伪钝绥螨的花粉饲养研究

在饲养伪钝绥螨的10种植物花粉中,核桃、洋槐、贴梗海棠、仙人球、迎春和卷心菜等可使其取食并完成发育,前4种还可使其产卵。花粉粒的外部形态结构,是影响该螨能否取食的重要因素之一。用桃、苹果花粉饲养伪钝绥螨,对其F_1代生活力有明显的不良影响。取食桃花粉的F_1代,幼螨间相互残杀,并取食未孵化的卵,使成活率降低。取食苹果花粉的F_1代可正常完成发育,但成螨性比降低,产卵时自食其卵。试验表明,单纯喂食桃或苹果花粉难以进行伪钝绥螨的累代饲养。     

拟长毛钝绥螨的生物学特性研究

拟长毛钝绥螨在18、22、26、30和34℃5种恒温下,卵和若螨的发育历期随温度的上升而加快,依次为12.58、8.79、5.72、3.66和3.54天。成螨的产卵前期,产卵期和寿命亦随温度的升高而缩短。成螨一生中有多次交配习性,产卵置随交配次数而增加,交尾3次的产卵68.24粒。在26℃下,该螨一生能捕食372.79粒叶螨卵,其中成螨期捕食量占总捕食量的98％,以产卵期捕食量最高。雌成螨发育和繁殖的最适温度为30℃,卵在90％高湿下孵化率达100％。温度为30、34℃时,卵完全致死的湿度范围为70％以下,而在18～26℃则为60％以下。致死低温对卵的临界作用期位于幼螨即将破壳而出的发育阶段。     

Effects of pesticides on mite predators (Acari: Phytoseiidae) and colonization of apple trees byTetranychus urticae

A 2-year survey of mite populations and pesticide use was carried out in Nova Scotia, Canada, in apple orchards where the two-spotted spider mite (Tetranychus urticae Koch) was the dominant phytophagous mite. Fungicides were the only class of pesticides that affected cumulative number ofT. urticae-days per leaf in tree canopies and colonization success — the ratio ofT. urticae-days to number of immigratingT. urticae caught in sticky bands on tree trunks. In 2000, increased numbers ofT. urticae-days in the tree canopy were associated with more frequent applications of ethylene bis-dithiocarbamate (EBDC) fungicides and with higher fungicide toxicity scores, which indicate cumulative level of suppression of the phytoseiid predatorTyphlodromus pyri Scheuten by all fungicide applications. Higher rates of colonization success were also associated with higher toxicity scores. EBDC’s applied in 2000 promotedT. urticae immigration as indicated by their counts on sticky bands. In 2000 and 2001, number ofT. pyri-days in the tree canopies was decreased by more frequent EBDC applications and by higher fungicide toxicity scores. Promotion ofT. urticae in tree canopies by EBDC’s was attributed to their toxicity toT. pyri. BothT. pyri and another phytoseiid,Amblyseius fallacis (Garman), were found in ground cover vegetation. Hence, increased immigration from the ground cover attributed to the toxicity of EBDC’s toT. pyri and, especially, toA. fallacis, which is a specialist predator of spider mites and an effective natural enemy ofT. urticae. http//www.phytoparasitica.org posting Sept. 13, 2006. Formerly, Atlantic Food and Horticulture Research Centre, now retired.     

江原钝绥螨对三种橘园害虫的捕食能力

江原钝绥螨Amblyseius eharai Amitai et Swirski广泛分布于我国各地的柑橘产区,是我国柑橘园的捕食螨优势种之一.由于滥用化学农药,大量叶螨天敌受到危害,叶螨的抗药性却逐年增强.利用天敌生物防治叶螨成为近年来柑橘害螨绿色防控的重要措施.本文主要研究了江原钝绥螨对柑橘全爪螨Panonychus...     

Molecular tools to investigate Rhizoctonia solani distribution in soil

Real-time PCR protocols were developed to detect and discriminate 11 anastomosis groups (AGs) of Rhizoctonia solani using ribosomal internal transcribed spacer (ITS) regions (AG-1-IA, AG-1-IC, AG-2-1, AG-2-2, AG-4HGI+II, AG-4HGIII, AG-8) or β-tubulin (AG-3, AG-4HGII, AG-5 and AG-9) sequences. All real-time assays were target group specific, except AG-2-2, which showed a weak cross-reaction with AG-2^tabac. In addition, methods were developed for the high throughput extraction of DNA from soil and compost samples. The DNA extraction method was used with the AG-2-1 assay and shown to be quantitative with a detection threshold of 10⁻⁷ g of R. solani per g of soil. A similar DNA extraction efficiency was observed for samples from three contrasting soil types. The developed methods were then used to investigate the spatial distribution of R. solani AG-2-1 in field soils. Soil from shallow depths of a field planted with Brassica oleracea tested positive for R. solani AG-2-1 more frequently than soil collected from greater depths. Quantification of R. solani inoculum in field samples proved challenging due to low levels of inoculum in naturally occurring soils. The potential uses of real-time PCR and DNA extraction protocols to investigate the epidemiology of R. solani are discussed.     

伪钝绥螨对二斑叶螨的捕食作用

室内条件下研究了伪钝绥螨对二斑叶螨的捕食作用。结果表明：伪钝绥螨雌成螨对二斑叶螨卵、幼螨、若螨和雌成螨的功能反应均符合HollingⅡ型方程,搜寻效率a′与处理时间Th值分别为0.5902、1.0025、0.9697、0.3146和0.0150、0.0240、0.0520、0.1681。伪钝绥螨的雌成螨喜食二斑叶螨的卵、幼螨和若螨,而对二斑叶螨雌成螨的捕食能力较弱。伪钝绥螨捕食率随着自身密度的增加而下降。捕食者密度低时,捕食率下降较快;随着捕食者密度进一步增加,捕食率下降缓慢,干扰反应方程拟合为E=0.3101P~（-0.412）。     

胡瓜钝绥螨捕食茶黄蓟马实验种群生命表研究

【 目 的】 明 确 胡 瓜 钝 绥 螨（Amblyseius cucumeris Oudemans） 以 茶 黄 蓟 马（Scirtothrips dorsalis Hood）为食物的生长发育和繁殖情况,获得其种群增长参数,为利用胡瓜钝绥螨防治茶黄蓟马提供参考依据。 【方法】采用传统的生物学观察方法,在室内观测以茶黄蓟马为食物的胡瓜钝绥螨的各虫态发育历期、存活率、 成虫寿命和产卵量,并组建实验种群生命表,分析种群生命表参数。【结果】胡瓜钝绥螨雌成螨对茶黄蓟马的 取食量最大,每天可达 122 头,其次为若螨,幼螨不取食;以茶黄蓟马为食物的胡瓜钝绥螨世代发育历期为 9.98 d,存活率为 94%;雌成螨平均寿命为 24 d,平均单雌产卵量为 28 粒,成虫的大量死亡出现在产卵高峰之后。 胡瓜钝绥螨的净增殖力为 26.95,内禀增长率为 0.15,世代平均周期为 22.32 d,周限增长率为 1.16,种群倍增 所需时间为 4.70 d。【结论】以茶黄蓟马为猎物,胡瓜钝绥螨可完成其世代生长发育和繁殖,可作为茶黄蓟马 的捕食性天敌进行其生物防治。     

混合花粉对胡瓜钝绥螨生长发育和繁殖的影响

胡瓜钝绥螨以苹果与石松混合花粉为食料,研究对其生长发育、存活和繁殖的影响.在取食花粉时,胡瓜钝绥螨前若螨期的存活时间明显长于对照,而且可以明显延长成螨的寿命,但雄成螨寿命与对照没有明显区别;只供给水时,胡瓜钝绥螨雌成螨不产卵,但取食混合花粉时胡瓜钝绥螨产卵量也很低.     

巴氏钝绥螨对椭圆食粉螨的捕食效能

在实验室RH85%、5个常温(16、20、24、28℃和32℃)条件下,研究了巴氏钝绥螨的雌成螨、雄成螨、若螨对椭圆食粉螨的捕食效能。结果表明:各个温度下的功能反应均属于HollingⅡ型。温度相同时,雌成螨的捕食能力最大,若螨其次,雄成螨的捕食能力最弱。温度对各螨态的捕食能力有一定的影响,在试验温度范围内,各螨态对椭圆食粉螨的捕食能力(a/Th值)随温度升高而增大,28℃时捕食能力最大。在椭圆食粉螨密度固定时,巴氏钝绥螨的平均捕食量随着其自身密度的提高而逐渐减少。     

胡瓜钝绥螨抗阿维菌素品系的筛选及抗性稳定性分析

为了使“以螨治螨”生防技术与病虫害综合治理中的其他防治方法合理结合,通过用玻片浸渍法对不同阿维菌素产品进行了毒力测定,确定了阿维菌素类农药对胡瓜钝绥螨具有中等毒性后,用在室内繁殖的多年未接触过任何农药的胡瓜钝绥螨敏感品系为材料,在实验室内用阿维菌素原粉进行胡瓜钝绥螨抗阿维菌素品系的汰选,并对筛选出的抗性品系进行抗性衰退...