The previous studies contributing knowledge of the evolutionary history and phylogenetic relationships of Lamiinae are mainly dealing with higher-level relationships and covering only a few laminin taxa (Farrell 1998; Gómez-Zurita et al. 2007; Hunt et al. 2007; Wang et al. 2014; Haddad et al. 2018; Zhang et al. 2018). Since the inception of diversification of herbivorous beetles has been set on relatively solid ground, the studies are bending to lower taxonomic levels. Phylogeny of Lamiinae, especially at tribal and generic levels, has remarkable progress owing to de Santana Souza et al. (2020), Ashman et al. (2022) and Dascălu et al. (2022). However, the relationships at tribal and generic levels still require intense effort due to the species richness, remarkable diversity and the worldwide distribution of the subfamily. The present study contributes to understanding tribal and generic level phylogenetic relationships and the evolutionary history of Lamiinae using Eurasian species as the sampling allows.
Phylogenetic Relationships
The topologies suggested by the multi-locus ML and the time-scaled BI analyses showed consistency in the clustering of the genera Morimus (Phrissomini syn. of Lamiini), Dorcadion (Dorcadionini), Monochamus (Monochamini) and Batocera (Batocerini) (Fig. 1, Fig. S2). Single-locus COI-based NJ and ML trees analyses provided a broader aspect due to covering more taxa, and clustered Dorcadion and Iberodorcadion (Dorcadionini); Imantocera (Gnomini), Batocera and Apriona (Batocerini) with genera Lamia, Morimus, Paraleprodera, Blepephaeus and Peblephaeus at (Supplementary Fig. S1, Supplementary Fig. S2). This propinquity has long been recognized and suggested merging all tribes which have the guise of Monochamini by Breuning (1961) and supported by the following studies (Ohbayashi et al. 2009; Toki and Kubota 2010; Gorring 2019; de Santana Souza et al. 2020). Additionally, de Santana Souza et al. (2020) perceived Dorcadionini as the closest relative of Lamiini, despite its apparent difference, which is most probably due to only adaptive characters (Löbl and Smetana 2010). The close kinship of Lamiini and Dorcadionini was also supported by Giannoulis et al. (2020); however, their results were dissimilar to other studies due to the placement of Phytoecia (Phytoeciini) at the base of the Lamiini+Dorcadionini branch together with Monochamus (Monochamini). Our results were conformable with the results of de Ashman et al. (2022) and de Santana Souza et al. (2020) on the station of Monochamus and Batocera closely. Ren et al. (2021) also supported the sisterships of Batocerini and Lamiini. Contemplating the results of the present study and the previous studies mentioned above, the expectations of Lacordaire (1869) and Pascoe (1866) (as per de Santana Souza et al. 2020) regarding the close relationship between Batocerini and Monochamini seem to be plausible, and Dorcadionini, Gnomini, and Monochamini (at least in terms of Monochamus) should be revised.
Mesosini split from Lamiini and close relatives mentioned above by the absence of a sharp tubercle or spine at the lateral margin of the pronotum and a simple mesotibia (Bílý and Mehl 1989; Bense 1995). However, for both tribes, the first antennal segment has a rounded apex with a carina, which separates them from Saperdini (Bílý and Mehl 1989). The proximity of Mesosini to the cluster of Lamiini has been shown in the phylogenetic trees of de Santana Souza et al. (2020) and is supported by our results. (Fig. 1, Fig. 2, Supplementary Fig. S1, Supplementary Fig. S2). However, unlike de Santana Souza et al. (2020), Mesosa was not in the same subcluster as Saperda (Saperdini) in our phylogenetic trees. Therefore, the apex structure of the first antennal segment might be evaluated as a mark for the synapomorphy of Mesosini and Lamiini.
Phrynetini, represented by P. leprosa, was nested in Pogonocherini in our phylogenetic trees, while it was at the base of the Acanthoderini, according to de Santana Souza et al. (2020)'s results. This tribe is mostly occurring Afrotropic and Indomalaya regions, and its closely related taxa were possibly not included in analyses; thus, it would not be accurate to conclude its relationships.
Our results support the closeness of Pogonocherus and Exocentrus shown by de Santana Souza et al. (2020) and Ashman et al. (2022). On the other hand, considering our COI-based ML tree (Supplementary Fig. S2), clusterings of Ecyrus and Exocentrus of Pogonocherini with Rosalba sp. (Apomecynini) and Bactriola sp. (Forsteriini), respectively might be a sign of a need for questioning monophyly of Forsteriini by extensive sampling and broader genetic data, in addition to 12 tribes and Apomecynini discussed by de Santana Souza et al. (2020)
The tribes Acanthocinini and Acanthoderini, which share some morphological traits such as antennae lacking long erect hairs and laterally closed joint sockets of middle coxa (Bílý and Mehl 1989; Bense 1995), were sister clades in our time-scaled-BI and ML analyses, A. clavipes, the sole representative of the Acanthoderini, stated at the base of Acanthocinini, while it was clustered with P. leprosa from Phrynetini in de Santana Souza et al. (2020).
Agapanthiini, the 12-segmented tribe of the subfamily, was not monophyletic at the COI-based NJ and ML gene trees of the present study; C. filum was clustered with the genus Agapanthia. In contrast, Hippopsis sp. from this tribe was clustered out of this group, with O. singularis from the tribe Acanthomerosternoplini (Supplementary Fig. S1). Agapanthiini seems polyphyletic at the ML tree of de Santana Souza (2020) et al., in terms of Hippopsis sp., also.
The closeness of Obereini, Phytoeciini, and Saperdini was shown by de Santana Souza et al. (2020), who used the genera Oberea from the tribe Obereini and Mecas (Dylobolus) and Phytoecia from Phytoeciini, and Glenea, Paraglenea, and Saperda from Saperdini the present study's COI-based NJ and ML gene trees supported their results. The Saperdini group included Eutetrapha, Glenea, Mecas, Saperda, Stenostola, Thyestilla, and Phytoecia (Supplementary Fig. S1, Supplementary Fig. S1). Same as Ren et al. (2021), and Ashman et al. (2022), our findings support the suggestion of de Santana Souza et al. (2020) that the tribe Phytoeciini should also be a synonym of Saperdini or all members should be evaluated separately.
Diversification Times
Initial evolutionary history studies rely on genetic data to estimate the emergence of cerambycids from the Late Cretaceous (Gómez-Zurita et al. 2007) to the Early Cretaceous (Wang et al. 2014; Zhang et al. 2018), while recent studies, which were conducted with broader samplings and genetic data, have pointed out earlier emergence time, around late Jurassic to early Cretaceous (Nie et al. 2021; Ashman et al. 2022). Our time-scaled BI analysis dated the crown age ~153 Mya, at Late Jurassic to Early Cretaceous, compatible with the emergence times presented in previous studies (Farrell 1998; Wang et al. 2014; Yu et al. 2015; Zhang et al. 2018; McKenna et al. 2019; Nie et al. 2020; Ashman et al. 2022). Ashman et al. (2022) and Nie et al. (2021), whose time estimation studies cover broader laminin samples, have conflicts in some emergence times of MRCA of tribes, probably due to differences between their genomic data, calibration points, and the taxa included in the analyses. Also, our estimations resulted in some discordances due to the same reasons. All three of us are probably missing the most major branching events due to the scarcity of the taxa.
According to the chronogram of Ashman et al. (2022), MRCA of the subfamily Lamiinae emerged at ~105 Mya; Acanthocinus griseus (Acanthocinini) split from the MRCA of Lamiinae and stated at the base of the Lamiinae clade. According to our chronogram, the emergence of the MRCA of the subfamily ~128 Mya was approximately 50 Mya earlier than the MRCA of Acanthocinini and Acanthoderini, which emerged ~78 Mya at the late Cretaceous. The split of A. griseus and A. aedilis was dated ~23 Mya, earlier than the oldest known fossil species of the genus Acanthocinus schmidti Schmidt 1967 3.6 to 2.588 Mya from Pliocene of Germany (Gersdorf 1976). Other fossil records Astynomus tertiarius Kolbe 1888 and Kallyntrosternidius bucarensis Vitali, 2009 of Acanthocinini address an earlier date (15.97 to 13.65 Mya) Miocene of Germany and 20.43 to 13.65 Mya Miocene of Dominican Republic (Vitali 2009), respectively. The fossil records of Acanthoderini, Acanthoderus lepidus Heer 1865, Acanthoderes phrixi Heer 1847 and Acanthoderus sepultus Heer 1865, are known from the Miocene of Croatia and Germany 12.7 to 11.6 Mya (Heer 1879). However, any study that mentions fossil traces of a common ancestor of Acanthocinini and Acanthoderini has yet to be encountered.
The MRCA of the Lamiini and close relatives, which include Monochamus and Batocera, appeared at the Eocene epoch of Paleogene, ~52.53 Mya according to our chronogram, relatively consistent, but a bit earlier than the chronogram of Ashman et al. (2022) and Nie et al. (2021) which point to ~63 Mya and ~55 Mya, respectively. This is the youngest clade compared to the other tribes included in this study (Fig. 2). The fossil records of Lamiini, Lamia antiqua Heer 1879, from Miocene of Germany (12.7 to 11.6 Mya) (Heer, 1879), Dorcadion bachense Handschin 1944 from Oligocene of France (28.4 to 23.03 Mya) (Handschin, 1944), and Dorcadion emeritum von Heyden 1862 from Oligocene of Germany (28.4 to 23.03 Mya) (Von Heyden 1862) are roughly concordant with our estimation, which dated splitting of Dorcadion from its last common ancestor genus Morimus ~26 Mya. The speciation event within the genus Dorcadion was 14.34 Mya in our estimation, earlier than the chronogram of Dascălu et al. (2022), who dated the beginning of speciation within the genera Dorcadion was around 9.8 Mya.
The emergence time of Mesosa was ~67 Mya according to our chronogram, but ~107 Mya according to Nie et al. (2020). All fossil records of Mesosa Latreille 1829 (syn. Sinocalosoma Hong 1983) were from the Miocene of China and the Oligocene of Germany (28.4 to 11.608 Mya) (Hong 1983; Hong and Wang 1986).
Considering our chronogram, the MRCA of four species of Agapanthia appeared about 55 Mya in Paleogene (Fig. 2), while the MRCA of two Agapanthia daurica individuals dated 51.79 Mya in Nie at el. (2021). However, we could not access any fossil record for this genus.
The MRCA of Pogonocherus and Exocentrus emerged around 65 Mya at the edge of the Cretaceous and Paleogene, according to the chronogram of Ashman et al. (2022), while it is 37 Mya around mid-Paleogene, according to the hypothesized chronogram in the present study (Fig. 2). The oldest fossil of Pogonocherus, Pogonocherus jaekeli Zang 1905, is from Baltic Amber, 37.2 to 33.9 Mya (Vitali 2009).
We estimated the MRCA of Saperdini and Phytoeciini as 65 million years old, which the latter might be a synonym of the preceding in addition to Obereini (de Santana Souza et al. 2020). Ashman et al. (2022) estimated the MRCA of Phytoecia and Oberea 36 Mya. The oldest fossil of the genus Saperda is Saperda caroli Vitali 2015, from Uintan of Colorado, America (46.2 - 40.4 Mya) and the oldest fossil from Eurasia is Saperda densipunctata Théobald 1937, from Oligocene of Germany, 33.9 to 28.4 Mya (Vitali 2015). The oldest Obereini fossil is the youngest in the group, Oberea praemortua von Heyden 1862, and from the Miocene of Germany, 15.97 to 11.608 Mya (Von Heyden, 1862).
According to our time estimation of the intrageneric diversification of the taxa involved in the analysis occurred during Cenozoic, mostly in Neogene, concurred with Ashman et al. (2022). Diversification of the members of Agapanthia seems to be occurred during Paleogene ~55 Mya, earlier than Phytoecia and Dorcadion members, ~23 Mya and ~14 Mya, respectively, during Neogene.
What our study reveals is the Lamiinae specimens from East of Marmara Basin, Türkiye, were closely related to European conspecifics and congeners. And, relying on our samples, we stand by the side of de Santana Souza et al. (2020) in supporting the hypothesis of uniting the tribes Dorcadionini, Gnomini, Monochamini (in terms of Monochamus) and the current Lamiini under a single tribe Lamiini. Considering all recent studies and the present study, the emergence time of the subfamily Lamiinae is Jurassic to early Cretaceous, and the extant species included in this study presently occur in the East of Marmara Basin that emerged during the Neogene period.