Dealing with a hairy beast–larval morphology and chaetotaxy of the Australian endemic diving beetle genus Spencerhydrus (Coleoptera, Dytiscidae, Cybistrini)

In this contribution, the larval morphology of Spencerhydrus Sharp, 1882 was studied, an Australian endemic genus in the diving beetle tribe Cybistrini. All instars of the only two species included in the genus (S. latecinctus Sharp, 1882 and S. pulchellus Sharp, 1882) are described and illustrated with the exception of the third instar of S. latecinctus. Detailed morphometric and primary chaetotaxic analyses were performed to discover useful characters for generic diagnosis and species distinction. Spencerhydrus can be distinguished from other Cybistrini genera by the medial projection of frontoclypeus slightly indented apically, with lamellae clypeales directed forward in a characteristic V-shaped pattern, the median process of prementum strongly developed, the presence of a single ventral sclerite on prothorax, the presence of basoventral spinulae on claws, and the reduced sclerotization of the abdominal segment VII which covers only the anterior half. Larvae of the two species of Spencerhydrus can readily be distinguished by the shape of the median process of prementum, which is visibly broader in S. pulchellus than in S. latecinctus.

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Phylogenetic relationships of Leuronectes Sharp (Coleoptera: Dytiscidae: Agabinae) based on larval morphology and chaetotaxy

Insect Systematics & Evolution ◽

10.1163/187631209x440078 ◽

2009 ◽

Vol 40 (2) ◽

pp. 209-228 ◽

Cited By ~ 10

Author(s):

Miguel Archangelsky ◽

Mariano Michat

Keyword(s):

Phylogenetic Relationships ◽

Abdominal Segment ◽

Anterior Margin ◽

Cladistic Analysis ◽

Lateral Margin ◽

Larval Morphology ◽

The Third ◽

Segment Viii ◽

First Time ◽

Diving Beetle

AbstractThe phylogenetic relationships of the diving beetle (Dytiscidae) genus Leuronectes Sharp are revised based on a cladistic analysis of seven Agabinae genera and 54 morphological and chaetotaxic characters from larvae. For this purpose, larvae of L. curtulus Régimbart are described and illustrated in detail for the first time, with particular emphasis on morphometry and chaetotaxy. The results show that Leuronectes is well placed within Agabinae based on the absence of natatory setae on tibia and tarsus in instars II and III, the urogomphus composed of two urogomphomeres, and the absence of secondary setae on urogomphus. Leuronectes is resolved as part of a basal polytomy along with Platynectes Régimbart and a clade formed by the remaining agabine genera. Leuronectes shares with Platynectes the setae UR2, UR3 and UR4 not inserted contiguously, with Platambus Thomson the anterolateral lobes of frontoclypeus not projected beyond anterior margin, with Hydrotrupes Sharp the seta AB9 inserted dorsolaterally, and with Ilybius Erichson the seta LA10 inserted submedially. Leuronectes is unique within Agabinae in having the apical lateroventral process of the third antennomere not protruding and additional ventroapical pores on third antennomere, and is unique within the dytiscid genera studied in having the seta LA12 inserted submedially and one additional spine-like seta inserted on the lateral margin of abdominal segment VIII.

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Phylogenetic relationships and comparative larval morphology of epigean and stygobitic species of Limbodessus Guignot, 1939 (Coleoptera: Dytiscidae: Bidessini), with a key of identification

Zootaxa ◽

10.11646/zootaxa.3584.1.1 ◽

2012 ◽

Vol 3584 (1) ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

MARIANO C. MICHAT ◽

YVES ALARIE ◽

CHRIS H. S. WATTS

Keyword(s):

Phylogenetic Relationships ◽

Abdominal Segment ◽

Variable Number ◽

Larval Morphology ◽

First Time ◽

Diving Beetle ◽

Occipital Foramen

The larvae of five epigean and 25 stygobitic species of the diving beetle genus Limbodessus Guignot, 1939 are describedand illustrated for the first time, with special emphasis on morphometry and chaetotaxy of the cephalic capsule, headappendages, legs, last abdominal segment and urogomphi. Those of the following five epigean species are described: L.amabilis (Clark, 1862), L. compactus (Clark, 1862), L. inornatus (Sharp, 1882), L. praelargus (Lea, 1899), L. shuckardii(Clark, 1862). The 25 stygobitic larvae described are: L. barwidgeeensis Watts & Humphreys, 2006, L. bigbellensis(Watts & Humphreys, 2000), L. challaensis (Watts & Humphreys, 2001), L. cooperi Watts & Humphreys, 2006, L.eberhardi (Watts & Humphreys, 1999), L. exilis Watts & Humphreys, 2006, L. fridaywellensis (Watts & Humphreys,2001), L. hillviewensis (Watts & Humphreys, 2004), L. hinkleri (Watts & Humphreys, 2000), L. leysi Watts & Humphreys,2006, L. macrohinkleri Watts & Humphreys, 2006, L. masonensis (Watts & Humphreys, 2001), L. millbilliensis Watts &Humphreys, 2006, L. mirandaae Watts & Humphreys, 2006, L. morgani (Watts & Humphreys, 2000), L. nambiensisWatts & Humphreys, 2006, L. ordinarius Watts & Humphreys, 2009, L. palmulaoides Watts & Humphreys, 2006, L.pulpa (Watts & Humphreys, 1999), L. raeae Watts & Humphreys, 2006, L. raesideensis (Watts & Humphreys, 2001), L.windarraensis (Watts & Humphreys, 1999), L. yandalensis Watts & Humphreys, 2006, L. yarrabubbaensis Watts & Humphreys, 2009, L. yuinmeryensis (Watts & Humphreys, 2003). The morphology and chaetotaxy of epigean vs.stygobitic species are compared, and a key for the identification of the species is presented. Contrary to their epigeancounterparts, larvae of stygobitic Limbodessus have turned out to be very divergent morphologically. In addition to thecommon characteristics associated with an underground living (i.e., absence of stemmata, reduced pigmentation, and thinor soft exoskeleton), larvae of these species have undergone a variable modification of the frontoclypeus and have evolvedrelatively shorter tarsal claws. Two morphological groups of stygobitic species are evident, one including species lessdeviated from the ancestral (epigean) condition and another group comprising more modified species that typically havea larger size, a more or less pyriform head with a digitiform nasale, and a strongly reduced occipital foramen. Primarychaetotaxy of the species has remained a very conservative expression of the phenotype. Secondary chaetotaxy showsvariation among the species, the most obvious being the variable number of lamellae clypeales and the presence or absenceof secondary setae on the urogomphus. The phylogenetic relationships of Limbodessus are analyzed cladistically. Larvaeof this genus lack the primary pore ABc, which is a synapomorphy of the tribe Bidessini. As presently defined, Limbodessus is probably paraphyletic with respect to Allodessus Guignot, 1953.

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Larval morphology, biology and distribution of Agabus setulosus (Coleoptera: Dytiscidae)

Insect Systematics & Evolution ◽

10.1163/187631289x00267 ◽

1988 ◽

Vol 19 (3) ◽

pp. 381-391 ◽

Cited By ~ 4

Author(s):

Anders N. Nilsson

Keyword(s):

Life Cycle ◽

Abdominal Segment ◽

Instar Larva ◽

Larval Morphology ◽

Northern Sweden ◽

Swedish Population ◽

The Third ◽

Northern Fennoscandia ◽

First Instar ◽

First Time

AbstractA lectotype is designated for Agabus setulosus (J. Sahlberg, 1895), a rare rheophilous dytiscid known mainly from northern Fennoscandia. The larval instars are described for the first time, based on material from northern Sweden. The first-instar larva is characterized by the presence of two dorsal spines on each femur and a pair of mediodorsal setae on last abdominal segment; both characters are seemingly unique among Agabus. The third instar differs from all other Palaearctic Agabus species in the complete sclerotization of the ring-like abdominal segment 6. The biology of A. setulosus is described from a Swedish population; semivoltine life cycle with overwintering eggs laid in summer followed by adult overwintering prior to breeding is suggested.

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Description of the larvae of three species of Laccophilus Leach and comments on the phylogenetic relationships of the Laccophilinae (Coleoptera: Dytiscidae)

Zootaxa ◽

10.11646/zootaxa.1922.1.4 ◽

2008 ◽

Vol 1922 (1) ◽

pp. 47-61 ◽

Cited By ~ 3

Author(s):

MARIANO C. MICHAT

Keyword(s):

Phylogenetic Relationships ◽

Abdominal Segment ◽

The Other ◽

Larval Morphology ◽

Neotropical Species ◽

First Instar ◽

Other Hand ◽

Dense Group ◽

First Time ◽

Diving Beetle

The larvae of three Neotropical species of the diving beetle genus Laccophilus Leach (Laccophilus obliquatus Régimbart, L. paraguensis Régimbart and L. testudo Régimbart) are described and illustrated for the first time, with an emphasis on morphometry and chaetotaxy of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. Larvae of these species lack the primary setae LA10 and LA12, and have the primary seta CO7 articulated proximally on all coxae, two apomorphies that define the subfamily Laccophilinae. They are also characterized by a frontoclypeus truncate proximally in the first instar, the presence of pectens on legs, and the presence of secondary setae on first urogomphomere. These character states are apomorphies that define the genus Laccophilus Leach. The absence of pore PAc and the presence of a dense group of secondary spiniform setae dorsally at the base of the siphon in instar III may also characterize this genus, as similar states are not found in other dytiscids. On the other hand, L. obliquatus, L. paraguensis and L. testudo differ from the other species of Laccophilus known in detail in the presence of an additional seta on the stipes and in the absence of pore ABc. Brief comments on the putative phylogenetic relationships of Laccophilinae and Laccophilus inferred from larval morphology, as well as on the characters potentially useful in studying relationships within the group are presented.

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Larval morphology and biology of some European Anomalini (Coleoptera: Scarabaeoidea: Rutelidae: Anomalinae). A phylogenetical approach

Insect Systematics & Evolution ◽

10.1163/187631205788838519 ◽

2005 ◽

Vol 36 (2) ◽

pp. 183-198 ◽

Cited By ~ 4

Author(s):

Eduardo Galante ◽

Estefanía Micó

Keyword(s):

Abdominal Segment ◽

Systematic Position ◽

Biological Data ◽

Larval Morphology ◽

The Third ◽

Phyllopertha Horticola ◽

Leg Morphology ◽

Third Instar Larvae

AbstractThe third instar larvae of five anomaline species, Anomala dubia (Scopoli, 1763), Anomala quadripunctata (Olivier, 1789), Blitopertha lineata (Fabricius, 1798), Mimela rugatipennis (Graells, 1849) and Phyllopertha horticola (Linnaeus, 1758) are described as well as their biological data. The analysis of the morphology of the four distinct genera studied revealed diagnostic differences in leg morphology, last abdominal segment, and spiracles. An approach to the phylogeny of the group based on larval characteristics is provided. Finally, the systematic position of Blitopertha Reitter, 1903 is discussed.

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Larval morphology of Liodessus Guignot, 1939: generic characteristics, descriptions of five species and comparisons with other members of the tribe Bidessini (Coleoptera: Dytiscidae: Hydroporinae)

Zootaxa ◽

10.11646/zootaxa.1516.1.1 ◽

2007 ◽

Vol 1516 (1) ◽

pp. 1-21 ◽

Cited By ~ 6

Author(s):

YVES ALARIE ◽

MARIANO C. MICHAT ◽

MIGUEL ARCHANGELSKY ◽

HELEN M. BARBER-JAMES

Keyword(s):

Abdominal Segment ◽

Head Capsule ◽

Larval Morphology ◽

The Third

The larvae of Liodessus affinis (Say, 1823), L. crotchi Nilsson, 2001, L. flavofasciatus (Steinheil, 1869), L. involucer (Brinck, 1948), and L. patagonicus (Zimmermann, 1923) are described with an emphasis on chaetotaxy of the head capsule, head appendages, legs, last abdominal segment and urogomphi. Larvae of these species are very uniform in terms of larval morphology. Considering all known bidessine larvae, Liodessus Guignot, 1939 is more similar to Hypodessus Guignot 1939, Amarodytes Régimbart, 1900, Anodocheilus Babington, 1841, Glareadessus Wewalka & Biström, 1998, Allodessus Guignot, 1953, and Neoclypeodytes Young, 1967, all these genera sharing a short siphon and an elongate first urogomphomere. Liodessus differs from Hypodessus, Amarodytes and Anodocheilus by absence of the primary pore PAj whereas it shares with Anodocheilus the absence of a ventroapical spinula on the third antennomere.

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The Puzzling Falcomurus Mandal (Collembola, Orchesellidae, Heteromurinae): A Review

Insects ◽

10.3390/insects12070650 ◽

2021 ◽

Vol 12 (7) ◽

pp. 650

Author(s):

Bruno C. Bellini ◽

Paolla G. C. de Souza ◽

Penelope Greenslade

Keyword(s):

New Species ◽

Abdominal Segment ◽

Antennal Segment ◽

Type Material ◽

Generic Diagnosis ◽

Monotypic Genus ◽

The Third ◽

Two New Species ◽

Key Characters

Falcomurus Mandal is currently a monotypic genus of Heteromurinae described from India in 2018. Its key characters are the first antennal segment subdivided, the second undivided and the third annulated; the first abdominal segment lacking macrochaetae; and the presence of a sinuous modified macrochaeta on the proximal dens. Some details of its morphology were recently put in doubt, and so its genus status and affinities remain uncertain. Here, we revise the genus based on the type material of Dicranocentrus litoreus Mari-Mutt, as well as provide the description of two new species from Australian archipelagos and a reinterpretation of the chaetotaxy of Falcomurus chilikaensis Mandal and D. halophilus Mari-Mutt. After our revision, Falcomurus shows a well-conserved chaetotaxy and overall morphology, which allowed us to provide an updated generic diagnosis. While the antennae morphology of Falcomurus resembles that of Dicranocentrus Schött, its dorsal sensillar and macrochaetotaxy suggest it is closely related to Heteromurus Wankel, as originally stated by Mandal. The main features useful to separate Falcomurus species are the head, mesothorax and fourth abdominal segment chaetotaxy. We also provide a key to its five species, a comparative table and notes on the affinities and distribution of Falcomurus.

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An emendation of the generic diagnosis of Phoreiobothrium Linton, 1889 (Tetraphyllidea: Onchobothriidae) with a detailed description of bothridia and hooks

Canadian Journal of Zoology ◽

10.1139/z85-179 ◽

1985 ◽

Vol 63 (5) ◽

pp. 1199-1206 ◽

Cited By ~ 5

Author(s):

J. N. Caira

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Monophyletic Group ◽

Generic Diagnosis ◽

The Third ◽

Scanning Electron

Hook terminology for the three-pronged hooks of Phoreiobothrium Linton, 1889 is reconciled with that for two-pronged hooks such that the two outermost prongs are considered homologous with the prongs of a two-pronged hook and the third inner prong is termed the basal prong. Scanning electron microscopy was performed on the scolex of Phoreiobothrium lasium Linton, 1889 and the solid nature of the bothridia was reconfirmed. Examination of material of all four species of Phoreiobothrium leads to the conclusion that each species possesses three-pronged hooks that are hollow and open to the outside via pores. The bothridia of each species are considered to be horizontally divided into two loculi, the posterior one being recessed and vertically subdivided. The diagnosis of the genus Phoreiobothrium is emended, and the four species allocated to it are redescribed. Phoreiobothrium is determined to be a monophyletic group on the basis of two synapomorphies and a key to the four species of the genus is presented.

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Contribution to the knowledge of the oribatid mite genus Zeasuctobelba (Acari, Oribatida, Suctobelbidae)

Systematic and Applied Acarology ◽

10.11158/saa.24.10.8 ◽

2019 ◽

Vol 24 (10) ◽

pp. 1893-1901

Author(s):

Sergey G. Ermilov

Keyword(s):

Anterior Margin ◽

Anterior Part ◽

Oribatid Mite ◽

Generic Diagnosis ◽

Southern Chile ◽

Ventral Plate ◽

Median Process ◽

A New Species ◽

Sphagnum Magellanicum ◽

Mite Genus

A new species of Zeasuctobelba (Oribatida, Suctobelbidae) is described from a moss Sphagnum magellanicum in swamp in southern Chile. Zeasuctobelba processa sp. nov. differs from all species of the genus by the presence of a median process on the anterior margin of the ventral plate (anterior part of epimere I), lateral sides of prodorsum with one pair of strong triangular processes and by bothridial setae having long setiform apices and long cilia. Revised generic diagnosis, identification key and data on distribution of known species of Zeasuctobelba are presented. Zeasuctobelba nodosa Hammer, 1966 and Z. arcuata Hammer, 1968 are excluded from Zeasuctobelba.

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Re-descriptions of larvae of Hoperius and Meladema and phylogenetic implications for the tribe Colymbetini (Coleoptera Dytiscidae)

Memorie della Società Entomologica Italiana ◽

10.4081/memoriesei.2006.307 ◽

2006 ◽

Vol 85 (1) ◽

pp. 307 ◽

Cited By ~ 7

Author(s):

Yves Alarie ◽

Samantha Hughes

Keyword(s):

Relative Position ◽

Abdominal Segment ◽

Variable Number ◽

Maxillary Palpus ◽

Dorsal Margin ◽

Ventral Margin ◽

Larval Morphology ◽

Parsimony Analysis ◽

Phylogenetic Implications ◽

Segment Viii

New descriptions of the larvae of Meladema lanio (Fabricius), M. coriacea Laporte and Hoperius planatus Fall are provided. Characters from larval morphology are analyzed to infer the phylogenetic relationships of the genera Meladema Laporte and Hoperius Fall with other genera of the tribe Colymbetini (Colymbetinae). Larvae of Meladema are unique among other Colymbetini being characterized by the presence of a variable number of additional setae along the dorsal margin of both femora and tibiae. Larvae of Hoperius reveal to be remarkably modified and autapomorphic being characterized by a short antennomere II, the presence of a variable number of secondary setae on antennomeres I - II and maxillary palpomere, an elongate maxillary palpus, and a narrow and elongate mandible. A parsimony analysis based on 30 informative larval characters is carried out. Whereas the 12 most parsimonious trees support the placement of Meladema as sister to Neoscutopterus J. Balfour-Browne, the relative position of Hoperius remains unresolved within the Colymbetini. Larvae of Meladema share with those of Neoscutopterus: (i) the presence of additional setae both on the frontoclypeus and parietale, (ii) the presence of a large number of secondary setae on trochantera, (iii) the absence of spinulae along ventral margin of mesotibia and mesotarsus and (iv) the presence of additional setae both on abdominal segment VIII.

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