Combined molecular and morphological data provide insights into the evolution and classification of Chilocorini ladybirds (Coleoptera: Coccinellidae)

Abstract

Ladybirds of the cosmopolitan tribe Chilocorini prey mainly on coccids and include several important biocontrol agents. The phylogenetic relationships of Chilocorini are poorly known. In this paper, we provide a phylogenetic reconstruction of Chilocorini containing all 27 genera based on five molecular markers and 86 adult morphological characters. Morphological character states were mapped on the combined data tree from Bayesian inference to analyse morphological traits of each genus. Sixteen morphological characters were selected to reconstruct the ancestral states using maximum parsimony and maximum likelihood methods. Divergence times were estimated based on the relaxed molecular clock approach. Our results indicate that Chilocorini, excluding Chilocorellus Miyatake, is monophyletic and closely related to Plotinini. The crown group Chilocorini was estimated to date back to the Middle Cretaceous. Anisorcus Crotch, Egius Mulsant, Phaenochilus Weise and Simmondsius Ahmad & Ghani are synonymized here with Chilocorus Leach (syn.n.). The genus Chilocorellus is excluded from Chilocorini. The split of current genera was estimated to have occurred during the Middle Paleogene to Late Paleogene.

Phylogeny and divergence dating of the ladybird beetle tribe Coccinellini Latreille (Coleoptera: Coccinellidae: Coccinellinae)

“…In agreement with previous studies (Magro et al ., 2010; Che et al ., 2017; Escalona et al ., 2017; but see also Li et al ., 2020), we recovered Coccinellini sister to Chilocorini. Interestingly this relationship is not supported by morphological evidence (Ślipiński & Tomaszewska, 2010).…”

“…The recent study of Li et al . (2020), focussing on the coccidophagous Chilocorini, recovered a median age of 168 Ma for Coccinellidae, and recovered a median age of 70 Ma for Coccinellini; however, only three species representing two genera of Coccinellini were included in their work. Considered altogether these studies suggest a median age between 105 and 196 Ma for the family, with uncertainty resulting from non‐overlapping confidence intervals (e.g., see McKenna et al ., 2015; Toussaint et al ., 2017).…”

New records and checklist of Chilocorini (Coleoptera: Coccinellidae) from China

“…The recent phylogenetic studies of Chilocorini indicated that the relationship between Exochomus and Brumus is not so close. Exochomus is the sister group of a large clade containing various genera, for example, Xanthocorus , Priscibrumus , Parexochomus , Brumus and Brumoides , while Brumus is closely related to Brumoides ( Li et al 2020 ). Actually, Brumus can be easily distinguished from Exochomus by the following characters: elytral epipleuron more or less horizontal; tarsal claws without basal tooth, only slightly swollen at base.…”

“…Many species of this tribe are widely used as biological control agents. In recent years, phylogenetic and evolutionary studies of Chilocorini indicated that this tribe is a monophyletic group, closely related to the tribe Coccinellini ( Magro et al 2010 , Seago et al 2011 , Escalona et al 2017 , Che et al 2017 ) or Plotinini ( Li et al 2020 ). At present, Chilocorini contains 22 genera and more than 280 species distributed worldwide ( Łączyński and Tomaszewska 2012 , Li et al 2020 ).…”

“…However, in Li et al (2017a) , the genus Brumus Mulsant was incorrectly recorded in the Chinese checklist of Chilocorini (no literature existed to indicate that the members of this genus were distributed in China). After a phylogenetic study of the Chilocorini , the genus Phaenochilus Weise was synonymised with Chilocorus Leach ( Li et al 2020 ).…”