Grey T. Gustafson

Ultraconserved elements show utility in phylogenetic inference of Adephaga (Coleoptera) and suggest paraphyly of ‘Hydradephega’

The beetle suborder Adephaga has been the subject of many phylogenetic reconstructions utilizing a variety of data sources and inference methods. However, no strong consensus has yet emerged on the relationships among major adephagan lineages. Ultraconserved elements (UCEs) have proved useful for inferring difficult or unresolved phylogenies at varying timescales in vertebrates, arachnids and Hymenoptera. Recently, a UCE bait set was developed for Coleoptera using polyphagan genomes and a member of the order Strepsiptera as an outgroup. Here, we examine the utility of UCEs for reconstructing the phylogeny of adephagan families, in the first in vitro application a UCE bait set in Coleoptera. Our final dataset included 305 UCE loci for 18 representatives of all adephagan families except Aspidytidae, and two polyphagan outgroups, with a total concatenated length of 83 547 bp. We inferred trees using maximum likelihood analyses of the concatenated UCE alignment and coalescent species tree methods (astral ii, ASTRID, svdquartets). Although the coalescent species tree methods had poor resolution and weak support, concatenated analyses produced well‐resolved, highly supported trees. Hydradephaga was recovered as paraphyletic, with Gyrinidae sister to Geadephaga and all other adephagans. Haliplidae was recovered as sister to Dytiscoidea, with Hygrobiidae and Amphizoidae successive sisters to Dytiscidae. Finally, Noteridae was recovered as monophyletic and sister to Meruidae. Given the success of UCE data for resolving phylogenetic relationships within Adephaga, we suggest the potential for further resolution of relationships within Adephaga using UCEs with improved taxon sampling, and by developing Adephaga‐specific probes.

Tip-dated phylogeny of whirligig beetles reveals ancient lineage surviving on Madagascar

The temporal origin of Madagascar’s extraordinary endemic diversity is debated. A preference for Cenozoic dispersal origins has replaced the classical view of Mesozoic vicariance in the wake of molecular dating. However, evidence of ancient origins is mounting from arthropod groups. Using phylogenetic ‘tip-dating’ analysis with fossils, we show that a whirligig beetle species, Heterogyrus milloti, inhabiting forest streams in southeastern Madagascar is the last survivor of a once dominant and widespread Mesozoic group. With a Late Triassic to Early Jurassic origin (226–187 Ma) it is the hitherto oldest dated endemic lineage of animal or plant on Madagascar. Island biotas’ sensitivity to extinction is well known, but islands can also provide refuge from continental extinction. Heterogyrus milloti is an irreplaceable link to the freshwater biota of the Mesozoic and serves as a reminder of what may be lost without critical conservation efforts on Madagascar.

The New World whirligig beetles of the genus Dineutus Macleay, 1825 (Coleoptera, Gyrinidae, Gyrininae, Dineutini)

Abstract All New World members of the whirligig beetle genus Dineutus Macleay, 1825 are treated. The New World Dineutus are found to be composed of 18 species and 6 subspecies: one species, Dineutus mexicanus Ochs, 1925, stat. n. is elevated from subspecies to species rank, and the subspecies Dineutus carolinus mutchleri Ochs, 1925, syn. n. is synonymized here with the typical form. Lectotypes are designated for Dineutus discolor Aubé, 1838, Dineutes metallicus Aubé, 1838, Dineutus solitarius Aubé, 1838, Dineutes analis Régimbart, 1883, and Gyrinus longimanus Olivier, 1795. Each taxonomic unit is provided with a taxonomic history, type locality, diagnosis, distribution, habitat information, and a discussion section. The aedeagus and male mesotarsal claws are illustrated, and dorsal and ventral habitus images of both sexes, for each species and subspecies are provided. General distribution maps are provided for all taxonimc units. A key to the genera of New World Gyrinidae, as well as all the New World Dineutus species is provided. General Dineutus anatomy as well as a clarification of homology and anatomical terms is included.

On the family- and genus-series nomina in Gyrinidae Latreille, 1810 (Coleoptera, Adephaga)

All available genus- and family- group nomina for the Gyrinidae (Coleoptera: Adephaga) are listed along with original citation, original and current status, type nominal taxon with method of designation, and known synonymies and incorrect subsequent spellings. The nomina included follow the most current classification. Discussion is provided clarifying numerous nomenclatural problems with original spellings, correct authorship and type designation. Dineutini Ochs, 1926 syn. nov. is found to be a junior homonym of Dineutini Desmarest, 1851, and Enhydrini Régimbart, 1882 syn. nov. and its justified emendation Enhydrusini (Anonymous 2012) are here synonymized with Dineutini Desmarest, 1851.

Larval morphology and chaetotaxy of Macrogyrus oblongus (Boisduval, 1835) (Coleoptera: Gyrinidae)

ABSTRACT The larvae of the grooved whirligig beetle Macrogyrus oblongus (Boisduval, 1835) are described and illustrated including detailed morphometric and chaetotaxic analyses of selected structures. Larvae of Macrogyrus Régimbart, 1882 exhibit the characters traditionally recognised as autapomorphies of the Gyrinidae. The first instars bear egg bursters on the parietal, a potential additional autapomorphy. Putative larval autapomorphies of the tribe Dineutini are the presence of additional setae on the mandible, the absence of the seta TR2, and the presence of pore-like additional structures on the ultimate palpomeres. Macrogyrus larvae differ from those of the other known dineutine genera (Andogyrus Ochs, 1924 and Dineutus MacLeay, 1825) in the absence of a neck constriction and in the distal position of the pore LAc. Other useful characters to distinguish genera within Dineutini are the presence or absence of additional setae on the cardo and coxa, and the posterior margin of the lacinia dentate or smooth.

Revision of the Neotropical burrowing water beetle genus Liocanthydrus Guignot (Coleoptera: Noteridae: Noterinae: Noterini) with the description of two new species

The burrowing water beetle genus Liocanthydrus Guignot, 1957 is redefined and its species are revised. Of the four current species, three are recognized as belonging to the genus and redescribed: L. angustus (Guignot, 1957), L. octoguttatus (Zimmermann, 1921) and L. uniformis (Zimmermann, 1921). The fourth species, L. buqueti (Laporte, 1835) is found to not be a member of Liocanthydrus, but of an undescribed genus. The noterid genus Siolius J. Balfour-Browne, 1969, is synonymized with Liocanthydrus (new synonymy) based on comparison of type specimens in both groups. Two of the three species described in Siolius, S. bicolor J. Balfour-Browne, 1969 and S. clayae J. Balfour-Browne, 1969, are recognized as valid, transferred to Liocanthydrus, and redescribed. The third, S. amazonicus J. Balfour- Browne, 1969, is synonymized with L. uniformis (new synonymy). Two new species from South America, L. armulatus sp. n. and L. nanops sp. n. are also recognized and described. A lectotype is designated for Canthydrus octoguttatus Zimmermann, 1921. After this revision, there are seven valid species of Liocanthydrus. Habitus photos are provided, diagnostic characters of all recognized species are illustrated, distributions are provided, and a key to the species is included.

The Morphology and Behavior of the Endemic Malagasy Whirligig Beetle Heterogyrus milloti Legros, 1953 (Coleoptera: Gyrinidae: Heterogyrinae)

Abstract The Malagasy endemic whirligig beetle Heterogyrus milloti Legros, 1953 is redescribed. Jumping behavior of H. milloti is reported here for the first time with video recordings provided. Results of a behavioral experiment conducted in the field demonstrate H. milloti jumps in a targeted manner in a downstream direction. The unique habitat of H. milloti is described in detail with both image and video of the habitat included. Morphology of H. milloti is discussed in detail, revealing symplesiomorphies with Spanglerogyrus Folkerts, 1979, characters forming transitional series between Spanglerogyrus and the Gyrininae, and features unique to H. milloti. The potential adaptive significance of these peculiar morphological features in association with the habitat of H. milloti is discussed. Finally, an argument for the necessity of conservation of this species is made, and common names in English, French, Malagasy, and Swedish for H. milloti are proposed to aid conservation efforts.

On Wet Rocks with Snorkels: Immature Stages of Tritonus Cascade Beetles with Unusual Modification of Spiracles (Coleoptera: Hydrophilidae: Laccobiini)

Abstract. The egg case and larvae of all three instars of the cascade beetle Tritonus complanatus Short, 2008 (Coleoptera: Hydrophilidae) are described based on specimens found co-occurring with adults and associated with them by comparing histone 3 nDNA sequences. The morphology of the larva is congruent with the phylogenetic position of Tritonus Mulsant, 1844 in the Paracymus-group of the Laccobiini, but also exhibits characters shared with larvae of Hydrobiusini, and some presumed adaptations to the hygropetric life style. The larva has open mesothoracic and abdominal spiracles situated on top of long spiracular tubes in the first instar, likely working as ‘spiracular snorkels’, and on low tubercles in later instars, along with a well-developed spiracular atrium. Similar spiracular morphology was found in the larva of the terrestrial laccobiine genus Tormus Sharp, 1884, and a brief examination of larvae of few other genera (Oocyclus Sharp, 1882, Hydrobius Leach, 1815) reveals that the peripneustic spiracular system (mesothoracic plus 8 abdominal functioning spiracles) may be more widespread in larval Hydrophilidae than currently believed.

A North American Biodiversity Hotspot Gets Richer: A New Species of Whirligig Beetle (Coleoptera: Gyrinidae) From the Southeastern Coastal Plain of the United States

Abstract A new species of Dineutus Macleay, 1825 is described from the Southeastern Coastal Plain of the United States. Habitus and aedeagus images as well as illustrations of elytral apices, protarsus, palps, and male mesotarsal claws are provided for Dineutus shorti n. sp. and compared to those of D. discolor Aubé, 1838. The importance of the southeastern Coastal Plain as a biodiversity hotspot and the potential conservation concern of D. shorti n. sp. also are discussed.

Rediscovery of Lutrochus laticeps Casey, 1893 (Coleoptera: Lutrochidae) and the Discovery of Dineutus productus Roberts, 1895 and Dineutus serrulatus analis Régimbart, 1882 (Coleoptera: Gyrinidae) in Kansas, USA, with Notes on Habitat Preference

Here, we report the first collection of the family Lutrochidae in Kansas, USA since 1920 and new records of Dineutus productus Roberts, 1895 and Dineutus serrulatus analis Régimbart, 1882 from Kansas. These new records are the result of a collecting trip by the authors in southeastern Kansas during the weekend of 21 June 2014. Six sites in southeastern Kansas were sampled for water beetles (Fig. 1). Sampling localities were selected based on historical collecting events, knowledge of local geological formations, and photographs of local streams on the Kansas Waterfalls website (Stokes 2014). Voucher specimens are deposited in the Snow Entomological Museum Collection, Lawrence, KS, USA.