Cladistics of the genera of Mesochorinae (Hymenoptera: Ichneumonidae)

Abstract. A cladistic analysis is presented for the genera of the ichneumonid subfamily Mesochorinae. Nine genera are recognized as valid. Previous work on larval morphology is reviewed and a number of larvae are newly illustrated and discussed. Four new synonyms are proposed: Oncocotta, Piestetron, Plectochorus and Rhaibaspis are all synonymized with Mesochorus , and Stictopisthus is placed back as a synonym of Mesochorus. Four new genera are described: Artherola from South Africa, Chineater from Chile, Thamester from Japan, and Varnado from Morocco. A new key is provided to the mesochorine genera of the world.     

A contribution to the Mesochorinae (Hymenoptera: Ichneumonidae) of Turkey

We present a first account of the species of the subfamily Mesochorinae (Hymenoptera: Ichneumonidae) found in Turkey and give distributional records for 5 genera and 23 species. Among them, 3 genera (Cidaphus Förster, 1869; Mesochorella Szepligeti, 1911; Stictopisthus Thomson, 1886) and 20 species are new for the fauna of Turkey.     

The larval hyobranchial apparatus of discoglossoid frogs: its structure and bearing on the systematics of the Anura (Amphibia: Anura)

The morphology of the larval hyobranchial apparatus of discoglossoid frog species representing the genera Ascaphus, Alytes, Bombina, and Discoglossus is described and the resulting characters were analysed cladistically. Seven species representing seven major lineages of frogs were included in the cladistic analysis of characters. Several changes in the terminology of the musculature are introduced, and a new interpretation of the subarcualis-muscle system is presented. The phylogenetic analysis suggest that the hyobranchial apparatus was substantially altered in the lineages leading to and within the Pipanura. This notably involved fusion, reduction and loss of skeletal structures and muscles, and splitting of certain muscles into muscle groups. The result confirm previous hypotheses based on the study of adults: discoglossoid species retain the most numlerous plesiomorphic characters among extant ianurans. The larval hyobranchial apparatus is in many features structrually similar to that of urodeles. Many of their character states were most likely present in the most recent common ancestor of all living forgs. The cladistic analysis of 31 characters of ithe larval hyobranchial apparatus supports major clades: Anura, Bombinanura, Pipanura, and Pelobatoidea + Neobatrachia. The cladiostic analysis and interpretation of larval characters is in part compatible with phylogenetic hypotheses based on characters of adults and rRNA sequences, but is in conflict with the Mesobatrachia and Archaeobatrachia concepts of other authors.     

Comparative morphology,biology and phylogeny of terminal‐instar larvae of the European species of Toryminae (Hym., Chalcidoidea,Torymidae) parasitoids of gall wasps (Hym. Cynipidae)

We present a phylogenetic and taxonomic study of the morphology and biology of the terminal‐instar larval stage of 19 species representing all the genera of Torymidae parasitoids of gall wasps in Europe, with the single exception of Megastigmus. The genera studied include Adontomerus Nikol'skaya, Idiomacromerus Crawford, Chalcimerus Steffan & Andriescu, Glyphomerus Förster, Pseudotorymus Masi and Torymus Dalman. We primarily used chaetotaxy and some head structures. The terminal‐instar larvae of all studied species are thoroughly described for the first time and illustrated with SEM images. We provide diagnostic characters for the family and the genera studied, and keys to genera and species for the identification of torymid larvae associated with cynipid galls. The majority of the torymid larvae studied are solitary monophagous parasitoids. Finally, to assess the potential use of larval characters in systematic studies of the family, a phylogenetic analysis of the studied taxa based on 42 larval morphological characters is proposed and compared with the current taxonomy of Torymidae. Our results suggest that body chaetotaxy, and characters of the head and mouthparts could be used for genera and species discrimination. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 676–721.     

The terminology of larval cestodes or metacestodes

The terminology associated with the nomenclature of larval or metacestodes is reviewed as well as the various morphological and developmental characters used to define different types of larval cestodes. Based on a review of the literature, the key characters differentiating the types of larval cestodes are the presence of a primary lacuna and the invagination/retraction of the scolex. The presence of a cercomer and of a bladder-like enlargement of the larval cestode were considered to be useful secondary characteristics. Using these characters, six basic types of larval cestodes were identified: the procercoid, an alacunate form which cannot develop further until ingested by a second intermediate host; the plerocercus, an alacunate form with a retracted scolex; the plerocercoid, an alacunate form with an everted scolex; the merocercoid, an alacunate form with an invaginated scolex; the cysticercoid, a lacunate form with a retracted scolex; and the cysticercus, a lacunate form with an invaginated scolex. The diversity of larval types within the broad classifications of cysticercoid and cysticercus can be differentiated by the use of appropriate prefixes. Deficiencies in knowledge of specific types of larval cestodes are identified and further avenues of research are indicated.Pseudonym for the contributors of a workshop on metacestode terminology, chaired by I. Beveridge, which took place during the Third International Workshop for Tapeworm Systematics,Sofia, Bulgaria, 20-24 July, 1999 (Organiser: B.B. Georgiev).     

Phylogeny of the intertidal aleocharine tribe Liparocephalini (Coleoptera: Staphylinidae)

The tribe Liparocephalini (genera Liparocephalus Mäklin, 1853;Diaulota Casey, 1893 [ = Genoplectes Sawada, 1955];Paramblopusa Ahn & Ashe, Amblopusa Casey, 1893;Salinamexus Moore & Legner, 1977 [ = Biophytosus Moore & Legner, 1977]), all of which are exclusively restricted to the Pacific coasts of the Holarctic Region, is hypothesized to be a monophyletic group based on the following synapomorphies: seta v absent (inferred to be lost) from mentum (reversed one time in the Liparocephalus lineage), setae distributed only on mesal surface of galea and apex with setae, one medial seta present on prementum, and contiguous mesocoxal cavities. Natural history and history of the classification of the Liparocephalini are discussed. Phylogenetic analyses of the species of the Liparocephalini are presented based on larval (21 characters, 57 states), adult (49 characters, 115 states), and a combination of larval and adult characters (70 characters, 172 states). Analysis of the combined larval and adult data sets with successive approximation resulted in a single most parsimonious tree (length = 937, CI = 0.885, RI = 0.930) with the following patterns of generic relationships (outgroup (Salinamexus + Biophytosus (Amblopusa (Paramblopusa (Diaulota + Genoplectes, Liparocephalus))))).     

Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda: Anomura: Diogenidae), under laboratory conditions, with a revision of the larval features of genus Clibanarius

The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5–11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.     

Larval development of mandi-pintado Pimelodus britskii (Siluriformes: Pimelodidae)

This study investigated the morphology, morphometric and meristic characters of 117 larval Pimelodus britskii showing early development of head, eye, barbel and snout. Body and mouth pigmentation increased throughout development; the mouth was ventrally situated in the yolk-sac stage, becoming subterminal afterwards, and an embryonic fin was visible in all four stages observed. Post-flexion larval P. bristskii are distinguished from larval P. ortmanni by having 47–50 myomeres (v. 36).     

Coding characters from different life stages for phylogenetic reconstruction: a case study on dragonfly adults and larvae,including a description of the larval head anatomy of Epiophlebia superstes (Odonata: Epiophlebiidae)

The exclusive use of characters coding for specific life stages may bias tree reconstruction. If characters from several life stages are coded, the type of coding becomes important. Here, we simulate the influence on tree reconstruction of morphological characters of Odonata larvae incorporated into a data matrix based on the adult body under different coding schemes. For testing purposes, our analysis is focused on a well‐supported hypothesis: the relationships of the suborders Zygoptera, ‘Anisozygoptera’, and Anisoptera. We studied the cephalic morphology of Epiophlebia, a key taxon among Odonata, and compared it with representatives of Zygoptera and Anisoptera in order to complement the data matrix. Odonate larvae are characterized by a peculiar morphology, such as the specific head form, mouthpart configuration, ridge configuration, cephalic musculature, and leg and gill morphology. Four coding strategies were used to incorporate the larval data: artificial coding (AC), treating larvae as independent terminal taxa; non‐multistate coding (NMC), preferring the adult life stage; multistate coding (MC); and coding larval and adult characters separately (SC) within the same taxon. As expected, larvae are ‘monophyletic’ in the AC strategy, but with anisopteran and zygopteran larvae as sister groups. Excluding larvae in the NMC approach leads to strong support for both monophyletic Odonata and Epiprocta, whereas MC erodes phylogenetic signal completely. This is an obvious result of the larval morphology leading to many multistate characters. SC results in the strongest support for Odonata, and Epiprocta receives the same support as with NMC. Our results show the deleterious effects of larval morphology on tree reconstruction when multistate coding is applied. Coding larval characters separately is still the best approach in a phylogenetic framework. © 2015 The Linnean Society of London     

Monophyly of Euaesthetinae (Coleoptera: Staphylinidae): phylogenetic evidence from adults and larvae,review of austral genera,and new larval descriptions

Abstract We develop a morphological dataset for the rove beetle subfamily Euaesthetinae comprising 167 morphological characters (135 adult and 32 larval) scored from 30 terminal taxa including 25 ingroup terminals (from subfamilies Euaesthetinae and Steninae) and five outgroups. Four maximum parsimony analyses using different sets of terminals and character sets were run to test the monophyly of (1) Euaesthetinae, (2) Steninae, (3) Euaesthetinae + Steninae, (4) euaesthetine tribes Austroesthetini, Alzadaesthetini, Euaesthetini, Fenderiini and Stenaesthetini, and (5) the ten currently known austral endemic genera together. Analyses of adult and larval character sets separately and in combination recovered the monophyly of Euaesthetinae, Steninae, and both subfamilies together, with strong support. Analysis of 13 ingroup terminals for which complete data were available suggests that monophyly of Euaesthetinae is supported by 19 synapomorphies (13 adult, six larval), of Steninae by 23 synapomorphies (14 adult, nine larval), and of both subfamilies together by 24 synapomorphies (21 adult, three larval). Within Euaesthetinae, only the tribe Stenaesthetini was recovered as monophyletic based on adult characters, and in no analyses were the ten austral endemic genera recovered as a monophyletic group. Phylogenetic relationships among euaesthetine genera were weakly supported, although analyses including adult characters supported monophyly of Octavius and Protopristus separately, and of Octavius + Protopristus, Austroesthetus + Chilioesthetus and Edaphus + Euaesthetus. Steninae may include a third genus comprising two undescribed species probably possessing a ‘stick–capture’ method of prey capture, similar to that in Stenus. These two species formed a strongly supported clade recovered as the sister group of Stenus based on adult characters. Diagnoses and a key to adults are provided for the 15 euaesthetine genera currently known from the austral region (Australia, New Zealand, South Africa and southern South America). Euaesthetine larvae previously were known only for Euaesthetus, and we describe the larvae of nine more genera and provide the first larval identification key for genera of Euaesthetinae.     

Phylogeny of Berosini (Coleoptera: Hydrophilidae,Hydrophilinae) based on larval and adult characters,and evolutionary scenarios related to habitat shift in larvae

Abstract A phylogenetic analysis of Berosini including 15 taxa, 11 of them belonging to Berosini (ingroup), was performed. Of the 58 characters used, 32 derive from the larval stages, and 26 from the adult stage. Two well‐supported clades are recognized, one comprising Hemiosus and Berosus, and the other comprising Derallus, Regimbartia and Allocotocerus. Several larval evolutionary trends are discussed: shifts to benthic and cryptic habits, morphological modifications and adaptations related to these habits, and morphological changes of the clypeolabrum and head appendages. A comparative table for the larval stages of the five genera is included.     

The larval development of an Australian limnadiid clam shrimp (Crustacea, Branchiopoda, Spinicaudata), and a comparison with other Limnadiidae

The adult morphology of the Australian Limnadopsis shows some remarkable differences to that of other Limnadiidae. These differences are not reflected in its larval development. In Limnadopsis parvispinus, larval development comprises six stages. In stages I and II only the three naupliar appendages are present: the antennule as a small bud, the biramous antenna as the main swimming organ, and the mandible. The antennal protopod bears two endites, the proximal naupliar process and a more distal endite. In stage III a bifid naupliar process (in earlier stages not bifid) and the first signs of the carapace and trunk limb anlagen (undifferentiated rudiments) appear. In stage IV the carapace anlagen become more pronounced. The number of trunk limb anlagens increases to five, and differentiation has commenced. In stage V the first five pairs of trunk limbs are differentiated to varying degrees. The anterior-most four pairs of trunk limbs are subdivided into five endites, a small endopod, an exopod and an epipod. The bivalved carapace covers the anterior-most limbs. In larval stage VI the carapace is larger and the trunk limbs are further differentiated. A general pattern in the sequence of larval stages is the increasing number of sensilla on the antennules. From the last larval to the first postlarval stage, a significant change in morphology takes place. The trunk limbs are now used for swimming. Typical larval organs are much smaller than in the last larval stage. A comparison with other representatives of the Limnadiidae shows a high degree of correspondence, with most differences explained by the heterochronous appearance of characters during development. Five to seven stages are described for all studied Limnadiidae, including one particular stage in which four fully developed setae, a bifid naupliar process and the first signs of carapace anlagen are present. These characters are found in stage III in L. parvispinus, Limnadia stanleyana, Eulimnadia texana, and Imnadia yeyetta but in stage IV in E. braueriana and L. lenticularis. Based on a comparison of the larval stages of six limnadiid and one cyzicid species, we conclude that at least six naupliar stages belong to the limnadiid ground pattern.     

Density‐dependent natural selection in Drosophila: correlations between feeding rate,development time and viability

We have previously hypothesized that density‐dependent natural selection is responsible for a genetic polymorphism in crowded cultures of Drosophila. This genetic polymorphism entails two alternative phenotypes for dealing with crowded Drosophila larval cultures. The first phenotype is associated with rapid development, fast larval feeding rates but reduced absolute viability, especially in the presence of nitrogenous wastes like ammonia. The second phenotype has associated with it the opposite set of traits, slow development, slow feeding rates and higher viability. We suggested that these traits are associated due to genetic correlations and that an important selective agent in crowded larval cultures was high levels of ammonia. To test this hypothesis we have examined viability and larval feeding rates in populations kept at low larval densities but selected directly for (i) rapid egg‐to‐adult development, (ii) tolerance of ammonia in the larval environment and (iii) tolerance of urea in the larval environment. Consistent with our hypothesis we found that (i) larvae selected for rapid development exhibited increased feeding rates, and decreased viability in food laced with ammonia or urea relative to controls, and (ii) larvae selected to tolerate either ammonia or urea in their larval environment show reduced feeding rates but elevated survival in toxin‐laced food relative to controls. It would appear that development time and larval feeding rate are important characters for larvae adapting to crowded cultures. The correlated fitness effects of these characters provide important insights into the nature of density‐dependent natural selection.     

The larval chondrocranium of Pelodytes punctatus,with a review of tadpole chondrocrania

The larval chondrocranium of the pelobatoid anuran Pelodytes punctatus was studied, using Alcian blue-alizarin stained and cleared whole preparations, serial sections, and gross dissections. This beaked tadpole is an unspecialized pond dweller and its chondrocranium closely resembles those of other ecologically similar tadpoles of diverse systematic relationships. Detailed analysis, however, shows many differences among the chondrocrania of anuran larvae. Among other features, these include the configurations of suprarostrals, fronto-parietal fenestrae, palatoquadrate suspensoria, the ligamentum or cartilago tectum of the muscular process of the quadrate and the circumoral ligaments. The lateral circumoral ligament permits differentiation of beaked discoglossoidean and ranoidean larvae. Microhyloids conform to the ranoidean pattern in this feature. Pipoids either lack it or seem to conform to the discoglossoidean pattern. Use of these larval features as key characters enables assignment of Pelodytes to an uncertain position among pelobatoid frogs. This is totally congruent with previous assignments based on adult features and is used to support the hypothesis that anuran phylogenies based on larval characters will closely resemble, in major features at least, those based solely on adult characters.     

Morphology of the first zoeal stages of eleven Sesarmidae (Crustacea,Brachyura, Thoracotremata) from the Indo-West Pacific,with a summary of familial larval characters

Summary

The first zoeal stages of eleven species of Sesarmidae from the Indo-West Pacific were obtained from ovigerous females. Those of Labuanium scandens, L. rotundatum, L. trapezoideum, L. politum, Metasesarma aubryi, Pseudosesarma crassimanum, Stelgistra stormi, and Sesarmops impressum, are described for the first time, while the first zoeal stages of Clistocoeloma merguiense, Metasesarma obesum and Sesarmops intermedium are re-described. Larval characters of all these species are compared with previously described ones for the family and morphological features are re-evaluated. Minute spines on the telson of the zoeae are described as a new larval character in Sesarmidae and their presence or absence in other grapsoid groups is discussed. The results demonstrate that a recurrent combination of reliable larval characters distinguishes zoeae and megalopae of the examined sesarmids from the rest of the Grapsoidea. This appears to be consistent with recent studies that redefine the Sesarmidae.     

Phylogeny of the tachyporine group subfamilies and 'basal' lineages of the Aleocharinae (Coleoptera: Staphylinidae) based on larval and adult characteristics

Abstract. This paper reports the conclusions of studies into the phylogeny of tachyporine group subfamilies and the ‘basal’ lineages of the subfamily Aleocharinae (Coleoptera: Staphylinidae) based on both larval and adult morphological data (133 adult characters, twenty-seven larval characters). Representatives of forty species of the tachyporine group were used in the analysis, including representatives of the Aleocharinae, Trichophyinae, Habrocerinae, Phloeocharinae, Olisthaerinae, and Tachyporinae. The Aleocharinae included representatives of the tribes Gymnusini, Deinopsini, Mesoporini, the ‘subfamily’ Trichopseniinae, and representatives of nine major tribes in the ‘higher’ Aleocharinae (Athetini, Hoplandriini, Falagriini, Lomechisini, Oxypodini, Aleocharini, Myllaenini, Homalotini, and Hypocyphtini). Analyses were performed first with adult characters alone and then with both larval and adult characters in a simultaneous analysis. The analysis based on adult characters produced eighty-five equally parsimonious trees (length = 499, consistency index = 42; retention index = 69). In the consensus tree, the Tachyporinae are not monophyletic, and the sister-group relationship between the Trichophyinae + Habrocerinae and the Aleocharinae is not resolved. The Aleocharinae are monophyletic, but, among the ‘basal’ Aleocharinae, the relationships of Gymnusini + Deinopsini, the Mesoporini, and the Trichopseniinae are unresolved. The combined adult and larval data, using Tachinus as the outgroup, produced six equally parsimonious trees (tree length = 588; consistency index = 43; retention index = 69). The strict consensus tree of the combined larval and adult data supports the following conclusions: (1) larval characters substantially stabilize the tree; (2) the subfamily Tachyporinae is not supported to be monophyletic; (3) the subfamilies Trichophyinae and Habrocerinae are sister groups, and together they are sister to the Aleocharinae; (4) the ‘basal’ Aleocharinae are not a monophyletic group, but the ‘higher’ Aleocharinae are monophyletic; (5) the sister group of the remaining Aleocharinae is a lineage made up of genera currently in the tribes Gymnusini and Deinopsini; (6) within the Gymnusini–Deinopsini lineage, the monophyly of the Gymnusini is weakly supported, but the monophyly of the Deinopsini is strongly supported; (7) the subfamily Trichopseniinae is strongly supported to be a member of the ‘basal’ Aleocharinae; (8) the Myllaenini are resolved well within the ‘higher’ Aleocharinae; (9) strong support for the monophyly of some tribes of ‘higher’ Aleocharinae suggests that morphological characters provide substantial phylogenetic signal for analysis of higher-level phylogeny of the Aleocharinae in spite of the preliminary nature of the analysis at this taxonomic level.