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Sweden requires all coniferous roundwood from countries outside Europe to have been debarked but makes no requirement for European wood. Six shipments of unbarked roundwood of Pinus pinaster from France and 14 shipments of debarked P. radiata logs from Chile were inspected in Sweden during 1988 and 1989. The imported wood from France yielded 92 insect species (90 Coleoptera and 2 Hymenoptera). Seventeen of these species do not occur in Sweden. All six consignments were thoroughly attacked by bark- and wood-boring insects, representing 25 species. The logs from Chile had been well debarked; less than 1% of the inspected logs contained living insects. Nevertheless, a total of 49 insect species (46 Coleoptera, 1 Isoptera, 1 Hymenoptera and 1 Orthoptera) were found in the 14 shipments. Of these species 21 are not indigenous to Sweden.  相似文献   

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4种螺旋线虫记述   总被引:1,自引:0,他引:1  
梅圆圆  郑炜  郑经武 《植物保护》2008,34(5):116-118
记述了采自山东、山西和浙江等地不同寄主根围的4个螺旋线虫群体,根据主要形态学特征分别鉴定为双角螺旋线虫(Helicotylenchus digonicus)、小头螺旋线虫(H.microcephalus)、双宫螺旋线虫(H.dihystera)和翅尾铗螺旋线虫(H.pteracerus)。其中H.pteracerus为国内新记录种,H.microcephalus为浙江省首次报道。  相似文献   

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This paper deals with the Arthropods fauna collected by bait and pheromone traps and categorized during one-year study in a Central Italy feed-mill. A total of 17,919 Arthropods were collected: Arachnida, Isopoda and Insecta. In the Arachnida we found mites, pseudoscorpions and mostly spiders; while in the Isopoda the only species noted wasPorcellio scaber (Latreille); in the Insecta 9 orders and 33 determined species were associated with the feed-mill: Collembola, Thysanura, Dermaptera, Psocoptera, Rhynchota, Lepidoptera, Coleoptera, Diptera and Hymenoptera.  相似文献   

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This paper deals with the Arthropods fauna collected by bait and pheromone traps and categorized during one-year study in a Central Italy feed-mill. A total of 17,919 Arthropods were collected: Arachnida, Isopoda and Insecta. In the Arachnida we found mites, pseudoscorpions and mostly spiders; while in the Isopoda the only species noted wasPorcellio scaber (Latreille); in the Insecta 9 orders and 33 determined species were associated with the feed-mill: Collembola, Thysanura, Dermaptera, Psocoptera, Rhynchota, Lepidoptera, Coleoptera, Diptera and Hymenoptera. In the order Lepidoptera about 55% of the insects were collected. Eight species of stored product Lepidoptera were cuaght:Ephestia kuehniella. Zeller, was the most abundant and wide-spread in the feed-mill (with 8,230 males, 83.53% of Lepidoptera trapped) followed byPlodia interpunctella (Hübner), (1,415 males) andEphestia elutella, (Hübner), (161 males). Coleopterans made up 40.43% of the insects collected.Tribolium confusum J. Du Val, was the most abundant and widespread in the feed-mill (with 5,451 specimens, 75.23% of Coleoptera trapped); less abundant wereOryzaephilus surinamensis (L.) (752 specimens),Tribolium castaneum (Herbst) (359 specimens),Attagenus brunneus Fald. (223 specimens),Stegobium paniceum (L.) (156 specimens) andSitophilus oryzae (L.) (118 specimens). Arthropods infestation level found during this survey were probably directly proportional to the amount of debris present in the departments. Because of these and other peculiarities, the feed-mill staff have to be continually alert to prevent, detect, and control pest problems within their work environment.  相似文献   

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Occurrence of barley yellow dwarf virus in pastures of western France   总被引:1,自引:2,他引:1  
As pasture grasses are preponderant in the agriculture of western France, their role as reservoirs of barley yellow dwarf virus (BYDV) and its aphid vectors has been studied from 1984 to 1986. Aphids were observed on most crops of five pasture grass species (brome grass, cocksfoot, tall fescue, Italian and perennial ryegrass) but in very low numbers. Rhopalosiphum padi was the most numerous species. The incidence of BYDV was high, with levels of infection ranging from 6 to 80% depending on the species of pasture grasses. Fescue pastures were highly infected with BYDV, whereas the virus was not detected in cocksfoot pastures. PAV-, RPV-, MAV-like isolates of BYDV were detected in pasture grasses, but RPV- and MAV-like isolates were only detected from ryegrass and brome grass, respectively. The role of these grasses as source of viruliferous aphids infecting cereals is discussed.  相似文献   

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芋艿田常见杂草有近30种,其中以禾本科、蓼科、苋科和玄参科杂草为主,在不同时间段杂草优势种类和数量有所不同,并且不同生境的芋艿田杂草种类也有所不同。  相似文献   

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Seasonal xylem water potentials (Ψ, MPa) and their relationship to soil water content and evaporative demand components were studied in the shrub species Acacia amentacea, Celtis ehrenbergiana, Forestiera angustifolia, and Parkinsonia texana var. macra. Predawn (Ψpd) and midday (Ψmd) water potentials were estimated at 15 days intervals, between January 15 and October 30, 2009 using a Scholander pressure bomb at 06:00 h (predawn) and 14:00 h (midday), respectively. During the humid period, Ψpd ranged from ?0.30 MPa (C. ehrenbergiana), to ?0.90 MPa (P. texana). In contrast, over the driest period, Ψpd varied between ?2.18 (P. texana) and ?3.94 MPa (F. angustifolia). At midday, P. texana and F. angustifolia showed the highest (?1.14 MPa) and lowest (?3.38 MPa) Ψ values, respectively. Average soil water content accounted for 35 to 70% of the variation in predawn Ψ. Furthermore, both Ψ reflected the environmental conditions, as indicated by typical correlations observed. The studied shrub species exhibited what seem to be different strategies to avoid damage caused by drought. Thus, P. texana behaved rather as an isohydric plant able to deal well with severe, but short periods of drought. Under exceptionally dry environmental conditions, Ψpd undercut Ψmd values. Similar observations have been made by researchers studying plants in dry ecosystems. All studied native species are recommended for reforestation of the Tamaulipan shrublands, although C. ehrenbergiana and F. angustifolia seem to have limited tolerances for extreme water stress.  相似文献   

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中国四省(区)葡萄根围螺旋线虫种类记述   总被引:5,自引:1,他引:5  
描述了采自陕西、山东、广西、宁夏 4省 (区)葡萄根际的 6种螺旋属线虫 :双宫螺旋线虫(Helicotylenchus dihystera)、外异螺旋线虫 (H exallus)、双角螺旋线虫 (H .digonicus)、H .digitiformisH .platyurusH .multicinctus。其中后 4种螺旋线虫均为我国葡萄上的首次报道  相似文献   

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从中国广西、陕西、山东、宁夏4省(区)36个葡萄品种的230份葡萄根际土样中鉴定出4种剑线虫和1种针线虫,分别为Xiphinema americanum,X.insigne,X.hunaniese,X.elongatumParatylenchus audriellus. ,其中X.elongatum为葡萄上的新记录种;P.audriellus在中国属首次记录,葡萄为其新寄主植物。  相似文献   

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For mechanical weeding, the uprooting force of whole seedlings and the shearing force of basal stems were measured in two grass weeds ( Setaria faberi and Echinochloa crus-galli var. crus-galli ) and two broad-leaved weeds ( Chenopodium album and Amaranthus patulus ), using balance-type equipment and a pair of scissors, respectively. Seedlings were grown in plastic pots. Uprooting and shearing experiments were carried out on the 11th, 16th, 21st, and 26th days after sowing. The uprooting force, the shearing force required to fracture the specimen, plant dry matter weight and cross-sectional area exponentially increased as seedlings grew, but the uprooting stress and shearing toughness maintained similar values after the 2nd sampling time, except for the 3rd and 4th sampling times in C. album . The increases in uprooting force and the shearing force required to fracture the specimen were supported by an expansion of the cross-sectional area of stems of the broad-leaved weeds or pseudostems of grass weeds. The higher values of uprooting stress and shearing toughness in C. album were related to an increased area of lignified organs in the basal stems. There was a significant correlation between uprooting and shearing forces. The shearing force was always higher than the uprooting force, so that most seedlings were uprooted and not fractured at the basal stems or pseudostems. The mean ratio of uprooting force to root dry matter weight after the 2nd sampling time suggested a high uprooting resistance at an extremely low amount of root dry matter weight.  相似文献   

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2014年-2018年, 对海南省蔬菜根结线虫病害进行了田间随机采样调查和病原种类分子鉴定?结果显示, 蔬菜根结线虫病在海南18市县均有发生, 且大部分旱田连作地块病株率达到80%以上?进一步对采集的295份根结线虫样本种类进行了分子鉴定, 共鉴定出象耳豆根结线虫?南方根结线虫和爪哇根结线虫3种病原种?其中, 象耳豆根结线虫单一检出率达到62.37%, 南方根结线虫单一检出率为23.39%, 爪哇根结线虫的检出率仅为5.76%, 象耳豆根结线虫和南方根结线虫复合侵染检出率为8.47%?除五指山市样本以外, 海南其余17市县样本均检测到象耳豆根结线虫侵染为害?本研究显示象耳豆根结线虫为海南省蔬菜上的优势病原根结线虫种类, 该结果对指导品种布局?制定根结线虫病害的防治策略具有重要意义?  相似文献   

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Fusarium poses food and feed safety problems because most species produce mycotoxins. To understand the epidemiology of the Fusarium disease, efforts must focus more precisely on how environmental variables affect disease presence. The objectives of the present study were to monitor the occurrence of Fusarium species in maize kernels in northwestern Spain to determine the risk of mycotoxin contamination and to identify environmental traits affecting the composition of the Fusarium species identified. A combination of 24 environments was evaluated. The percentage of kernels infected by F. verticillioides ranged from 33 to 99%, supporting the idea that fumonisin contamination is the main maize‐based feed and food safety concern in this area. In this region, temperature and humidity primarily affected Fusarium spp. occurrence. Warmer temperatures during the later stages of kernel development and during kernel drying increased the frequency of F. verticillioides in maize kernels, while the presence of F. subglutinans was increased by higher relative humidity during the silking stage and cooler temperatures during kernel drying.  相似文献   

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Invasive Phytophthora species are responsible for severe tree diseases in many forest ecosystems in Europe. In Hungary, the symptoms were first noted when P. alni infection led to a serious decline and mortality of alder stands in the late 1990s. Between 2001 and 2009, over 300 soilborne Phytophthora isolates were collected from declining broadleaf forests in Hungary, and 10 Phytophthora species identified based on morphological traits and the molecular characteristics of the internally transcribed spacer (ITS) regions of the nuclear ribosomal DNA. The most diverse species spectrum, found in diseased alder stands, included P. gonapodyides, P. gregata, P. inundata, P. lacustris, P. megasperma, P. plurivora, one informally designated taxon: P. taxon hungarica, and one unnamed species P. sp.1. P. cactorum and P. plurivora isolates were prevalent in the soil of a declining eastern black walnut forest, and three species, P. gonapodyides, P. multivora and P. plurivora were recovered from a declining oak stand. More than one ITS-based genotype was identified for four species, including six genotypes for P. gonapodyides, and two each for P. cactorum, P. plurivora and P. inundata. The high genetic diversity of the P. gonapodyides isolates may indicate that the species is indigenous to the region. In contrast, the frequently recovered, widely distributed P. lacustris with a single ITS genotype may represent a recent colonizer. The P. multivora isolates are, to date, the first reported from a European native forest.  相似文献   

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本文记述了深圳口岸2016年从进境美国松木中截获的4种长角天牛,对其形态特征及分布和寄主进行了详细描述并编制了相应的检索表,可为口岸木材检疫提供参考。  相似文献   

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YAO Linlin 《干旱区科学》2022,14(5):521-536
Hydrothermal condition is mismatched in arid and semi-arid regions, particularly in Central Asia (including Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, and Turkmenistan), resulting many environmental limitations. In this study, we projected hydrothermal condition in Central Asia based on bias-corrected multi-model ensembles (MMEs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under four Shared Socioeconomic Pathway and Representative Concentration Pathway (SSP-RCP) scenarios (SSP126 (SSP1-RCP2.6), SSP245 (SSP2-RCP4.5), SSP460 (SSP4-RCP6.0), and SSP585 (SSP5-RCP8.5)) during 2015-2100. The bias correction and spatial disaggregation, water-thermal product index, and sensitivity analysis were used in this study. The results showed that the hydrothermal condition is mismatched in the central and southern deserts, whereas the region of Pamir Mountains and Tianshan Mountains as well as the northern plains of Kazakhstan showed a matched hydrothermal condition. Compared with the historical period, the matched degree of hydrothermal condition improves during 2046-2075, but degenerates during 2015-2044 and 2076-2100. The change of hydrothermal condition is sensitive to precipitation in the northern regions and the maximum temperatures in the southern regions. The result suggests that the optimal scenario in Central Asia is SSP126 scenario, while SSP585 scenario brings further hydrothermal contradictions. This study provides scientific information for the development and sustainable utilization of hydrothermal resources in arid and semi-arid regions under climate change.  相似文献   

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甘肃省玉米籽粒中镰孢菌分离频率及伏马毒素含量监测   总被引:1,自引:1,他引:1  
为了解甘肃省玉米籽粒中病原镰孢菌的种类以及籽粒中伏马毒素的含量,通过形态学特征、分子生物学鉴定和高效液相色谱法对2011—2012年间采自甘肃省5个地区的225份玉米籽粒样品进行了镰孢菌的分离、鉴定和伏马毒素含量的测定。结果表明,分离获得的516株镰孢菌经鉴定分别属于拟轮生镰孢菌Fusarium verticillioides、层出镰孢菌F.proliferatum、禾谷镰孢复合种F.graminearum species complex、亚粘团镰孢菌F.subglutinans、藤仓镰孢菌F.fujikuroi、木贼镰孢菌F.equiseti、尖镰孢菌F.oxysporum和F.temperatum;其中拟轮生镰孢菌分离频率最高,属甘肃省的优势病原菌。2011和2012年,镰孢菌的分离频率分别为31.0%和10.7%,禾谷镰孢复合种和拟轮生镰孢菌为当年的优势种群。同时,2011和2012年样品中伏马毒素的污染率分别为30.5%和50.9%,平均含量分别为175μg/kg和224μg/kg,但未发现伏马毒素含量超过欧盟委员会限量标准(4 000μg/kg)的样品。  相似文献   

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 西洋参(Panax quinquefolium L.)原产北美洲,1978年引入我国并试种成功。西洋参作为一种名贵中药材,是我国中医药及医药保健品的重要成分之一,同时也是中草药栽培的主要品种之一。随着种植面积和种植区域的扩大,西洋参根部病害在生产上具有逐年加重的趋势,严重制约了西洋参产业的发展。在真菌和细菌病原物引致根病中,根际的植物寄生线虫往往是复合侵染的重要因子之一。  相似文献   

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