An updated annotated checklist of scale insects (Hemiptera, Sternorrhyncha, Coccomorpha) of Poland

Abstract A checklist of scale insects recorded to date in Poland is presented. The data provided here are based on literature records and include the latest taxonomic and nomenclatural changes and updates on Coccomorpha reported in Poland. Changes in comparison with ScaleNet and Fauna Europaea electronic databases are also discussed. A total of 185 species belonging to 98 genera and 16 families are included in the list. Of this group, 47 species are alien introduced species and live only indoors, and one species, Pulvinaria floccifera (Westwood), develops both indoors and outdoors.


Introduction
Scale insects form a relatively small group of insects in the Polish fauna and represent only approximately 0.7% of the 27,000 insect species currently known in Poland. However, a few species are identified as pests of economic importance, and especially, in recent years, the invasion of alien scale insects has been observed in several parts of Poland (Łagowska et al. 2015, 2018Golan et al. 2017).
Scale insects have been known for centuries in Poland for the carmine dye extracted from the Polish cochineal scale Porphyrophora polonica (Linnaeus). The presence of P. polonica in Poland was reported for the first time in the 16 th century (Miechowita 1521) and information about the harmful scale insects was published in later years by some authors (Trzebiński 1916;Ruszkowski 1925Ruszkowski , 1933Minkiewicz 1926). Advanced studies on the scale insect fauna of Poland were initiated by Kawecki, whose results have been presented in numerous publications from 1935 to 1985. In the same period and later, Koteja and Koteja and Żak-Ogaza, in publications from1964 to 2000, extensively studied the Coccomorpha and greatly contributed to the knowledge of the scale insect fauna in Poland. Further contributions are due to the studies by Komosińska (1961Komosińska ( -1987, Komosińska and Podsiadło (1967), Dziedzicka (1970Dziedzicka ( -1990, Podsiadło (1975); Podsiadło and Komosińska (1976), Łagowska (1990-2005), Łagowska and Koteja (1996), Dziedzicka and Karnkowski (1999), Łagowska and Golan (2005) and Łagowska et al. (2015, 2017, 2018).
Finally, 90 native and greenhouse species of scale insects that were new to the Polish fauna were discovered in the years -1980(Koteja 1985Łagowska and Golan 2005). However, the records of species new to the Polish fauna significantly decreased from 32 in the period 1971-1980to 8 in 1991-2005(Łagowska and Golan 2005, and only another 8 new species were recorded in Poland in 2006-2019. The early data on the distribution of scale insects in Poland were summarized by Kawecki (1985) in a catalogue listing 170 species, including 34 indoor species, and 11 records of misidentified species or species for which no host plants or localities were given. Later, two checklists of scale insects in Poland were presented by Koteja (1996) and Łagowska (2004) who reported 184 and 185 species respectively, each including 44 indoor species. In addition, an annotated list of alien scale insects present in Poland was published by Łagowska et al. (2015).
Two electronic databases provide important world-wide information on scale insect distribution: the Fauna Europaea (FaEu) database (Burckhardt 2013), which reports 163 species of scale insects from Poland, and the ScaleNet database (García Morales et al. 2016), which lists 177 species. Since the last checklist (Łagowska 2004), several new records of scale insects from Poland have been published (Łabanowski 2009;Kalandyk and Węgierek 2010;Kozár et al. 2013;Łagowska et al. 2015, 2018. In the meantime, the nomenclature of the scale insects has also been partially changed. Moreover, several records reported in FaEu and ScaleNet databases were regarded as doubtful or erroneous and need revision. The present paper provides a comprehensive revised list of the scale insects of Poland with updated nomenclature and references to the first reliable Polish records of each species. In addition, discrepancies between the present list and the last checklist (Łagowska 2004) as well as differences from the records reported in the FaEu and ScaleNet databases are discussed.
The aim of the present checklist is to provide baseline reliable data for future faunistic and taxonomic studies.

Materials and methods
The list presented in this paper is based on the literature records of Coccomorpha in Poland available up to September 2019. A reference to the first reliable record of each species is included. Fossil species of scale insects and those that have been intercepted only once on imported plant materials are excluded. Families and species within each family are listed in alphabetical order according to the classification used in the ScaleNet database (García Morales et al. 2016). The references to species recorded in Poland reported in FaEu and ScaleNet have been checked and, if erroneous, corrected in the present lists. Changes in systematic status and synonymies, mostly proposed by Kozár et al. (2013) and Danzig andGavrilov-Zimin (2014, 2015), and presently accepted in ScaleNet database, have been adopted in the present list. Scale insect species recorded in Poland are listed in Table 1. They belong to four categories as follows: (i) native species; (ii) alien species established outdoors; (iii) alien species established indoors; and (iv) alien species that can live and develop both outdoors and indoors. The definition of alien species in this paper is the one proposed by Łagowska et al. (2015).

Discussion
The scale insect species recorded in Poland represent only ca. 7.3% of the 2536 species known in the Palearctic region (García Morales et al. 2016) and ca. 41.1% of the 450 species reported in Europe (Pellizzari and Germain 2010). The previous checklist of scale insects of Poland was published 15 years ago (Łagowska 2004) and listed 185 species distributed in nine families and 94 genera. In the present list, the families Cryptococcidae, Matsucoccidae, Monophlebidae, Steingeliidae, Xylococcidae, Putoidae, and Rhizoecidae have been added, using the currently accepted classification of Coccomorpha. Moreover, eleven species new for the country have been added and ten species removed. The new entries are: Asterodiaspis quercicola, Pulvinaria hydrangeae, P. regalis, Aspidiotus palmarum, Aulacaspis yasumatsui, Lepidosaphes tokionis, Acanthococcus macedoniensis, Icerya purchasi, Spilococcus mamillariae, Volvicoccus volvifer, and Rhizoecus americanus. Of these V. volvifer, P. hydrangeae, P. regalis, and A. macedoniensis are established outdoors (Kalandyk and Węgierek 2010;Kozár et al. 2013;Łagowska et al. 2018), whereas A. yasumatsui, L. tokionis, S. mamillariae, and R. americanus, are indoors species (Łabanowski 2009). Icerya purchasi and A. palmarum were overlooked in the previous checklist and are therefore added to the present one. Asterodiaspis quercicola is here considered as a valid species (García Morales et al. 2016), despite the fact that Podsiadło (1990) and Stumpf and Lambdin (2006) considered A. quercicola and A. variolosa as synonyms.
Of the ten species removed from the list, six have been synonymized with other species (Eulecanium slavum (Kawecki, 1961), Lepidosaphes oleae Leonardi, 1908, Heliococcus danzigae Bazarov, 1974, Trionymus isfarensis Borchsenius, 1949, T. singularis Schmutterer, 1952, and Phenacoccus evelinae Tereznikova, 1975. The presence in Poland of the other four species removed from the list, Ripersia corynephori Signoret, 1875, Carulaspis visci (Schrank, 1781, Fiorinia fioriniae (Targioni-Tozzetti, 1867) and Oceanaspidiotus spinosus (Comstock, 1883) is here considered as doubtful or erroneous. Kiritchenko (1940) listed R. corynephori as found near Warsaw, but Kawecki (1985) assumed that this record was incorrect and the species might be a misidentification of Pseudococcus parvus Borchsenius, 1949(now Mirococcopsis subterranea (Newstead, 1893). Similarly, the record of C. visci was very likely incorrect and the species may be a misidentification of Carulaspis juniperi (Bouchѐ, 1851). In addition, the records of F. fioriniae and O. spinosus are questionable because no host plants or localities were given in the list published by Czyżewski (1937). All the species mentioned above have not been collected again since they were first recorded.
Based on the distribution data reported by Łagowska (2001), the native species currently known from Poland are all Palearctic. Almost half of them are widely distributed in this region, and relatively few are known only from three or four countries. This latter group includes the following species: Anophococcus confusus, Rhizococcus cantium, Boreococcus ingricus, Mirococcus festucae, and A. macedoniensis. Two species, Parthenolecanium smreczynskii and Kiritshenkella lianae, are known so far only from Poland and are possibly endemic.
Recently, much attention has been paid to the alien species of scale insects that have been introduced or have spread into Poland. This group includes 47 indoor and five outdoor species. One species (P. floccifera) has been recorded on ornamental plants in greenhouses in Poland as well as on outdoor ornamentals, mostly on Ilex sp., and appears to be established (Łagowska et al. 2017). Of the 47 species established indoors, 29 (61.7%) belong to the Diaspididae. This high proportion of species from Diaspididae family introduced into Poland is similar to the results presented by Pellizzari and Germain (2010) for Europe. According to these authors, the 60 alien species belonging to the Diaspididae account for nearly half (44.6%) of the 130 alien species estimated to occur in Europe. Of the five alien species established outdoors in Poland, only C. perniciosa and P. floccifera are considered as invasive (Łagowska et al. 2017, 2018). Currently, C. perniciosa poses the greatest threat, affecting a number of fruit trees in Poland .
Some differences in the species richness were found between the data reported in the databases ScaleNet and FaEu and the present checklist. Scale insects that are erroneously recorded as present in Poland in the above recorded databases are discussed below: Antecerococcus cistarum (Balachowsky, 1927), A. laniger (Goux, 1932), and A. pocilliferus (Neves, 1954) The presence of these three species in Poland, cited by the ScaleNet database, is a misunderstanding of the text of Koteja (1984), which records them as present in several European countries (Portugal, France, Algeria, Cyprus) but not in Poland. These three species were not listed by any of the researchers studying the fauna of scale insects in Poland, so they are excluded from the present list. The same species have also been incorrectly recorded in the FaEu database.
Asterodiaspis minor (Russell, 1941) This species was recorded by Russell (1941) in Poland, but Podsiadło (1975) recognized only Asterodiaspis quercicola and A. variolosa in Poland based on extensive morphological studies. Since this time, A. minor was not listed in the subsequent publications pertaining to the fauna of scale insects in Poland and is excluded from the present list, although it is listed in the ScaleNet database.

Epidiaspis leperii (Signoret, 1869)
In the ScaleNet database Poland is included among the locations of distribution of this species based on the paper of Danzig and Pellizzari (1998). However, the paper does not provide any precise indication of its presence in Poland. The species was also not listed later by the researchers who studied the fauna of scale insects in Poland, so it is excluded from the present list.

Kermes bacciformis Leonardi, 1908 and Kermes ilicis (Linnaeus, 1758)
These two species are recorded as hosts of a parasitoid by Sugonyaev (1965), and are cited by the ScaleNet database as records of distribution of scale insects, but this is probably a misunderstanding of the text, as the distribution records concern the parasitoid species and not the scale insects. These two species have also been incorrectly included in the FaEu database.

Lecanopsis turcica (Bodenheimer, 1951)
Poland was included among the countries in which this species is distributed in the FaEu database, but the source of information is missing. As there is no published evidence for the presence of this coccid in Poland, it is excluded from the present list.

Leucaspis pusilla Löw, 1883
This species is erroneously recorded in the ScaleNet catalogue citing Danzig and Pellizzari (1998), but those authors do not mention Poland as a location of its distribution.

Matsucoccus matsumurae (Kuwana, 1905)
Poland was included among the countries where this species is present in the FaEu database, but the source of information is missing. As there is no evidence for the presence of this species in Poland, it is excluded from the present list.

Parlatoria oleae (Colvee, 1880) and Parlatoria theae Cockerell, 1896
These two species are recorded as present in Poland in the FaEu database with an incorrect citation of ScaleNet as the source of information. We have been unable to trace the original sources of publication concerning the presence of these species in Poland and therefore we consider these records erroneous.

Parlatoria ziziphi (Lucas, 1853)
This species is cited in ScaleNet based on Komosińska (1964). However, this species was only found on citrus fruits imported to Poland. Since P. ziziphi was not mentioned in subsequent papers, we assume that this species is not established in Poland.

Pseudococcus viburni (Signoret, 1875)
Poland was included among the countries in which this species is present in the FaEu database, but the source of information is missing. As there is no evidence of the presence of this mealybug in Poland, this species is excluded from the present list.
Trionymus levis (Tang, 1992) Koteja (1974) and Koteja and Żak-Ogaza (1983) do not provide evidence of the presence of T. levis in Poland as cited by the ScaleNet database. Moreover, this species was not listed in the subsequent publications related to the Polish fauna of scale insects and is therefore removed from the present checklist. It has also been incorrectly included in the FaEu database. Komosińska H (1968) Investigations on the scale insects (Homoptera, Coccoidea, Diaspididae)