ABSTRACT
Three new species of genus Metapocyrtus Heller, 1912, subgenus Orthocyrtus Heller, 1912 (Coleoptera, Curculionidae, Entiminae, Pachyrhynchini) from Mindanao Island, Philippines are described: M. (O.) regalissp. nov., M. (O.) tbolisp. nov., and M. (O.) reaganisp. nov. Photographs of their habitus and male genitalia are presented.
ABSTRACT
The brilliant appearance of Easter Egg weevils, genus Pachyrhynchus (Coleoptera, Curculionidae), originates from complex dielectric nanostructures within their elytral scales and elytra. Previous work, investigating singular members of the Pachyrhynchus showed the presence of either quasi-ordered or ordered 3D photonic crystals based on the single diamond ( Fd3¯m ) symmetry in their scales. However, little is known about the diversity of the structural coloration mechanisms within the family. Here, the optical properties within Pachyrhynchus are investigated by systematically identifying their spectral and structural characteristics. Four principal traits that vary their appearance are identified and the evolutionary history of these traits to identify ecological trends are reconstructed. The results indicate that the coloration mechanisms across the Easter Egg weevils are diverse and highly plastic across closely related species with features appearing at multiple independent times across their phylogeny. This work lays a foundation for a better understanding of the various forms of quasi-ordered and ordered diamond photonic crystal within arthropods.
Subject(s)
Coleoptera , Nanostructures , Weevils , Animals , Coleoptera/chemistry , Diamond , Nanostructures/chemistry , PhotonsABSTRACT
BACKGROUND: The genus Metapocyrtus Heller, 1912 is the most speciose and taxonomically complex genus in the tribe Pachyrhynchini. It is known to be endemic in the Philippines, with most species having a very narrow range of distribution. There are already more than 230 species of Metapocyrtus documented in the Philippines. NEW INFORMATION: Metapocyrtusdagtum sp. nov., a new species of the genus Metapocyrtus Heller, 1912 from Davao de Oro, Mindanao Island, Philippines, is described with brief notes about its ecology. Its specific epithet is from the Cebuano word "dagtum" which means pitch black referring to the colour of the integument of the species.
ABSTRACT
Patterns of genomic architecture across insects remain largely undocumented or decoupled from a broader phylogenetic context. For instance, it is unknown whether translocation rates differ between insect orders. We address broad scale patterns of genome architecture across Insecta by examining synteny in a phylogenetic framework from open-source insect genomes. To accomplish this, we add a chromosome level genome to a crucial lineage, Coleoptera. Our assembly of the Pachyrhynchus sulphureomaculatus genome is the first chromosome scale genome for the hyperdiverse Phytophaga lineage and currently the largest insect genome assembled to this scale. The genome is significantly larger than those of other weevils, and this increase in size is caused by repetitive elements. Our results also indicate that, among beetles, there are instances of long-lasting (>200 Ma) localization of genes to a particular chromosome with few translocation events. While some chromosomes have a paucity of translocations, intra-chromosomal synteny was almost absent, with gene order thoroughly shuffled along a chromosome. This large amount of reshuffling within chromosomes with few inter-chromosomal events contrasts with patterns seen in mammals in which the chromosomes tend to exchange larger blocks of material more readily. To place our findings in an evolutionary context, we compared syntenic patterns across Insecta in a phylogenetic framework. For the first time, we find that synteny decays at an exponential rate relative to phylogenetic distance. Additionally, there are significant differences in decay rates between insect orders, this pattern was not driven by Lepidoptera alone which has a substantially different rate.
Subject(s)
Coleoptera/genetics , Synteny/genetics , Weevils/genetics , Animals , Biological Evolution , Chromosomes/genetics , Evolution, Molecular , Genome, Insect/genetics , Genomics/methods , PhylogenyABSTRACT
Background: The genus Metapocyrtus Heller, 1912 is the most speciose and complex amongst the tribe Pachyrhynchini with seven subgenera and more than 200 described species. The genus is endemic to the Philippines and remains largely unknown particularly in the less explored areas or mountains. New information: Four new species of Metapocyrtus Heller, 1912 (Coleoptera, Curculionidae, Entiminae, Pachyrhynchini), are described from Mindanao Island, Philippines. Brief bionomical notes and mimicry with their sympatric beetles and other insect counterparts are also reported.
