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

2009 ◽  
Vol 40 (2) ◽  
pp. 209-228 ◽  
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.

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

Zootaxa ◽  
2012 ◽  
Vol 3584 (1) ◽  
pp. 1 ◽  
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.

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

Zootaxa ◽  
2008 ◽  
Vol 1922 (1) ◽  
pp. 47-61 ◽  
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.

Phylogenetic relationships, larval morphology, and chaetotaxy of the subfamily Coptotominae (Coleoptera: Dytiscidae)

2013 ◽  
Vol 145 (3) ◽  
pp. 247-264 ◽  
Author(s):  
Mariano C. Michat ◽  
Yves Alarie
Keyword(s):  
Phylogenetic Relationships ◽  
Abdominal Segment ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
First Instar ◽  
Segment Viii ◽  
Tracheal Gills

AbstractLarval morphology of the monogeneric subfamily Coptotominae (Coleoptera: Dytiscidae) is described and illustrated in detail, with particular emphasis on morphometry and chaetotaxy. Larvae ofCoptotomusSay are unique within Dytiscidae in the presence of tracheal gills on the abdominal segments I–VI, a short bifid horn or nasale in instar I, long spinulae on the urogomphus in instar I, and rows of natatory setae on both the internal and external margins of the urogomphus in instars II and III. A cladistic analysis based on 125 larval characters sampled among representatives of other dytiscid subfamilies supports a sister-group relationship between Coptotominae and Laccophilinae based on the shared absence of setae LA10 and LA12 on the second labial palpomere and of pore ABc on the abdominal segment VIII. The clade Coptotominae + Laccophilinae resolved as sister to Lancetinae, all three subfamilies sharing the presence of an unusually low number of lamellae clypeales in the first instar (a condition called four-peg-pattern), postulated to have evolved secondarily within Dytiscidae.

Larval morphology and analysis of primary chaetotaxy in the genus  Suphis Aubé, 1836 (Coleoptera: Noteridae)

Zootaxa ◽  
2019 ◽  
Vol 4619 (1) ◽  
pp. 121-138 ◽  
Author(s):  
JUAN I. URCOLA ◽  
YVES ALARIE ◽  
CESAR J. BENETTI ◽  
GEORGINA RODRIGUEZ ◽  
MARIANO C. MICHAT
Keyword(s):  
Abdominal Segment ◽  
Distal Portion ◽  
The Other ◽  
Larval Morphology ◽  
Larval Instars ◽  
Ancestral Condition ◽  
Ground Plan ◽  
Other Hand ◽  
Segment Viii ◽  
First Time

The three larval instars of Suphis cimicoides Aubé, 1837 are described and illustrated, including morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphus. A preliminary ground plan of primary chaetotaxy for noterid larvae is presented for the first time, based on the species described herein and examination of larvae of the genera Hydrocanthus Say, 1823 and Suphisellus Crotch, 1873. This ground plan is compared with previous systems proposed for other adephagan families. Larvae of Noteridae can be distinguished from those of other families of Hydradephaga by the following combination of characters: (1) antennomere 3 with a rugged area on distal portion; (2) abdominal segment VIII with a U-shaped wavy membranous area ventrally; (3) absence of pore FRd; and (4) presence of seta AB16. Several sensilla present in noterid larvae (notably setae TR2 and TA1 and pores PAl, PAm, COd, TRb and FEb) are absent in larvae of Meruidae. On the contrary, parietal seta PA5 is present in Meruidae but absent in Noteridae. The presence of pore COc in Noteridae may indicate that this family has retained the ancestral condition found only in Carabidae. On the other hand, the absence of setae FE7, FE8, FE9 and FE10 in Noteridae is similar to the condition found in Carabidae, Gyrinidae and Meruidae. 

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

1988 ◽  
Vol 19 (3) ◽  
pp. 381-391 ◽  
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.

Descriptions of the first-instar larva of the hypogaeic species Neobidessodes limestoneensis (Watts & Humphreys) and of the third-instar larva of Hydroglyphus balkei Hendrich (Coleoptera: Dytiscidae: Bidessini) with phylogenetic considerations

Zootaxa ◽  
2010 ◽  
Vol 2658 (1) ◽  
pp. 38 ◽  
Author(s):  
MARIANO C. MICHAT ◽  
YVES ALARIE ◽  
CHRIS H. S. WATTS
Keyword(s):  
Abdominal Segment ◽  
Cladistic Analysis ◽  
Instar Larva ◽  
Morphological Characters ◽  
The Other ◽  
The Third ◽  
First Instar ◽  
First Time ◽  
Third Instar Larva ◽  
Occipital Foramen

The first-instar larva of Neobidessodes Hendrich & Balke (through the hypogaeic species N. limestoneensis (Watts & Humphreys)) and the third-instar larva of Hydroglyphus Motschulsky (through H. balkei Hendrich) (Dytiscidae: Bidessini) are described and illustrated in detail for the first time, including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. A cladistic analysis including 51 characters and 32 hydroporine taxa is performed, which supports the inclusion of both genera in the tribe Bidessini based on the absence of the primary pore ABc on the last abdominal segment. The third instar of H. balkei is characterized by the absence of secondary setae on the urogomphi and anterior secondary setae on the coxa, and the presence of 8–9 secondary setae on the mesofemur. On the other hand, the first instar of N. limestoneensis bears 14 lamellae clypeales on the anteroventral margin of the nasale. This species has evolved several morphological characters that are probably associated with its hypogaeic existence, including a lightly sclerotized body, relatively longer cephalic capsule and mandibles, a strongly reduced occipital foramen, absence of stemmata, and short claws. However, primary chaetotaxy apparently has remained as a very conservative expression of the phenotype.

Phylogenetic relationships of the intertidal genus Halorhadinus Sawada and key to the genera of the Liparocephalini (Coleoptera: Staphylinidae: Aleocharinae)

2001 ◽  
Vol 32 (2) ◽  
pp. 123-132 ◽  
Author(s):  
Kee-Jeong Ahn
Keyword(s):  
Phylogenetic Relationships ◽  
Anterior Margin ◽  
Cladistic Analysis ◽  
Basal Part ◽  
Diagnostic Features ◽  
First Time ◽  
Generic Relationships

AbstractHalorhadinus Sawada is redescribed and illustrations of diagnostic features are presented. Median lobes and parameres of H. aequalis Sawada and H. inaequalis Sawada are described for the first time. A key is provided for separation of the known species of Halorhadinus. Based on contiguous mesocoxal cavities, galea with several setae only on mesal surface and apex with setae, Halorhadinus is hypothesized to be a member of the tribe Liparocephalini. A revised cladistic analysis of the Liparocephalini based on 50 adult characters suggests that Halorhadinus belong to the Liparocephalini with the following patterns of generic relationships (outgroup (Salinamexus Moore & Legner (Halorhadinus Sawada (Amblopusa Casey (Paramblopusa Ahn &Ashe (Diaulota Casey + Liparocephalus Mäklin)))))). Monophyly of the genus Halorhadinus is supported by three synapomorphies (mentum with anterior margin deeply sinuate and antero-lateral parts triangular; ligula round and very long, almost reaching to half of palpi; spatulate setae mostly located on basal part of palpi). A key to the genera of the Liparocephalini is given.

Larval morphology of the diving beetle Celina and the phylogeny of ancestral hydroporines (Coleoptera:Dytiscidae:Hydroporinae)

2007 ◽  
Vol 21 (3) ◽  
pp. 239 ◽  
Author(s):  
Mariano C. Michat ◽  
Yves Alarie ◽  
Patricia L. M. Torres ◽  
Yoandri S. Megna
Keyword(s):  
Phylogenetic Relationships ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Reduced Form ◽  
Larval Morphology ◽  
Unique Character ◽  
Phylogenetic Studies ◽  
Diving Beetles ◽  
The Family ◽  
First Time

Phylogenetic relationships within diving beetles (Dytiscidae) are imperfectly known. In particular, some authors have considered that the tribe Methlini is included in the subfamily Hydroporinae (a large group including about half of the dytiscid species worldwide), whereas others have argued in favour of excluding Methlini from the Hydroporinae and giving it subfamilial rank. Larval characters have been underutilised in phylogenetic studies, mainly because the larvae of many taxa within the family are still unknown. The larval morphology of the dytiscid tribe Methlini, in particular, remains poorly known. In this study, the phylogenetic relationships among ancestral lineages of the Hydroporinae are investigated based on a cladistic analysis of 34 taxa and 127 morphological larval characters. For this purpose, larvae of the Methlini (Celina parallela (Babington, 1841)) and C. imitatrix Young, 1979) are described and illustrated in detail for the first time, with particular emphasis on morphometry and chaetotaxy. The results show high support for a monophyletic origin of the Hydroporinae, including Methlini, based on eight unique character states. Giving Methlini subfamily rank would leave Hydroporinae with a single unique larval apomorphy. This supports the inclusion of Methlini as a tribe of Hydroporinae. Other interesting but less well supported results include: 1, the clade Laccornini + Hydrovatini + Canthyporus Zimmermann, 1919 (Hydroporini) resolved as the sister-group to the other Hydroporinae minus Methlini; and 2, Hydrovatini and Canthyporus resolved as sister-groups. The presence of a galea, albeit in a reduced form, in larvae of Methlini, Laccornini and Hydrovatini is of the utmost interest. The putative hypothesis of an ancestral position for these genera within Hydroporinae suggests that hydroporines lost the galea secondarily.

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

ZooKeys ◽  
2019 ◽  
Vol 884 ◽  
pp. 53-67
Author(s):  
Mariano C. Michat ◽  
Yves Alarie ◽  
Chris H. S. Watts
Keyword(s):  
Abdominal Segment ◽  
Generic Diagnosis ◽  
Larval Morphology ◽  
Endemic Genus ◽  
The Third ◽  
Anterior Half ◽  
Median Process ◽  
Species Distinction ◽  
Shaped Pattern ◽  
Diving Beetle

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.

First description of the larvae of the fishfly genus Anachauliodes Kimmins, 1954 (Megaloptera: Corydalidae: Chauliodinae)

Zootaxa ◽  
2019 ◽  
Vol 4700 (2) ◽  
pp. 270-278
Author(s):  
YUEZHENG TU ◽  
FUMIO HAYASHI ◽  
XINGYUE LIU
Keyword(s):  
Abdominal Segment ◽  
Immature Stages ◽  
Oriental Region ◽  
Close Relationship ◽  
Segment Viii ◽  
First Time

Anachauliodes Kimmins, 1954 (Megaloptera: Corydalidae: Chauliodinae) is a fishfly genus endemic to the Oriental Region with only one recognized species, Anachauliodes laboissierei (Navás, 1913). Currently, the immature stages of this genus are completely unknown. Here we describe the larvae of A. laboissierei for the first time. The larval characters, especially the strongly developed respiratory tubes on the abdominal segment VIII, support a close relationship between Anachauliodes and the eastern Nearctic Chauliodes Latreille, 1796. 

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