First Maltese record of Stephanopachys quadricollis (Marseul, 1879) (Coleoptera, Bostrichidae)

Abstract Three specimens of Stephanopachys quadricollis (Marseul, 1878) were recently found in Malta in UV light traps and represent the first record of this species for this country. Although Stephanopachys quadricollis is native to the Mediterranean basin, it is not yet clear if these Maltese records are due to a natural population or to an interception. Distributional, nomenclatural and biological data on this species are summarized, and a new synonymy is established: Stephanopachys quadricollis (Marseul, 1879) = Stephanopachys quadraticollis Kocher, 1956, syn. n.


Introduction
The Bostrichidae of the Maltese Islands are represented by ten species of which two are definitely aliens but their establishment is unclear (Nardi and Mifsud 2015). A recent capture of Stephanopachys quadricollis (Marseul, 1879) in Malta, discussed herein, is recorded for the first time from the Maltese Islands.

Material and methods
The beetles were identified following the work of Borowski and Węgrzynowicz (2012). The authorship of Stephanopachys quadricollis is attribute to Marseul (1879) (see forward "Notes"). The distribution pattern is expressed also by a chorotype according to Vigna Taglianti et al. (1999). The systematic and botanic nomenclature follow The Plant List (2013). Possible interpolations are given in square brackets. The following abbreviations are used in the text: ex = specimen/s; leg. = legit or legerunt.  Halperin and Damoiseau 1980, Nardi 2004, Borowski 2007, Brustel et al. 2013). Moreover, it was intercepted in Sweden (Lundberg 1995, Borowski 2007, Brustel et al. 2013, Germany and Argentina (Walker 2005), while the record for Israel (Halperin and Damoiseau 1980) was recently overlooked (Borowski 2007, Brustel et al. 2013.
Most of the above-mentioned Italian literature records provide only the region of collection for S. quadricollis, with the consequence that few precise locations are known. These include: Cugno Ruggeri, 1400-1500 m, on the Pollino Massif in Basilicata ); Camigliatello, 1250-1300 m, on the Sila plateau in Calabria (Angelini 1991); contrada Tremonti near Messina (Vitale 1928), andMessina (Luigioni 1929) in Sicily. Stephanopachys quadricollis was collected from very few coastal regions in Italy. These include localities in Sicily and Mount of Portofino in Liguria (see material examined). In Sicily, Vitale (1927) collected a specimen of this species beating Juglans regia tree on the 1 st of April 1927.
The occurrence of Stephanopachys quadricollis in Malta, is not the sole insular record so far known; this species is also recorded from the Balearic Islands (cf. Bahillo de la Puebla et al. 2007), from Meleda Island in Croatia (Ganglbauer 1904, Vrydagh 1961) and from Lesbos Island in Greece (Sahlberg 1913a(Sahlberg , 1913b. Moreover it is also known to occur in some mainland coastal areas: e.g. Mount of Portofino in northern Italy (see above), in southern France (Brustel and Aberlenc 2014), in the Iberian Peninsula (Español 1955, 1965, 1974, Bahillo de la Puebla et al. 2007, Baena and Zuzarte 2013, as S. quadricollis (Fairmaire, 1878 [sic!]) and in Turkey (Vrydagh 1962).
The native status of Stephanopachys quadricollis in Malta is highly probable considering the fact that is a typical Mediterranean species and that its main host plant, Pinus halepensis is autochthonous (Haslam et al. 1977). However, an anthropic origin cannot be excluded. The location from where the Maltese specimens were collected is mainly an industrialized area with several pharmaceutical companies however some pine trees are also present. Interceptions of Palaearctic Stephanopachys species are known in other countries. These include S. quadricollis in Sweden, Germany and Argentina (see above), S. substriatus (Paykull, 1800) in Belgium (Coulon 1993) and Germany (Lucht 1987, Köhler and Klausnitzer 1998, Geis 2002, and a southern European unidentified species in USA (Haack andCavey 2000, Haack 2006).
As reported above, the Maltese specimens were taken at UV light. The use of light traps is a useful method to capture Bostrichidae. In fact, four other species of this family were previously collected at light in Malta (Nardi and Mifsud 2015), while 17 species were collected during a large light-traps project in Israel (Chikatunov et al. 2006). However, in Israel S. quadricollis was not collected in this project possibly due to the fact that its abundance was reported as "sporadic and rare" (Halperin and Damoiseau 1980: 48). In France, in a large artificial forest of Pinus pinaster, a single specimen of S. quadricollis was collected by an emergence trap (Brin et al. 2011), and the capture of Stephanopachys spp. using intercept traps is rare (Brustel et al. 2013).
In the IUCN Red List of European saproxylic beetles, Stephanopachys quadricollis is classified as "Least concern" (Nieto and Alexander 2010), whereas in the Italian list its status is indicated as "Vulnerable" (Nardi et al. 2014(Nardi et al. , 2015. The only recent Italian record of this species is from the Sila National Park, and this provides further evidence of the coleopterological importance of this Park (cf. Angelini 1991, Mazzei et al. 2011, where the species probably develops on Pinus nigra ssp. laricio Maire. This same host plant for S. quadricollis was also recorded by Sainte-Claire Deville (1914: 545) in Corsica. From a conservation point of view, S. quadricollis is known from other Italian localities such as Pollino and Portofino which are already designated as protected areas and this should therefore contribute towards the survival of this species in Italy.
Finally, Kocher (1956: 114) published an unjustified emendation (ICZN 1999, art. 33.2.1) of Stephanopachys quadricollis: "S. quadraticollis (err. quadricollis) Mars.". Unfortunately, this name is an available one (ICZN 1999, art. 19.1) and so the following synonymy is here established: Stephanopachys quadricollis (Marseul, 1879: 83) = Stephanopachys quadraticollis Kocher, 1956: 114, syn , for help in the field or in the lab, and/or for enabling us to study the collections in their care. We thank Jerzy Borowski (Warsaw University of Life Sciences, Poland), and an anonymous colleague for their reviews. Part of the work that contributed to this publication has been funded in the framework of the project LIFE09 ENV/IT/000078 ManFor C.BD. "Managing forests for multiple purposes: carbon, biodiversity and socio-economic wellbeing", coordinated by Giorgio Matteucci (Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche (IBAF-CNR), Monterotondo Scalo, Rome).