蔽果金腰叶内寄生链格孢属真菌特性研究(英文)

[目的]了解虎耳草科植物蔽果金腰内生菌的生物学特性。[方法]利用 PDA 培养基分离蔽果金腰叶内的真菌,利用 PDA 培养基、察氏培养基、改良型 KB 培养基分别对分离得到的菌株进行培养。[结果]菌株在 PDA 培养基、KB 培养基和察氏培养基上均为菌落舒展,白色毡帽状,等径生长,边缘整齐,呈波状,菌落到后期变为青褐色;孢子黑色,在 PDA 培养基上生长在菌落表面,基质呈黑色;而在 KB 培养基和察氏培养基上生长在菌落边缘,基质呈黑色。孢子形态多样,多数为倒棒状,也有球形和椭圆形的,具有纵、横或斜的真隔膜,呈砖格状分隔,喙为短柱状假喙。[结论]分离得到的菌株属于半知菌亚门丝孢纲丝孢目暗色孢科链格胞属真菌的一种。     

Soil-living parasitic Hymenoptera: comparison between a forest and an open landscape habitat

Community structures and local diversity patterns of parasitic Hymenoptera with soil and leaf litter hosts were studied in a German beech forest and a meadow. Hymenoptera appeared to be one of the most species-rich taxa associated with the soil. Eighty-eight species were found in the meadow (total density of 128 ind. m⁻² yr⁻¹) and 188 species (149 ind. m⁻² yr⁻¹) in the forest. The mean parasitism rates were above 60% for parasitoids of mycetophagous Diptera and between 7% and 26% for parasitoids of saprophagous Diptera. Species overlap between both habitats was higher than expected from a random sample model. Species common to both habitats were primarily parasitoids of predatory Coleoptera. High mean densities of these species support the hypothesis of a positive correlation between local abundance and range size.     

Enhanced pest control in cabbage crops near forest in The Netherlands

Landscapes are composed of a multitude of habitat types which, potentially, can influence natural enemy populations. The contribution of specific habitat types to sustaining natural enemy populations in agricultural landscapes and the associated ecosystem service of pest control is not well understood. We investigated how landscape composition affected parasitism rates in 22 organic Brussels sprout fields in The Netherlands. Second and third instar larvae of Plutella xylostella were placed on experimental Brussels sprout plants in Brussels sprout fields and were recovered after two days in the field. Parasitism rates ranged between 4 and 94% and were related to landscape variables at a scale of 0.3, 1, 2 and 10 km. Univariate analysis using a generalized linear mixed model indicated that parasitism rates were positively related with area of forests at a scale of 1, 2 and 10 km, forest edges at a scale of 1 and 2 km and road verges at a scale of 1 km. Forest and road verges are likely to provide food and alternative hosts for parasitoids and are less disturbed habitats than agricultural fields. These results suggest that forests and road verges may play an important role in sustaining effective densities of parasitoids of P. xylostella in agricultural landscapes.     

Evaluation of the effect of eprinomectin in young dairy heifers sub-clinically infected with gastrointestinal nematodes on grazing behaviour and diet selection

Inappetence is commonly associated with parasitism and has been observed in both housed and pastured ruminants. In seeking a functional explanation for these observations, it has been hypothesised that parasitized animals may feed more selectively in order to proportionally increase the protein content of their diet and thus partially compensate for their reduced feed intake. Support for this theory is found principally in studies in housed animals under carefully controlled experimental conditions. Grazing animals face a far more heterogeneous environment and a multiplicity of potentially confounding factors that could influence diet selection. Controlled grazing of adjacent monocultures of grass and clover can mitigate some of these variables and was used in the current study to examine the dietary preference of dairy heifers with sub-clinical parasitic gastroenteritis when compared to those receiving regular anthelmintic treatments. Grazing behaviour and herbage intake rates were determined through the use of jaw-movement recorders, direct observation and short-term liveweight change. Consistent with previous observations and despite evidence that nematode burdens were low in the untreated control heifers, a reduction in daily grazing time of 56 min (P = 0.054) was observed in the control animals. There was, however, no evidence that the control heifers showed greater preference for clover compared with ryegrass: partial preference for clover was 73.0% in the untreated controls and 75.5% in the treated heifers. Furthermore control heifers were observed grazing the clover swards significantly (P = 0.032) less frequently than the treated heifers. This study provides additional evidence in grazing cattle for parasite-induced inappetence, manifest as a reduction in grazing time and in subtle changes in ingestive behaviour. The observed partial preference for clover in both treated and control cattle was not significantly affected by the level of parasitism.     

淡紫拟青霉PL04菌株抗逆性及其对香蕉根结线虫的寄生作用

抗逆性测定结果表明,淡紫拟青霉PL04菌株有较强的抗逆性和对化学农药的兼容性.PL04菌株在PSA培养基上菌落生长和产孢的适温为5～40℃ (最适温度为29℃). PL04菌株在pH4～13(最适pH为7)范围内的培养基上均可生长;PL04菌株在40℃和50℃条件下的LT50分别为78.8 min和40.8 min.PL04菌株有较强的耐盐碱能力;PL04菌株对氯霉素有较强的耐受性;PL04菌株对杀菌剂多菌灵、百菌清、苯醚甲环唑、除草剂百草枯以及消毒防腐剂福尔马林较敏感,其EC50分别为0.021、0.013、0.006、0.016和0.120 mg/mL,PL04菌株对杀线虫剂阿维菌素和辛硫磷,杀菌剂三唑酮不敏感,其EC50分别为0.175 、0.338和0.337 mg/mL.采用双温测定法,室内测定淡紫拟青霉PL04菌株对香蕉根结线虫的寄生作用,不同处理具有显著性差异,PL04菌株孢子悬浮液处理18 d后对香蕉根结线虫卵的相对寄生率为94.3%.     

Evaluation of corn plant as potential banker plant for supporting predatory gall midge, Feltiella acarisuga (Diptera: Cecidomyiidae) against Tetranychus urticae (Acari: Tetranychidae) in greenhouse vegetable production

The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important and highly polyphagous pests of vegetables and other crops worldwide. Experiments were conducted in the laboratory and greenhouse to evaluate corn (Zea mays L.) as a banker plant for the predatory gall midge, Feltiella acarisuga (Vallot) (Diptera: Cecidomyiidae) to potentially control T. urticae. Choice and no-choice experiments were carried out to determine the host plant preference of an alternative prey, Oligonychus pratensis (Banks)(Acari: Tetranychidae) to corn and green bean (Phaseolus vulgaris L.). Results showed that O. pratensis adults strongly preferred corn as a host plant and posed no risk to green bean. F. acarisuga was found to fly at least 7.0 m to search for new preys on green bean plants, and over 176 F. acarisuga larvae per leaf were recorded at 14 d after dispersal. F. acarisuga proved to be an excellent predator of both T. urticae and O. pratensis. The predation by F. acarisuga to T. urticae and O. pratensis ranged from 43.7 to 67.9% and 59.2 to 90.3%, respectively, under laboratory conditions. In a non-cage study, 81.2% of T. urticae population was suppressed by F. acarisuga in reference to the control (cage treatment). The results showed that this banker plant system has potential for controlling T. urticae in greenhouse vegetable production.     

印度实蝇姬小蜂寄生习性研究

【目的】探明印度实蝇姬小蜂Aceratoneuromyia indica(Silvestri)在广州地区阳桃园内的自然寄生情况及其寄生习性。【方法】以橘小实蝇和印度实蝇姬小蜂为研究对象,采集田间落果和采用室内饲养的方法研究了印度实蝇姬小蜂对橘小实蝇的自然寄生情况,并在室内研究了印度实蝇姬小蜂的寄生习性。【结果】田间调查表明,印度实蝇姬小蜂在广州阳桃园的田间寄生率可高达43.8%。印度实蝇姬小蜂对寄主具有选择性,能寄生于橘小实蝇的幼虫和蛹,但不能寄生黄粉虫卵、幼虫和蛹以及米蛾卵。从单只橘小实蝇蛹中羽化出的印度实蝇姬小蜂成虫数为16.4±4.2只;补充营养能显著增加印度实蝇姬小蜂成虫寿命;从繁殖印度实蝇姬小蜂后代的效果来看,不同营养物质对F1代的影响并不一致,室内饲养时,可用10%蔗糖和10%蜂蜜喂养印度实蝇姬小蜂成虫。【结论】印度实蝇姬小蜂是橘小实蝇幼虫和蛹期寄生蜂,可科学利用印度实蝇姬小蜂防治橘小实蝇。     

寄生对四川盆地园林树木的影响

本文在四川盆地寄生植物类别及主要被寄生园林树木记载的基础上，分析了寄生对园林树木的影响，提出了减少或消除寄生的方法。     

西藏龙胆根内寄生附球霉属真菌菌株特性研究

[目的]研究西藏龙胆根内寄生附球霉属真菌的菌株特性。[方法]以从新鲜西藏龙胆根部内分离得到的附球霉属菌株为材料,对其进行菌株鉴定与形态学观察。[结果]①菌株在PDA培养基和察氏培养基上菌落舒展,呈白色垫状,菌落到后期变为黄色,孢子黑色,基质呈黄色;而在KB培养基上菌落舒展,呈白色绒毛状,菌落到后期变黄色,孢子黑色,基质呈黄色;②菌株在25℃下培养2 d后,分生孢子在黄色菌落表面形成分散的点状黑色菌落,并有黄色色素分泌。[结论]通过相关文献查阅,发现分离得到的菌株属半知菌亚门丝孢纲瘤座孢目附球霉属的一种;菌株孢子的外形与附球霉孢子的外形相似,但在孢子纵、横隔膜隘缩的描述和柄细胞结构上与有关文献的描述有区别。