水葫芦象甲对水葫芦的生物防治效应

通过在室内塑箱释放专食性天敌昆虫——水葫芦象甲以控制水葫芦的研究。初步探明了水葫芦象甲不同释放密度对水葫芦植株生长的影响、控制效果以及适宜的水葫芦象甲释放密度,为水葫芦生物防除的推广应用提供了一定的理论基础。     

利用水葫芦象甲和农达综合控制水葫芦

试验表明同时应用水葫芦象甲和农达控制水葫芦,可达到快速、持续的控制效果,但农达使用剂量应选择适当。药量４.５ｋｇ／ｈｍ^２的综防处理区中,由于农达的作用水葫芦植株在２０～５０ｄ内大部分死亡,水葫芦象甲亦很快死亡,象甲很难发挥有效的作用;药量为０.４５ｋｇ／ｈｍ^２的综防区中,水葫芦象甲和农达同时作用,对水葫芦的叶片数、繁殖量和生物量起到了明显的抑制作用,与单独施用同样药量的化防区和只释放象甲的生防区有显著差异,而且象甲保持了一定的种群密度;而药量为０.０４５ｋｇ／ｈｍ^２的综防区与只放象甲的生防区控制水葫芦的效果一样。     

水葫芦象甲的生物学及其寄主专一性

在室温 2 5～ 2 8℃的养虫室内 ,水葫芦象甲雌成虫寿命最长可达 1 6 1d ,最大卵量为 1 0 91粒。产卵期为 2 0～ 1 59d。卵主要产在叶柄内。幼虫孵化后在叶片内和叶柄中取食 ,并向植株基部钻蛀。幼虫期 30～ 4 0d。老熟幼虫在活的水葫芦植株根部化蛹 ,蛹期 2 5～ 30d。在温州自然条件下 ,象甲年发生 2代 ,并有明显的世代重叠现象。以成虫和幼虫越冬。利用 2 3科 4 6种植物进行的寄主专一性测定发现 ,该象甲只为害水葫芦 ,可安全用于水葫芦的生物防治     

农达对水葫芦象甲的影响

用４１％农达加水分别稀释３０、１００、３００、１０００和３０００倍,在室内测试了对水葫芦象甲的影响。结果表明,象甲卵和初孵幼虫直接接触药液对孵化率和化蛹率没有明显的影响。将药液直接喷施于成虫体表后再饲喂新鲜健康的叶片对象甲存活没有明显的影响。用不同浓度药液处理的叶片饲喂象甲成虫１月后,存活率分别为１０．０％、４５．０％、４２．５％、６６．７％和７７．５％,对照为７２．５％。室外种群动态试验发现,用１００倍以下药液处理有象甲成虫和幼虫的水葫芦小区３个月后,水葫芦和象甲全部死亡;而用３００倍以上农达处理的小区内象甲仍保持一定的种群数量。本项研究表明低浓度农达对象甲比较安全,可与象甲配合控制水葫芦。     

用不同日龄水葫芦叶片饲养对水葫芦象甲的影响

水葫芦(Eichnornia crassipes(Mart)Solms-Laub)是目前世界上危害最严重的多年生水生杂草(私人通信).近年来大面积覆盖我国南方的很多水体,带来严重的生态、经济和社会危害[1].为控制水葫芦的蔓延为害,中国农科院1995从美国和阿根廷引进了两种天敌昆虫(Neochetina eichhorniae和N.brachi),有效地抑制了已释省区水葫芦的生长[2].国外曾就水葫芦叶龄对N.eichhorniae卵和幼虫在植株体内分布的影响进行过研究[3],本文就用不同日龄水葫芦叶片饲养对象甲的影响进行了研究,为人工饲养象甲提供科学依据.     

41％BIOFORCE水剂防除河道水葫芦效果初报

41％BIOFORCE水剂防除河道中水葫芦的药效试验结果表明，在水葫芦生长旺盛期施药，用该药剂100倍液喷细雾，对水葫芦防效好，且对水生生物安全。     

防除水葫芦高效除草剂筛选试验

对18种除草剂防除水葫芦的药效比较结果表明，水花生净1500倍液可有效控制水葫芦的发生，药后30d株死亡率超过90％，下沉率超过50％。药后40d死亡率超过97％，下沉率超过77％，并可兼治水花生。农达与草克星的药效虽略低于水花生净，但也能有效控制水葫芦的发生。     

三种化学除草剂对水葫芦象甲的影响

室内外就草甘膦、克芜踪、农得时３种除草剂对水葫芦象甲卵、幼虫、蛹和成虫的影响进行了初步测试。象甲卵直接接触３种除草剂药液和清水对照后,孵化率分别为８３．３％、９３．３％、９２．２％和９５．６％;处理有卵植株叶片后,卵的孵化率分别为９０．０％、５３．４％、８５．６％和９３．６％。３种除草剂对初孵幼虫存活和蛹的羽化影响不大。但用克芜踪和农得时处理的叶片喂食象甲后,成虫产卵量分别为０．１７和０．２７粒／（对ｄ－１）,取食量分别为１０．８０和８．７０个取食斑／（对ｄ－１）,明显低于对照的产卵量１．１４粒和取食量１５．４０个／（对ｄ－１）,而草甘膦处理后象甲产卵量为１．１４粒／（对ｄ－１）,取食斑为１６．５０个／（对ｄ－１）,与对照差异不显著;克芜踪处理后７０天,象甲全部死亡,而草甘膦、农得时和对照的存活率分别为９２．５％、９５．０％和９７．５％。综合比较结果,３种除草剂对象甲的毒性影响依次为克芜踪＞农得时＞草甘膦     

水葫芦生防菌Cercospora piaropi的病理学特性

尾孢菌属的Cercospora piaropi是一种有潜力开发成为防除水葫芦的生物除草剂的真菌。水葫芦原生叶片从被C．piaropi感染到完全死亡，需要约6周时间。C．piaropi接种水葫芦的适宜孢子浓度为10^5CFU/ml，适宜保湿时间为24h。30℃时C．piaropi感染水葫芦的原生叶片病害严重度最高。除水葫芦和鸭舌草外，cpiaropi对其他被测农作物和杂草均不产生病理作用，表现出较强的专一性。     

习水县稻水象甲发生为害情况及防治技术

<正>稻水象甲Lissorhoptrus oryzophilus Kuschel属鞘翅目象甲科,原产北美洲,被国际自然保护联盟列为全球100种最具威胁性的外来入侵生物之一,为我国农业植物检疫有害生物,1988年在河北省唐山市唐海县首次发现,现已在全国23个省、区、市的324个县、市、区相继发生,发生面积63.34万hm~2次。2012年在习水县寨坝镇发现稻水象甲疫情,到2015年全县共有7个乡镇24个村发现该虫,发生面积     

Richtlinien der Verbände des ökologischen Landbaus zum Vorratsschutz

Zusammenfassung Verbände des ökologischen Landbaus wie z. B. Bioland, Gäa, Demeter; Naturland, Ernte für das Leben oder Bio Suisse beschränken ihre Mitglieder bei der Wahl von Vorratsschutzmaßnahmen. Vorrang besitzen Maßnahmen zur Vermeidung von Schädlingen gegenüber Bekämpfungsmaßnahmen. Fallen müssen zur Befallsüberwachung eingesetzt werden, um einen Befall durch Vorratsschädlinge frühzeitig zu erkennen. Diese Maßnahmen sollen den weitgehenden Verzicht auf chemisch-synthetische Mittel ermöglichen. In diesem Beitrag werden die Empfehlungen der Verbände mit den derzeit verfügbaren chemischen Mitteln für den Vorratsschutz abgeglichen. Erfahrung in der praktischen Umsetzung von physikalischen und biologischen Verfahren werden diskutiert und Defizite bei der Befallsüberwachung und Bekämpfung beschrieben.     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Development of protocols for detection of Colletotrichum acutatum and monitoring of strawberry anthracnose using real-time PCR

Real-time PCR (TaqMan®) assays were developed for the specific detection and discrimination of Colletotrichum spp., C. acutatum and C. gloeosporioides causing anthracnose in strawberry using the most divergent area of the internal transcribed spacers (ITS1 and ITS2) and 5·8S ribosomal RNA (rRNA) gene region. The specificity of the new assays was tested using DNA from six species of Colletotrichum and nine fungal species commonly found associated with strawberry material, and additionally by comparing the sequences with those from databases using a blast search. The sequences only showed identity with homologous sequences from the desired target organisms. The new assays were 10–100 times more sensitive than conventional PCR methods previously published for the diagnosis of strawberry anthracnose. When real-time PCR was compared with ELISA methods, PCR improved the sensitivity of the identification by obtaining positive results for samples of strawberry plant material that tested negative with ELISA. The development of C. acutatum was monitored using artificially infected strawberry crowns from two strawberry cultivars (Camarosa and Ventana) and a real-time PCR assay specific for this species between January and June 2006. The amount of C. acutatum detected using real-time PCR varied significantly by month ( P  < 0·001), but not by cultivar ( P  = 0·394). The new assays were shown to be useful tools for rapid detection and identification of these pathogens and to allow rapid and accurate assessment of the casual agents of anthracnose in strawberry.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.