Genomics Reveals Widespread Ecological Speciation in Flightless Insects

Recent genomic analyses have highlighted parallel divergence in response to ecological gradients, but the extent to which altitude can underpin such repeated speciation remains unclear. Wing reduction and flight loss have apparently evolved repeatedly in montane insect assemblages, and have been suggested as important drivers of hexapod diversification. We test this hypothesis using genomic analyses of a widespread wing-polymorphic stonefly species complex in New Zealand. We identified over 50,000 polymorphic genetic markers generated across almost 200 Zelandoperla fenestrata stonefly specimens using a newly generated plecopteran reference genome, to reveal widespread parallel speciation between sympatric full-winged and wing-reduced ecotypes. Rather than the existence of a single, widespread, flightless taxon (Zelandoperla pennulata), evolutionary genomic data reveal that wing-reduced upland lineages have speciated repeatedly and independently from full-winged Z. fenestrata. This repeated evolution of reproductive isolation between local ecotype pairs that lack mitochondrial DNA differentiation suggests that ecological speciation has evolved recently. A cluster of outlier SNPs detected in independently wing-reduced lineages, tightly linked in an approximately 85 kb genomic region that includes the developmental ‘supergene’ doublesex, suggests that this ‘island of divergence’ may play a key role in rapid ecological speciation.

The genus Neoheegeria with a new species from Iran exhibiting wing-dimorphism (Thysanoptera: Phlaeothripidae)

Neoheegeria astragali sp.n. is described as the first known member of this genus to exhibit wing-dimorphism. Collected on Astragalus sp. [Fabaceae] in Iran, it is also unique among Neoheegeria species in having the tube unusually short. Neoheegeria sinaitica is recorded from Iran for the first time, and an illustrated key is provided to the five species of Neoheegeria. Wing reduction among Haplothripini is discussed briefly, and it is concluded that most species of Neoheegeria are associated with species of Astragalus.

Genotyping-by-sequencing supports a genetic basis for alpine wing-reduction in a New Zealand stonefly

Wing polymorphism is a prominent feature of numerous insect groups, but the genomic basis for this diversity remains poorly understood. Wing reduction is a commonly observed trait in many species of stoneflies, particularly in cold or alpine environments. The widespread New Zealand stonefly Zelandoperla fenestrata species group (Z. fenestrata, Z. tillyardi, Z. pennulata) contains populations ranging from long-winged (macropterous) to vestigial-winged (micropterous), with the latter phenotype typically associated with high altitudes. The presence of flightless forms on numerous mountain ranges, separated by lowland fully winged populations, suggests wing reduction has occurred multiple times. We use Genotyping by Sequencing (GBS) to test for genetic differentiation between fully winged (n=62) and vestigial-winged (n=34) individuals, sampled from a sympatric population of distinct wing morphotypes, to test for a genetic basis for wing morphology. We found no population genetic differentiation between these two morphotypes across 6,843 SNP loci, however we did detect several outlier loci that strongly differentiated morphotypes across independent tests. This indicates small regions of the genome are likely to be highly differentiated between morphotypes, indicating a genetic basis for morphotype differentiation. These results provide a clear basis for ongoing genomic analysis to elucidate critical regulatory pathways for wing development in Pterygota.

Morphological convergences in Ameles Burmeister and Pseudoyersinia Kirby: Taxonomic implications of wing reduction and flight predisposition in some West-Mediterranean Amelini (Insecta: Mantodea)

Species in the genus Ameles Burmeister and Pseudoyersinia Kirby (Amelini) are traditionally defined as small-sized, ground-dwelling mantids whose males are distinct for being, respectively, macropterous and brachypterous. However, comparative morphological studies across Amelini confirmed the existence of short-winged males in Ameles, suggesting that this traditional diagnostic concept does not apply to all species. Our analyses of several species from West Mediterranean localities (Canary Islands, Spain, Italy, and Morocco) resulted in the relocation of Pseudoyersinia andreae Galvagni, 1976 to Ameles as Ameles andreae (Galvagni, 1976) (n. comb.) with Ameles insularis Agabiti, Ippolito & Lombardo, 2010 as its new synonym (n. syn.), the clarification of the taxonomic identity of A. gracilis (Brullé, 1838) and A. maroccana Uvarov, 1931, including diagnoses of their males, and the description of Ameles spallanzania obscura (n. ssp.) (from Spain). We also take the opportunity to describe Pseudoyersinia maroccana (n. sp.) (from Morocco) based on museum specimens separating it from Ameles maroccana Uvarov, 1931. We also found that wing length is positively correlated to ocelli size. We discuss this trend from an ecological, evolutionary, and biogeographic perspectives to both facilitate species circumscription and justify the taxonomic modifications herein introduced.

A revision of Prespelea Park (Staphylinidae, Pselaphinae)

We revise the genus Prespelea Park, redefining and redescribing the two previously known species, P. copelandi Park and P. quirsfeldi Park, and adding ten new species: P. parki Caterino & Vásquez-Vélez, sp. n., P. minima Caterino & Vásquez-Vélez, sp. n., P. morsei Caterino & Vásquez-Vélez, sp. n., P. divergens Caterino & Vásquez-Vélez, sp. n., P. carltoni Caterino & Vásquez-Vélez, sp. n., P. myersae Caterino & Vásquez-Vélez, sp. n., P. georgiensis Caterino & Vásquez-Vélez, sp. n., P. enigma Caterino & Vásquez-Vélez, sp. n., P. wagneri Caterino & Vásquez-Vélez, sp. n., and P. basalis Caterino & Vásquez-Vélez, sp. n.. The genus is still only known from a relatively small area in the southern Appalachian Mountains, but the diversity is much greater than previously suspected. The new species exhibit considerable diversity in male secondary sexual characters. A preliminary phylogenetic analysis cannot conclusively resolve the polarity of eye and wing reduction across Speleobamini, but the monophyly of Park’s subgenus Fusjugama, if expanded to include all species with full-eyed and winged males, is not supported, and we therefore synonymize it with Prespeleas. str.