.5–2.0 m level caught more beetles than those at either ground level (0–0.5 m) or at 3.5–4.0 m. Ips duplicatus can be attracted to pheromone‐baited traps over a distance of > 100 m from the forest edge in an open grassy field. There was a strong diurnal pattern of flight activity, with catches on window‐slot traps occurring during the daytime with one broad peak at mid‐ to late afternoon. The seasonal flight activity of I. duplicatus as monitored by pheromone‐baited window‐slot traps during 2007–2008 indicated that three major flight peaks occurred in early June, late June–early July and late July respectively, suggesting the existence of a potential second generation. CONCLUSION: The optimal trap characteristics will improve the performance of pheromone‐baited traps as a critical monitoring or mass‐trapping tool to combat outbreaks of this pest species. Copyright © 2009 Society of Chemical Industry  相似文献   

13.
The Nearctic eastern cherry fruit fly species Rhagoletis cingulata (Loew) (Dipt., Tephritidae) has been detected several times in different European countries during the last decades. This species as well as Rhagoletis indifferens (Curran) are major pests of cultivated cherries in North America and are classified as quarantine pests in Europe. The introduction and establishment of both species could result in severe problems for Austrian cherry production due to additional infestation pressure caused by overlapping developmental cycles of American and native cherry fruit flies. A survey of both non-European cherry fruit fly species was carried out during the growing seasons of 2007 and 2008 at eleven sampling sites in the eastern part of Austria. Pherocon® AM yellow sticky traps were installed in cherry trees and replaced at weekly or fortnightly intervals. Identification of the cherry fruit flies caught was based on morphological characteristics. Two specimens of R. cingulata were caught in 2007 in different weeks and at different locations while none were caught in 2008. R. indifferens was not detected at all. While it is possible that these specimens originate from established populations with low densities, it is more likely that the catches derived from accidental introductions.  相似文献   

14.
The effects of the insecticide lambda-cyhalothrin (Karate) on non-target arthropods in winter wheat were studied throughout two successive seasons in 1998 and 1999. The study particularly focussed on the crop in the growing season after insecticide application (also winter wheat) for detection of potential long-term effects and for determination of the suitability of different sampling methods.The investigations were based on the assumption that arthropod immigration from surrounding areas is limited in large fields. For this reason a simple approach seemed to be feasible. Two plots of equal size (10 ha, adjusted to each other) were defined in a 100 ha field and designated control and treatment plots. Ten sampling points were established on each plot. The following monitoring methods were utilised: visual counting, sweep netting and pitfall trapping. In the first year of investigation, countings and catches were carried out 2 days prior to insecticide application and 2, 16, 30 and 44 days after application. In the next year, they were carried out 365 days and 384 days after insecticide application in the successive crop of winter wheat.At the time of the first sampling prior to insecticide application, the two plots showed significant differences with respect to arthropod density or activity, particularly in visual counting and to a minor degree to sweep netting and pitfall trapping. Lower densities or activities were observed in the plot reserved for treatment. Measures for mathematical equalisation of the results of population densities before pesticide treatment should be considered.After insecticide application, the densities or activities of non-target arthropods decreased, particularly in visual counting and sweep netting. After one year, these effects disappeared to a large extent. Several groups of arthropods reached even higher levels in the treated plot than in the untreated one. The pitfall traps revealed weak activity-decreasing effects in carabids and spiders in the treated plot, but the opposite tendency for staphylinids. Hence, it seems that the conditions in a large field are less homogeneous, and that smaller scale conditions can support processes of recovery in non-target populations.  相似文献   

15.
The effects of the insecticide lambda-cyhalothrin (Karate) on non-target arthropods in winter wheat were studied throughout two successive seasons in 1998 and 1999. The study particularly focussed on the crop in the growing season after insecticide application (also winter wheat) for detection of potential long-term effects and for determination of the suitability of different sampling methods.The investigations were based on the assumption that arthropod immigration from surrounding areas is limited in large fields. For this reason a simple approach seemed to be feasible. Two plots of equal size (10 ha, adjusted to each other) were defined in a 100 ha field and designated control and treatment plots. Ten sampling points were established on each plot. The following monitoring methods were utilised: visual counting, sweep netting and pitfall trapping. In the first year of investigation, countings and catches were carried out 2 days prior to insecticide application and 2, 16, 30 and 44 days after application. In the next year, they were carried out 365 days and 384 days after insecticide application in the successive crop of winter wheat.At the time of the first sampling prior to insecticide application, the two plots showed significant differences with respect to arthropod density or activity, particularly in visual counting and to a minor degree to sweep netting and pitfall trapping. Lower densities or activities were observed in the plot reserved for treatment. Measures for mathematical equalisation of the results of population densities before pesticide treatment should be considered.After insecticide application, the densities or activities of non-target arthropods decreased, particularly in visual counting and sweep netting. After one year, these effects disappeared to a large extent. Several groups of arthropods reached even higher levels in the treated plot than in the untreated one. The pitfall traps revealed weak activity-decreasing effects in carabids and spiders in the treated plot, but the opposite tendency for staphylinids. Hence, it seems that the conditions in a large field are less homogeneous, and that smaller scale conditions can support processes of recovery in non-target populations.  相似文献   

16.
为评价转cry1Ie基因(IE09S034转化体)抗虫玉米对田间节肢动物群落的影响,采用直接观察、地面陷阱、吸虫器和空中水盆诱捕4种方法,连续2年调查了转cry1Ie基因抗虫玉米田和非转基因对照玉米田在自然条件下的节肢动物物种数和个体数,比较分析了节肢动物群落各特征参数。结果显示,2012年依次采用此4种方法调查转cry1Ie基因抗虫玉米与非转基因对照玉米田间的节肢动物群落物种数、Simpson优势集中性指数、Shannon-Wiener多样性指数、Pielou均匀度指数分别为29.1、0.7、2.6、0.5,12.6、0.6、2.2、0.6,13.7、0.9、3.1、0.9和6.7、0.4、1.3、0.5,各参数之间均无显著差异。2013年调查结果与2012年一致,也显示2种玉米田的节肢动物群落各特征参数之间均无显著差异。表明转cry1Ie抗虫玉米对田间节肢动物群落多样性无显著影响。  相似文献   

17.
Abstract

One‐week‐old traps made from split banana pseudostems were 1.5–1.7‐fold more attractive to adult banana weevils than 2–3‐week‐old traps. In one experiment, all available pseudostem material was used for trapping, and weekly collecting of weevils over an 11‐month trapping period led to a 50% reduction in weevil catches in one field. In another field with a lower initial weevil density the trapping did not reduce weevil populations. In another experiment, the effect of intensive use of pseudostem traps and daily collecting of trapped weevils was estimated by a mark and recapture method over a period of 6 weeks. Reductions in weevil densities were calculated using a modified version of the Lincoln‐Index. Weevil populations were reduced by 48.5% after 3 weeks and by 62.5% after 6 weeks. Trapping efficiency declined during the experiment and appeared to be related to weevil population densities. This cultural control system may be effective in weevil control in small‐farm situations where labour availability is not a limiting factor.  相似文献   

18.
In this article, we review studies of the ecology of the larger grain borer, Protephanus truncatus, both outside and within the maize storage systems. Laboratory studies have shown that P. truncatus can breed on a wide range of woody substrates (branches, roots, and seeds). Pheromone trap catches in different habitats strongly suggest that P. truncatus is well-established in certain non-agricultural environments, presumably breeding in dead or dying wood. In Meso-America, West and East Africa, P. truncatus reproduction in the field has been documented in branches ring-barked by cerambycid beetles. Within a maize store, P. truncatus densities can increase from very small initial colonies of probably less than 200 individuals to densities in excess of 1000 beetles per kg after about 4–6 months of storage. Insect parasitoids are very often found in smallholders' grain stores attacked by P. truncatus, but they do not contribute significantly to population regulation. Declines in maize store population levels in Benin from 1993 to 1996, and in adult abundance in pheromone traps in the natural environment in Kenya, have been attributed to predation by the introduced predator, Teretrius nigrescens, but in recent years pheromone trap catches in West Africa suggest that the situation may be complex. Several environmental factors, notably temperature, humidity, and daylength, and their interactions, have been correlated with P. truncatus flight activity, as well as, in West Africa, the emptying of maize stores. Laboratory experiments have shown food quality also affects flight activity. Factors terminating dispersal and flight are most likely attraction to the male-released aggregation pheromone. Short range attraction to plant volatiles has also been recorded. In Africa the highest densities of P. truncatus tend to occur in humid lowlands, which contrasts with the situation in meso-America where P. truncatus tend to occur in greatest numbers in cooler upland regions. Pheromone trap catches can be significant predictors of the risk of stores becoming infested. Coupled with the development of a rule-based model of flight activity, these studies may offer the prospect of predicting the risk of store infestation based upon temperature and humidity measurements.  相似文献   

19.
云南桔小寡鬃实蝇种群动态研究   总被引:16,自引:0,他引:16  
经过水平和垂直地带的性诱观测与室内外调查试验,发现云南桔小寡鬃实蝇年发生4-5代。第二代为主害代,主要为害芒果、桃、番石榴等。成虫诱集高蜂期除柑桔点(高峰期为9-10月)、甜橙点(高峰期为10-12月)外,蓁各点均在6-7月间。各年高峰期早晚和诱集量不同。同年各点成虫高峰期出现的时间也有差异,主要表现为从南到北高峰期推迟。冬季除昆明外,其它各点均可诱到成虫。以高温高湿的西双版纳数量最多。同一地区随  相似文献   

20.
BACKGROUND: Chlorantraniliprole, the first anthranilic diamide insecticide labeled for turf, combines strong selective activity against key pests with low vertebrate toxicity. The hypothesis that it is less disruptive to beneficial invertebrates and their ecosystem services than are other prevailing insecticide classes was tested. Plots in golf course settings were treated with chlorantraniliprole, or with a representative nicotinoid (clothianidin), pyethroid (bifenthrin) or a combination (clothianidin–bifenthrin) formulation. Non‐target effects were assessed via pitfall traps (epigeal predators), Tullgren funnel extraction (soil microarthropods), hand sorting (earthworms), counting ant mounds and earthworm casts on tees and putting greens, assessing predation on sentinel pest eggs and comparing grass clipping decomposition in treated versus untreated turf. RESULTS: Chlorantraniliprole had little or, in most cases, no impact on predatory or soil invertebrates, predation or decomposition. Each of the other insecticides temporarily reduced abundance and activity of one or more predator groups. Clothianidin and the clothianidin–bifenthrin combination retarded grass clipping decomposition, and the combination suppressed earthworms and casts more than did carbaryl, a toxic standard. CONCLUSION: Chlorantraniliprole is compatible with conservation biocontrol and a good fit for industry initiatives to use relatively less toxic pesticides. One caveat is that its use on golf courses may require targeted management of ant mounds and earthworm casts that are suppressed as a side effect by some less selective insecticides. Copyright © 2011 Society of Chemical Industry  相似文献   

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