Greenhouses provide different environmental conditions for animal colonization and survival compared with natural or synanthropic habitats outside. Greenhouses are characterized by a lack of frost and higher, usually constant temperatures, high humidity, permanent, regular watering, the presence of plants from mostly tropical countries and lack of or only low amounts of leaf litter and dead wood provide a more or less unique ecosystem inside such artificial buildings.

Examples of possible pathways of introduction of myriapods in the greenhouses can be found in Attems (1901) and Kraepelin (1901). Myriapods from all developmental stages (eggs, juveniles, adults) can be introduced easily within soil and other substrates associated with plants during shipment.

The apparent  first record of a myriapod species from greenhouses in Germany is that by Schnur (1857), who recorded "Scolopendra germanica C. L. Koch, 1837". This species should be referred to either Cryptops hortensis (Donovan, 1810) or C. parisi Brölemann, 1920 (Attems 1930: 211). Which of these two species in fact was found by Schnur (1857) cannot be certain now today because the specimens have been lost. Another species recorded by Schnur (1857) is Mecistocephalus maxillaris (as Geophilus maxillaris). The identity of this species is doubtful and its specific status requires verification (Bonato and Minelli 2004). The same is true for the records by Latzel (1895) (Mecistocephalus guildingii Newport, 1844, later repeated as M. maxillaris by Jeekel (1964a)) and Eichler (1952).

Latzel (1895) recorded Oxidus gracilis (as Paradesmus gracilis), M. maxillaris, Lithobius forficatus and Paraspirobolus lucifugus (as Spirobolus dictyonotus Latzel, 1885) (Fig. 1) from a hothouse in a nursery in Hamburg and Poratia digitata (as Scytonotus digitatus Porat, 1899) from a tannery near Hamburg. The record of P. lucifugus was wrongly referred to the tannery in Bergedorf near Hamburg by Schubart (1934).

Figure 1.  

Living individual of Paraspirobolus lucifugus in the Hamburg Botanical Garden.

Silvestri (1907) later described Pectiniunguis pauperatus Silvestri, 1907 from plant soil in the Hamburg Botanical Garden, but this species has never been found subsequently.

Reports of other species were published by Boettger (1929), Hahmann (1929a), Hahmann (1929b), Schubart (1925), Schubart (1929b), Schubart (1929a), Verhoeff (1891), Verhoeff (1907), Verhoeff (1934) and other authors. Most of these are summarized by Eichler (1952) together with his own observations in the Berlin-Dahlem Botanical Garden. In total this author listed 20 diplopod and nine chilopod species for Germany. In the following decades sparse records by Adis et al. (2000), Decker and Hannig (2011), Golovatch et al. (2001), Jeekel (1964a), Läffert (1984), Richter (1967), Schubart (1957), Thiele (1968), Wilck (2000) increased the number of species known from German greenhouses to a total of 23 diplopod and 12 chilopod species.

With regard to the other two myriapod groups, no Pauropoda are so far known from German greenhouses and for Symphyla the three species Hanseniella oligomacrochaeta Scheller, 2002, Symphylella vulgaris (Hansen, 1903) and Hanseniella orientalis (Hansen, 1903) were recorded from the greenhouses in the Berlin-Dahlem Botanical Garden (Scheller 2008). We did not carry out further investigationa for these two groups.

Records of millipedes and centipedes in greenhouses for most of other European countries are mostly scattered in the literature, e.g.: Austria (Golovatch and Sierwald 2001, Golovatch et al. 2001a, Golovatch et al. 2001, Gruber and Christian 2002, Gruber 2002), Belgium (Kime 2004), Denmark (Andersson et al. 2005, Blower and Rundle 1986, Enghoff 1975, Enghoff 1987), Czech Republic (Kocourek 2013), France (Brölemann 1896, Geoffroy and Iorio 2009, Gervais 1836, Golovatch and Sierwald 2001, Golovatch et al. 2001), Netherlands (Berg et al. 2008, Jeekel 1953), Poland (Jedryczkowski 1982, Jedryczkowski 1996), Slovakia (Mock 2001), Sweden (Andersson et al. 2005, Blower and Rundle 1986, Lohmander 1925, Porat 1889) and Switzerland (Bigler 1913, Holzapfel 1932, Pedroli-Christen 1993). Only the greenhouse fauna of Great Britain is quite well studied (e.g. Barber 1992, Barber 2005, Barber 2009, Blower 1985, Blower and Rundle 1980, Blower and Rundle 1986, Lee 2005a, Lee 2005b, Lee 2006, Lewis 2007, Pocock 1906, Read 2008) but lacks a comprehensive overview. A general overview of alien myriapods in Europe is provided by Stoev et al. (2010).

Currently, the increasing number of new constructions of tropical houses in Germany (Fig. 2) as pleasure grounds, butterfly houses or similar institutions has increased the number of exotic plants, mostly imported directly from tropical countries. The exchange of common plant stocks among botanical gardens has also supported the dispersal of alien myriapods.

Figure 2.  

View from the top-of-the-tree-path in the greenhouse 'Gondwanaland', Zoological Garden Leipzig. Photograph: N. Lindner.