Sexual competitiveness of Vienna 4/Tol-94 ‘genetic sexing’ sterile mediterranean fruit fly males in Israel

The sterile insect technique (SIT) is used as an environment-friendly means of suppressing Mediterranean fruit fly (Ceratitis capitata; ‘medfly’) populations in the Arava valley of Israel. The technique depends on released sterile males effectively wresting the reproductive potential away from wild, fertile males. Studies carried out in other countries have indicated that sterile males may sometimes be of inferior sexual competitiveness in comparison with their wild counterparts and that this may inhibit SIT efficacy. In the present study, field-cage experiments were conducted to investigate the sexual competitiveness of sterile male medflies (genetic sexing strain Vienna 4/Tol-94) produced in and shipped from Guatemala, in the presence of wild males in Israel. In addition, we checked whether pre-release chilling affects their sexual success. Sterile and wild males were found to be similar in mating frequency, latency until mating, insemination probability, and duration of copulations during which no sperm were stored. There was, however, weak evidence that copulations involving sperm storage were shorter for sterile males. Chilling did not influence any element of male sexual performance. In both experiments, copulations culminating in sperm storage by females were longer than those that failed, suggesting that processes occurring early on in copulation may sometimes be the source of sexual failure. Overall, these results indicate a high standard of vigor in the sterile male medfiies used in the SIT program presently followed in Israel.     

地中海实蝇入侵中国的风险评估

地中海实蝇Ceratitis capitata(Weidemann)是全球分布范围最广、为害最大的害虫之一。为评估地中海实蝇入侵中国风险并制定针对性的检疫措施,基于其在全球的分布数据,选取与其发生相关的温度、湿度等7个变量,利用MaxEnt模型预测其适生区,并结合我国进境口岸截获数据及寄主分布情况评估其入侵风险。结果显示,地中海实蝇在全球的适生区范围主要集中在热带、亚热带地区,在我国的适生区范围主要集中在南部地区。该虫在越南、老挝、缅甸、印度、不丹和尼泊尔等我国邻国多地适生,且在我国进境口岸每年也均有截获,2003—2015年共截获274批次;其主要寄主苹果、咖啡、榅桲和无花果在我国的适生区范围内种植面积及产量均较高。因此中国具备了该虫进入、定殖的适生条件,具有较高的扩散风险。为预防其入侵,需完善边境疫情监测体系,加强进境口岸管理力度,并制定科学管理措施以降低其进入、定殖及扩散的风险。     

利用四季豆饲养盲蝽的方法

四季豆是多种盲蝽的寄主植物,该研究旨在发展一个利用四季豆豆荚规模化饲养多种盲蝽的技术.研究结果表明:绿盲蝽与中黑盲蝽的若虫最佳饲养密度约为100头/盒(2L),成虫为60～80头/盒.绿盲蝽成虫喜好在切头豆荚的两端伤口处产卵,而中黑盲蝽喜欢在完整豆荚的两端产卵.养虫盒内添加一些弯曲的纸条有助于提高若虫存活率和成虫产卵量.产卵后的豆荚需晾干后放置在25～28℃、相对湿度60%～70%、光照16:8(L:D)的环境下,以减少豆荚腐烂和提高卵的孵化率.利用这一方法饲养盲蝽的若虫存活率、成虫产卵量和卵孵化率分别达60%、40粒和80%.     

Tomato fruits as an alternative host for a laboratory strain of the olive fruit flyBactrocera oleae

In nature, oviposition and larval growth of the olive fruit flyBactrocera oleae (Rossi) (Diptera: Tephritidae) occur only in the mesocarp of fruits of the genusOlea, including the cultivated olive. Here we report on its growth in tomatoes, in the laboratory, as affected by a number of factors. Caged flies from a colony reared for more than 100 generations on an artificial diet, oviposited in intact fruits of four tomato cultivars in an unheated greenhouse and in the open. In choice tests, at 25°C, 16L:8D and 65% r.h., medium (5–6 cm diam) and large (>6 cm diam) fruits received more eggs than small (3–4 cm diam) fruits, but differences were not significant in all cases. In all cultivars, more eggs were laid in greenhouse than in open-air tomatoes of three different degrees of maturity, the differences being significant in most cases. The smaller the resistance of a cultivar’s epicarp to penetration by flat ended 0.2 and 1 mm square probes, the greater the number of eggs a cultivar received. Green (unripe) fruits proved unsuitable for larval growth. Half-ripe and fully ripe (red) fruits of cvs. ‘Isidro’, ‘204’, ‘Tobo’ and ‘Ace’ yielded pupae of acceptable weight (mean 5.6 to 6.7 mg) with a high percentage of adult emergence, yet the yield was considerably lower than that of olive fruit. Fully ripe greenhouse Isidro tomatoes yielded an average of 3.2 adults per fruit and 20.4% of the eggs laid developed into adults, whereas the other categories and cultivars yielded less. The mean percentages of pupae over eggs were higher in fully ripe Isidro and 204 fruits, than in half-ripe Tobo and Ace ones. The mean time from oviposition to pupation ranged from 16.2 to 25 days, depending on the cultivar and degree of fruit maturity. In fully ripe Isidro and 204 fruits, the fewer the eggs laid per fruit, the higher the percent yield in pupae and the longer the time from oviposition to pupation. Greenhouse fully ripe fruits of cv. 204 maintained under a low light intensity of 50 lux gave a much lower yield in pupae and slower larval growth than under 1600 lux. The usefulness of tomatoes as substitutes of artificial diets in rearing the fly is discussed. http://www.phytoparasitica.org posting May 20, 2005.     

异色瓢虫人工繁育中滞育成虫的冷藏条件

为延长异色瓢虫Harmonia axyridis成虫的货架期,提高规模化生产的灵活度,于室内条件下测定不同温度和光周期对异色瓢虫滞育率的影响、不同温度对异色瓢虫滞育持续时间的影响及不同冷藏温度和冷藏时间对异色瓢虫生物学特性的影响。结果表明,在低温和短光照条件下能诱导异色瓢虫成虫滞育,当温度为20℃、光周期为10 L:14 D时其雌、雄成虫的滞育率均高于95.0%。异色瓢虫的滞育持续时间受滞育诱导温度影响较小,在温度15℃、光周期10 L:14 D和温度20℃、光周期10 L:14 D两种条件下诱导的滞育异色瓢虫在温度25℃、光周期14 L:10 D下均能快速解除滞育,在该条件下饲养10 d时其滞育解除率达90.0%以上。与8℃和12℃冷藏30 d相比,4℃冷藏30 d时异色瓢虫的存活率、总产卵量和捕食量均显著下降;当冷藏温度为12℃,冷藏时间显著影响异色瓢虫雌成虫的捕食量、寿命、产卵前期、总产卵量和卵孵化率,但对雄成虫的捕食量无显著影响。异色瓢虫冷藏期间主要以脂类和糖类作为能量物质,其冷藏期间存活率与相对总脂含量、总糖含量正相关。综上,在实际生产中异色瓢虫可在温度20℃、光周期10 L:14 D条件下诱导滞育,在12℃冷藏90 d不会降低生物适合度。     

Laboratory evaluation of natural pyrethrins, pymetrozine and triflumuron as alternatives to controlCeratitis capitata adults

Three insecticides, pyrethrins + piperonil butoxide (PBO), pymetrozine and triflumuron, were tested as potential alternatives for controlling the Mediterranean fruit flyCeratitis capitata (Wiedemann) (Diptera: Tephritidae). The compounds were administered to adult flies in the laboratory by different uptake methods at the recommended rates currently used in fruit crops in Spain. Pyrethrins + PBO (80 + 320 ppm a.i.) exhibited a comparable knock-down effect to malathion (1,500 ppm a.i.) in the laboratory, irrespective of the method of application used. After these results were obtained, the number of concentrations tested was increased to carry out a dose-response analysis. Pymetrozine (300 ppm a.i.) and triflumuron (150 ppm a.i.) did not kill adults at the concentrations tested. However, pymetrozine diminished the fecundity, especially when adults were fed the insecticide; egg hatch was decreased by 59.3% compared with controls. Further experiments showed that increased period of ingestion and higher concentrations had a clear effect in reducing both fecundity and fertility. The possible use of pyrethrins + PBO and pymetrozine to reduce populations ofC. capitata is discussed. http://www.phytoparasitica.org posting July 22, 2006. Corresponding author     

天山野果林塞威士苹果和短距凤仙花叶斑病病原真菌的鉴定

为了解新疆天山野果林中塞威士苹果Malus sieversii与其林下伴生植物短距凤仙花Impatiens brachycentra两种植物叶斑病病原菌的多样性及同源性,采用组织分离法获得病原菌,基于rDNA-ITS序列构建系统发育树,并进行ITS序列BLAST同源性比对,对病原菌进行鉴定分类,并依据科赫氏法则测定致病性。结果显示,从新疆新源县天山野果林中的塞威士苹果及短距凤仙花病叶上共分离得到18株菌落形态各异的病原菌,分属于2属4种,绝大多数属于半知菌亚门。其中,链格孢属Alternaria sp.为塞威士苹果和短距凤仙花叶斑病病原真菌中的优势菌群。致病性测定结果显示,其中11株病原真菌对塞威士苹果具有致病性,7株病原真菌对短距凤仙花具有致病性;塞威士苹果所有的病原真菌对短距凤仙花均有致病性,而且短距凤仙花所有的病原真菌对塞威士苹果也有致病性。推测2种植物叶斑病可能由相同来源的病原真菌引发,短距凤仙花染病加剧了塞威士苹果叶斑病暴发,可能是野果林退化的重要原因。     

山东省樱桃主产区果蝇的调查与鉴定

为了解山东省樱桃主产区果蝇的发生情况,本研究选择了山东省主要樱桃产区的7个地点进行调查,并通过形态学特征和分子鉴定法对果蝇的种类进行鉴定。结果发现,山东省樱桃主产区有4种果蝇,通过形态特征与分子鉴定法最终确定4种果蝇,分别为斑翅果蝇Drosophila suzukii、黑腹果蝇D.melanogaster、海德果蝇D.hydei和伊米果蝇D.immigrans。这4种果蝇对樱桃的为害程度与种植地区、果实腐烂程度和樱桃的品种均有关系;莱芜和泰安地区果蝇分别有4种和3种;烟台和威海地区则只有斑翅果蝇和黑腹果蝇2种。烟台地区果蝇为害率最高,且数量最多,其中烟台丁家夼村樱桃为害率高达45.16%,在第2次采集中烟台薛家村每100粒樱桃中斑翅果蝇和黑腹果蝇的数量最多。美早和先锋2个品种樱桃对果蝇的吸引力较强;采摘后期腐烂的果实可吸引大量的果蝇产卵。因此,应对烟台地区进行重点预防、早期防治,并减少美早和先锋品种樱桃在山东省的种植。     

中华卵索线虫人工室内培养技术

为室内大量繁殖中华卵索线虫Ovomermis sinensis,采用个体由大到小的斜纹夜蛾Spodoptera litura、棉铃虫Helicoverpa armigera和黏虫Mythimna separata作为宿主,测定被中华卵索线虫寄生后3种宿主的体长和体重,研究宿主种类对中华卵索线虫有效率、雌雄比和体长的影响以及寄生强度对线虫雌雄比的影响。结果显示,被中华卵索线虫寄生后,斜纹夜蛾、棉铃虫和黏虫生长减缓。在相同感染比例下（除宿主与线虫比为1∶15外）,3种宿主的线虫有效率之间差异不显著。当寄生强度为5时,3种宿主体内脱出的中华卵索线虫均为雌线虫;当寄生强度从10增到40时,斜纹夜蛾、棉铃虫和黏虫所脱出的雌性比分别由100.0%、90.0%、83.9%降为0;相同寄生强度下,从斜纹夜蛾体内脱出的雌性比显著高于从棉铃虫与黏虫体内脱出的雌性比。斜纹夜蛾、棉铃虫和黏虫体内脱出雌线虫和雄线虫平均体长分别为14.8、13.8、12.8 cm和8.0、7.5和7.5 cm。当中华卵索线虫与宿主按照比例20∶1～25∶1侵染斜纹夜蛾、按照15∶1侵染棉铃虫和黏虫时,能获得线虫最适雌雄比（1∶1...     

Polygalacturonase-inhibiting protein activity in cantaloupe fruit as a function of fruit maturation and tissue origin

Netted cantaloupe (Cucumis melo var. cantalupensis cv. Magnum 45) were harvested from 5 to 35 days postanthesis. The fruit of each age group were divided into exocarp, outer mesocarp, mid mesocarp, inner mesocarp, placenta, and seed. Each tissue was extracted and assayed for polygalacturonase-inhibiting protein (PGIP) activity against polygalacturonases (PGs) from three fungal pathogens of cantaloupe fruit. The PGIP activity of all tissues except placenta was high from the flower stage through the first week of fruit development but decreased markedly between 5 and 10 days postanthesis. PGIP activity against Phomopsis cucurbitae PG remained high and nearly constant in placental tissue throughout fruit development. However in this same tissue, PGIP activity against Fusarium solani PG decreased during fruit development to about 25% of its level in the 5-day-old fruit. This differential change in PGIP activity toward the two PGs suggests that different forms of the inhibitor are expressed between early and late stages of cantaloupe fruit development. The results also illustrate the importance of using multiple pathogen enzyme systems that can provide an opportunity for more accurate elucidation of mechanisms involved in the host–pathogen interaction. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture. All programs and services of the US Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status, or handicap. The article cited was prepared by a USDA employee as part of his/her official duties. Copyright protection under US copyright law is not available for such works. Accordingly, there is no copyright to transfer. The fact that the private publication in which the article appears is itself copyrighted does not affect the material of the US Government, which can be freely reproduced by the public.     

Infection of<Emphasis Type="Italic">Ceratitis capitata</Emphasis> by two species of the<Emphasis Type="Italic">Entomophthora muscae</Emphasis> species complex (Zygomycetes: Entomophthorales) in the field

Adult Mediterranean fruit flies (Ceratitis capitata), collected in the field, were infected with entomophthoralean fungi. The fungi sporulated poorly on the cadavers, and resting spores, rhizoids and cystidia were not observed. Measurements of conidia and nuclei and counts of nuclei per conidium from different specimens suggest that the causative agents wereEntomophthora muscae sensu stricto andEntomophthora schizophorae, species recently separated from theEntomophthora muscae species complex. This is the first report ofC. capitata as a host for entomopathogenic fungi. http://www.phytoparasitica.org posting Jan. 29, 2003.     

黄瓜绵腐病病原菌鉴定及防治药剂的筛选

为有效防控黄瓜绵腐病,本研究对自江西省南昌市南昌县武阳镇和八一乡采集的黄瓜绵腐病病样进行分离,基于致病性测定、形态学特征和分子生物学方法对其进行鉴定,并采用菌丝生长速率法测定甲霜灵、霜霉威、霜脲氰、烯酰吗啉4种常用杀菌剂对该病原菌和辣椒疫霉Phytophthora capsici的抑制效果。结果表明,自武阳镇和八一乡采集的病样经分离、纯化培养后分别获得12株和10株菌株;自武阳镇分离的病原菌的藏卵器柄较直,藏卵器大小为18.1~32.9 μm;自八一乡分离的病原菌的藏卵器柄较弯曲,藏卵器大小为15.1~25.3 μm;结合致病性测定及rDNA-ITS测序结果,将自武阳镇分离的病原菌鉴定为瓜果腐霉Pythium aphanidermatum,将自八一乡分离的病原菌鉴定为德里腐霉Py.deliense。室内毒力测定结果表明,甲霜灵对瓜果腐霉和德里腐霉抑制效果最好,EC₅₀分别为0.71 μg/mL和0.25 μg/mL;霜脲氰次之,EC₅₀分别为3.68 μg/mL和3.36 μg/mL,甲霜灵、霜霉威、霜脲氰3种杀菌剂对瓜果腐霉、德里腐霉和辣椒疫霉的抑制效果差别不大,但烯酰吗啉对瓜果腐霉、德里腐霉和辣椒疫霉抑制效果差异明显,EC₅₀分别为18.06、33.58和0.18 μg/mL,表明防治黄瓜绵腐病优先选择甲霜灵。     

A new method for inoculation of fruit with <Emphasis Type="Italic">Guignardia citricarpa</Emphasis>, the causal agent of citrus black spot

Citrus black spot (CBS) is a fungal disease, caused by Guignardia citricarpa, that has a high economic impact on citrus. Although G. citricarpa has been associated with black spot of citrus, an adequate pathogenicity test is still not available. Thus, our objective was to develop and evaluate a simple, safe, and practical pathogenicity test. We used fruits from Pera-Rio and Valencia sweet orange trees from two different orchards, located in the State of São Paulo, Brazil. Inoculation was performed by placing six disks colonized by G. citricarpa, onto the peel of healthy fruits, previously bagged. In the Pera-Rio sweet orange grove, initial symptoms of the false melanose type resulting from the inoculations were observed 55 days after inoculation (dai). In the Valencia grove, initial symptoms also of the false melanose type resulting from the inoculations occurred 73 dai. A total of 92.8% and 86.6% of the Pera Rio and Valencia fruits inoculated, respectively, showed symptoms of CBS. Citrus black spot symptoms were not observed in any of the control fruits.     

Factors influencing external fruit rot of cucumber caused by Didymella bryoniae

Several factors influencing the occurrence and extent of external fruit rot caused byDidymella bryoniae on cucumbers in the post harvest period were studied.The minimum, optimum and maximum temperatures for growth of the fungus on fruits were circa 10, 23 and 35°C, respectively. The influence of the temperature on the growth of the fungus in vitro and in vivo was about similar. The fitness of the fungus diminished by storing inoculated fruits at about the maximum temperature for growth of the fungus for one day, but this temperature influenced fruit quality negatively. Storing at 10 to 12°C is more advisable.Isolates ofD. bryoniae showed variation in virulence. There was a linear relationship between growth on fruits and growth in vitro of these isolates, but no correlation was found with disease incidence on plants.The degree of fruit rot was increased by more severe wounding, by storing in the dark instead of in the light and by higher nitrogen fertilization of the crop. Relative humidity during storage had no effect on fruit decay. It is very likely that the amount and composition of available nutrients for fungus growth determine the degree of rotting of the fruits.With the present cultivars, external fruit rot can be best controlled by reducing the changes of wounding in the pre- and post-harvest period.Samenvatting Verschillende factoren die van invloed kunnen zijn op het ontstaan en de mate van uitwendig vruchtrot op komkommers in de periode na de oogst, veroorzaakt doorDidymella bryoniae, zijn onderzocht.De minimum, optimum en maximum temperatuur voor de groei van de schimmel op vruchten waren respectievelijk circa 10, 23 en 35°C. De invloed van de temperatuur op de groei van de schimmel in vitro en in vivo was nagenoeg gelijk. Door geïnoculeerde vruchten een dag bij de maximum temperatuur voor de groei van de schimmel te bewaren, werd de groeikracht van de schimmel verminderd, maar de vruchtkwaliteit werd door deze temperatuur negatief beïnvloed. Het is raadzamer de vruchten bij 10–12°C te bewaren.Isolaten vanD. bryoniae vertoonden een variatie in virulentie. Tussen de groei van deze isolaten op vruchten en de groei in vitro bleek een lineair verband te bestaan, maar er bestond geen verband met de aantasting van planten.De mate van vruchtrot nam toe door de vruchten ernstiger te verwonden, ze in het donker in plaats van in het licht te bewaren en door een hogere stikstofbemesting tijdens de teelt. De relatieve luchtvochtigheid tijdens de bewaarperiode had geen effect op de vruchtaantasting. De hoeveelheden en de samenstelling van de voor de groei van de schimmel beschikbare voedingsstoffen bepalen zeer waarschijnlijk de mate van vruchtrot.Uitwendig vruchtrot kan bij de huidige cultivars nog het best worden tegengegaan door de mogelijkheden van verwonding, zowel in de periode voor als na de oogst, te verkleinen.     

桑椹菌核病菌实时荧光定量PCR检测体系的建立和应用

为及时高效地鉴别桑椹菌核病的病原菌桑实杯盘菌Ciboria shiraiana和肉阜状杯盘菌C. carunculoides,根据RPB2基因序列设计引物并验证其特异性,建立这2种病原菌的实时荧光定量PCR(real-time fluorescent quantitative PCR,q PCR)检测体系,运用该体系对抗、感果桑品种不同时间点芽(果)内的2种病原菌进行检测。结果表明,设计的2对引物特异性强,qPCR检测灵敏度均为10^-4ng/μL,均为常规PCR灵敏度的10~5倍,建立的桑实杯盘菌和肉阜状杯盘菌qPCR标准曲线的扩增效率分别为104.89%和95.30%。利用所建方法成功从采集的果桑样品中检测出病原菌主要为肉阜状杯盘菌,且感病品种中肉阜状杯盘菌的含量随着时间不断增加,在将要显症时激增。表明所建qPCR体系适用于桑椹菌核病早期无症状芽(果)的检测,可通过监测其病原菌类型和含量为该病害的预测预报及早期防治提供依据。     

Infection frequency of mature apple fruit with Erwinia amylovora deposited on pedicels and its survival in the fruit stored at low temperature

The infection frequency of mature apple fruit by Erwinia amylovora and the survival of E. amylovora in the fruit stored at low temperature were investigated. The fruit stems (pedicels) of 460 mature apple fruit were inoculated with 10⁵ or 10⁴ cfu of bioluminescent E. amylovora, tagged with lux genes. Nine days after inoculation, 43% and 27% of the fruit inoculated with 10⁵ and 10⁴ cfu, respectively, were infected. All infected fruit looked healthy. After 6 months of storage at 5°C, almost all of the 142 infected fruit had viable E. amylovora. Of the fruit containing E. amylovora internally, 19.5% had latent infections and the rest had blight symptoms. E. amylovora was not uniformly distributed in the fruit flesh, and internal brown lesions were observed where E. amylovora was densely distributed. These findings showed that mature apple fruit may be infected with E. amylovora, especially as latent infections, and act as a source for long-range dissemination.     

Simultaneous detection and genetic variability of stone fruit viroids in the Czech Republic

In this paper, we report a large-scale survey for the incidence of Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd) in stone fruit collections and commercial orchards in the Czech Republic. From the 645 samples analysed, PLMVd was detected in 80 (26.6%) of peaches and the HSVd in 3 (1.3%) of apricot and 1 (0.33%) of peach trees. Sixty-seven accession of peach (44.6%) from the Czech Clonal GeneBank were infected by PLMVd. In addition, we used naturally infected trees to standardise the simultaneous detection of PLMVd and HSVd plus host mRNA as the control by means of one-step multiplex RTC-PCR. Eleven PLMVd and two HSVd isolates were sequenced and analysed. All the PLMVd variants were highly homologous (97–100%) to previously reported PLMVd variants from Tunisian peach and almond trees, and clustered together in the previously reported phylogenetic group III. The HSVd variants obtained from apricot and peach trees were included in the previously proposed recombinant group PH/cit3.     

西瓜品种资源抗细菌性果斑病苗期鉴定

为筛选高抗瓜类细菌性果斑病的西瓜资源,以24份西瓜品种资源为试材,采用苗期喷雾接种法分别接种分离自甜瓜上的瓜类嗜酸菌Acidovorax citrulli菌株pslb96和ZZ-1,鉴定各品种资源对瓜类细菌性果斑病的苗期抗性。结果表明,24份西瓜品种资源中未发现有对2株菌株表现免疫的材料,有7份资源对菌株pslb96表现高抗,12份资源对菌株ZZ-1表现高抗;9份资源对菌株pslb96表现中感或感病,7份资源对菌株ZZ-1表现中感和感病;对2株菌株均表现高抗的品种资源有野生型种质资源A9及商品种华欣、申蜜968、申选958和申抗988,占总品种资源的20.83%。部分品种资源A4、A13和申蜜7号对菌株pslb96和ZZ-1的抗性表现出明显的差异,表明相同寄主来源的2株不同菌株致病力存在差异。