Sylvain Hugel

Laying the foundations of evolutionary and systematic studies in crickets (Insecta, Orthoptera): a multilocus phylogenetic analysis

Orthoptera have been used for decades for numerous evolutionary questions but several of its constituent groups, notably crickets, still suffer from a lack of a robust phylogenetic hypothesis. We propose the first phylogenetic hypothesis for the evolution of crickets sensu lato, based on analysis of 205 species, representing 88% of the subfamilies and 71% tribes currently listed in the database Orthoptera Species File (OSF). We reconstructed parsimony, maximum likelihood and Bayesian phylogenies using fragments of 18S, 28SA, 28SD, H3, 12S, 16S, and cytb (~3600 bp). Our results support the monophyly of the cricket clade, and its subdivision into two clades: mole crickets and ant‐loving crickets on the one hand, and all the other crickets on the other (i.e. crickets sensu stricto). Crickets sensu stricto form seven monophyletic clades, which support part of the OSF families, “subfamily groups”, or subfamilies: the mole crickets (OSF Gryllotalpidae), the scaly crickets (OSF Mogoplistidae), and the true crickets (OSF Gryllidae) are recovered as monophyletic. Among the 22 sampled subfamilies, only six are monophyletic: Gryllotalpinae, Trigonidiinae, Pteroplistinae, Euscyrtinae, Oecanthinae, and Phaloriinae. Most of the 37 tribes sampled are para‐ or polyphyletic. We propose the best‐supported clades as backbones for future definitions of familial groups, validating some taxonomic hypotheses proposed in the past. These clades fit variously with the morphological characters used today to identify crickets. Our study emphasizes the utility of a classificatory system that accommodates diagnostic characters and monophyletic units of evolution. Moreover, the phylogenetic hypotheses proposed by the present study open new perspectives for further evolutionary research, especially on acoustic communication and biogeography.

Gryllacrididae and Tettigoniidae (Insecta, Orthoptera, Ensifera) from Espiritu Santo, Vanuatu

Hugel S. 2009. — Gryllacrididae and Tettigoniidae (Insecta, Orthoptera, Ensifera) from Espiritu Santo, Vanuatu. Zoosystema 31 (3): 525-576. ABSTRACT In the present article, the Gryllacrididae and Tettigoniidae fauna of Espiritu Santo Island (Vanuatu) is examined. We took advantage of the examination of the material collected during the SANTO 2006 biological survey to give description complements, or to redescribe and/or redefine the concerned species and genera. We recorded 15 species in the island. Five are recorded for the first time in Espiritu Santo and in the Vanuatu archipelago. A 16th species, Conocephalus laetus (Redtenbacher, 1891), recorded by Willemse (1925) has not been collected during the survey. Two new Gryllacrididae Amphibologryllacris butmasi n. sp. and Psilogryllacris tchancha n. sp. are described. Amphibologryllacris macrocera (Walker, 1869) is redescribed. Amphibologryllacris poultoni (Willemse, 1925) is synonymised under A. macrocera. The two related genera Amphibologryllacris and Nannogryllacris are redefined. All Xonthogryllacris punctipennis (Walker, 1869) subspecies recognized by Karny are re-established as subspecies under this genus: X. p. punctipennis (Walker, 1869); X. p. confluens (Griffini, 1909); X p. erimae (Griffini, 1909); X. p. fenestrigera (Griffini, 1913); X. p. gemmicula (Hebard, 1922); X. p. keyica Karny, 1925 (n. comb.); X. p. zatricia Karny, 1928. Epacra cyaneoterminata Karny, 1935 is transferred to Amphibologryllacris. The song and stridulatory file of most Tettigoniidae occurring in Espiritu Santo are described, most of them for the first time: Salomona redtenbacheri Brongniart, 1897; Phaneroptera gracilis Burmeister, 1838; Furnia insularis (Stål, 1876) ; Ityocephala francoisi Bolívar, 1909; Conocephalus upoluensis (Karny, 1907); C. semivittatus (Walker, 1869); Pseudorhynchus lessonii Serville, 1838; Phisis holdhausi Karny, 1926. The female of Ityocephala francoisi, a Mecopodinae possibly endemic to Espiritu Santo is described for the first time. Salomona redtenbacheri is redescribed and synonymised with S. magnifica Willemse, 1925 and S. haani Brongniart, 1897. Keys to species of Amphibologryllacris, Nannogryllacris, and Furnia are given and characters are illustrated. Keys to Tettigoniidae and Gryllacrididae of Espiritu Santo are given and illustrated.

Mouthparts and nectar feeding of the flower visiting cricket Glomeremus orchidophilus (Gryllacrididae).

Glomeremus orchidophilus (Gryllacrididae) is a flower visiting cricket on the tropical island La Réunion. This species is the only Orthoptera shown to be a pollinator of a plant. We studied its nectar feeding behavior and mouthpart morphology in detail. Since G. orchidophilus possesses biting-and-chewing mouthparts, our objective was to find behavioral and/or structural specializations for nectar-feeding. The comparative analysis of feeding behavior revealed that fluid is taken up without movements of the mouthparts in Glomeremus. A comparative morphological examination of two Glomeremus species, together with several representatives of other Gryllacrididae and other Ensifera taxa revealed subtle adaptations to fluid feeding in Glomeremus. All representatives of Gryllacrididae were found to possess a distinct patch of microtrichia at the tip of their galeae. However, in Glomeremus a channel is formed between the distal components of the maxillae and the mandibles on each side of the body. Micro-CT and SEM examination revealed a longitudinal groove that extends over the galea beginning at the patch of microtrichia in the studied Glomeremus species. We hypothesize that the microtrichia take up fluid by capillarity and the action of the cibarium and pharyngeal pumps transports fluid along the channels between the maxillae and mandibles into the preoral cavity. These mouthpart features allow nectar uptake from flowers that is unique in Orthoptera.

Neuronal networks and nociceptive processing in the dorsal horn of the spinal cord.

The dorsal horn (DH) of the spinal cord receives a variety of sensory information arising from the inner and outer environment, as well as modulatory inputs from supraspinal centers. This information is integrated by the DH before being forwarded to brain areas where it may lead to pain perception. Spinal integration of this information relies on the interplay between different DH neurons forming complex and plastic neuronal networks. Elements of these networks are therefore potential targets for new analgesics and pain-relieving strategies. The present review aims at providing an overview of the current knowledge on these networks, with a special emphasis on those involving interlaminar communication in both physiological and pathological conditions.

Predicting Where a Radiation Will Occur: Acoustic and Molecular Surveys Reveal Overlooked Diversity in Indian Ocean Island Crickets (Mogoplistinae: Ornebius).

Recent theory suggests that the geographic location of island radiations (local accumulation of species diversity due to cladogenesis) can be predicted based on island area and isolation. Crickets are a suitable group for testing these predictions, as they show both the ability to reach some of the most isolated islands in the world, and to speciate at small spatial scales. Despite substantial song variation between closely related species in many island cricket lineages worldwide, to date this characteristic has not received attention in the western Indian Ocean islands; existing species descriptions are based on morphology alone. Here we use a combination of acoustics and DNA sequencing to survey these islands for Ornebius crickets. We uncover a small but previously unknown radiation in the Mascarenes, constituting a three-fold increase in the Ornebius species diversity of this archipelago (from two to six species). A further new species is detected in the Comoros. Although double archipelago colonisation is the best explanation for species diversity in the Seychelles, in situ cladogenesis is the best explanation for the six species in the Mascarenes and two species of the Comoros. Whether the radiation of Mascarene Ornebius results from intra- or purely inter- island speciation cannot be determined on the basis of the phylogenetic data alone. However, the existence of genetic, song and ecological divergence at the intra-island scale is suggestive of an intra-island speciation scenario in which ecological and mating traits diverge hand-in-hand. Our results suggest that the geographic location of Ornebius radiations is partially but not fully explained by island area and isolation. A notable anomaly is Madagascar, where our surveys are consistent with existing accounts in finding no Ornebius species present. Possible explanations are discussed, invoking ecological differences between species and differences in environmental history between islands.

True Katydids (Pseudophyllinae) from Guadeloupe: Acoustic Signals and Functional Considerations of Song Production

Abstract Guadeloupe, the largest of the Leeward Islands, harbors three species of Pseudophyllinae (Orthoptera: Tettigoniidae) belonging to distinct tribes. This study examined the basic aspects of sound production and acousto-vibratory behavior of these species. As the songs of many Pseudophyllinae are complex and peak at high frequencies, they require high quality recordings. Wild specimens were therefore recorded ex situ. Collected specimens were used in structure-function experiments. Karukerana aguilari Bonfils (Pterophyllini) is a large species with a mirror in each tegmen and conspicuous folds over the mirror. It sings 4–6 syllables, each comprising 10–20 pulses, with several peaks in the frequency spectrum between 4 and 20 kHz. The song is among the loudest in Orthoptera (> 125 dB SPL in 10 cm distance). The folds are protective and have no function in song production. Both mirrors may work independently in sound radiation. Nesonotus reticulatus (Fabricius) (Cocconotini) produces verses from two syllables at irregular intervals. The song peaks around 20 kHz. While singing, the males often produce a tremulation signal with the abdomen at about 8–10 Hz. To our knowledge, it is the first record of simultaneous calling song and tremulation in Orthoptera. Other males reply to the tremulation with their own tremulation. Xerophyllopteryx fumosa (Brunner von Wattenwyl) (Pleminiini) is a large, bark-like species, producing a syllable of around 20 pulses. The syllables are produced with irregular rhythms (often two with shorter intervals). The song peaks around 2–3 kHz and 10 kHz. The hind wings are relatively thick and are held between the half opened tegmina during singing. Removal of the hind wings reduces song intensity by about 5 dB, especially of the low frequency component, suggesting that the hind wings have a role in amplifying the song.

pH‐dependent inhibition of native GABAA receptors by HEPES

BACKGROUND AND PURPOSE Artificial buffers such as HEPES are extensively used to control extracellular pH (pHe) to investigate the effect of H+ ions on GABAA receptor function.

First North American Records of the Old World Ant Cricket Myrmecophilus americanus (Orthoptera, Myrmecophilidae)

Abstract The Old World ant cricket Myrmecophilus americanus Saussure (Orthoptera, Myrmecophilidae) inhabits nests of the Old World tramp ant Paratrechina longicornis (Latreille) (Hymenoptera: Formicidae). Paratrechina longicornis has spread worldwide through human commerce, whereas M. americanus has been reported from sites in Asia, Oceania, South America, the West Indies, and the Mediterranean region. Here, we report the first North American records of M. americanus, all from peninsular Florida and the Florida Keys. In addition to older unpublished records of M. americanus from Archbold Biological Station (N 27.2°) and Gainesville (N 29.7°), we collected M. americanus from 5 of 13 P. longicornis nests surveyed in southernmost Florida (N 24.5–26.0°), but only from 1 of 20 P. longicornis nests surveyed further north (N 26.5–27.3°) in Florida. Although P. longicornis is common throughout most of Florida south of N 30°, its symbiont M. americanus appears to be common only in southernmost Florida. If climate limits populations of M. americanus in northern Florida, then it is likely that the higher latitude records reported as M. americanus from subtropical semi-arid Mediterranean sites (Egypt, Libya, and Israel; N 30–32°) are actually misidentifications of one or more distinct species, possibly Myrmecophilus cottami Chopard and/or Myrmecophilus surcoufi Chopard.

Review of Hebridea Willemse, 1926, an endemic genus of grasshoppers from Vanuatu (Orthoptera, Caelifera) with the description of a new species from Malekula

ABSTRACT The grasshopper genus Hebridea Willemse, 1926 is redefined, the species Hebridea rufotibialis Willemse, 1926 from Espiritu Santo is redescribed and life history traits are given. Hebridea amedegnatoae n. sp. is described from Malekula Island. Examination of its morphology reveals that Hebridea belongs to Catantopinae Brunner von Wattenwyl, 1893 and not to Cyrtacanthacridinae Kirby, 1902. Relations of Hebridea with closely related Catantopinae genera are discussed. MOTS CLÉS Orthoptera, Caetifera, Acrididae, Catantopinae, Cyrtacanthacridinae, sud-ouest du Pacifique, espèce nouvelle.

Insect mimicry of plants dates back to the Permian

In response to predation pressure, some insects have developed spectacular plant mimicry strategies (homomorphy), involving important changes in their morphology. The fossil record of plant mimicry provides clues to the importance of predation pressure in the deep past. Surprisingly, to date, the oldest confirmed records of insect leaf mimicry are Mesozoic. Here we document a crucial step in the story of adaptive responses to predation by describing a leaf-mimicking katydid from the Middle Permian. Our morphometric analysis demonstrates that leaf-mimicking wings of katydids can be morphologically characterized in a non-arbitrary manner and shows that the new genus and species Permotettigonia gallica developed a mimicking pattern of forewings very similar to those of the modern leaf-like katydids. Our finding suggests that predation pressure was already high enough during the Permian to favour investment in leaf mimicry.