Systematics of ladybird beetles (Ooleoptera: Coccinellidae)
Giorgi, Jose Adriano
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Despite the familiarity and economic significance of Coccinellidae, the family has thus far escaped analysis by rigorous phylogenetic methods. As a result, the internal classification remains unstable and there is no framework with which to interpret evolutionary events within the family. We analyzed coccinellid phylogeny using a combined dataset of seven genes: 12S rDNA, 16S rDNA, 18S rDNA, 28S rDNA, Cytochrome oxidase I, Cytochrome oxidase II, and Histone 3. The entire dataset consists of 6565 aligned nucleotide sites, 1305 of which are parsimony informative. Our study included 20% of the generic-level diversity and 80% of the tribal-level diversity and 100% previously recognized subfamilies. We analyzed the dataset using parsimony and Bayesian methods. Our study supports the monophyly of Coccinellidae; however, most of the traditional subfamilies are not supported as monophyletic. Three recently proposed, but not widely accepted, subfamilies are recognized. A new subfamily is proposed to accommodate Monocoryni. We recognize eight subfamilies of Coccinellidae: Microweiseinae, Monocorynae (new subfamily), Coccinellinae, Chilocorinae, Sticholotidinae, Scymninae, Exoplectrinae, and Hyperaspidinae. The circumscription of Hyperaspidinae (Hyperaspidini Mulsant, Brachiacanthini Mulsant and Selvadiini Gordon) is extended to accommodate Platynaspidini Redtenbacher and Aspidimerini Mulsant. The tribe Coccinellini Latreille is paraphyletic with respect to Tytthaspidini Mulsant (syn. nov.) and Halyziini Mulsant (confirmed status). The tribes Noviini Mulsant, Cryptognathini Casey, Poriini Mulsant, and Diomini Gordon are treated as incertae sedis. The relationship between some of the subfamilies and the placement of several tribes remain ambiguous. We also utilized the phylogenetic hypothesis to provide an evolutionary perspective on the feeding preferences of coccinellids. Coccinellids exhibit a wide range of preferred food types, spanning kingdoms and trophic levels. Our study suggests that the ancestral feeding condition for the family is coccidophagy and that polyphagy served as an evolutionary stepping stone for primarily predaceous groups to adopt new feeding habits. The Australian members of the ladybird beetle tribe Chilocorini are revised. Identification keys for genera and species are provided. Habitus and diagnostic characters from mouthparts, legs, and genitalia are illustrated. Major conclusions of the present study include recognition of the following: (1) five new species; (2) eleven junior synonyms at the species level; one junior synonym at the generic level; and (3) sixteen new lectotypes. According to our study, the Chilocorini in Australia consists of 23 species classified in 6 genera: Brumoides, Chilocorus, Exochomus, Halmus, Orcus and Trichorcus.