大螟的转移为害规律及其测报技术探讨

通过系统调查大螟的寄主范围，明确了大螟在不同寄主植物上的转移为害规律，并将大螟的发 生分为侨居代、繁殖积累代和主害代。在明确各发生代主要虫源的基础上，提出了虫情预测的技术要点。     

三代三化螟重发情况下化学防治技术的探讨

泗洪县地处洪泽湖西岸，常年种植水稻面积５．３万hm２，以单季晚稻种植为主，特别是优质品种武育粳３号种植比例大，占８５％以上。水稻三化螟自１９９６年以来已连续６a大发生。其主害代第三代为害单季中晚稻，造成白穗，未防治的稻田一般减产８成以上。近６a来，笔者就三化螟严重发生情况下化学防治技术进行了研究和探讨。１三化螟的生活习性进一步观察１．１发生时期在泗洪地区三化螟１a发生３代。第一代盛孵期在５月下旬至６月上旬，主要为害秧田期水稻；第二代在７月中、下旬，主要为害分蘖期水稻；第三代在８月中旬至９月上旬，往往…     

水稻螟虫发生为害现状及控制对策初探

20世纪90年代中后期，水稻螟虫发生为害出现了一些新特点、新变化。其总的趋势是：2、3代螟交替发生，混合为害，二者主害代别增加，主害代发生时期拉长，全年为害时期延长，为害面积扩大，为害损失加重。其主要原因；一是冬季油菜面积扩大，有效虫源田增加；二是气候变暖；三是杂交稻及优质稻面积增加；四是抛秧技术的推广；五是杀螟药剂单一，防效不理想。主要治理对策：捡拾稻桩，灌水灭蛹，压缩混截面积，科学用药，加快治螟药剂品种的研究推广步伐。     

三斑果螟生物学特性及防治

三斑果螟是天峨县大果山楂的主要害虫，一年发生４－５代，以老熟幼虫越冬，翌年３月下旬出现成虫，４－１０幼虫为害，１０月下旬后以第五代幼虫在其叶丝粘连在树枝上的被害果内越冬。     

台湾稻螟在汕头部分地区上升为稻螟优势种群

１发生为害基本情况台湾稻螟是广东省的３种水稻螟虫之一，长期以来都是局部轻发生。汕头市水稻螟虫一直以三化螟为主，但是近几年来台湾稻螟的发生为害逐渐加重，每年发生面积０．３万～０．７万ｈｍ２，大发生年份达１．３万ｈｍ２，尤以澄海市发生严重。主害代第二、四代白穗率一般为０．５％～２％，最高达１０％以上。澄海市２０００年８月下旬至９月上旬调查第三代稻螟密度，平均６６７ｍ２有３种稻螟１９３５头。其中台湾稻螟１４５１头，占７５％，三化螟１９３头，占１０％，大螟２９１头，占１５％。枯心率平均１．８％，最高１０…     

枣阳市水稻大螟发生特点及原因分析

枣阳市常年水稻种植面积4．83万hm^2。2011年由于特殊干旱气候的影响,水稻插秧期延长,大螟危害越来越严重,水稻大螟在枣阳市二代中等发生,三代大发生。造成水稻普遍存在白穗、枯孕穗、虫伤株,严重影响了枣阳市的水稻产量。因此,为确保水稻生产安全,摸清大螟的发生特点和原因,为来年大螟的综合防治提供科学的依据,降低大螟危害,十分必要。     

甘蔗二点螟的生物学与测报调查方法初探

二点螟是我省甘蔗上的主要害虫。根据笔者多年的调查观察,本文报导甘蔗二点螟的生物学及测报调查方法。1甘蔗二点螟的生物学在我省,甘蔗二点螟一年发生4～5代,以老熟幼虫和少数低龄幼虫在宿根蔗残、残留蔗茎及秋冬笋枯南内越冬。越冬幼虫在3月底至4月下旬化蛹、羽化为成虫。各代幼虫主害时期：第一代4月底～5月下旬;第2代6月下旬～7月中旬;第三代7月下旬～8月中旬;第四代8月下旬～9月上旬。成虫多在夜晚羽化,白天躲避,晚间活动,靠雌蛾分泌性外激素,引诱雄蛾交尾;第二天晚上开始产卵,持续4～5d,产卵200粒左右。卵多产在l～4叶的…     

波阳湖地区三化螟种群动态及今后五年内发生趋势初析

波阳湖区(以下简称湖区)包括25个县市,稻田面积1046万亩,三化螟在湖区一年发生四代,一、三代为害造成枯心苗,二、四代造成白穗。解放后至1986年大发生的年份有19561959、1963—1965、1969—1974年,其中尤以1964年和1974年为特大发生年。1975年螟害开始下降,1980年后,连续七年螟害十分轻微,其根本原因是早、晚二季水稻品种早熟化;春耕灌田和夏耕灭茬进度的加快,以及稻区耕作栽培制度改革从根本上恶化了此虫乃以生存繁殖的环境条件,使各代三化螟处于逆境状态。此外,药剂治螟技术的提高亦对控制螟害起了一定的作用。预计今后五年乃至十年内,上述抑制三化螟种群数量增长的基本因素将会有进     

衡阳地区大螟的发生情况

衡阳地区大螟危害水稻也是生产上的一个重要问题,尤其在大发生年份造成损失相当严重。 大螟的发生,各年密度因条件而不相同。从历年看,分布在稻田中单位虫口密度不大,但面积广,总虫量并不小,一般以中稻田多于一季晚稻,更大于连作晚稻。     

割除枯心、枯鞘苗防治获钻心虫

荻Miscanthus saccharilorus(Ma-xim.)是我国重要的造纸原料之一。湖北苇医蛀入荻心或茎秆中为害的主要害虫有荻蛀茎夜蛾Sesamia sp.、棘禾草螟Chilo hy-rax Bleszynski、大螟Sesamia inferens(Walker)、条螟Chilo sacchariphagusstramineellus Caradja等,尤以荻蛀茎夜蛾、棘禾草螟的第一代害荻最重。春季大量     

中国全新世暖期农业考古文化分区及人地关系特征

论文首先讨论中国全新世时期农业考古文化区划的研究进展,并提出了我国全新世暖期的农业考古文化总体可以分出四个文化区:1)北方粟黍旱作农业文化区;2)旱作北界以北以西的渔猎采集或游牧文化区;3)南方稻作文化区;4)东南沿海的渔猎文化区。最后从人地关系的角度讨论了全新世暖期的农业考古文化与环境的关系。     

Absorption and metabolism of permethrin and cypermethrin in the cockroach and the cotton-leafworm larvae

Permethrin was metabolised by attack at the ester bond, in vivo by adult cockroaches, Periplaneta americana and in vitro by esterase preparations. Metabolites retaining the ester linkage could not be detected. In all cases, the (1RS)-trans-isomer (transpermethrin) was more labile than the (1RS)-cis-isomer. Cypermethrin was metabolised at one-fifth the rate for permethrin. In-vitro and in-vivo studies with synergists indicated that cleavage of the ester bond in permethrin can be both oxidative for the (1RS)-cis-isomer and hydrolytic for the (1RS)-trans-isomer. The penetration of permethrin through the cuticle of the cockroach was significantly greater than that of cypermethrin. The penetration and metabolism of permethrin and cypermethrin in sixth-instar larvae of susceptible and resistant strains of the Egyptian cotton-leafworm, Spodoptera littoralis, were studied as possible factors in resistance. No significant differences were found. It is suggested that the major resistance factor to permethrin in S. littoralis is probably non-metabolic.     

陕西秦岭南北旱涝灾害时空变化趋势分析

根据1961-2009年秦岭南北57个站点的月降水资料,采用区域旱涝指标和Z指数,运用Mann-Kendall检验、小波分析、Kriging插值等方法,对秦岭南北旱涝时空变化趋势进行分析。结果表明：①关中地区年平均气温倾向率大于陕南,气温突变年均为1996年。②近49年来,关中地区暖干化及春旱、夏涝的趋势较陕南显著。气...     

工程行为对古尔班通古特沙漠植被的破损及恢复

随着准噶尔盆地石油开发力度不断加大和工程建设相继上马 ,古尔班通古特沙漠环境脆弱的生态平衡受人为活动影响日益严重。突出表现在工程行为造成沙漠植被的破损 ,如碾压、铲除、压埋、油污 ,以及对植物生长环境地表的扰动等。通过观察试验发现 ,当工程行为方式及强度对生态环境的干扰未使生态稳定性瓦解时 ,则沙漠植被具有自然恢复能力 ,但恢复过程需要较长的时间才能完成。若要加速和强化恢复过程 ,就要在工程中采取及时固沙、适时补播灌草植物的有效人工辅助措施     

On the specificity of the in vitro and in vivo antifungal activity of benomyl

With respect to sensitivity to benomyl in vitro four categories of fungi were distinguished; taxonomically related fungi usually proved to belong to the same category. Within the form-class Deuteromycetes a correlation appeared to exist between sensitivity to this fungicide and morphogenesis of conidia.Phoma betae, in contrast to all otherPhoma spp., was shown to be highly resistant to benomyl. This, however, may be expected on account of its perfect state. The data on the in vitro antifungal activity of benomyl conformed to those on the effectiveness of benomyl against plant diseases.     

宁夏近40多年积温及不同积温期降水量变化研究

选取宁夏22个地面气象站1961~2005年逐日平均气温、逐日降水量资料,统计计算日平均气温稳定通过0℃和10℃期间的积温,结果表明:随着气候的变暖,宁夏各地≥0℃和≥10℃积温呈明显增加趋势,近19 a增加显著;≥10℃积温不同等值线明显向地势较高地区移动,喜温作物面积扩大;积温持续日数明显增加,有利于作物的成熟;≥0℃和≥10℃积温期间降水量主要在部分干旱地带增加,这有利于干旱地带农牧业生产和植被恢复。     

天山北坡城市群地表温度时空差异及贡献度分析

城市化的加快推进使得土地利用变化加剧,进而导致城市热环境问题日益突出.基于2005年和2018年夏季的MYD21A2地表温度数据,运用空间统计学方法分析了LST的时空分布格局,并结合土地利用数据,通过贡献度指数,对天山北坡城市群地表覆盖类型和行政区划的源汇角色特征进行了分析.结果表明:(1)2005—2018年建设用地...     

孔雀河中下游土壤特性及开发利用区划--以尉犁县生态园区为例

2000年对尉犁县生态园区进行了测图、土壤和生物资源调查,同时对土壤理化性质进行分析。结果表明：该区土壤主要类型有：盐土、盐化和碱化林灌草甸土、风沙土、草甸土等;土壤特性为：盐分含量大,特别是碱性强;土地资源评价：农耕地为一、二、三等宜农地,其余为二等宜农、宜林、宜牧地,限制因素为土壤盐、碱含量和质地;土地资源条件为：地下水位高、风沙大、部分土地受洪水淹没、农业灌溉缺水、生态环境恶化等;该区基本代表了塔里木河～孔雀河中下游地区的土壤气候特性。土地开发利用原则以生态环境保护为主,低产农田改良为辅,方案为：将受盐、碱限制的部分二等地和全部三等土地,进行退耕还林(草),共划分出6个区：生态胡杨林保护区、高效农业利用区、退耕还林防洪区、退耕还草改土区、旅游开发区、湿地保护区。     

The metabolism of the carbamate insecticide bendiocarb in the rat and in man

The metabolism of the carbamate insecticide bendiocarb (2,2-dimethylbenzo-1, 3-dioxol-4-yl methylcarbamate) has been investigated in male and female rats and in a male human volunteer using radiolabelled material. The compound was rapidly and extensively absorbed and completely metabolised following oral administration. In man, absorption was complete, >99% of the dose being excreted in the urine within 22 h. In the rat, > 86% of the radiolabel was excreted in the urine within the first 24 h. Faecal excretion from the rat was minor (3–8% of dose) and a small amount of the compound (1–3%) was metabolised and excreted as [¹⁴C]carbon dioxide. The major metabolic pathway in both species involved cleavage of the carbamate ester group to yield the phenol,2,2-dimethylbenzo-1, 3-dioxol-4-ol (I). This metabolite, occurring as sulphate and glucuronide conjugates, accounted for more than 95% of the dose excreted by the human volunteer. In man, small amounts of conjugates of 2, 2-dimethylbenzo-1, 3-dioxol-4-yl N-(hydroxymethyl)carbamate (II) were also found in early samples. In the rat, the metabolism was more complex with the formation of small amounts of conjugates of II and several minor metabolites, thought to be ring-hydroxylated derivatives of bendiocarb and I.     

Changes in the content of steroidal glycoalkaloids in potato tubers grown in the field and in the greenhouse under different conditions of light, temperature and daylength

Differences in the content of steroid glycoalkaloids (SGA) were noted in the peels of potato tubers cultivars Alpha, Cara, Désirée and LT-7. Cultivar LT-7 had always the highest SGA content, Désirée was intermediate and Alpha and Cara had the lowest SGA content, regardless of growing conditions, tuber ageing and tuber treatments. Tubers grown during the summer developed the highest SGA content as compared to those grown in the spring and winter seasons, respectively. Tubers grown during winter showed an increase in SGA toward the end of the storage period. Similar results were obtained with tubers of LT-7 grown in a greenhouse under cool temperatures in combination with short days (which imitate the winter conditions in Israel). A decrease in SGA content was observed in tuber slices treated with a fungal cell-wall preparation fromPhytophthora citrophthora. This decrease was much stronger in the pith than in the peel, indicating a possible role for SGA in the defence mechanism because peels are the first part of the tuber to be invaded by pathogens. The above results were observed in tubers of all cultivars regardless of the growing season or tuber ageing.