Control methods against invasive Aedes mosquitoes in Europe: a review

Five species of invasive Aedes mosquitoes have recently become established in Europe: Ae. albopictus, Ae. aegypti, Ae. japonicus japonicus, Ae. koreicus and Ae. atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. There is a crucial need to evaluate methods as part of an integrated invasive mosquito species control strategy in different European countries, taking into account local Aedes infestations and European regulations. This review presents the control methods available or in development against invasive Aedes mosquitoes, with a particular focus on those that can be implemented in Europe. These control methods are divided into five categories: environmental (source reduction), mechanical (trapping), biological (e.g. copepods, Bacillus thuringiensis var. israelensis, Wolbachia), chemical (insect growth regulators, pyrethroids) and genetic (sterile insect technique and genetically modified mosquitoes). We discuss the effectiveness, ecological impact, sustainability and stage of development of each control method. © 2015 Society of Chemical Industry     

索线虫科线虫对白背飞虱和褐飞虱的寄生动态及其防控效果

为明确田间水稻白背飞虱Sogatella furcifera(Horváth)和褐飞虱Nilaparvata lugens(St?l)的主要寄生性天敌索线虫科线虫的寄生动态及防控效果,于2013—2015年在湖南省长沙市宁乡市通过田间调查和线虫罩笼法研究了索线虫科线虫对白背飞虱和褐飞虱的寄生动态以及优势种长沙多索线虫Agamermis changshaensis Bao,Luo et Luo对褐飞虱的防控效果。结果表明,在长沙市,索线虫科线虫寄生白背飞虱始见期为6月底至7月初,1个月后出现高峰期,基本与白背飞虱发生高峰期同步;对褐飞虱寄生高峰期早稻多发生在7月中下旬,而晚稻在8月底至9月中旬。索线虫科线虫对白背飞虱雌虫、高龄若虫和雄虫最高寄生率分别为16.95%、14.81%和7.69%;而对褐飞虱雌虫、高龄若虫和雄虫最高寄生率分别为43.33%、20.93%和11.63%。2014年和2015年罩笼盆栽试验结果表明,处理后45 d长沙多索线虫对褐飞虱的防控效果分别为36.11%和33.19%。研究结果表明长沙多索线虫可以作为水稻稻飞虱绿色防控的一种重要辅助性措施。     

Comparative analysis of genetic structures and aggressiveness of Fusarium pseudograminearum populations from two surveys undertaken in 2008 and 2015 at two sites in the wheat belt of Western Australia

Fusarium crown rot (FCR), caused predominantly by Fusarium pseudograminearum (Fp) in Australia, is an important fungal disease of wheat and barley. FCR causes significant yield losses and reduced grain quality worldwide. This study investigated the population dynamics of FCR-causing F. pseudograminearum isolates from Western Australia (WA), a major wheat-growing region. Wheat samples were collected from a total of seven different sites in 2008 and 2015. Two sites, Tammin and Karlgarin, with moderate to high FCR incidence, were intensively sampled in both years. The results revealed significant increase in Fp isolation frequency between 2008 and 2015. Over 86% of 1100 Fusarium isolates were Fp in 2015 compared with 59% of 639 isolates from 2008. Mating type idiomorphs, toxin chemotypes and population genetic structures were determined for a subset of 279 Fp isolates (132 isolates from 2008 and 165 from 2015). Mating type analysis revealed differences in MAT1-1 and MAT1-2 distributions between Tammin and Karlgarin for both years. Results also showed that 97.6% of Fp isolates analysed had the 3-ADON trichothecene chemotype. Additionally, for the first time in Australia, the 15-ADON chemotype was identified in 2.3% and 2.4% of Fp isolates from 2008 and 2015, respectively. The genetic structure of Fp population determined using 21 cleaved amplified polymorphic sequence (CAPS) markers revealed a high level of genetic variation within and between populations. In addition, 2015 isolates from Tammin and Karlgarin were significantly more aggressive (P < 0.0001) than 2008 isolates. This finding may have implications in managing this significant fungal disease.     

First report of Pauesia silana Tremblay, 1969 (Hymenoptera: Aphidiidae), a natural enemy of the aphid Cinara pini L., in Algeria

A survey of aphids and their parasitoids in a garden park located in Algiers from March 2015 to March 2016 detected the presence of Cinara pini Linnaeus, 1758 for the first time in Algiers. This species had previously been reported in one other location in Algeria. This aphid was found on Pinus nigra and Pinus halepensis. Mummies of C. pini were found to be parasitized by Pauesia silana Tremblay, 1969. This paper provides the first report of P. silana in Algeria.     

Scale insect species (Hemiptera: Coccoidea) in Syria

Scale insects in Syria were surveyed between 2009 and 2015. This study showed that Diaspididae and Coccidae were the most common families, comprising 5 and 8 species, respectively. The remaining families found comprised 1 species each. New records of Coccoidea fauna from Syria were Parlatoria blanchardi, Phoenicococcus marlatti, Coccus hesperidum, Coccus pseudomagnoliarum and Chionaspis etrusca.     

Diversity and detections of Phytophthora species from trade and non‐trade environments in Ireland

The genus Phytophthora is one of the genera of organisms that poses the most threat to plant health worldwide. Statutory monitoring for Phytophthora species focuses on the species regulated in the European Union and recommended for regulation by EPPO (Plant Health Directive 2000/29 EC and the EPPO A2 List). This research provides details of the Phytophthora species detected from trade and non‐trade environments in Ireland between 2013 and 2015. The results of statutory surveys for the regulated species Phytophthora ramorum, Phytophthora kernoviae and Phytophthora lateralis from 2003 to 2015 are also presented. Testing of more than 11 000 samples was carried out using morphological and/or DNA identification with specifically designed Phytophthora conserved primers. This led to the detection of 19 species and 3 informally designated taxa of Phytophthora, including 8 new records for Ireland. Eight species were found in both trade and non‐trade locations, and three informally designated taxa were also detected. Phytophthora ramorum was found on the most hosts (30 hosts), followed by Phytophthora syringae (6 hosts) and Phytophthora kernoviae (3 hosts). Rhododendron was the host on which Phytophthora species were most frequently detected (12 Phytophthora species). The role of the plant trade in spreading invasive Phytophthora species is discussed.     

Thousand cankers disease in Europe: an overview

Walnut (Juglans regia L.) is traditionally present in most European countries as an ornamental tree, and in Southern Europe in particular it is grown for both fruit and wood. Since the 1980s, to supply the increasing demand for walnut timber, large areas of southern and central Europe, from France to Hungary, have been planted with black walnut (Juglans nigra L.) to provide wood for furniture production. The fungus Geosmithia morbida and its vector Pityophthorus juglandis, causing the thousand cankers disease of walnut in the USA in the last 2 decades, were recently reported in Europe (in Italy) on both walnut species. Thousand cankers disease can have a high negative impact on the landscape and economy of many agricultural and forest areas. Following a detailed pest risk analysis performed by EPPO in 2015, both organisms were included in the EPPO A2 List of pests recommended for regulation as quarantine pests. The main biological, epidemiological and monitoring aspects of thousand cankers disease and its status in Europe are reported.     

Several subspecies and sequence types are associated with the emergence of Xylella fastidiosa in natural settings in France

Xylella fastidiosa is a plant pathogenic bacterium emerging in Europe. In France its emergence has been demonstrated through interceptions of contaminated coffee plants and, in 2015, by a survey of natural settings. The first French focus of contamination was detected in 2015 in Corsica; since then, almost 300 foci have been found and nearly 30 plant species have been declared contaminated, with Polygala myrtifolia remaining the principal host, suffering from severe leaf scorch. This study reports on the diversity of X. fastidiosa identified in France in 2015. Multilocus sequence analysis/typing revealed the presence of mainly X. fastidiosa subsp. multiplex sequence types (STs) ST6 and ST7. A focus of X. fastidiosa subsp. pauca ST53 was identified in mainland France; one sample contaminated by X. fastidiosa subsp. sandyi ST76, one novel recombinant, and coinfections of different isolates in individual samples were also identified, but could not be confirmed by successive samplings, indicating limited or transient contamination. Koch's postulates were fulfilled for two isolates of X. fastidiosa subsp. multiplex on P. myrtifolia, one being ST6 and the other ST7. Comparative genomics of the genome sequences of three French isolates (one ST6 and two ST7) with available sequences revealed that, unlike the American Dixon strain, the French ST6 and ST7 strains are devoid of a plasmid encoding a complete type IV secretion system. Other differences regarding phage sequences were highlighted. Altogether, the results suggest that the emergence of X. fastidiosa in France is linked to several introduction events of diverse strains from different subspecies.     

First report of the Opuntia cochineal scale Dactylopius opuntiae (Hemiptera: Dactylopiidae) in Morocco

The Opuntia cochineal scale Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) causes severe damage to prickly pear (Opuntia ficus‐indica (L.) Miller). This scale insect was first detected in Morocco in 2015 during sampling in the cactus crop in the Sidi Bennour region (120 km north‐west of Marrakech). Methods for sampling, preservation and identification are described. Although this scale insect can be used for the production of the natural dye carmine, the damage it can cause is considerable. A pest risk analysis should be carried out and the ensuing management measures implemented to prevent severe economic and ecological losses.     

Geographic location and year determine virulence,and year determines genetic change,in populations of Neopseudocercosporella capsellae

White leaf spot (Neopseudocercosporella capsellae) can be severe and problematic worldwide across both horticultural and oilseed Brassicaceae, including susceptible rapeseed. In this study, 82 isolates from 2015 and 106 isolates from across Australia in 2016 were first assessed for their virulence against three different rapeseed (Brassica napus) cultivars. For both years there were significant (P < 0.001) differences. Also, there were significant (all P < 0.001) differences between isolates in each year, and between cultivars. For 2016 isolates, there were also significant differences (P < 0.001) between isolates across three different Australian states, and a significant interaction (P < 0.001) between isolates with cultivars. Of the three Australian states, isolates from Victoria were most virulent. Among tested cultivars, cv. Scoop was most susceptible. Subsequently, phylogenetic analysis of 114 of these same 2015 and 2016 isolates showed current isolates clustered separately from the majority of 2005 N. capsellae isolates collected from Western Australia a decade earlier, confirming significant genetic change within N. capsellae populations over the past decade. However, isolate clusters showed no association with geographical location. The results suggest that phylogenetic association among 2005 and 2015–2016 N. capsellae isolates is complementary with pathogenicity variations explained by geographically different N. capsellae pathogen populations. Neopseudocercosporella capsellae populations are evolving rapidly, challenging management through host resistance at a time of increasing incidence and severity of white leaf spot disease over the past decade. The outcome is well illustrated by cv. Scoop, previously resistant to 2005 isolates but moderately susceptible to 2015 and highly susceptible to 2016 isolates.     

Distribution of the box tree moth (Cydalima perspectalis Walker 1859) in the north‐eastern part of the Carpathian Basin with a new Ukrainian record and Hungarian data

After it was recorded in South‐West Germany and the Netherlands in 2007, the box tree moth (Cydalima perspectalis) spread rapidly in Europe and appeared in West Hungary in 2011. In the eastern part of the country the first specimen was caught in 2015 with a blacklight trap. On the basis of specimens of C. perspectalis caught in blacklight, pheromone or feeding attractant traps, the authors summarize its distribution and publish four new records from Hungary and the first data from West Ukraine (Transcarpathia). The flight dynamics of three generations of this pest are also described for 2015 and 2016.     

Discontinuance of tebuconazole in the field restores sensitivity of Monilinia fructicola in stone fruit orchards

Demethylation inhibitor (DMI) fungicides are used to control brown rot in stone fruit worldwide. However, their specific mode of action can select resistant isolates of Monilinia fructicola. Monilinia fructicola resistant to DMI fungicides are associated with a fitness cost in the absence of selective pressure, indicating that the sensitive population can be re-established when discontinuing the fungicide in the field. This work aimed to build up the sensitive population of M. fructicola after discontinuing the use of tebuconazole for successive crop seasons. The sensitivity of M. fructicola to tebuconazole was assessed in four commercial peach orchards in Paraná and São Paulo States from 2012/13 to 2015/16. Different fungicide programmes were used and DMI fungicides were discontinued from 2013/14. The sensitivity of M. fructicola to tebuconazole was assessed by a mycelial growth assay in vitro and by determining the frequency of the G461S mutation in the MfCYP51 gene. The isolates from Paraná had high sensitivity to the fungicide across all seasons and the frequency of the G461S mutation remained below 5%. The isolates from São Paulo were highly resistant in the 2012/13 season; however, there was a gradual decline until 2015/16. In addition, the G461S mutation frequency in Sao Paulo State was about 80% in the 2012/13 season, but reduced until it was completely undetectable in 2015/16. These results provide evidence that resistance can be managed in orchards with high selective pressure to tebuconazole after discontinuing the use of the fungicide for at least 3 years.     

Species prevalence and disease progression studies demonstrate a seasonal shift in the Alternaria population composition on potato

To assess the incidence of early blight/brown spot (EB/BS) in Flanders (Belgium), potato fields in 22 locations were monitored and scored over the duration of the growing seasons 2014 and 2015. The average disease incidence was shown to be higher in 2014 than in 2015. Soil type, rainfall and temperature were also analysed in relation to disease incidence. In 2014, potato plants grown in sandy soils had more EB/BS disease than those grown in clay or loamy soils. However, the low disease incidence in 2015 meant that differences in disease levels between soil types could not be discerned for that growing season. A windowpane analysis demonstrated that rainfall and humidity accounted for the differences in disease incidence between the two growing seasons. During the course of the survey, the species composition in leaves with symptoms was assessed using real‐time PCR. Remarkably, small‐spored Alternaria species, such as A. alternata and A. arborescens, rather than the more virulent A. solani were the predominant species on potato leaves throughout the growing season. As the disease progressed, the proportion of A. solani increased. In view of these results, the virulence of a collected set of Alternaria isolates was assessed by an in vitro assay. Despite A. solani being more virulent than A. alternata or A. arborescens, the most abundant species isolated from potato leaves with symptoms was A. arborescens.     

Potential of a coevolved rust fungus for the management of Himalayan balsam in the British Isles: first field releases

In 2014, the rust fungus Puccinia komarovii var. glanduliferae, native to the foothills of the Himalayas from Kashmir to Western Nepal, became the first fungal agent to be released into Europe for the classical biological control of a non-native weed. The target, Impatiens glandulifera or Himalayan balsam, is a prolific invader of riparian habitats in Europe and North America. During the period 2015–2018, a strain of the rust from India was released at a total of 36 sites, in 17 counties in England and Wales. There was limited field infection in 2015 and inoculation experiments conducted under controlled conditions revealed significant variation in the susceptibility of plant populations to the rust, with some showing immunity. Subsequently, a second strain of the rust from Pakistan was released in 2017 and was found to infect a different cohort of Himalayan balsam populations. The rust mass production methodology, and field inoculation and monitoring protocol, are detailed, and plants were tested for susceptibility to both rust strains prior to field release. Levels of foliar infection at selected sites in 2017 and 2018 are presented, as well as seedling infection rates in the spring of 2019. The results show that the rust is able to overwinter and establish populations in stands of Himalayan balsam in England. The issues involved with measuring the impact of the biological control agent are discussed.     

合肥市白毫早、乌牛早茶园天敌与蓟马的空间跟随关系

为利用天敌有效防治茶园蓟马,2015—2016年选择安徽农业大学农业科技试验基地的白毫早和乌牛早2种茶园进行试验,对2种茶园的蓟马数量及其天敌数量进行调查,采用地学统计学方法与灰色关联度法相结合方法综合分析与蓟马空间跟随关系密切的天敌种类。结果表明,2015年和2016年2年,白毫早茶园蓟马共2 408头,其捕食性天敌共12 156头,与蓟马空间跟随关系密切的前4位天敌依次是锥腹肖蛸Tetragnatha maxillosa、茶色新圆蛛Neoscona theisi、粽管巢蛛Clubiona japonicola和草间小黑蛛Erigonidium graminicolum,2年密切指数之和分别为1.952、1.843、1.800和1.751;2015年和2016年2年,乌牛早茶园蓟马共6 540头,其捕食性天敌共12 376头,与蓟马空间关系密切的前4位天敌依次是八斑球腹蛛Theridion octomaculatum、异色瓢虫Harmonia axyridis、茶色新圆蛛和锥腹肖蛸,2年密切指数之和分别为1.863、1.829、1.762和1.759。综合分析2年白毫早和乌牛早2种茶园,与蓟马空间关系密切的前4位天敌依次是锥腹肖蛸、茶色新圆蛛、异色瓢虫和草间小黑蛛,密切指数之和为3.710、3.605、3.512和3.473。     

Phytophagous insect fauna of Onopordum spp. thistles in the south of Syria

Thistles from the genus Onopordum (Asteraceae) are of Mediterranean and Eurasian origin. They are very common in the south of Syria, in particular in Damascus and Al Suwayda, and are found in fallow fields, pastures, roadsides and neglected areas. In 2015–2017, several sites with large populations of Onopordum spp. were identified. Weekly surveys of some of the sites, mainly in the regions of Damascus and Al Suwayda, revealed a significant diversity of phytophagous insect species, some of which had a very high population density. A total of 29 insect species were detected, belonging to four orders and 21 families. The most abundant species were from the order Coleoptera. These were observed to be feeding on different plant parts of Onopordum spp. Purely endophagous species comprised 38% of the species observed on Onopordum spp., ectophagous species comprised 45% with 17% of species mixed ectophagous and endophagous. Species that only fed on Onopordum spp. represented 34% of all the species observed.     

The role of Tetrastichus giffardianus Silvestri (Eulophidae: Hymenoptera) in natural control of Bactrocera zonata (Saunders) (Tephritidae: Diptera) and its temporal abundance in Sudan

Bactrocera zonata is an alien fruit fly which was introduced into Sudan in 2012 and spread throughout the country, severely hampering the production and export of fruit and vegetable crops. Cataloguing indigenous natural enemies of pests, especially parasitoids, is key to successful biological control programmes, to mitigate damage and decrease reliance on insecticides. This study was conducted to determine the parasitoids of B. zonata in two orchards in Gezira State, Sudan from November 2015 to May 2016 and from February to December, 2016 and to determine their role in natural control of the pest. Three parasitoids emerged from puparia of B. zonata, these were: Tetrastichus giffardianus Silvestri (Eulophidae), an Aganaspis sp. (Figitidae: Eucoilinae) and a Psyttalia sp. (Braconidae Opiinae). Tetrastichus giffardianus was the most numerous parasitoid throughout the study period. The mean percentages of B. zonata from guava fruits that were parasitized by T. giffardianus for the whole study period were 13.7% and 13.2% with 3.1 ± 0.3 and 2.8 ± 2.4 parasitoids per puparium at Fadasi and Gazirat Elfil sites respectively. Data on the temporal abundance of T. giffardianus is presented. Strenuous efforts should be considered to involve the reported natural enemies of B. zonata in integrated management programmes for fruit flies in Sudan.     

苹果绵蚜田间种群的抗性监测

为了掌握果园重要害虫苹果绵蚜Eriosoma lanigerum的抗药性水平及动态变化,于2012–2015年间利用浸叶法监测了中国新疆察布查尔、山东济南、陕西乾县、河北昌黎和江苏丰县苹果绵蚜对常用药剂吡虫啉、毒死蜱和高效氯氟氰菊酯的敏感性,同时测定了不同苹果绵蚜种群的酯酶和谷胱甘肽S-转移酶活力。以2012年察布查尔苹果绵蚜为相对敏感品系,结果发现:所有种群在不同年度均对吡虫啉产生了低到高水平抗性（最大抗性倍数 >2000倍）;对于高效氯氟氰菊酯,昌黎、乾县及察布查尔2014种群均为敏感,济南、丰县和察布查尔2015种群均产生了中到高水平抗性;对于毒死蜱,乾县种群保持敏感,察布查尔、昌黎、丰县和济南种群产生了低到高水平抗性。酶活力测定结果显示:谷胱甘肽S-转移酶活力与苹果绵蚜对吡虫啉和高效氯氟氰菊酯的抗性水平呈正相关性,而酯酶活力与苹果绵蚜抗药性水平无明显相关性。本研究表明,新疆察布查尔、山东济南、陕西乾县、河北昌黎和江苏丰县的苹果绵蚜对吡虫啉、毒死蜱和高效氯氟氰菊酯的抗性水平均呈逐年提高趋势,其中对吡虫啉的抗性程度最严重,防治中应注意合理轮换用药。     

Incidence,pathogenicity and diversity of Alternaria spp. associated with alternaria leaf spot of canola (Brassica napus) in Australia

Studies were undertaken to determine Alternaria spp. associated with leaf spot symptoms on canola (Brassica napus) in two cropping seasons (2015, 2016) across southern Australia. Major allergen Alt a1 and plasma membrane ATPase genes were used to identify Alternaria spp. In 2015, 112 isolates of seven Alternaria spp. were obtained, with A. metachromatica predominating. In 2016, 251 isolates of 12 Alternaria spp. were obtained, with A. infectoria predominating. Alternaria spp. isolates were morphologically and phylogenetically identified and studies to determine their pathogenicity on both B. napus (cv. Thunder TT) and B. juncea (cv. Dune) confirmed 10 species (A. alternata, A. arborescens, A. brassicae, A. ethzedia, A. hordeicola, A. infectoria, A. japonica, A. malvae, A. metachromatica and A. tenuissima) as pathogenic on both Brassica species. Alternaria ethzedia, A. hordeicola and A. malvae were recorded for the first time in Australia on any host and the record of A. arborescens was the first for New South Wales (NSW) and South Australia (SA). Other first records included A. infectoria on B. napus in NSW; A. japonica on B. napus in NSW and Western Australia (WA); A. metachromatica on any host in NSW, Victoria (VIC), WA and SA; and A. tenuissima on B. napus in NSW, SA and WA. It is evident that alternaria leaf spot on canola across southern Australia is not solely caused by A. brassicae, but that a range of other Alternaria spp. are also involved to varying degrees, depending upon the year and the geographic locality.     

安徽省茶园假眼小绿叶蝉优势种天敌的评判

为明确茶园天敌与假眼小绿叶蝉Empoasca vitis之间关系的变化动态,用灰色关联度法和生态位法研究天敌与假眼小绿叶蝉在数量、时间、空间上的关系,综合分析假眼小绿叶蝉优势种天敌位次在茶树品种间和年份间的差异。结果显示,根据密切指数之和比较发现,2015年在乌牛早茶园与白毫早茶园中,与假眼小绿叶蝉跟随关系密切的前3位天敌中均有锥腹肖蛸Tetragnatha maxillosa和粽管巢蛛Clubiona japonicola,这2种天敌在2种茶园中的密切指数之和分别为5.493和5.784;2016年天敌中均有八斑球腹蛛Theridion octomaculatum和粽管巢蛛,这2种天敌在2种茶园中密切指数之和分别为5.296和5.448。2015年与2016年相比,乌牛早茶园前3位天敌中均有粽管巢蛛,白毫早茶园前3位天敌中均有锥腹肖蛸和粽管巢蛛。表明2个品种茶园不同年份假眼小绿叶蝉前3位优势种天敌为粽管巢蛛、锥腹肖蛸和八斑球腹蛛。