Ant-fungus Interactions : Laboulbenia camponoti Batra in Italy and a New Host for L .

Laboulbeniales, with over 2000 species, are obligate ectoparasites living attached to the cuticle of arthropod hosts (Tavares, 1985). Most are known to parasitize Coleoptera, although Diptera, Dermaptera, Dyctioptera, Acari and Diplopoda are also known to harbour specific Laboulbeniales (Weir & Hammond, 1997). Only six species of Laboulbeniales parasitize Hymenoptera, and all attach to ants (Formicidae). Ant Laboulbeniales are globally distributed, being known from the Palaearctic, Nearctic, Neotropical and Indo-Malayan regions, with the Afrotropical and Australasian regions still lacking any register (Santamaria & Espadaler, 2015). Here we deal with two species from this last, and small, group of Laboulbeniales.


Introduction
Laboulbeniales, with over 2000 species, are obligate ectoparasites living attached to the cuticle of arthropod hosts (Tavares, 1985).Most are known to parasitize Coleoptera, although Diptera, Dermaptera, Dyctioptera, Acari and Diplopoda Ants were directly preserved in alcohol and examined under a dissecting microscope.All ant samples were scrutinised with a Leica SMZ16 with magnifications ranging from 40x to 115x.Special attention was given to femora and tibiae as those parts use to be the surfaces were fungi are most visible.Due to the non-systematic sampling method, our results have to be taken more as descriptive of the scarcity of fungi rather than a quantitative measure of infestation prevalence in a given area.
Permanent slides were prepared following Benjamin (1971) and are kept in the BCB Mycotheca of Universitat Autònoma de Barcelona (BCB slides).Ant specimens with attached fungi are kept in the private collection of K. Gómez (KGAC).Although the database is meagre, we explore host specificity of the two antparasite Laboulbenia, which accumulate 61 world records.Following Poulin et al. (2011), we use Simpson and Shannon indices as metrics for host structural diversity.Indices were obtained using EstimateS (Colwell, 2013).

Discussion
One hundred years have elapsed since the first instance of an ant-infesting Laboulbenial was collected in Italy.Rickia wasmannii Cavara was detected by Spegazzini (1914) on workers of Myrmica scabrinodis Nylander from Conegliano (Veneto).We are unaware of any other register of ant-Laboulbenial interaction in Italy.
The two Laboulbenia species here discussed seem to be limited to the Northern hemisphere.The genus Camponotus has a world distribution.Instead, the diverse ant genera known as hosts for L. formicarum (see below) have a Northern hemisphere distribution (http://www.antwiki.org/wiki/Category:Genus_Distribution_Map accessed March 2016).The absence of data for ant Laboulbeniales from Central and Eastern Eurasia calls for a dedicated search.
Host specificity encompasses several components: 1) structural (=basic) specificity or the number, and proportion, of host use; 2) phylogenetic specificity, the range of phylogenetic spectrum of hosts; 3) geographic specificity, the consistency of host use across the parasite geographical distribution.Depending on the quantity and quality of available knowledge, those different components may be singly explored, or in their interactions (Poulin et al. 2011).A simple analysis of the structural and phylogenetic components of host specificity indicates a lower specificity in L. formicarum (Table 2).The low host phylogenetic specificity in L. formicarum -sensu Poulin et al. 2011 -is the exception, rather than the rule, with host-Laboulbeniales relationships (Tavares, 1985;Weir & Hammond, 1997).Geographic specificity is likely low in L. camponoti as shows its detection on three Camponotus (C.aethiops, C. pilicornis, C. sylvaticus) at a single organic citrus grove in La Selva del Camp (Tarragona, Spain ; 41º13'07"N, 01º08'35"E) (unpub.obs.).A similar example of extremely low phylogenetic specificity is exhibited by the ant parasitic fungus Myrmicinosporidium Hölldobler.Known from the Palaearctic, the Nearctic and a single location in the Southern hemisphere, its spores have been detected in a wide host range of 38 species, 17 genera, and three ant subfamilies (Gonçalves et al., 2012;Lapeva-Gjonova, 2014;Giehr et al. 2015).Furthermore, geographic specificity seems to be also very low in Myrmicinosporidium since it was documented on seven ant hosts, belonging to seven genera, from five tribes, and three subfamilies at a single olive grove from Póvoa de São Miguel (Portugal) (Gonçalves et al., 2012).
With this note we add one more Laboulbenial to the list of the Italian mycoflora and prove right experimental, cross-infection laboratory results by Tragust et al. (2015) in the wild for Laboulbenia formicarum infecting Lasius niger in France.The ant genera Camponotus (subg.Tanaemyrmex) with eight species in Italy, and Lasius (s.str.) with nine species (Baroni Urbani, 1971;Poldi et al., 1995) offer ample host opportunities for the fungi.The genus Messor, with eight species in Italy (op.cit.), provides also possible hosts for the recently described Rickia lenoirii Santam.from Greece (Santamaria & Espadaler, 2015).Thus, it can be only expected an enlargement of the database for those interesting antfungus interactions when a dedicated search for is undertaken, either in the field as in this paper, or in Museum collections (Suarez & Tsutsui, 2004;Báthori et al., 2014Báthori et al., , 2015)).Ant genera Myrmica, Camponotus (Tanaemyrmex), Lasius (s.str.) and Messor should be specifically focused.Although a mere six Camponotus species are known from the state of Delhi, the genus has 83 species in India (Bharti et al. 2016).We take the conservative approach to consider the two registers of L. camponoti from India to belong in two different host species.
Table 2. Ant host structural and phylogenetic diversity of two Laboulbenia species.
Table 1 summarizes the localities where Lasius or Camponotus species were collected.