中国植食性瓢虫寄生蜂的初步调查

1984年9月至10月在中国南部和中部地区的调查中共发现了4种廿八星瓢虫的寄生性天敌,其中包括瓢虫姬小蜂,啮小蜂、金小蜂和一种尚未定名的寄生蜂。以瓢虫姬小蜂分布广泛,被寄生后的瓢虫形成蛹干尸。经室内饲养证明啮小蜂为瓢虫姬小蜂的寄生蜂。金小蜂仅只采集到一头标本,它的寄生作用还有待于进一步的研究。瓢虫姬小蜂已引种到美国农业部益虫研究室。     

植物乙醇提取物对美洲斑潜蝇寄生性天敌的影响

本文研究了马缨丹（Lantana camara、飞机草Chromolaena odorata和蟛蜞菊Wedelia chinensis乙醇提取物以及机油乳剂对美洲斑潜蝇两种主要寄生蜂底比斯釉姬小蜂Chrysochairis pentheus((Walker）和丽潜蝇姬小蜂Neuchrysocharis formosa(Westwood)的影响，研究结果表明：供试的上植物乙醇提取物对美洲斑潜蝇上述两种寄生蜂的成、幼蜂无毒杀作用，对底比斯釉姬小蜂和丽潜蝇姬小蜂的寄生行为均无影响。     

杀虫药剂对茄二十八星瓢虫及瓢虫柄腹姬小蜂的选择毒性

在室内测定了8种杀虫剂对茄二十八星瓢虫幼虫及其主要天敌瓢虫柄腹姬小蜂的毒力。结果 表明，阿维菌素对茄二十八星瓢虫和瓢虫柄腹姬小蜂具有较高的选择性，氰戊菊酯次之，而氟虫腈等则无选择性，建议在天敌较丰富的季节，优先选用阿维菌素防治茄二十八星瓢虫，氰戊菊酯可与阿维菌素交替使用。     

5种药剂对瓢虫柄腹姬小蜂实验种群的影响

测定了5种不同类型的药剂对瓢虫柄腹姬小蜂实验种群的影响,结果表明:Bt、阿维菌素、苦皮藤素对当代瓢虫柄腹姬小蜂种群没有显著影响,而敌敌畏、氯氰菊酯处理组不出蜂,这为协调化学防治和生物防治提供了科学依据。     

几种杀虫剂对茄二十八星瓢虫及其优势寄生蜂的影响

室内初步试验了敌敌畏等５种杀虫剂对茄二十八星瓢虫的毒力效果,并从中挑选出杀虫效果较好的敌敌畏、速灭杀丁、害极灭３种杀虫剂,研究其对茄二十八星瓢虫优势寄生蜂－瓢虫柄腹姬小蜂的影响。     

桂南桉树主栽品种对桉树枝瘿姬小蜂抗性林间试验研究

2009年4月至2010年8月,选用桂南桉树5个主栽品种(无性系)：尾巨桉(Eucalyptus urophylla×E.grandis)DH32-26、DH33-27、DH32-28、DH32-29和巨尾桉(Eucalyptus grandis×E.urophylla)G19,在广西壮族自治区宁明县桉树枝瘿姬小蜂(Leptocybe invasa Fisher&La Salle)虫源地进行对桉树枝瘿姬小蜂抗性林间试验。结果表明,尾巨桉DH32-26和DH32-28对桉树枝瘿姬小蜂有高抗性,14月树龄植株未产生桉树枝瘿姬小蜂虫瘿,可作为造林优先选用品种;选择立地条件较好(立地类型Ⅱ类)的林地和加强抚育、施肥等营林措施可提高桉树对桉树枝瘿姬小蜂抗性。     

寄主植物对美洲斑潜蝇幼虫寄生蜂的影响

通过对云南地区豇豆、丝瓜和番茄叶上的美洲斑潜蝇幼虫期寄生蜂调查 ,结果发现 ,美洲斑潜蝇幼虫的寄生蜂有丽灿姬小蜂、黄潜蝇釉姬小蜂、点腹灿姬小蜂、底比斯釉姬小蜂、异角亨姬小蜂和姬小蜂 6种。这些寄生蜂对美洲斑潜蝇的寄生率均以作物生长前期最低 ,后期最高。对豇豆叶上美洲斑潜蝇的寄生率为15.24%～35.16% ,以黄潜蝇釉姬小蜂为优势种 ;对丝瓜、番茄叶上美洲斑潜蝇的寄生率分别是 18.88%～42.36%、24.40%～50.55% ,均以丽灿姬小蜂为优势种     

美洲斑潜蝇幼虫寄生蜂两种

本文报道美洲斑潜蝇幼虫寄生蜂两种,分别为丽潜蝇姬小蜂Neochrysocharis formosa(Westwood)、横柄金色潜蝇姬小蜂Chrysocharis crassiscapus(Thomson),前者为当地美洲斑潜蝇寄生性天敌的优势种。     

蚕豆田潜蝇姬小蜂白昼活动规律

本文就蚕豆上潜蝇姬小蜂白昼活动规律进行了研究,在午间13：00-14：00时气温最高时,为潜蝇姬小蜂的活动高峰期,种群(Y)和温度(X)的白昼活动模式为Y=-2．41 1．38x-0．09x^2,r=0．7221;在蚕豆成熟时,潜蝇姬小蜂种群数量最大。     

云南派姬小蜂对微红梢斑螟不同日龄蛹的选择性及其后代发育表现

云南派姬小蜂(Pediobius yunnanensis Liao)是微红梢斑螟(Dioryctria rubella Hampson)蛹期的重要寄生蜂。本文在温度为(25±1)℃、相对湿度(70±10)%、光周期L//D=14h//10h的条件下,研究了不同日龄微红梢斑螟蛹对云南派姬小蜂的寄生率、发育历期、子代性比和个体大小的影响。结果表明,云南派姬小蜂对4日龄的微红梢斑螟蛹寄生率(76.19%)显著高于对2、6、8日龄和10日龄蛹的寄生率,且随着微红梢斑螟蛹日龄的增加,云南派姬小蜂对其寄生率呈下降趋势。云南派姬小蜂能在2～10日龄的微红梢斑螟蛹上产卵并发育至成虫,在寄主5种龄期下云南派姬小蜂的发育历期差异不显著;云南派姬小蜂寄生4日龄和10日龄蛹的子代雌雄性比显著低于寄生2、6日龄和8日龄蛹的雌雄性比;在寄生4日龄蛹时,寄生蜂子代个体最大,子代个体随着蛹日龄的增加其体型大小呈下降趋势。     

拟短体线虫属一新种

 甘薯拟短体线虫新种(Pratylenchoides batatae n. sp.)根据采自河北省卢龙县前双庙的甘薯根部及根际土壤中的一个拟短体线虫种群进行描述和作图。新种的主要鉴别特征是:唇区有5个唇环,侧区4条侧线并有网格纹,尾呈圆柱形、有24~26个体环,尾端圆、具粗纵纹。食道腺末端覆盖于肠背面,2个亚腹食道腺核均在背食道腺核之后,一个亚腹食道腺核位于食道-肠瓣门前的腹面、另一个位于食道-肠瓣门稍后。近似种为齿尾拟短体线虫(P. crenicauda),该种与新种的主要区别是:唇区3~4个唇环,侧区有6条侧线、无网纹,亚腹食道腺核一个在背食道腺核前、另一个在背食道腺核后。新种为两性种。模式标本保存于福建农林大学植物保护学院植物线虫学实验室。     

A new Monogenean species, Bicotyle lucknowensis sp. n. (Monogenea: Heteraxinidae), from the Indian fish, Gudusia chapra (Ham.)

A new monogenean species, Bicotyle lucknowensis sp. n. of the family Heteraxinidae, has been described from the fish, Gudusia chapra (Ham.), from Lucknow, India. The new species is characterized by the number and shape of cirral spines, presence of an unarmed vagina and details of copulatory complex and haptoral armature.     

PCR-based sensitive and specific detection of Pectobacterium atrosepticum using primers based on Rhs family gene sequences

A sensitive and specific assay was developed to detect potato blackleg caused by Pectobacterium atrosepticum in potato. Primers PEAF and PEAR from the Rhs family gene homologous to RhsA (cell envelope biogenesis – outer membrane) were used to amplify a 904 bp DNA fragment. PCR was used to detect the pathogen in artificially inoculated potato seed tubers. The PCR product was only produced from 12 isolates of P. atrosepticum from various countries among 36 isolates of other species of Pectobacterium , Pseudomonas , Xanthomonas , as well as Escherichia coli and the soilborne fungus Fusarium oxysporum f.sp. dianthi .     

Pectobacterium spp. associated with bacterial stem rot syndrome of potato in Canada

Pectobacterium atrosepticum, P. carotovorum subsp. brasiliensis, P. carotovorum subsp. carotovorum, and P. wasabiae were detected in potato stems with blackleg symptoms using species- and subspecies-specific polymerase chain reaction (PCR). The tests included a new assay for P. wasabiae based on the phytase gene sequence. Identification of isolates from diseased stems by biochemical or physiological characterization, PCR, and multi-locus sequence typing (MLST) largely confirmed the PCR detection of Pectobacterium spp. in stem samples. P. atrosepticum was most commonly present but was the sole Pectobacterium sp. detected in only 52% of the diseased stems. P. wasabiae was most frequently present in combination with P. atrosepticum and was the sole Pectobacterium sp. detected in 13% of diseased stems. Pathogenicity of P. wasabiae on potato and its capacity to cause blackleg disease were demonstrated by stem inoculation and its isolation as the sole Pectobacterium sp. from field-grown diseased plants produced from inoculated seed tubers. Incidence of P. carotovorum subsp. brasiliensis was low in diseased stems, and the ability of Canadian strains to cause blackleg in plants grown from inoculated tubers was not confirmed. Canadian isolates of P. carotovorum subsp. brasiliensis differed from Brazilian isolates in diagnostic biochemical tests but conformed to the subspecies in PCR specificity and typing by MLST.     

A new stem nematode associated with peanut pod rot in China: morphological and molecular characterization of Ditylenchus arachis n. sp. (Nematoda: Anguinidae)

Surveys conducted in peanut production areas of China revealed peanut pod rot in several fields in Shandong and Hebei Provinces, China. A large quantity of an unknown stem nematode was isolated from the hulls and seeds of peanuts, herein described as Ditylenchus arachis n. sp. The new species is characterized by a combination of the following features: lateral lip sectors distinctly projected, stylet delicate, 8·4–10 μm in length, six lines in the lateral field, tail elongate–conoid, bursa covering about 68–86% of tail length. Pathogenicity tests showed that D. arachis n. sp. could infect peanut (Arachis hypogaea), but not sweet potato (Ipomoea batatas) or potato (Solanum tuberosum). Morphologically, D. arachis n. sp. appears closest to D. africanus, D. myceliophagus and D. destructor, but can be differentiated based upon a combination of morphological characteristics, host preference and molecular sequence data. The results of the phylogenetic analysis, based on 18S rDNA, the D2–D3 expansion region of 28S rDNA, and the ITS1–5·8S–ITS2 region, confirmed its status as a new species. A sister relationship with D. destructor was appointed, rather than with its ecologically very similar congener D. africanus.     

Biocontrol potential of Alternaria sp. PMK2, against a devastating weed: Parthenium hysterophorus L

Parthenium hysterophorus (Asteraceae) is known as one of the most aggressive invasive weeds, causing severe economic, environmental, human and animal health problems in India and around the world. During a series of extensive surveys for natural enemies of P. hysterophorus, a leaf spot pathogen was isolated from the affected parts of the parthenium following the standard isolation techniques using potato dextrose agar (PDA) and parthenium dextrose agar (PeDA) media. Koch's postulates were performed and found satisfactory for the isolate and proved to be pathogenic to this weed. On the basis of cultural, morphological and molecular characteristics, the pathogen was identified as Alternaria sp. PMK2. The growth of the pathogen was studied on eight selected media and it exhibited varying degrees of growth on different media. Phytotoxicity of fungal cultural filtrates was also confirmed on parthenium leaves in laboratory conditions. Due to the virulent nature of the isolated pathogen, it may be selected for further studies to develop mycoherbicide for control of this devastating weed.     

A Novel Population of Phytophthora, Similar to P. infestans, Attacks Wild Solanum Species in Ecuador

ABSTRACT Twenty-six isolates of a Phytophthora population from two wild solanaceous species, Solanum tetrapetalum (n 11) and S. brevifolium (n = 15), were characterized morphologically, with genetic and phenotypic markers, and for pathogenicity on potato and tomato. Based on morphology, ribosomal internal transcribed spacer region 2 (ITS2) sequence, and pathogenicity, all isolates closely resembled P. infestans and were tentatively placed in that species. Nonetheless, this population of Phytophthora is novel. Its primary host is neither potato nor tomato, and all isolates had three restriction fragment length polymorphism (RFLP) bands (probe RG57) and a mitochondrial DNA haplotype that have not been reported for P. infestans. All the isolates were the A2 mating type when tested with a P. infestans A1 isolate. The A2 mating type has not been found among isolates of P. infestans from potato or tomato in Ecuador. Geographical substructing of the Ecuadorian A2 population was detected. The three isolates from the village of Nono, identical to the others in all other aspects, differed by three RFLP bands; those from Nono lacked bands 10 and 16, but possessed band 19. Most of the Ecuadorian A2 isolates were nonpathogenic on potato and tomato, but a few caused very small lesions with sparse sporulation on necrotic tissue. Cluster analysis of multilocus genotypes (RFLP, mating type, and two allozymes) dissociated this A2 population from genotypes representing clonally propagated populations of P. infestans worldwide. The current hypotheses for the historical global movements of P. infestans do not satisfactorily explain the origin or possible time of introduction into Ecuador of this A2 population. Assuming the population is P. infestans, its presence in Ecuador suggests either a hitherto unreported migration of the pathogen or an indigenous population that had not previously been detected.     

Sweet potato stem blight caused by Alternaria sp.: A new disease in Ethiopia

A new sweet potato disease was discovered in Ethiopia. The disease mainly affects the stems and petioles of sweet potato and the name sweet potato stem blight is proposed. The pathogen is a species ofAlternaria, for which no definite name has been found so far. Sweet potatoes were most susceptible, tomatoes were slightly susceptible, and muskmelons and chilli peppers were resistant. Thorn apples and onions showed slight to moderate symptoms, butAlternaria was not reisolated from these two species. Although all sweet potato varieties tested were susceptible, there were significant differences in sensitivity.     

白僵菌粘膏的研制和林间应用

白僵菌粘膏新剂型是以白僵菌孢子粉与废糖蜜、甘薯粉混合拌匀而成。菌膏直接涂于蛀干害虫排粪孔口,对多纹豹蠹娥和相思拟木蠹蛾,小区试验防治效果达93.6～96.8％,但对防治星天牛三无效。林间大面积防治木麻黄多纹豹蠹蛾583.7公顷,死亡率达88.5～98.4％。白僵菌膏成本费0.128元/公顷。菌膏在宣温下贮藏90天仍有效。