Alien Invasive Species in Europe: Three Case Studies

The incidental introduction of alien phytophagous insects and mites has become quite a common event in the world owing to intensive commercial exchanges of plants and goods and ever-increasing tourist traffic. There is evidence that this phenomenon is increasing, in spite of the control measures of the EU phytosanitary system in order to minimize unintentional introductions. The introduction of an alien species in a new ecosystem and the interaction between an alien species and the autochthonous species usually has many disadvantages. The alien species can dominate the invaded ecosystems and eventually become an invasive species due also to the absence or paucity of natural enemies. These invasions can affect the native species that become less common or threatened with extinction. Apart from the environmental impacts alien species are known for their economic and health impacts. In this study were investigated mostly 3 recently introduced alien species in Italy, namely Tuberocephalus (Trichosiphoniella) tianmushanensis Zang (Hemiptera Aphididae), Cydalima perspectalis (=Glyphodes) (Walker, 1859) (Lepidoptera Crambideae), the box caterpillar and Phenacoccus defectus Ferris (Rhynchota Pseudococcidae). The first chapter is a background of invasive ecology and presents with graphs the high number of alien species introduced in Europe the last years.. The second chapter is dealing with Tuberocephalus (Trichosiphoniella) tianmushanensis Zang, an Asiatic heteroecious species so far not recorded in Italy. This species was collected in the University Botanical Garden of Padova in spring 2012. On May 30, 2012 reddish-pink galls, with aphids inside, were observed on the leaves of two Prunus subhirtella cv. pendula trees (Rosaceae) (Weeping Higan Cherry), about 40 years old. Once mounted on slides the aphids were identified as Tuberocephalus (Trichosiphoniella) tianmushanensis Zang. The purposes of this study were to collect data on species distribution over the territory, by monitoring ornamental cherry trees in the Veneto region, to observe the phenology and biology of the Asiatic aphid, to study the life-cycle in screen houses and outdoors, to verify if its secondary host plant was an Artemisia sp., as reported in bibliography. Another aspect of the work was to provide an overview of the species belonging to the genus Tuberocephalus so far described, by consulting the available literature. It was made an effort to gather all the currently available information for each species, its distribution and information on their biology mainly regarding the first and secondary host plants. Results showed that Tuberocephalus (T.) tianmushanensis, is now considered acclimatized in our environment. The aphid is closely related to the presence of its primary host Prunus subhirtella v. pendula with pink flowers. The aphid can carry on two generations on Prunus and can induce two types of leaf galls. The gall A is induced by the fundatrix, while the gall B is induced by the fundatrigeniae. The trial of colonization on Artemisia vulgaris, failed for the second successive year so possibly Artemisia vulgaris is not the secondary host plant of the aphid, as reported in literature. The third chapter concers Cydalima perspectalis (Lepidoptera, Crambiidae) (Walker, 1859), an asiatic pest of Buxus. It was reported for the first time in Europe in Germany in 2007. In Italy it was detected in 2011, in Lombardy, Como province. In a very short time it invaded the other northern regions and was recorded in Veneto in 2012. The larvae feed on leaves and shoots of the box trees and the infestations lead to defoliation of the plants. The objective of this study was to investigate the phenology of C. perspectalis. More precisely we examined the biological cycle of life, the number of molts and the overwintering stage. In addition host plants were monitored by regular samplings, from late winter to late fall to collect data on species distribution over the territory. The life-cycle was studied in screen houses and in the field, to investigate the role of potential predators and parasitoids. Additionally experiments were conducted with pheromones traps with the purpose of checking, monitoring and collecting data on species distribution over the territory, finding any possible differences based on climate, checking the potential differences between types of traps. According to the results of 2014 and 2015 in the Veneto Region C. perspectalis develops three generations / year. In 2014 the overwintering larvae started their activity early in February until mid-April while in 2015 one month later until end of April probably due to different climate conditions between these years. C. perspectalis overwinters in a silk cocoon in-between the leaves as a larva of 2nd instar and the number of larval instar is 5. The number of captures from the sex pheromones traps was low. No differences were observed between the two types of pheromones. C. perspectalis has spread quickly in our environment proving that it has acclimatized. So far, it seems there has been no adaptation by indigenous natural enemies (parasitoids) to C. persectalis. The next chapter is focued on the difficulty to separate the Phenacoccus solani Ferris and P. defectus Ferris (Hemiptera: Pseudococcidae). They are morphologically similar and the microscopic morphological characters of the adult female alone are not enough. In order to resolve their identity, a canonical variates morphological analysis of 199 specimens from different geographical origins and host plants and a molecular analysis of the CO1 and 28S genes were performed. The morphological analysis supported synonymy of the two species, as although the type specimens of the "species" are widely separated from each other in the canonical variates plot, they are all part of a continuous range of variation. The molecular analysis showed that P. solani and P. defectus are grouped in the same clade. On the basis of the morphological and molecular analyses, P. defectus is synonymized under the senior name P. solani, syn. n. Finally a zoogeographic analysis of the Greek scale insects fauna (Hemiptera, Coccoidea) was carried out with the aim to highlight how many alien scale insects species are so far present in the Greek territory. According to the last data, the scale insect fauna of whole Greek territory comprehends 207 species; a total of 187 species are recorded in mainland Greece and minor islands, whereas only 87 scale species are known so far in the island of Crete. The most numerous families are the Diaspididae, with 86 species in total, followed by Coccidae, with 35 species and by Pseudococcidae, with 34 species. The results of a first zoogeographical analysis of scale insect fauna of mainland Greece and the island of Crete is also presented. Five scale species, respectively four in mainland Greece and one in Crete, are considered as endemic. This analysis demonstrated that alien scale insects, introduced and acclimatized a long time ago or recent invaders, make up 30% of the Greek scale insects fauna

Phenacoccus defectus

<p> <i>Phenacoccus defectus</i></p> <p> <b>Material at UCD: Type material</b>: holotype, U.S.A., California, Santa Clara Co., Permanente Creek, on roots of <i>Eriophyllum confortiflorum</i>, coll. G.F. Ferris, 5.v.1917. Paratypes, same data as holotype, 5; and California, Santa Clara Co., Stevens Cr., on <i>Monardella</i> sp., coll. G.F. Ferris, 26.viii.1917, 1.</p> <p> <b>Material at CSCA: U.S.A.</b>, California:- Alameda County, Berkeley, on <i>Echeveria rubella</i>, coll. G.B. Laing, 24.i.1949, 3; Los Angeles County, Huntington Gardens, on <i>Echeveria carnicolor</i>, coll. A. Wiens, 8.iii.1993, 7; on <i>Centaurea diluta</i>, coll. T.C. Fuller, 27.vi.1963, 4; Sacramento County, Sacramento, on <i>Hibiscus</i> sp., coll. K. Casanave, 21.ii.2001, 4; San Diego County, Ramona, on <i>Echeveria</i> sp., coll. G.L. Hill, 1.ii.1957, 3; Vista, on <i>Echeveria</i> sp., coll. Mariscal, 5.x.1981, 4; Ramona, on <i>Echeveria</i> sp., coll. G.L. Hill, 16.i.1957, 4; Siskyu County, Etna, on <i>Sempervirens</i> sp., coll. W. Ferlatte, 8.ix.1995, 3; Ventura County, Oxnard, on <i>Ophiopogon japonicus</i>, coll. E. Kragh, 5.iv.1995, 4; Nevada; Orovada, on <i>Atriplex confertifolia</i>, coll. B.L. & K., 26.viii.1959, 4; ex Nevada, Las Vegas, intercepted at California, Yermo Inspection Station, on <i>Solanum lycopersicum</i>, coll. Martin, 24.viii.2009, 10.</p> <p> <b>Canada</b>, British Columbia, White Lake, on <i>Centaurea diffusa</i> with ants, coll. T.P. Cuda, 25.iv. 1989, 1.</p> <p> <b>Material at RUMF: Japan</b>, Okinawa, collected by H. Tanaka: Ginowan, Ganeko, on <i>Ruellia brittoniana</i>, 30.viii.2011, 5; Naha, Shikina garden, on <i>Ruellia brittoniana</i>, 9.iii.2011, 12; Naha, Tomari, on <i>R. brittoniana</i>, 30.vii.2014, 2; on <i>Sphagneticola trilobata</i>, 30.vii.2014, 10; Nishihara, Sakata, on <i>Ruellia brittoniana</i>, 9.iii.2011, 12.</p> <p> <b>Material at DAFNAE</b> (from the cultures from which the DNA samples were taken): <b>Italy</b>, material reared at the DAFNAE laboratory, collected by G. Pellizzari: on <i>Sempervivum</i> sp., 7.vii.2010, 2; on <i>Echeveria</i> sp.*, 30.ix.2013, 2; on <i>Echeveria</i> sp.*, 11.vii.2014, 2; on <i>Solanum lycopersicum</i>, 7.x.2013, 5; on <i>S. tuberosum</i> sprouts, 30.ix.2013, 4; on <i>S. tuberosum</i> sprouts, 26.vi.2014, 1; on <i>Sedum</i> sp., 2.ix.2011, 1.</p>Published as part of <i>Chatzidimitriou, Evangelia, Simonato, Mauro, Watson, Gillian W., Martinez-Sañudo, Isabel, Tanaka, Hirotaka, Zhao, Jing & Pellizzari, Giuseppina, 2016, Are Phenacoccus solani Ferris and P. defectus Ferris (Hemiptera: Pseudococcidae) distinct species?, pp. 539-551 in Zootaxa 4093 (4)</i> on page 541, DOI: 10.11646/zootaxa.4093.4.5, <a href="http://zenodo.org/record/264159">http://zenodo.org/record/264159</a&gt

Phenacoccus solani

<p> <i>Phenacoccus solani</i></p> <p> <b>Material at UCD: Type material</b>: holotype, U.S.A., California, Santa Clara County, Palo Alto, Stanford University campus, on <i>Hemizonia rudis</i>, coll. G.F. Ferris, 21.x.1916. One paratype on same slide as holotype.</p> <p> <b>Non-type material identified by G.F. Ferris</b>: <b>U.S.A.</b>, California:- Glenn County, Orland, on roots of pigweed, coll. H.S. Smith, 15.x.1922, 3; Los Angeles County, Montebello, on <i>Eucharis amazonica</i>, coll. L.E. Meyers, 21.vii.1942, 2; Orange County, between Orange and Olive, on nutgrass, coll. R.J. Bumgardner, 11.x.1956, 2; Riverside County, Riverside, on injured tomato fruit, coll. Mr. French, ix.1924, 2; 3.4 mi. N.E. of Gilman Springs, on <i>Artemisia absinthum</i>, coll. D.R. Miller, 9.iii.1963, 2; Ventura County, on purslane, coll. A.H. Call, 1924, 2; Yolo County, Davis, on <i>Sida hereaceae</i>, coll. M.F. Benson, D.R. Miller & H.L. McKenzie, 2.vii.1964, 2; Florida, Alachua County, Gainesville, on <i>Ambrosia actinifolia</i>, coll. C.Q. Drake, vii.1918, 2.</p> <p> <b>Material at CSCA: U.S.A.</b>, Arizona, Navajo County, Show Low, host not recorded, coll. D.M. Tuttle, 24.vii.1964, 1; California:- Fresno County, Fresno, on <i>Lycopersicon</i> sp., coll. G. Gaffney, 19.viii.2004, 3; Imperial County, Salton City, on <i>Mangifera indica</i>, coll. J. Barcinas, 9.i.1994, 3; Inyo County, Independence, on <i>Ambrosia</i> sp., coll. R.P. Allen, 28.vii.1965, 2; Lassen County, Milford, on <i>Nicotiana</i> sp., coll. Ogden, Pfeiffer & Rulofson, 15.vii.1992, 6; Modoc County, Cedarville, on roots of composite, coll. T.R. Haig, 21.v.1962, 1; Monterey County, King City, Oasis Road, on <i>Vitis vinifera</i>, coll. L. Bettiga, 19.v.2008, 9; Florida, Broward County, Fort Lauderdale, host not recorded, coll. B. Steinberg, 5.vi.1988, 3; ex Texas, intercepted at California, Needles Inspection Station, on <i>Gossypium hirsutum</i>, coll. K.R. Hansen, 16.viii.1985, 1; Utah, Tooele County, Knolls, on roots of <i>Hermazoni</i> a sp., coll. R.F. Wilkey, 10.vii.1964, 1; Washington, Walla Walla County, Walla Walla, on <i>Achillea</i> sp., coll. S. Nakahara, 29.v.1966, 4.</p> <p> <b>Canada</b>, British Columbia, White Lake, on <i>Centaurea diffusa</i>, coll. T.R. Cuda, 25.ix.1989, 2.</p> <p> <b>Guam</b>, Tamuning, on spider lily, coll. R. Quitugua, 18.xii.2006, 1.</p> <p> <b>Israel</b> *, Jordan valley, Patza’el, 32°02′39″N, 35°26′57″E, 270 m, on <i>Capsicum annuum</i>, coll. Z. Mendel, viii.2013, 3. Bet-Dagan, host not specified, coll. unknown, 15.vii.2007, 1;?ex Israel via U.S.A., New York, intercepted at California, San Francisco County, San Francisco, on <i>Artemisia dracunculus</i>, coll. D. Fulford, 22.x.2007, 1.</p> <p> <b>Iran</b>, Shiraz, on <i>Vitis vinifera</i>, coll. V. Roumi, viii.2009, 5.</p> <p> <b>Brazil</b>, Rio de Janeiro, on <i>Citrus</i> sp., coll. M. Rose, 13.iii.1973, 3.</p> <p> <b>American Samoa *</b>, Tutuila I., Ottoville, Tafuna, on <i>Hymenocallis littoralis</i>, coll. M. Schmaedick, 22.xi.2013, 6.</p> <p> Ex <b>Australia</b> via U.S.A., Oregon, intercepted at California, Hornbrook Inspection Station, on <i>Citrus sinensis</i> fruit, coll. Pastell, 16.viii.2000, 1.</p> <p> <b>Japan *</b>, Okinawa, Ginowan, Ganeko, on <i>Ruellia brittoniana</i>, coll. H. Tanaka, 30.viii.2011, 2.</p> <p> <b>Turkey *</b>, Adana, originally collected from Reşatbey on <i>Gazania rigens</i>, coll. A.F. Çalışkan, 27.ix.2012, subsequently laboratory reared on <i>Solanum tuberosum,</i> 2 measured specimens killed 19.vii.2013.</p> <p> <b>Material at RUMF: Japan</b>, Honshu, Yamaguti Pref., Yamaguti, reared on <i>Solanum melongena</i>, coll. Y. Higashiura,?. i.2011, 3.</p>Published as part of <i>Chatzidimitriou, Evangelia, Simonato, Mauro, Watson, Gillian W., Martinez-Sañudo, Isabel, Tanaka, Hirotaka, Zhao, Jing & Pellizzari, Giuseppina, 2016, Are Phenacoccus solani Ferris and P. defectus Ferris (Hemiptera: Pseudococcidae) distinct species?, pp. 539-551 in Zootaxa 4093 (4)</i> on page 542, DOI: 10.11646/zootaxa.4093.4.5, <a href="http://zenodo.org/record/264159">http://zenodo.org/record/264159</a&gt

Genetic diversity of the invasive box tree moth, Cydalima perspectalis, in its native and invaded areas and preliminary phylogeographic approach.

During the recent decades, ornamental plant trade has triggered the introduction of alien invasive insects in Europe. An ever increasing number of these alien species originates from Asia, such as the box tree moth Cydalima perspectalis, a species native of China, Korea and Japan, which has recently been introduced into Europe. Since its first observation in Germany in 2007, the box tree moth has spread rapidly all over Europe, causing important damage on commonly planted ornamental box trees. The ornamental trade between Europe and China is hypothesized as the pathway of its primary introduction while the trade within Europe could have favored its rapid spread. In order to disentangle invasion pathways, samples of C. perspectalis were collected in China, Korea and in 13 of the 25 invaded European countries. We analyzed 174 sequences of mitochondrial markers COI and COII from the native and invaded areas in order to check the genetic variability, and to develop a preliminary phylogeographical approach. In the Asian populations, we observed 7 haplotypes divided into 3 haplogroups, and 4 of those haplotypes were also observed in Europe. Our preliminary results did not show evidence of genetic structure in the native range, which did not allow to define the potential donor regions but the presence of several Asian haplotypes in Europe in addition to a low but significant geographical structure is in favor of multiple introductions. Nevertheless, more populations need to be sampled in the area of origin together with the definition of more polymorphic markers in order to better understand the invasion pathways of C. perspectalis

Molecular Epidemiology of SARS-CoV-2 in Greece Reveals Low Rates of Onward Virus Transmission after Lifting of Travel Restrictions Based on Risk Assessment during Summer 2020.

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly during the first months of 2020 and continues to expand in multiple areas across the globe. Molecular epidemiology has provided an added value to traditional public health tools by identifying SARS-CoV-2 clusters or providing evidence that clusters based on virus sequences and contact tracing are highly concordant. Our aim was to infer the levels of virus importation and to estimate the impact of public health measures related to travel restrictions to local transmission in Greece. Our phylogenetic and phylogeographic analyses included 389 full-genome SARS-CoV-2 sequences collected during the first 7 months of the pandemic in Greece and a random collection in five replicates of 3,000 sequences sampled globally, as well as the best hits to our data set identified by BLAST. Phylogenetic trees were reconstructed by the maximum likelihood method, and the putative source of SARS-CoV-2 infections was inferred by phylogeographic analysis. Phylogenetic analyses revealed the presence of 89 genetically distinct viruses identified as independent introductions into Greece. The proportion of imported strains was 41%, 11.5%, and 8.8% during the three periods of sampling, namely, March (no travel restrictions), April to June (strict travel restrictions), and July to September (lifting of travel restrictions based on thorough risk assessment), respectively. The results of phylogeographic analysis were confirmed by a Bayesian approach. Our findings reveal low levels of onward transmission from imported cases during summer and underscore the importance of targeted public health measures that can increase the safety of international travel during a pandemic. IMPORTANCE Our study based on current state-of-the-art molecular epidemiology methods suggests that virus screening and public health measures after the lifting of travel restrictions prevented SARS-CoV-2 onward transmission from imported cases during summer 2020 in Greece. These findings provide important data on the efficacy of targeted public health measures and have important implications regarding the safety of international travel during a pandemic. Our results can provide a roadmap about prevention policy in the future regarding the reopening of borders in the presence of differences in vaccination coverage, the circulation of the virus, and the presence of newly emergent variants across the globe

Molecular Epidemiology of SARS-CoV-2 in Greece Reveals Low Rates of Onward Virus Transmission after Lifting of Travel Restrictions Based on Risk Assessment during Summer 2020

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly during the first months of 2020 and continues to expand in multiple areas across the globe. Molecular epidemiology has provided an added value to traditional public health tools by identifying SARS-CoV-2 clusters or providing evidence that clusters based on virus sequences and contact tracing are highly concordant. Our aim was to infer the levels of virus importation and to esti-mate the impact of public health measures related to travel restrictions to local transmission in Greece. Our phylogenetic and phylogeographic analyses included 389 full-genome SARS-CoV-2 sequences collected during the first 7 months of the pandemic in Greece and a random collection in five replicates of 3,000 sequences sampled globally, as well as the best hits to our data set identified by BLAST. Phylogenetic trees were reconstructed by the maximum likelihood method, and the putative source of SARS-CoV-2 infections was inferred by phylogeographic analysis. Phylogenetic analyses revealed the presence of 89 genetically distinct viruses identified as independent introductions into Greece. The proportion of imported strains was 41%, 11.5%, and 8.8% during the three periods of sampling, namely, March (no travel restrictions), April to June (strict travel restrictions), and July to September (lifting of travel restrictions based on thorough risk assessment), respectively. The results of phylogeographic analysis were confirmed by a Bayesian approach. Our findings reveal low levels of onward transmission from imported cases during summer and underscore the importance of targeted public health measures that can increase the safety of international travel during a pandemic. IMPORTANCE Our study based on current state-of-the-art molecular epidemiology methods suggests that virus screening and public health measures after the lifting of travel restrictions prevented SARS-CoV-2 onward transmission from imported cases during summer 2020 in Greece. These findings provide important data on the efficacy of targeted public health measures and have important implications regarding the safety of international travel during a pandemic. Our results can provide a roadmap about prevention policy in the future regarding the reopening of borders in the presence of differences in vaccination coverage, the circulation of the virus, and the presence of newly emergent variants across the globe

Dating the Origin and Estimating the Transmission Rates of the Major HIV-1 Clusters in Greece: Evidence about the Earliest Subtype A1 Epidemic in Europe

Our aim was to estimate the date of the origin and the transmission rates of the major local clusters of subtypes A1 and B in Greece. Phylodynamic analyses were conducted in 14 subtype A1 and 31 subtype B clusters. The earliest dates of origin for subtypes A1 and B were in 1982.6 and in 1985.5, respectively. The transmission rate for the subtype A1 clusters ranged between 7.54 and 39.61 infections/100 person years (IQR: 9.39, 15.88), and for subtype B clusters between 4.42 and 36.44 infections/100 person years (IQR: 7.38, 15.04). Statistical analysis revealed that the average difference in the transmission rate between the PWID and the MSM clusters was 6.73 (95% CI: 0.86 to 12.60; p = 0.026). Our study provides evidence that the date of introduction of subtype A1 in Greece was the earliest in Europe. Transmission rates were significantly higher for PWID than MSM clusters due to the conditions that gave rise to an extensive PWID HIV-1 outbreak ten years ago in Athens, Greece. Transmission rate can be considered as a valuable measure for public health since it provides a proxy of the rate of epidemic growth within a cluster and, therefore, it can be useful for targeted HIV prevention programs