Chaetotaxy and morphometry of the head capsule and head appendages of the genus Derallus Sharp (Coleoptera: Hydrophilidae)

Zootaxa ◽  
2020 ◽  
Vol 4722 (5) ◽  
pp. 423-442
Author(s):  
GEORGINA RODRIGUEZ ◽  
PATRICIA L. M. TORRES ◽  
MIGUEL ARCHANGELSKY
Keyword(s):  
Head Capsule ◽  
Morphometric Characters ◽  
Larval Instars ◽  
First Time

The primary and secondary chaetotaxy of the head capsule and head appendages of the three larval instars of the water scavenger beetle genus Derallus Sharp are described for the first time based on two species: D. angustus Sharp and D. paranensis Oliva. Morphometric characters derived from the head capsule and mouthparts are included, together with detailed illustrations of all characters. Chaetotaxy of these larvae is compared with that of Regimbartia attenuata (Fabricius), another species belonging to the Derallus-clade of Berosini.

scholarly journals Larval chaetotaxy and morphometry of Oosternum costatum (Coleoptera: Hydrophilidae) including a discussion of larval characters with phylogenetic relevance

2018 ◽  
Vol 58 (2) ◽  
pp. 499-511 ◽  
Author(s):  
Miguel Archangelsky
Keyword(s):  
Phylogenetic Analyses ◽  
Head Capsule ◽  
Morphometric Characters ◽  
Larval Instars ◽  
First Time

Abstract The primary and secondary chaetotaxy of the head capsule and head appendages of the first and third larval instars of Oosternum costatum (LeConte, 1855) (Coleoptera: Hydrophilidae: Sphaeridiinae, Megasternini) are described for the first time. Morphometric characters derived from the head capsule and mouthparts are included, together with detailed illustrations of all characters. The morphology and chaetotaxy of these larvae is compared to that of other larvae of the tribe Megasternini, confirming that chaetotaxy is a useful source of characters for phylogenetic analyses. Comparative notes with Sphaeridium Fabricius, 1775 (Sphaeridiini) are also included.

scholarly journals Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae)

2009 ◽  
Vol 43 (1) ◽  
pp. e-15-e-24
Author(s):  
I. Dolinskaya
Keyword(s):  
Pattern Formation ◽  
Larval Instar ◽  
Head Capsule ◽  
Diagnostic Character ◽  
Key To Species ◽  
Larval Instars ◽  
Diagnostic Characters ◽  
Ontogenetic Stages ◽  
First Time ◽  
Taxonomic Relations

Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae) Pattern and colouration of caterpillar head of all larval instar of 7 species from genus Peridea Stephens, 1828 are studied. Formation of caterpillar head pattern in ontogenesis is discussed. Diagnostic characters, both specific and larval instars, are recorded for the first time. Key to species according to larval instars is given. Evidently, only larvae of the 1st instar demonstrate different directions in the pattern formation. This characteristic can be used for clearing of taxonomic relations in the genera and on the earliest ontogenetic stages (1st larval instar) only. In the following (2nd-5th) instars, the pattern became more or less of the same type. It depends on stripes shape or colouration only and can serve as good specific diagnostic character. To determine larval instar, both width of the head capsule and head pattern should be taken into account.

Re-description of larvae of Chostonectes nebulosus (Macleay, 1871) (Coleoptera: Dytiscidae, Hydroporinae, Hydroporini, Sternopriscina) with an identification key to the known larvae of Chostonectes Sharp, 1882

Zootaxa ◽  
2020 ◽  
Vol 4718 (3) ◽  
pp. 436-446
Author(s):  
EDWARD TSYRLIN ◽  
MELISSA CAREW ◽  
YVES ALARIE
Keyword(s):  
Abdominal Segment ◽  
Head Capsule ◽  
Identification Key ◽  
Molecular Approach ◽  
Larval Instars ◽  
First Time

The second and third larval instars of the Australian endemic dytiscid Chostonectes nebulosus (Macleay, 1871) are described and illustrated for the first time including a detailed chaetotaxic analysis of head capsule and appendages, legs, last abdominal segment and urogomphi. Collected larvae were successfully associated with adults using rearing and a molecular approach. The identification key and COI barcodes for C. nebulosus, C. gigas (Boheman, 1858) and C. johnsonii (Clark, 1862) are provided. 

Morphology of the immature stages of Meligethes aeneus (F.) and M. viridescens (F.) (Coleoptera, Nitidulidae)

1965 ◽  
Vol 55 (4) ◽  
pp. 747-759 ◽  
Author(s):  
P. Osborne
Keyword(s):  
Experimental Evidence ◽  
Head Capsule ◽  
Immature Stages ◽  
Meligethes Aeneus ◽  
Larval Instars ◽  
Head Capsule Width ◽  
Laboratory Conditions ◽  
First Time

Experimental evidence is given to show that only two larval instars occur during the development of Meligethes aeneus (F.) (Coleoptera, Nitidulidae) under laboratory conditions in Scotland, based on the facts that there is only one moult and only one increase in head-capsule width. The egg, first- and second-instar larvae, prepupa and pupa of M. aeneus are described and compared with the corresponding stages of M. viridescens (F.). The larvae of the two species are differentiated for the first time by the arrangement of dorsal cuticular tubercles, the size and form of the urogomphi and the width of the head capsules.

The Hydraenidae of Cuba (Insecta: Coleoptera) II: Morphology of preimaginal stages of six species and notes on their biology

Zootaxa ◽  
2017 ◽  
Vol 4238 (4) ◽  
pp. 451 ◽  
Author(s):  
ALBERT DELER-HERNÁNDEZ ◽  
JUAN A. DELGADO
Keyword(s):  
Instar Larva ◽  
Morphological Characters ◽  
Larval Instars ◽  
First Instar ◽  
Preimaginal Stages ◽  
First Time ◽  
Third Instar Larvae

Preimaginal stages of the six species of Hydraenidae presently known from Cuba were obtained by rearing adults in the laboratory. Eggs of Hydraena perkinsi Spangler, 1980, H. decui Spangler, 1980 and H. franklyni Deler-Hernández & Delgado, 2012 are described and illustrated for the first time. The first instar larva of Gymnochthebius fossatus (LeConte, 1855) is redescribed, adding some new remarkable morphological characters including what could be the first abdominal egg-burster reported for this family. All larval instars of H. perkinsi, H. guadelupensis Orchymont, 1923 and Ochthebius attritus LeConte, 1878 are described and illustrated for the first time, with a special emphasis on their chaetotaxy. The second instar larva of G. fossatus along with first and third instar larvae of H. decui and H. franklyni are also studied for the first time. The pupal morphology and vestiture of a species belonging to the genus Hydraena are described for the first time, based on the pupa of H. perkinsi. Biological notes for several preimaginal stages of the studied species are also given. 

scholarly journals Breaking the rule: Five larval instars in the podonomine midge Trichotanypus alaskensis Brundin from Barrow, Alaska

2018 ◽  
Author(s):  
Alec R. Lackmann ◽  
Malcolm G. Butler
Keyword(s):  
Life Cycle ◽  
Larval Instar ◽  
Adult Emergence ◽  
Head Capsule ◽  
The Arctic ◽  
Larval Instars ◽  
Daily Monitoring ◽  
Field Samples ◽  
Standard Life ◽  
Capsule Size

Except for one unconfirmed case, chironomid larvae have been reported to pass through four larval instars between egg and pupal stages. We have observed a fifth larval instar to be a standard life-cycle feature of the podonomine Trichotanypus alaskensis Brundin 1966 in tundra ponds on the Arctic Coastal Plain near Barrow, Alaska. T. alaskensis has a one-year life cycle in these arctic ponds. Adults emerge in June ~2-3 weeks after pond thaw, then mate and oviposit; most newly-hatched larvae reach instar IV by October when pond sediments freeze. Overwintering larvae complete instar IV within a few days of thaw, then molt again to a fifth larval instar. Imaginal discs, normally seen only during instar IV in Chironomidae, develop across both instars IV & V prior to pupation and adult emergence. While monitoring larval development post-thaw in 2014, we noticed freshly-molted T. alaskensis larval exuviae a week or more prior to any pupation by that species. In 2015-16 we reared overwintering instar IV larvae from single pond sources, individually with daily monitoring, through molts to instar V, pupa, and adult. Some overwintering instar II and III larvae were reared as well, but were few in number. During 2016 we also reared T. alaskensis progeny (from eggs) through instar II, thus documenting head capsule size ranges for all five instars in a single pond’s population. Without individual rearings, the fifth larval instar was not readily apparent for two reasons: 1) The molt itself occurs immediately after thaw and is so synchronous it is difficult to discern in daily field samples. 2) The head capsule size increment between instars IV-V is much lower than the ratio predicted by the Brooks-Dyar Rule. Up through instar IV, the Brooks-Dyar ratio for T. alaskensis ranged 1.30-1.61, but during the IV-V molt head capsule dimensions (sexes pooled) increased by a ratio of 1.09 – comparable to the magnitude of sexual dimorphism in head capsule size within each of the final two larval instars. Individual rearings coupled with 2014-2016 field surveys in nine other ponds suggest that five larval instars is an obligatory trait of this species at this location. As this is the first confirmed case of five larval instars in a chironomid, the phylogenetic uniqueness of this trait needs further investigation.

scholarly journals Australian mycophagous species of the genus Deplorothrips (Thysanoptera, Phlaeothripinae)

Zootaxa ◽  
2016 ◽  
Vol 4208 (3) ◽  
pp. 201
Author(s):  
LAURENCE A. MOUND ◽  
DESLEY J. TREE
Keyword(s):  
New Species ◽  
Body Size ◽  
Head Capsule ◽  
Identification Key ◽  
Structural Polymorphism ◽  
First Time

The genus Deplorothrips Mound & Walker is recorded from Australia for the first time. The genus is found widely across the continent, and descriptions and an illustrated identification key are provided to 14 new species. These have been found living on dead twigs and branches, particularly of Eucalyptus trees. Typical members of this genus have short maxillary stylets that are scarcely retracted into the head capsule, but some of the species have more deeply retracted stylets. Structural polymorphism is recorded in several species, associated both with sex and with body size. Remarkable variation is recorded for some species in the number of sense cones on the antennal segments. 

Filling missing links in albuneid crab distributions (superfamily Hippoidea) in the Bay of Bengal, eastern Indian Ocean

Crustaceana ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1495-1504 ◽  
Author(s):  
Rajan Kumar ◽  
Shikha Rahangdale ◽  
Subal Kumar Roul
Keyword(s):  
Indian Ocean ◽  
Bay Of Bengal ◽  
Morphological Characters ◽  
Eastern Indian Ocean ◽  
Species Discrimination ◽  
Gulf Of Mannar ◽  
Fishing Gear ◽  
Morphometric Characters ◽  
First Time

Abstract Albuneid crabs are specialized and active sand-burrowing organisms. Despite their substantial diversity, their ability to avoid fishing gear leads to “under collection” and a discontinuous record of distribution. The present study documents the first distributional record of Albunea occulta Boyko, 2002 from the Bay of Bengal, eastern Indian Ocean. Albunea thurstoni Henderson, 1893 is also recorded for the first time from the area, i.e., from the Gulf of Mannar, southwestern Bay of Bengal. This study further reports variation in morphological characters, especially in the carapace grooves (CG) from previous records and across specimens from different regions. Morphometric characters were found useful in species discrimination, which is explained as well.

Morphological variation in Xenoxybelis boulengeri (Procter, 1923) (Serpentes, Xenodontinae, Philodryadini)

Zootaxa ◽  
2008 ◽  
Vol 1743 (1) ◽  
pp. 53 ◽  
Author(s):  
ANA LÚCIA DA COSTA PRUDENTE ◽  
MÁRCIO ANDRÉ AMORIM DA SILVA ◽  
WÁLDIMA ALVES DA ROCHA ◽  
FRANCISCO LUÍS FRANCO
Keyword(s):  
Morphological Variation ◽  
Rare Species ◽  
Original Description ◽  
External Morphology ◽  
Time Analysis ◽  
Morphometric Characters ◽  
Permit Allocation ◽  
Scientific Collections ◽  
First Time ◽  
Molecular Characters

The genus Xenoxybelis contains two species, X. argenteus and X. boulengeri, characterized by semi-arboreal habits and an extremely thin rostral area, classified in the subfamily Xenodontinae (Colubridae). Xenoxybelis boulengeri is considered a rare species and is poorly represented in scientific collections. Its external morphology is known only from the original description and seven other specimens. In this study, twenty additional specimens were examined from the Brazilian states of Acre, Amazonas and Rondônia. Variation in meristic and morphometric characters are described, and new characters are incorporated in a revised diagnosis of the species. Illustrations and a description of the hemipenes of X. boulengeri are presented for the first time. Analysis of morphological and molecular characters permit allocation of Xenoxybelis to the tribe Phylodryadini, together with Ditaxodon, Philodryas, Pseudablabes and Tropidodryas.

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