稻赤斑黑沫蝉发生世代的观察研究

通过2a时间的系统观察,初步发现稻赤斑黑沫蝉每年有2个羽化高峰,分别在6月下旬至7月上旬和8月下旬至9月上旬,并观察到稻田改为旱作的蕹菜田在8月下旬至9月上旬也出现羽化高峰。据此推断稻赤斑黑沫蝉每年可发生2个世代,与目前国内学术界普遍认为稻赤斑黑沫蝉1a发生1个世代的结论不同。并提出铲除杂草是控制该虫发生为害的关键技术措施。     

柑橘白蛾蜡蝉的发生与防治技术

白蛾蜡蝉是北碚区新近发生的柑橘害虫．2008年7月下旬在北温泉街道梅花村长坝嘴社首次发现该虫的若虫为害柑橘,随后又在歇马、澄江等镇果园发现白蛾蜡蝉若虫,目前该虫在北碚区的发生面积和为害程度呈逐年上升趋势。     

吉林省水稻二化螟发生动态研究

2018-2020年,对吉林省不同水稻种植区水稻二化螟发生世代及发生动态进行了系统调查。结果显示,在中西部稻区白城市(洮北区)、扶余市和公主岭市二化螟一年可发生2代,性诱监测越冬代和第1代成虫发生高峰期分别在6月上、中旬和8月上、中旬。在中东部稻区的榆树市和吉林市(昌邑区),二化螟一年发生1~2代,榆树市在6月上、中旬和8月上、中旬,吉林市在6月中、下旬和8月中旬各有1个诱蛾高峰。在东南部稻区的柳河县和和龙市,二化螟1年发生1代,柳河县诱蛾高峰期在6月下旬到7月上旬,和龙市未发现明显诱蛾高峰。通过为害情况调查发现,水稻收获前2代区二化螟为害情况普遍重于1代区,应加强对2代区第2代二化螟的监测与防治。     

罗田县稻田赤斑沫蝉发生为害特点及防治

赤斑沫蝉,又称稻赤斑沫蝉[Callitetix versicolor(Fabricius)],属同翅目,沫蝉科. 1 发生概况 在20世纪70年代末80年代初,赤斑沫蝉仅在罗田县九资河镇等北面山区稻田有零星发生,为害较轻.进入21世纪后,发生面积逐年扩大,发生地域由北向南逐渐扩展,为害逐年加重.     

鄂南茶树新害虫——碧蛾蜡蝉与柿广翅蜡蝉

2006年6月上旬，笔者一行几人到咸宁温泉几个茶场调查茶树病虫害，调查中发现：碧蛾蜡蝉与柿广翅蜡蝉严重为害茶树。碧蛾蜡蝉主要为害茶树，还可为害柑桔、梨等多种果树，但在鄂南茶树上属第1次发现；柿广翅蜡蝉主要为害果树，特别是柑桔，该害虫以前未见过为害荼树的报道。碧蛾蜡蝉与柿广翅蜡蝉均以成虫及若虫以吸汁方式为害茶树上部的枝条及嫩梢，初孵若虫lOh后出现白色蜡丝，2龄前群集叶背危害，3龄后稍分散到嫩枝及叶片上危害，还可跳跃到周围其他寄主上，同时也危害茶果。     

苦参野螟的形态特征和生物学特性

通过室内饲养和田间定点观察的方法,对苦参野螟(Uresiphita prunipennis)的形态及生物学特性进行了调查研究。结果表明,苦参野螟在吉林市1年发生3代,以茧蛹在枯枝落叶下或表土中越冬。每年5月中旬越冬代成虫开始羽化,幼虫分别于6月上、中旬,7月中、下旬,8月下旬至9月上旬严重为害苦参,老熟后分散于地被物下或表土层中结茧化蛹。针对苦参野螟提出了防治建议。     

广翅蜡蝉优势种对园林植物的为害调查与防控策略探讨

调查发现为害铜仁地区园林植物的广翅蜡蝉科害虫主要有圆纹广翅蜡蝉、八点广翅蜡蝉、柿广翅蜡蝉、白斑广翅蜡蝉等种类,系统观察了圆纹广翅蜡蝉和八点广翅蜡蝉2个优势种的形态特征、为害特点、生活史和生活习性,并提出了综合防控对策。     

茶小绿叶蝉田间防治效果试验

山东省日照市是我国秦岭淮河以北最大的茶叶主产区,现有茶园面积10 666hm2。茶小绿叶蝉是日照茶区茶树主要害虫,该虫在日照茶区一年约发生9代,以成虫在茶树、杂草上越冬,翌年5月上旬开始为害茶树,5月中下旬第一代若虫出现,以后每20d左右发生一代,常年有1～2个虫口高峰期,特别以9月中下旬的高峰期最为严重,10月下旬成虫进入越冬期。日照茶区长期施用吡虫啉10%可湿性粉剂、噻嗪酮     

湖南水稻白翅叶蝉的研究

白翅叶蝉Erythroneura subrufa(Motschulsky)成虫与若虫均以刺吸口器刺进水稻叶片组织内吸取叶汁和叶绿素,被害初期,叶片上出现零星小白点,随后出现长短不一的点状白色斑条,受害严重的稻叶上满布白色斑纹,叶绿素丧失,叶片干萎。在稻叶蝉中除一点小叶蝉被害状出现小白点外,其他叶蝉为害水稻时,并不直接破坏叶绿素,亦不呈现白色斑纹,而是直接吸食叶液,使禾苗发黄而死。因而纠正了过去认为黑尾叶蝉、白翅叶蝉为害水稻后,都会造成叶片出现白色或褐色斑纹的报道。白翅叶蝉在湖南一年发生三代,在晚稻收割后以成虫迁向麦田、杂草等场所越冬,因其寿命很长,故长期不同世代交错。白翅叶蝉除为害水稻外,在初冬与早春还为害冬小麦。近年在湖南及我国南方部分稻区有回升趋势。     

小贯小绿叶蝉区域性发生规律和综合防治

小贯小绿叶蝉[Empoasca (Matsumurasca) onukii Matsuda]是茶园中的主要害虫,通过刺吸方式为害茶树嫩芽、叶和嫩茎,严重影响茶叶品质,并造成一定经济损失。本文综述了小贯小绿叶蝉的生活习性和为害特点,以及在我国四大茶区的发生代次、为害盛期等发生规律。总结了近年来农业、物理、生物、化学等相关领域的最新防治手段和方法,并对小贯小绿叶蝉综合治理方向进行了展望。     

Macropsis mendax as a vector of elm yellows phytoplasma of Ulmus species

A 3-year study was carried out in north-east Italy, the site of recent elm yellows epidemics, to identify vectors for the elm yellows phytoplasma. Using PCR analysis, Ulmus minor and Ulmus pumila , each with and without symptoms, were positive for the elm yellows phytoplasma. Macropsis mendax , a univoltine and monophagous leafhopper, was shown to be the vector of the elm yellows-associated disease agent. PCR analyses demonstrated that the insect was infected both in natural conditions and in the screenhouse after acquisition-feeding on infected elm plants. Groups of M. mendax , collected from naturally infected elm trees, transmitted elm yellows phytoplasma to elm test plants. In nature, Alnus glutinosa trees affected by alder yellows were found in the surroundings of yellows-affected elm trees; the associated disease agent of alder yellows was transmitted under controlled conditions from alder to elm test plants by grafting.     

科尔沁沙地榆树疏林草原及其封育更新研究

榆树疏林草原是科尔沁沙地古老的、持续期最长的原生植被 ,具有极强的适应性、稳定性 ,抗干扰能力和恢复能力 ,而且生物产量高 ,它是科尔沁沙地植被演替的顶级群落。榆树疏林草原广布于科尔沁沙地 ,经过长期的破坏 ,已经残缺不全 ,到 1 998年总面积 41 39平方公里。在科尔沁沙地榆树疏林草原是生产力最高的一种草原群落 ,年地上生物产量可达45 0 0 kg/hm2以上 ,而其他类型的草原群落均在 40 0 0 kg/hm2以下。榆树疏林草原具有较高的自然更新能力 ,封育保护以后每公顷可以产生幼苗 6万多株 ,但由于环境的限制幼苗的保存率很低 ,由于水分胁迫 ,加速了树木的死亡 ,这一趋势说明榆树疏林草原的疏林性质是由资源的丰富度来决定的     

北亚脉扁蜂形态特征和生物学特性

为明确李树上新纪录害虫北亚脉扁蜂Neurotoma sibirica的生物学特性，通过田间调查和室内饲养观察，记述该虫的形态特征、生活史及生物学特性。结果表明，北亚脉扁蜂在吉林省吉林市1年发生1代，以老熟幼虫在树下5~15 cm深的土层中做土室越冬。每年4月中旬幼虫开始化蛹，5月上旬成虫羽化出土，5月中旬为成虫盛期，成虫产卵从5月上旬持续到5月下旬，单雌产卵量为13~43粒，卵期5~9 d。6月上旬为北亚脉扁蜂幼虫为害盛期，幼虫为6龄或7龄，幼虫期14~21 d，6月中、下旬老熟幼虫陆续入土越冬。北亚脉扁蜂幼虫在李、紫叶李、杏、榆叶梅4种寄主上均可完成发育，在自然条件下李树受害率可达100%，紫叶李树受害率为40%，杏树受害率为20%。北亚脉扁蜂天敌有龟纹瓢虫Propylea japonica、异色瓢虫Harmonia axyridis、斯马蜂Polistes snelleni、日本弓背蚁Camponotus japonicus、2种姬蜂及1种病原菌。     

Dutch elm disease revisited: past,present and future management in Great Britain

The arrival of a new species of the fungus which causes Dutch elm disease into Great Britain in the 1960s caused widespread elm death and continues to be problematic following elm regeneration. Attempts at managing the disease have been largely unsuccessful. Forty years after the outbreak, however, researchers continue to be interested in both the underlying biology of such a severe and dramatic disease event and in the policy lessons that can be drawn from it. We develop a spatial model at a 1 km² resolution. Following parameterization to replay the historical epidemic, the model is used to explore previously proposed counterfactual management strategies. A new introduction date of late 1962 is estimated. We show that, even had there been high intervention at a national level in terms of disease management early in the epidemic, there would have been little long‐term effect on elm numbers. In Brighton, a local pocket of elm which survived the peak of the initial epidemic has been successfully managed. However, Brighton and similar locations are subject to repeated waves of the disease at a 15‐ to 20‐year intervals following regeneration and reinfection of the surrounding areas, during which much more intensive management is required.     

Sanitation campaign against Ceratocystis ulmi in The Netherlands1

The introduction and rapid spread of the aggressive strain of Ceratocystis ulmi in The Netherlands led to development of a 100% subsidised nationwide felling campaign. Since 1978, all elms have been assessed twice a year for health and viability, and diseased trees have been destroyed within a month. This limited losses to 1% of the important elm clones planted along roads, but at high annual cost (6 million F1) because of the need also to destroy diseased field elms. In future, long-term costs will be reduced by destruction of the less important field elms in the west of the country. In the east, the campaign has been abandoned (with some exceptions round cities).     

Carbendazim formulations for the eradication of Dutch elm disease

Formulations containing carbendazim (40 or 80 mM) in hydrochloric acid (180 or 320 mM) were pressure-injected into elms previously inoculated with the fungus Ceratocystis ulmi (the cause of Dutch elm disease) and their performance as eradicants assessed. All formulations caused some damage to foliage but leaves regenerated. Treatment with carbendazim (80 mM) in hydrochloric acid (180 mM) resulted in four out of five trees remaining free from disease, not only immediately after treatment, but also throughout the following season. Injection of acid alone resulted in rapid death of the trees.     

Evaluating Verticillium dahliae for biological control of Ophiostoma novo-ulmi in Ulmus minor

The ability of isolate Vd-48 of Verticillium dahliae to induce resistance against subsequent challenge with Ophiostoma novo-ulmi was examined in Ulmus minor . In the first experiment, conditioning inoculation of 5-year-old elm trees (2–3 m in height) with Vd-48 15 days prior to challenge inoculation with O. novo-ulmi significantly reduced wilting ( P  ≤ 0·05) compared with trees not conditioned with Vd-48. However, in another experiment on 6-year-old trees (2–3·5 m in height), no protection was achieved when the length of time between conditioning and challenge inoculations was 45 or 60 days. In a further experiment, inoculations with Vd-48 alone resulted in severe wilting in 22 out of 118 trees (6–10 years old and 4–7 m in height). Across the 2 years of this last trial, nine trees showed massive feeding wounds made by Scolytus sp., while O. novo-ulmi strains were isolated from six trees. Vd-48 provided a variable prophylactic effect against O. novo-ulmi in U. minor . Major difficulties with this approach to control Dutch elm disease are discussed.     

Plant diseases in the mediterranean region

The Mediterranean region is a well-defined ecological unit with hot and dry summers and relatively cold and rainy winters. Its climate is very changeable and the seasonal irregularity renders agriculture particularly hazardous. Some characteristics of plant diseases or the behavior of pathogens in the Mediterranean region are discussed briefly, with particular reference to some important crops such as olive, grapevine, citrus, date palm and cereals, as well as certain woody trees like chestnut, elm and cypress. 1 Lecture presented at the First Israeli-Italian Phytopathological Symposium, Bet Dagan, Israel, February 13–15, 1989.     

A trial to determine the persistence of carbendazim pressure-injected into elms

The persistence of carbendazim in elm twigs, after pressure-injection of the commercial formulation ‘Lignasan’ into the trunks, was monitored by bioassay. Initial distribution was poor (38% of twigs contained no detectable fungitoxicant) and after 53 days carbendazim was detected in only 19% of the twigs. In groups of control and injected trees inoculated with Ceratocystis ulmi (the cause of Dutch elm disease) on one of five dates between July and September, disease development was limited and a significant (P=0.05) reduction in symptoms in injected trees was detected only in those inoculated on the first date (2 July 1976). Both the very erratic distribution of fungitoxicant and the restricted disease development, which precluded demonstration of a correlation between fungitoxicant level at inoculation and subsequent symptom expression, were attributed to the effects of the abnormally hot, dry summer in 1976.