Giant Sex Chromosomes in Omophoita Species (Coleoptera, Chrysomelidae): Structural and Evolutionary Relationships Revealed by Zoo-FISH and Comparative Genomic Hybridization (CGH).

The beetles of the subtribe Oedionychina (Chrysomelidae, Alticinae) are the only ones that have the atypical giant and achiasmatic sex chromosomes, which are substantially larger than the autosomes. Previous cytogenetic analyses suggest a large accumulation of repetitive DNA in the sex chromosomes. In this study, we examined the similarity of X and Y chromosomes in four Omophoita species and compared genomic differentiation to better understand the evolutionary process and the giant sex chromosomes origin. Intraspecific genomic comparation using male and female genomes of O. octoguttata and interespecific analyses using genomic DNA of O. octoguttata, O. sexnotata, O. magniguttis, and O. personata were performed. In addition, whole chromosome painting (WCP) experiments were performed with X and Y chromosome probes of O. octogutatta. CGH analysis revealed great genomic similarity between the sexes and a sex-specific region on the Y chromosome, and interspecific analysis revealed a genomic divergence between species. In contrast, WCP results revealed that the sex chromosomes of O. octoguttata have high intra- and interspecific similarity with the studied species. Our data support a common origin under the canonical evolution of the sex chromosomes in this group, as they have high genomic similarity between them.

Elevating Omophoita octoguttata elytralis Bechyné, 1956 (Coleoptera: Chrysomelidae: Galerucinae: Alticini) to species

An updated morphological description for Omophoita elytralis (Bechyné, 1956), stat. nov., is presented, including the first account of the genitalia for this species. The separation Omophoita elytralis from O. octoguttata (Fabricius, 1775) is supported by differences found in the median lobe of males, elytral tegument uniform in color (not patterned), and their allopatric geographical distribution.

Description of the immature stages of the flea beetle Omophoita personata (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

Alticini is the most diverse tribe of Chrysomelidae with approximately 8,000 species. Despite of its high diversity, little is known about their natural history and immature stages. Herein, we describe the immatures of Omophoita personata (Illiger, 1807) reared in laboratory from adults sampled in field. We also investigated and compared with immatures of O. octoguttata (Fabricius, 1775). Detailed morphology and chaetotaxy are presented. Larvae of O. personata have their bodies covered with tubercles and the stemmata are absent. These characteristics are shared with other Oedionychina species, reinforcing the stability of these morphological characteristics as diagnostic of this subtribe. This study provides important descriptive and comparative data that increases the knowledge about Alticini immatures.(AU)

Redescription of Omophoita octoguttata (Coleoptera: Chrysomelidae) and its immature stages, with notes on life history

Given that many descriptions of Coleoptera were made with only external and superficial characters, an update to the original characterization of species is deemed necessary. This study focuses on updating the know morphological data for the adults of Omophoita octoguttata (Fabricius,1775) (Galerucinae, Alticini), a flea beetle native of southern Brazil. We also give insights on the morphology of its immature stages. The adult can be easily recognized by the pale macula at vertex, six large pale maculae, and two smaller in the humeral region at the elytra. The immatures are similar to other know Oedionychina. Eggs oval and orange. Mature larvae present setae bearing scoli, a reddened body, pygopod present, and lacking stemmata, but with curved hook-like tarsal claws. The pupae present slender black setae through its yellowed body, with the elytral and hind wing thecae curved around the body. The eggs are laid in small clutches in the soil and when the larvae eclode they stay in the aerial parts of plants. The mature larvae form a cocoon of soil matter around themselves for their pupal phase. Morphological remarks for larva and pupa of this species when compared to other members of the genus remain limited, demanding further studies with other species.(AU)

Redescription of Omophoita octoguttata (Coleoptera: Chrysomelidae) and its immature stages, with notes on life history

Given that many descriptions of Coleoptera were made with only external and superficial characters, an update to the original characterization of species is deemed necessary. This study focuses on updating the know morphological data for the adults of Omophoita octoguttata (Fabricius,1775) (Galerucinae, Alticini), a flea beetle native of southern Brazil. We also give insights on the morphology of its immature stages. The adult can be easily recognized by the pale macula at vertex, six large pale maculae, and two smaller in the humeral region at the elytra. The immatures are similar to other know Oedionychina. Eggs oval and orange. Mature larvae present setae bearing scoli, a reddened body, pygopod present, and lacking stemmata, but with curved hook-like tarsal claws. The pupae present slender black setae through its yellowed body, with the elytral and hind wing thecae curved around the body. The eggs are laid in small clutches in the soil and when the larvae eclode they stay in the aerial parts of plants. The mature larvae form a cocoon of soil matter around themselves for their pupal phase. Morphological remarks for larva and pupa of this species when compared to other members of the genus remain limited, demanding further studies with other species.

Redescription of Omophoita octoguttata (Coleoptera: Chrysomelidae) and its immature stages, with notes on life history

ABSTRACT Given that many descriptions of Coleoptera were made with only external and superficial characters, an update to the original characterization of species is deemed necessary. This study focuses on updating the know morphological data for the adults of Omophoita octoguttata (Fabricius,1775) (Galerucinae, Alticini), a flea beetle native of southern Brazil. We also give insights on the morphology of its immature stages. The adult can be easily recognized by the pale macula at vertex, six large pale maculae, and two smaller in the humeral region at the elytra. The immatures are similar to other know Oedionychina. Eggs oval and orange. Mature larvae present setae bearing scoli, a reddened body, pygopod present, and lacking stemmata, but with curved hook-like tarsal claws. The pupae present slender black setae through its yellowed body, with the elytral and hind wing thecae curved around the body. The eggs are laid in small clutches in the soil and when the larvae eclode they stay in the aerial parts of plants. The mature larvae form a cocoon of soil matter around themselves for their pupal phase. Morphological remarks for larva and pupa of this species when compared to other members of the genus remain limited, demanding further studies with other species.

Immatures of Syphrea uberabensis guerini Bechyné (Coleoptera, Chrysomelidae, Alticini)

Immatures of Syphrea uberabensis guerini Bechyné (Coleoptera, Chrysomelidae, Alticini). Larva and pupa of Syphrea uberabensis guerini are described and illustrated for the first time and a comparison with the described immatures of other Alticini species from Neotropical region and also with Hermaeophaga mercurialis (Fabricius, 1792), from Palearctic region, is presented. Tibouchina stenocarpa (DC.) Cogn. (Melastomataceae) (quaresmeira-do-cerrado) is registered as a new host plant for this species of Alticini.

Imaturos de Syphrea uberabensis guerini Bechyné (Coleoptera, Chrysomelidae, Alticini). Larva e pupa de Syphraea uberabensis guerini são descritas e ilustradas pela primeira vez e comparadas com as formas imaturas descritas de outras espécies de Alticini da região Neotropical e também com Hermaeophaga mercurialis (Fabricius, 1792), da região Paleártica. Tibouchia stenocarpa (DC.) Cogn. (Melastomataceae) (quaresmeira-do-cerrado) é registrada como novo hospedeiro para esta espécie de Alticini.