黄淮海地区不同种植结构下点蜂缘蝽的发生规律

为明确大豆-玉米带状间作种植模式对点蜂缘蝽Riptortus pedestris发生规律的影响,2023年在山东省大豆单作田中进行诱捕效果试验,筛选诱捕效果最好的诱捕器对黄淮海地区山东、河南和安徽3个省6个市不同种植模式下点蜂缘蝽的发生动态进行监测。结果显示,风叶型诱捕器对点蜂缘蝽的诱捕效果最佳。在大豆单作田内点蜂缘蝽的发生高峰期为7月中旬—8月中旬,此时大豆正值盛花-始荚期。在大豆-玉米带状间作田内点蜂缘蝽的发生动态与大豆单作田的无明显差异,但点蜂缘蝽发生数量及高峰期发生时间可能与杀虫剂的施用时间和次数密切相关。     

Eremothecium ashbyi causes soybean yeast-spot and is associated with stink bug, Riptortus clavatus

Many fusiform ascospores observed on soybean seeds with yeast spot disease symptoms differed significantly from those of Eremothecium coryli, the known causal agent of yeast spot disease in soybean. On the basis of morphological and physiological characteristics and sequence data of the internal transcribed spacer regions including the 5.8S rDNA and D1/D2 regions of 26S rDNA, this fungus was identified as E. ashbyi. Pathogenicity of E. ashbyi was confirmed by reinoculation test. This report is the report on E. ashbyi causing soybean yeast spot disease. In addition, this study showed that E. ashbyi was transmitted by the stink bug, Riptortus clavatus, as was E. coryli, the two Eremothecium yeasts may have been acquired when the stink bug fed on infected soybeans and overwintered in this insect species. The nucleotide sequence data reported are available in the GeneBank/EMBL/DDBJ database as accessions AB294407 to AB294412 for E. ashbyi EA1, EA7 and EA11.     

大豆荚饲养点蜂缘蝽实验种群生殖力及其种群趋势分析

点蜂缘蝽(Riptortus pedestris)是大豆生产上的重要害虫.为明确结荚期大豆对点蜂缘蝽生殖力及种群发育的影响,为了解种群发生动态、预测预报及制定综合治理措施提供科学依据,在24±1℃恒温下,采用离体豆荚饲养法,系统观测点蜂缘蝽存活和生殖等生物学指标,通过种群生命表分析,进一步探讨其种群生殖力及种群趋势.结...     

大豆“荚而不实”型“症青”与蝽类害虫为害的相关性及防控策略

为探明大豆症青与蝽类害虫的相关性,解决目前黄淮海流域大豆生产上"荚而不实"型"症青"的问题,归纳总结最新研究进展,对"荚而不实"型"症青"与点蜂缘蝽(Riptortus pedestris)等蝽类害虫为害的相关性做了简要剖析,结合大豆蝽类害虫的发生及为害特点,提出了当前大豆"症青"的防控策略。重点针对点蜂缘蝽等蝽类害虫开展统防统治和兼防兼治,控制越冬和早春虫源,抓住花荚期科学防治。以期为开展大豆"症青"发生及防控研究提供参考。     

Mode of transmission and morphological structures of two <Emphasis Type="Italic">Eremothecium</Emphasis> species between <Emphasis Type="Italic">Riptortus pedestris</Emphasis> and soybean

Eremothecium ashbyi and E. coryli were present in the maxillary and mandibular stylet pouches of the contaminated heads of the true bug Riptortus pedestris collected during a field survey, 2007. Ascospores of E. ashbyi and E. coryli were taken up in the stylet pouch when R. pedestris fed on soybean seeds infected with the respective fungus. In the case of E. ashbyi, the ascospores had subsequently germinated and were recognized as large masses of mycelia in the stylet pouch. In contrast, masses of E. coryli including buds of irregular size and shape were recognized about 3 days after. These results proved that these yeasts are taken up and become lodged in the stylet pouch when the insect feeds on infected host plants. In stylet sheaths stained with erythrosine, E. ashbyi was found as fragments of mycelia and E. coryli was found as small buds. These observations yield evidence to confirm that E. ashbyi and E. coryli are transmitted as fragments of mycelia and as small buds, respectively, after the insect has fed on infected host plants.     

利用累积虫日法评估点蜂缘蝽种群密度与春播大豆产量的关系

笔者于2019年研究了河北省中部地区春播大豆田点蜂缘蝽发生动态,据此制作了点蜂缘蝽在大豆田内的累积虫日指数图,并分析大豆不同生育时期点蜂缘蝽累积虫日与大豆产量的线性关系。结果表明,河北省点蜂缘蝽第1代成虫于7月中下旬开始转移到春播大豆田为害,待第2代成虫羽化后便逐渐迁出大豆田。分析点蜂缘蝽累积虫日与大豆产量关系,发现大豆嫩果期点蜂缘蝽累积虫日指数与大豆产量显著相关(P=0.026 6,R2=0.746 0),点蜂缘蝽高峰期累积虫日与大豆产量相关性次之,其R2为0.726 9,而大豆全生育期累积虫日与大豆产量R2为0.663 4。三种利用累积虫日法研究点蜂缘蝽对大豆产量影响线性相关性均高于采用点蜂缘蝽高峰期虫量的分析结果(R2为0.597 7),其中大豆嫩果期点蜂缘蝽累积虫日指数最能准确反映出其对大豆产量的影响。本研究将为大豆田点蜂缘蝽防治指标的确定,及其合理化学防治提供理论依据。