Sixteen species of cockroaches have been reported for Austria so far. This study is the first record of the parthenogenetic Surinam cockroach, Pycnoscelus surinamensis (L.) for Austria (and thus Central Europe). The species is natively distributed in Indo‐Malaysia but has been unintentionally introduced in many, mainly tropical, countries throughout the world. Sequencing the DNA barcoding region revealed that all Austrian P. surinamensis samples had the same haplotype, which they shared with samples from the United States of America, Guyana and French Polynesia, indicating that all these samples/populations belong to the same clonal lineage. Even though in temperate regions, the occurrence of P. surinamensis is currently limited to greenhouses, we advocate proper monitoring of the populations with respect to global warming and the expected increasing independence of this species from greenhouses that comes along with it.

1 INTRODUCTION Cockroaches (Blattodea) are an insect order that comprises many highly adaptable species, some of which are feared as peridomestic pest species that were unintentionally introduced in many countries throughout the world. Even though most of these pest species are of tropic origin, some species such as the American cockroach, Periplaneta americana (Linnaeus 1758), the German cockroach, Blattella germanica (Linnaeus 1758) and the oriental cockroach Blatta orientalis (Linnaeus 1758) even established populations in temperate regions (Cochran, 1999). Sixteen species of cockroaches have been reported for Austria so far (Table 1). Only seven of these species are native to the country and found in the wild and not considered pests. They belong to the family Ectobiidae and are placed in two genera, Ectobius (4 species) and Phyllodromica (3). The remaining nine species, all of which are alien, belong to three families: Ectobiidae (2), Blaberidae (2) and Blattidae (5). Of Nyctibora sp. (Ectobiidae) and Rhyparobia maderae (Fabricius, 1781) (Blaberidae), only one specimen was ever found in Austria (Ebner, 1946). Most of the alien cockroach species are not (yet) present in the wild, but mainly found in synanthropic indoor habitats such as houses, tropical green houses, gardening shops or supermarkets. Several of these species are known to undergo mass reproductions. They can not only destroy and contaminate food reserves, but, because of their potential for transmitting diseases and triggering allergies, might also pose a risk to human health (Baur, Landau Lüscher, Müller, Schmidt, & Coray, 2004; Hubert, Stejskal, Athanassiou, & Throne, 2018; Pospischil, 2010). Table 1. Cockroach species recorded in Austria so far Taxon and author Red list Note Published in Ectobiidae Ectobius erythronotus Burr, 1898 VU Native Ebner ( 1951 1999 Ectobius lapponicus (Linnaeus, 1758) Not listed Native Ebner ( 1951 1999 Ectobius supramontes Bohn, 2004 Not listed Native Bohn ( 2004 Ectobius sylvestris (Poda, 1761) Not listed Native Ebner ( 1951 1999 Ectobius vittiventris (A. Costa, 1847) Not listed NE Introduced Zimmermann ( 2014 Nyctibora sp. Burmeister, 1838 Not listed NE Introduced Ebner ( 1946 Phyllodromica brevipennis (Fischer, 1853) Not listed Native Derbuch and Berg ( 1999 Phyllodromica maculata (Schreber, 1781) Not listed Native Ebner ( 1951 1975 1983 2011 Phyllodromica megerlei (Fieber, 1853) VU Native Ebner ( 1951 1997 Blaberidae Panchlora nivea (Linnaeus, 1758) Not listed NE Introduced Ebner ( 1946 Pycnoscelus surinamensis (Linnaeus, 1758) Not listed NE Introduced This study Rhyparobia maderae (Fabricius, 1781) Not listed NE Introduced Ebner ( 1946 Blattidae Blatta orientalis Linnaeus, 1758 Not listed NE Introduced Ebner ( 1946, 1951 1983 Blattella germanica (Linnaeus, 1767) NE Introduced Ebner ( 1951 1995 Periplaneta americana (Linnaeus, 1758) Not listed NE Introduced Ebner ( 1946, 1951, 1953 1998 Periplaneta australasiae (Fabricius, 1775) NE Introduced Ebner (1946, 1951, 1953 ) and Ressl (1983) This study Supella longipalpa (Fabricius, 1798) Not listed NE Introduced Rabitsch and Essl ( 2010 Here, we report the first records of the originally tropic Surinam cockroach, P. surinamensis (L.), for Austria and thus Central Europe, which were encountered by chance when capturing P. australasiae at the botanical garden in Graz for a student's course and amongst other cockroaches in the Butterfly House in Vienna.

2 MATERIAL AND METHODS We first discovered the Surinam cockroach in the Tropic House of the botanical garden in Graz (47°4ʹ53.75ʺN, 15°27ʹ24.88ʺE) on May 30, 2015. A single specimen (Figure 1a) was found among several Australian cockroach, Periplaneta australasiae (Fabricius, 1775), individuals. Three years later, on March 11, 2018, only a few Australian cockroaches remained, whereas numerous P. surinamensis were observed. On March 5, 2018, another population of the Surinam cockroach, including both adults and nymphs (Figure 1b,c), was discovered in the Butterfly House in Vienna (48°12ʹ19.26ʺN, 16°21ʹ59.74ʺE). The morphologically indistinguishable but bisexually reproducing Indian cockroach (P. indicus) was excluded as only females (and nymphs) were found. Three and four specimens of P. surinamensis were collected in the botanical garden in Graz and the Butterfly House in Vienna, respectively, put in >99% ethanol and deposited in the collection of the Natural History Museum in Vienna (Supporting Information Table S1). Figure 1 Open in figure viewer PowerPoint Pycnoscelus surinamensis, from Austria. Photographs of (a) the first specimen found in the Tropic House of the botanical garden in Graz (2015‐05‐30), (b) a female collected in the Butterfly House in Vienna and (c) a nymph from the same locality. (d) neighbour‐joining tree, (based on K2P‐distances) including all sequences of P. surinamensis and other Pycnoscelus species available from GenBank and BOLD, including our new records from Austria (in bold). Acronyms indicate origin of the specimen (Thailand: T; French Polynesia: FP; Australia: Aus; United States of America: USA; Guyana: G and Austria: Aut; see Supporting Information Table Surinam cockroaches,, from Austria. Photographs of (a) the first specimen found in the Tropic House of the botanical garden in Graz (2015‐05‐30), (b) a female collected in the Butterfly House in Vienna and (c) a nymph from the same locality. (d) neighbour‐joining tree, (based on K2P‐distances) including all sequences ofand otherspecies available from GenBank and BOLD, including our new records from Austria (in bold). Acronyms indicate origin of the specimen (Thailand: T; French Polynesia: FP; Australia: Aus; United States of America: USA; Guyana: G and Austria: Aut; see Supporting Information Table S1 ). Numbers at nodes indicate bootstrap support values (only values >70 are shown) [Colour figure can be viewed at wileyonlinelibrary.com Total genomic DNA was extracted using the DNeasy® Blood & Tissue Kit (Quiagen) from leg muscle tissue. A 684 bp fragment of the first part of the mitochondrial COI gene, corresponding to the typical DNA barcoding region (Hebert, Cywinska, Ball, & de Waard, 2003), was amplified using the Phusion polymerase (Thermo Fischer Scientific) protocol, following the manufacturer's instructions using the primers LCO1490 and HCO2198 (Folmer, Black, Lutz, & Vrijenhoek, 1994). PCR products were purified with ExoSAP‐IT (Thermo Fisher Scientific). The sequencing reaction followed the protocol in Duftner, Koblmüller, and Sturmbauer (2005), using the same primers as for PCR. Sequencing products were purified with SephadexTM G‐50 (Amersham Biosciences) and visualized on an ABI 3130xl capillary sequencer (Applied Biosystems). Sequences were aligned using MUSCLE (Edgar, 2004), as implemented in MEGA6 (Tamura, Stecher, Peterson, Filipski, & Kumar, 2013). Additional sequences of P. surinamensis and other Pycnoscelus species that were available on GenBank and/or BOLD were downloaded and added to the alignment. A neighbour‐joining tree (Saitou & Nei, 1987) applying the K2P model (Kimura, 1980)—the model typically employed in DNA barcoding studies—and 1,000 bootstrap replicates for statistical node support (Felsenstein, 1985) was inferred using MEGA6. Following Bourguignon et al. (2018), the tree was rooted with P. femapterus. MEGA6 was also used for calculating K2P‐distances among species and within P. surinamensis.

3 RESULTS DNA barcodes grouped the Austrian samples with previously published COI sequences of P. surinamensis, thus confirming the morphology‐based identification. Furthermore, all specimens from Austria shared a single haplotype, which was identical to specimens from the United States of America, Guyana and French Polynesia (Figure 1d). Haplotypes were also shared between P. surinamensis and its bisexually reproducing ancestor P. indicus. Pairwise K2P distances ranged from 0% to 3.9% within P. surinamensis, and from 0% to 11.9% among the Pycnoscelus species included in our study.

4 DISCUSSION With the detection of the originally Indo‐Malaysian Surinam cockroach Pycnoscelus surinamensis in Austria, the number of cockroach species reported for Austria increases to seventeen (Table 1), ten of which are alien. These Austrian P. surinamensis are also the first records of this species for Central Europe. Previously, the species has been reported from mainly tropical and subtropical regions, such as Florida, Louisiana, Texas and Hawaii in the United States, Cuba, Puerto Rico, the Bahama Islands, the Dominican Republic, Trinidad, Barbados, Martinique, Grenada, St. Vincent, Jamaica, Mexico, Costa Rica, Guiana, Brazil, Bermuda, Mauritius, the Central African Republic, Cameroon, Senegal, China, Taiwan, Australia, the Loyalty Islands, Japan, but also Spain and Sweden (Bell, Roth, & Nalepa, 2007; Garanto, 2015; Grandcolas, Dejean, & Deleporte, 1996; Schwabe, 1949). It is considered a peridomestic species that invades households and causes considerable damage to commercial rose, orchid and lily plantations, but also feeds on roots of pineapples, potato tubers, cucumbers, palm, tomatoes, papayas, figs, sweet potatoes and other plants (de Carvalho Moretti, Quirán, Solis, Rossi, & Thyssen, 2011; Schwabe, 1949). Outside its native range, it relies on human‐mediated activities, especially transportation of soil, mulch, vegetable mould or plants from one human settlement to the next, to colonize new areas (Bell et al., 2007). Due to its synanthropic or peridomestic lifestyle (Grandcolas et al., 1996), it often finds itself in suitable climatic conditions right away, even when transported to subtropical or temperate regions, as P. surinamensis has been repeatedly reported from greenhouses (Schwabe, 1949; Pellens & Grandcolas, 2002; Yamauchi & Kato, 2009; Komatsu, Kawakami, Banzai, Ooi, & Uchida, 2015; Garanto, 2015; this study). Pycnoscelus surinamensis is the thelytokous descendant of its bisexually reproducing progenitor P. indicus (Linnaeus 1758) (Bourguignon et al., 2018; Roth, 1967). Its parthenogenetic mode of reproduction facilitates a rapid establishment of new populations, with only a single female being sufficient to found a new population. It is noteworthy that many invasive species are parthenogenetic (e.g., Lombardo & Elkinton, 2017; Gutekunst et al., 2018) and that many taxa for which sexual reproduction is common in the native range, tend to switch to obligate or facultative parthenogenesis in introduced populations (e.g., Dybdahl & Kane, 2005; Caron, Ede, & Sunnucks, 2014). Pycnoscelus surinamensis is no exception as its almost global distribution contrasts the restricted distribution of P. indicus in the Indo‐Malayan region (plus some introduced populations in Hawaii and Australia; Roth and Willis, 1960). Numerous clonal lineages have been reported for P. surinamensis. This high clonal diversity and the establishment of general purpose genotypes are believed to underlie the species’ adaptability and considered one of the main reasons for the species’ colonization success (Parker, Selander, Hudson, & Lester, 1977; Niklasson & Parker, 1994). For Austria, we thus far identified only a single mitochondrial haplotype—likely corresponding to one clone—that is shared with samples from the USA, Guyana and French Polynesia. Overall, genetic distances among P. surinamensis haplotypes published so far are similar to levels of intraspecific divergence in other (sexually reproducing) cockroach taxa (Cho, Suh, & Bae, 2013; Che, Gui, Lo, Ritchie, & Wang, 2017). Although the prevailing opinion is that this species’ dispersal ability is very limited without human intervention (de Carvalho Moretti et al., 2011; Pellens & Grandcolas, 2002), it may be considered as a potential pest species in Central Europe in the light of the current climate change. Global warming increasingly provides suitable conditions even outside of conditioned greenhouses, likely enhancing winter survival as well as redefining/broadening current species’ distributions (Dukes & Mooney, 1999; Robinet & Roques, 2010). Thus, to prevent an unintended spread of alien species, monitoring of all introduced cockroach species as well as careful handling of plants, soil and food to prevent further accidental dispersal of P. surinamensis and other exotic species is advised.

ACKNOWLEDGEMENTS We are grateful to the HBLFA (Höhere Bundeslehr‐ und Forschungsanstalt für Gartenbau) and especially to Renate Wölflmaier for providing the specimens from Vienna. We also thank Iphigenie Jäger for the hint to the population in Vienna. We also thank Susanne Randolf for checking the collection of the Natural History Museum in Vienna and Wolfgang Rabitsch for additional information on Austrian cockroaches. Financial support was provided by the Austrian Federal Ministry of Education, Science and Research via an ABOL (Austrian barcode of Life; www.abol.ac.at) associated project within the framework of the “Hochschulraum‐Strukturmittel” Funds and the University of Graz.

AUTHOR CONTRIBUTION LZ, GK and SK designed the study. GK and CB collected samples. LZ conducted the laboratory work. LZ and SK analysed the data. LZ, GK and SK wrote the manuscript. All authors read and approved the manuscript.

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