Morphology and Phylogenetic Position of Two New Gregarine Species (Apicomplexa: Eugregarinorida) Parasitizing the Lubber Grasshopper Taeniopoda centurio (Drury, 1770) (Insecta: Orthoptera: Romaleidae) in Mexico.

Eugregarines are understudied apicomplexan parasites of invertebrates inhabiting marine, freshwater, and terrestrial environments. Most currently known terrestrial eugregarines have been described parasitizing the gut from less than 1% of total insect diversity, with a high likelihood that the remaining insect species are infected. Eugregarine diversity in orthopterans (grasshoppers, locusts, katydids, and crickets) is still little known. We carried out a survey of the eugregarines parasitizing the Mexican lubber grasshopper, Taeniopoda centurio, an endemic species to the northwest of Mexico. We described two new eugregarine species from the gut of the host: Amoebogregarina taeniopoda n. sp. and Quadruspinospora mexicana n. sp. Both species are morphologically dissimilar in their life-cycle stages. Our SSU rDNA phylogenetic analysis showed that both species are phylogenetically distant to each other, even though they parasitize the same host. Amoebogregarina taeniopoda n. sp. clustered within the clade Gregarinoidea, being closely related to Amoebogregarina nigra from the grasshopper Melanoplus differentialis. Quadruspinospora mexicana n. sp. clustered within the clade Actinocephaloidea and grouped with Prismatospora evansi, a parasite from dragonfly naiads. Amoebogregarina taeniopoda n. sp. and Q. mexicana n. sp. represent the first record of eugregarines found to infect a species of the family Romaleidae.

On the origin of the New World Pyrgomorphidae (Insecta: Orthoptera).

The gaudy grasshopper family Pyrgomorphidae (Orthoptera: Caelifera) shows a peculiar geographical distribution. Of the 487 described species, less than 10% of the diversity is found in the New World, while the rest occur throughout Africa, Asia, and Australia. Only 41 species belonging to four tribes are found in Central and South America and Dominican Republic, and the phylogenetic positions of these taxa within the large phylogeny of Pyrgomorphidae and the relationships among them have never been investigated. Regarding the biogeography, three different hypotheses about the origin of the New World Pyrgomorphidae have been proposed, but these have not been empirically tested. In this study, we present the first molecular phylogeny of Pyrgomorphidae that includes the members of all four New World tribes and representative genera from the Old World based on entire mitochondrial genome and four nuclear genes to investigate the biogeography of this fascinating lineage. Our results recover Pyrgomorphidae as monophyletic and the New World Pyrgomorphidae as a paraphyletic group comprising three clades, consisting of: (1) The Caribbean Jaragua + the South American Algete; (2) The Mexican and Central American Sphenarium + Prosphena; and (3) The Mexican lineages Ichthiacridini + Ichthyotettigini. The divergence time estimation analysis suggested that the Pyrgomorphidae diverged from its relatives in the Early Cretaceous (139-104 mya). The biogeographic analysis using BioGeoBEARS showed that after diversifying in the Old World, the first New World Pyrgomorphidae clade (Algete + Jaragua) diverged 96 mya (Late Cretaceous, Cenomanian) and that their current distribution in the New World is explained by two possible events, a transatlantic colonization from Africa to Northern South America or a vicariance event between these two landmasses, followed by a subsequent dispersal to the Caribbean. The second wave of colonization occurred about 69 mya towards the end of the Late Cretaceous (Maastrichtian) with dispersal from Africa to South America and then to North America with a subsequent diversification in Mexico including Baja California.

Studies in Mexican Grasshoppers: Liladownsia fraile, a new genus and species of Dactylotini (Acrididae: Melanoplinae) and an updated molecular phylogeny of Melanoplinae.

Liladownsia fraile gen. nov. sp. nov. Fontana, Mariño-Pérez, Woller & Song (Lila Downs' friar grasshopper) of the tribe Dactylotini (Orthoptera: Acrididae: Melanoplinae) is described from the pine-oak forest of the Sierra Madre del Sur Mountain Range in Oaxaca, Mexico. Taxonomic placement of this new genus is justified based on morphological characters as well as a molecular phylogeny. Information about the probable host plant, phenology, and known localities is also presented. We also present an updated molecular phylogeny of Melanoplinae, which includes representatives of five of the seven recognized tribes. The monophyly of the subfamily and the included tribes is tested and we find Dactylotini to be paraphyletic because of the placement of Hesperotettix Scudder, 1876. We also recover strong close relationships between the new genus and Perixerus Gerstaecker, 1873 and Dactylotum Charpentier, 1845.  

Studies in Mexican Tettigoniidae: a new genus of Copiphorini and the first description of male Conocephalus (Aphauropus) leptopterus Rehn and Hebard and the female of Insara acutitegmina Fontana, Buzzetti, Mariño-Pérez & García García.

A new genus belonging to the katydid tribe Copiphorini (Tettigoniidae: Conocephalinae) is established, Brachycaulopsis gen. nov., collected from the state of Chiapas, Mexico. Also provided are first descriptions for both the male of Conocephalus (Aphauropus) leptopterus Rehn & Hebard, 1915 (Conocephalinae: Conocephalini) and the female of Insara acutitegmina Fontana et al., 2011 (Phaneropterinae: Insarini).

A new species of Colpolopha Stål, 1873 (Orthoptera: Romaleidae) from Brazil.

Colpolopha minuta sp. nov. (Orthoptera: Romaleidae) is described from Floresta Nacional do Aripe near Crato in Ceará State, Brazil from 17 specimens collected by Moacyr Alvarenga deposited at the Insect Collection of the University of Michigan Museum of Zoology. This new species is characterized by its small size and brachypterous tegmina compared to other known Colpolopha species. A comparison with other short-winged Colpolopha species is provided. A discussion about some iNaturalist records is provided in order to help us identify possible new records or species in the region.

Periacineta mexicana n. sp. (Ciliophora, Suctoria, Discophryida), epizoic on Mexican backswimmers of the genus Buenoa (Insecta, Hemiptera, Notonectidae).

A new species of suctorian in the genus Periacineta, epibiotic on aquatic bugs (Hemiptera, Heteroptera, Nepomorpha), is described on the basis of morphological characteristics of the cell body, lorica, tentacular placement, and stalk, and its 18S rRNA partial sequence gene. Periacineta mexicana n. sp. is a loricate suctorian with elongate body and rounded apical region; tentacles are distributed randomly over apical region and not grouped into fascicles. Macronucleus in adult is elongate and located centrally. The suctorian usually forms closely aggregated pseudocolonies. We provide morphological data based on optical and scanning electron microscopy. A comparison with similar congeners, and emended diagnosis of the genus Periacineta also are provided. The ciliates were found attached to the first two pairs of legs of Mexican notonectids Buenoa pallens and Buenoa spp. (backswimmers).

An Illustrated Key of Pyrgomorphidae (Orthoptera: Caelifera) of the Indian Subcontinent Region.

The Indian subcontinent is known to harbor a high level of insect biodiversity and endemism, but the grasshopper fauna in this region is poorly understood, in part due to the lack of appropriate taxonomic resources. Based on detailed examinations of museum specimens and high-resolution digital images, we have produced an illustrated key to 21 Pyrgomorphidae genera known from the Indian subcontinent. This new identification key will become a useful tool for increasing our knowledge on the taxonomy of grasshoppers in this important biogeographic region.

A new discovery of a long-winged form of Mexican endemic grasshopper Melanotettix dibelonius Bruner, 1904 (Orthoptera: Acrididae: Gomphocerinae) and notes on wing polymorphism and geographic distribution.

The species Melanotettix dibelonius Bruner, 1904 was previously recorded from Michoacán and Guerrero states in Mexico. This species is characterized by its tegmina, which are always shorter than head and pronotum together and sometimes shorter than the pronotum. After recent field expeditions (2015-2019) and an extensive review of museum specimens from the most important Orthoptera collections in Mexico and USA (291 specimens), we discovered a long-winged form of this species south of its previous known range, which effectively expanded its distribution range into Oaxaca state. We discuss some aspects regarding the patterns of geographic distribution and morphological variation among the long-winged and short-winged morphs. We conduct statistical analyses and observed that on average, the tegmina of long-winged individuals (both females and males) are slightly longer than twice the length of pronotum; whereas in short-winged individuals the tegmina are nearly as long or slightly longer than the length of the pronotum. Moreover, on average, females appear to have longer tegmina than males in both morphotypes. We provide photographic records of both forms live and mounted, the most comprehensive distribution map to date and a discussion of evolutionarily interesting patterns found in this species.

Predictability in the evolution of Orthopteran cardenolide insensitivity.

The repeated evolutionary specialization of distantly related insects to cardenolide-containing host plants provides a stunning example of parallel adaptation. Hundreds of herbivorous insect species have independently evolved insensitivity to cardenolides, which are potent inhibitors of the alpha-subunit of Na+,K+-ATPase (ATPα). Previous studies investigating ATPα-mediated cardenolide insensitivity in five insect orders have revealed remarkably high levels of parallelism in the evolution of this trait, including the frequent occurrence of parallel amino acid substitutions at two sites and recurrent episodes of duplication followed by neo-functionalization. Here we add data for a sixth insect order, Orthoptera, which includes an ancient group of highly aposematic cardenolide-sequestering grasshoppers in the family Pyrgomorphidae. We find that Orthopterans exhibit largely predictable patterns of evolution of insensitivity established by sampling other insect orders. Taken together the data lend further support to the proposal that negative pleiotropic constraints are a key determinant in the evolution of cardenolide insensitivity in insects. Furthermore, analysis of our expanded taxonomic survey implicates positive selection acting on site 111 of cardenolide-sequestering species with a single-copy of ATPα, and sites 115, 118 and 122 in lineages with neo-functionalized duplicate copies, all of which are sites of frequent parallel amino acid substitution. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

Studies in Mexican Grasshoppers: A new species of Pedies Saussure (Acrididae: Melanoplinae) with comments on the unusual blue coloration on the abdomens of females and live specimen images for three other congenerics.

A new species of Melanoplinae (Orthoptera: Acrididae) is described from Central Mexico: Pedies andreae sp. nov. Fontana, Mariño-Pérez, Woller and is added to the 12 existing species. Taxonomic placement of this species is justified based on distinct morphology and comparisons with congeneric species are provided. Additionally, species in this genus are associated with higher elevations (1,700 to 3,700 masl) that possess larger fluctuations in temperatures. We observed that females of P. andreae sp. nov. exhibit blue coloration on their abdomens and we discuss the possible reasons for this peculiar pigmentation. Interestingly, we did not observe this coloration in males. Finally, images are provided for three live previously described species of Pedies.

Phylogeny of locusts and grasshoppers reveals complex evolution of density-dependent phenotypic plasticity.

Locusts are grasshoppers that can form dense migrating swarms through an extreme form of density-dependent phenotypic plasticity, known as locust phase polyphenism. We present a comprehensive phylogeny of the genus Schistocerca, which contains both non-swarming grasshoppers and swarming locusts. We find that the desert locust, S. gregaria, which is the only Old World representative of the genus, is the earliest diverging lineage. This suggests that the common ancestor of Schistocerca must have been a swarming locust that crossed the Atlantic Ocean from Africa to America approximately 6 million years ago, giving rise to the current diversity in the New World. This also implies that density-dependent phenotypic plasticity is an ancestral trait for the genus. Through ancestral character reconstruction of reaction norms, we show that colour plasticity has been largely retained in most species in the genus, but behavioural plasticity was lost and regained at least twice. Furthermore, we show that swarming species do not form a monophyletic group and non-swarming species that are closely related to locusts often express locust-like plastic reaction norms. Thus, we conclude that individual reaction norms have followed different evolutionary trajectories, which have led to the evolutionary transition between grasshoppers and locusts - and vice versa.

Studies in Mexican Grasshoppers: Three new species of Dactylotini (Acrididae: Melanoplinae) from Mexico and a review of existing conspecifics with comments on their geographical distributions.

Three new species of the tribe Dactylotini (Acrididae: Melanoplinae) are described from Central and Southern Mexico. 1) Dasyscirtus monicae sp. nov. Fontana, Mariño-Pérez, Sanabria-Urbán, & Woller is described from the eastern portion of the Balsas River Basin and the outer slope of the Mexican Volcanic Belt; 2) Perixerus obscurus sp. nov. Fontana, Mariño-Pérez, Sanabria-Urbán, & Woller is described from the Sierra Norte de Oaxaca mountain range; and 3), Perixerus triqui sp. nov. Fontana, Mariño-Pérez, Sanabria-Urbán, & Woller is described from the Sierra Madre del Sur mountain range and towards the Pacific Coast of Oaxaca. Taxonomic placement of these species is justified based on distinct morphology and comparisons with congeneric species are provided. Finally, we provide a biogeographical explanation for the distribution of the species in both genera.