Studies on raspy crickets: New Triaenogryllacris species (Orthoptera: Gryllacrididae).

The genus Triaenogryllacris is redescribed and a key for identification of the species is provided. When dealing with observations of iNaturalist, accurate data about the distribution of T. triaena (the type species) are obtained, and three color forms are indicated: yellow, pink and green. Two new species are described here: T. diaena n. sp. and T. horaciotrianai n. sp., expanding the expected geographic distribution for the genus, thus recorded, from the Andean forests of Ecuador and Colombia's three mountain ranges. Finally, the characters and distribution of Triaenogryllacris are discussed, contrasting with the other taxa described for the family Gryllacrididae.

The Genomic Basis of Color Pattern Polymorphism in the Harlequin Ladybird.

Many animal species comprise discrete phenotypic forms. A common example in natural populations of insects is the occurrence of different color patterns, which has motivated a rich body of ecological and genetic research [1-6]. The occurrence of dark, i.e., melanic, forms displaying discrete color patterns is found across multiple taxa, but the underlying genomic basis remains poorly characterized. In numerous ladybird species (Coccinellidae), the spatial arrangement of black and red patches on adult elytra varies wildly within species, forming strikingly different complex color patterns [7, 8]. In the harlequin ladybird, Harmonia axyridis, more than 200 distinct color forms have been described, which classic genetic studies suggest result from allelic variation at a single, unknown, locus [9, 10]. Here, we combined whole-genome sequencing, population-based genome-wide association studies, gene expression, and functional analyses to establish that the transcription factor Pannier controls melanic pattern polymorphism in H. axyridis. We show that pannier is necessary for the formation of melanic elements on the elytra. Allelic variation in pannier leads to protein expression in distinct domains on the elytra and thus determines the distinct color patterns in H. axyridis. Recombination between pannier alleles may be reduced by a highly divergent sequence of ∼170 kb in the cis-regulatory regions of pannier, with a 50 kb inversion between color forms. This most likely helps maintain the distinct alleles found in natural populations. Thus, we propose that highly variable discrete color forms can arise in natural populations through cis-regulatory allelic variation of a single gene.