The rate of allelism of lethal genes in a geographically structured population

The expected rate of allelism, E[I(x)], of lethal genes between two colonies with distance x in a structured population is studied by using one- and two-dimensional stepping-stone models. It is shown that E[I(x)] depends on the magnitude of selection in heterozygous condition (h), the rate of migration among adjacent colonies (m), the number of loci which produce lethal mutations (n) and the effective population size of each colony (N).——E[I(x)] always decreases with distance x. The rate of decrease is affected strongly by the magnitude of m. The rate of decrease is faster when m is small. E[I(x)] also decreases with increasing N and n. The effect of h on E[I(x)] is somewhat complicated. However, E[I(0)] is always smaller when h is small than when it is large.——For large x, the following approximate formulae may be obtained: (see PDF) where q and Var (q) are the mean and the variance of gene frequencies in each colony, t is approximated as t=h, (see PDF), -h for the partially recessive, completely recessive, and overdominant lethals, respectively, and C₀ is a function of m and t. It is clear that E[I(x)] declines exponentially with x in a one-dimensional habitat. The decrease E[I(x)] is faster in a two-dimensional habitat than in a one-dimensional habitat. The present result is applied to some of the existing data and the estimation of population parameters is also discussed.     

On the validity of Epeorella Ulmer, 1939 (Ephemeroptera,Heptageniidae) with general considerations on the Heptageniidae of the Sunda Islands

The type material of Epeorella borneonia Ulmer, 1939, the sole species of the genus Epeorella Ulmer, 1939 is reinvestigated and a lectotype (male imago) is designated. Based on several morphological structures, the synonymy with Epeorus Eaton, 1881 (Rhithrogeninae) is rejected. Epeorella stat. prop., known only at the winged stages, belongs to the subfamily Ecdyonurinae, and is a probable endemic of the island of Borneo. The newly erected genus Darthus Webb & McCafferty, 2007, also endemic to Borneo and only known by one species at the nymphal stage, is shown to be a junior subjective synonym of Epeorella. The new combination Epeorella vadora (Webb & McCafferty, 2007) is proposed for the species. The distribution of known heptageniid species from the Sunda Islands is discussed.     

Phylogenetics of Tribe Collabieae (Orchidaceae,Epidendroideae) Based on Four Chloroplast Genes with Morphological Appraisal

Collabieae (Orchidaceae) is a long neglected tribe with confusing tribal and generic delimitation and little-understood phylogenetic relationships. Using plastid matK, psaB, rbcL, and trnH-psbA DNA sequences and morphological evidence, the phylogenetic relationships within the tribe Collabieae were assessed as a basis for revising their tribal and generic delimitation. Collabieae (including the previously misplaced mycoheterotrophic Risleya) is supported as monophyletic and nested within a superclade that also includes Epidendreae, Podochileae, Cymbidieae and Vandeae. Risleya is nested in Collabiinae and sister to Chrysoglossum, a relationship which, despite their great vegetative differences, is supported by floral characters. Ania is a distinct genus supported by both morphological and molecular evidence, while redefined Tainia includes Nephelaphyllum and Mischobulbum. Calanthe is paraphyletic and consists four clades; the genera Gastrorchis, Phaius and Cephalantheropsis should be subsumed within Calanthe. Calanthe sect. Ghiesbreghtia is nested within sect. Calanthe, to which the disputed Calanthe delavayi belongs as well. Our results indicate that, in Collabieae, habit evolved from being epiphytic to terrestrial.     

Bathycamptus eckmani gen. et spec. nov. (Copepoda,Harpacticoida) with a review of the taxonomic status of certain other deepwater harpacticoids

Bathycamptus eckmani gen. et spec. nov., which is associated with mudballs produced by the. cirratulid Tharyx luticastellus, is described from bathyal muds in San Diego Trough, off California. ?Heteropsyllus minutus Wells from the Haden Ground, Scotland is considered to be its closest relative and is placed in the same genus. The genera Bathycamptus and Psammocamptus Mielke are regarded as sister groups on the basis of the shared sexual dimorphism shown by P3-P4. Relationships with other marine Canthocamptidae are discussed, and a re-evaluation of the genus Hemimesochra Sars is made. It is concluded that this genus should encompass only the type species H. clavularis Sars. ?Leimia dubia Wells and H. nympha Por are transferred to the new genus Boreolimella, which is closely related to Bathycamptus but not to Leimia Willey. The genus Perucamptus gen. nov. is established to include H. rapiens Becker and shows no clear relationship with the other genera. H. trisetosa Coull is assigned to Caroliiaicola gen. nov., which is regarded as being an advanced member of the Paranannopidae. H. secunda Wells is recognised as belonging to Mesopsyllus Por; whilst H. nixe Por is considered the type species of a new genus Pusillargillus.     

Redescription of Brochopeltis mjoebergi Verhoeff, 1924 and description of a second Brochopeltis species from Australia (Diplopoda,Polydesmida, Paradoxosomatidae)

Brochopeltis mjoebergi Verhoeff, 1924 is redescribed from type and new material, a lectotype is designated and Brochopeltis mjoebergi queenslandica Verhoeff, 1924 is synonymised with Brochopeltis mjoebergi. Brochopeltis mediolocus sp. n. is the first native paradoxosomatid described from Australia’s Northern Territory.     

Fixation probabilities and effective population numbers in diploid populations with overlapping generations

A finite diploid population, observed at times t = 0, 1, 2,…, is studied. An individual is said to be in age group i at time t if its age is between i and i + 1 units at that time, where i ? 1. It is assumed that the number of individuals in a particular age-sex class is the same for every t and that the probability that a male offspring was produced by a mating of a male in age group i and a female in age group j is p_ij^m (with a corresponding probability p^f_ij for a female offspring), regardless of when the individual is born. The probability of ultimate fixation of an allele A₁ and the inbreeding effective number, for large populations, is calculated under the further assumptions that A₁ is neutral and that mating is random, given the ages of the mates.     

Revision ofMesorhyphus Handlirsch,Eoplecia Handlirsch andHeterorhyphus Bode (Diptera: Anisopodomorpha,Bibionomorpha) from the upper liassic of Germany

The holotypes of the Lower Jurassic DipteraMesorhyphus nanus Handlirsch 1920,M. areolatus Handlirsch 1939,M. anomalus Handlirsch 1939,Eoplecia primitiva Handlirsch 1920,Heterorhyphus latus Bode 1953,H. analivarius Bode 1953 andProtorhyphus (?)ovisimilis Bode 1953 were re-examined. The holotype ofEoplecia primitiva is the counterpart ofMesorhyphus areolatus. M. areolatus is a junior synonym ofM. nanus. Mesorrhyphoides Rohdendorf 1962 is a synonym ofHeterorhyphus Bode 1953.Heterorhyphus analivarius is a synonym ofProtorhyphus (?)ovisimilis, being mistakenly described from the counterpart of the holotype of the latter. The genusHeterorhyphus is valid and comprises onlyH. anomalus (Handlirsch 1939) n. comb.;H. latus is a synonym of the latter species. As the wing venation ofHeterorhyphus is conspicuously different from all fossil and Recent Anisopodomorpha, it is placed into a new family, Heterorhyphidae, within the Bibionomorpha.     

A neotype designation for the bone-skipper Centrophlebomyia anthropophaga (Diptera,Piophilidae, Thyreophorina), with a review of the?Palaearctic?species?of Centrophlebomyia

The European bone-skippers (Diptera: Piophilidae: Thyreophorina), long considered extinct, have recently been the object of much interest by dipterists after their unexpected rediscovery. Considerable faunistic work has been done on these flies in recent years. However, some nomenclatural and taxonomic issues still require attention. A neotype is designated for Thyreophora anthropophaga Robineau-Desvoidy, 1830 (now in the genus Centrophlebomyia Hendel, 1903) to fix the identity of this nominal species. Centrophlebomyia anthropophaga is recognized as a valid species. It is described and illustrated in detail, and information on its preimaginal instars is provided for the first time. Four Palaearctic species of Centrophlebomyia are recognized and reviewed and a key is provided for their identification. Centrophlebomyia orientalis Hendel, 1907 from northern India, is removed from synonymy with Centrophlebomyia anthropophaga and recognized as a valid species of Centrophlebomyia, stat. r. The nominal genus Protothyreophora Ozerov, 1984 is considered a junior synonym of Centrophlebomyia, syn. n.     

A revision of the continental species of Copa Simon, 1885 (Araneae,Corinnidae) in the Afrotropical Region

The cryptic ground-dwelling castianeirine genus Copa Simon, 1885 (Araneae: Corinnidae) is revised in the continental Afrotropical Region. The type species of the genus, Copa flavoplumosa Simon, 1885, is redescribed and considered a senior synonym of Copa benina Strand, 1916 syn. n. and Copa benina nigra Lessert, 1933 syn. n. It is widespread throughout the Afrotropical Region but has not been introduced to any of the associated regional islands. A new species, Copa kei sp. n., is described from South Africa. Copa agelenina Simon, 1910, originally described from a subadult female from southern Botswana, is considered a nomen dubium. Copa flavoplumosa is a characteristic species of leaf litter spider assemblages and is particularly prevalent in savanna habitats on the continent, but also occurs in various forest types, grasslands, fynbos and semi-arid Nama Karoo habitats. In contrast, Copa kei sp. n. has only been recorded from Afromontane and coastal forests in south-eastern South Africa.     

A new Eastern Asian Hycleus and key to the Chinese species of the phaleratus group (Coleoptera,Meloidae, Mylabrini)

A new species of Hycleus belonging to the phaleratus group, and close to Hycleus phaleratus, is described. The new species, Hycleus marcipoli, is distributed in China (Gansu and Taiwan), Laos, and northern Thailand. A key to the Chinese species of this group is presented.     

Status of Exosphaeroma amplicauda (Stimpson, 1857), E. aphrodita (Boone, 1923) and description of three new species (Crustacea,Isopoda, Sphaeromatidae) from the north-eastern Pacific

Exosphaeroma amplicauda (Stimpson, 1857) from the west coast of North America is reviewed and redescribed and revealed to be a group of closely related species. A neotype is designated and the species redescribed based on the neotype and topotypic specimens. Exosphaeroma amplicauda is known only from the coast of California, at Marin, Sonoma and San Mateo Counties. Exosphaeroma aphrodita (Boone, 1923), type locality La Jolla, California and previously considered nomen dubium is taken out of synonymy and re-validated. A further three species: Exosphaeroma paydenae sp. n., Exosphaeroma russellhansoni sp. n., and Exosphaeroma pentcheffi sp. n. are described herein. Sphaeroma octonctum Richardson, 1899 is placed into junior synonymy with Exosphaeroma amplicauda. A key to the Pacific West Coast Exosphaeroma is provided.     

The brachylaimidae (Trematoda: Digenea) of Australian native mammals and birds,including descriptions of Dasyurotrema n. g. and four new species of Brachylaima

The Brachylaimidae of Australian native animals are revised. Brachylaima dasyuri (Johnston, 1913) is redescribed from Dasyurus viverrinus, Phascogale tapoatafa and Isoodon macrourus. B. simile (Johnston, 1913) is removed from synonymy with B. dasyuri, reinstated as a valid species and redescribed from Perameles nasuta, Isoodon obesulus and Antechinus stuartii. B. antechini Peisley & Howell, 1975 is reduced to synonymy with B. simile. B. brindabellensis n. sp. is described from Rattus fuscipes. B. walterae n. sp. is described from Antechinus swainsonii and A. stuartii. B. delecta n. sp. is described from Antechinus flavipes. B. sandarsae n. sp. is described from Antechinus godmani. B. pulchellum (Johnston, 1917) is redescribed from Leucosarcia melanoleuca. An unnamed Brachylaima species is described from Isoodon macrourus. New host records are Brachylaima dasyuri from Phascogale tapoatafa and B. simile from Perameles nasuta. Dasyurotrema mascomai n. g., n. sp. is described from Antechinus swainsonii. The new genus is placed in the Panopistinae. It differs from the existing genera by having a single loop of the uterus passing anterior to the ventral sucker and the genital pore posterior to the posterior testis but still distinctly ventral. A second species of Dasyurotrema is recorded, but not described, from Antechinus stuartii. Brachylaimid metacercariae are described from Rhytida capillacea, Helicarion virens, H. mastersi and Vercularion strangei. In no case was a host species found to harbour more than one species from any brachylaimid genus at a single geographical site.     

New species of subgenus Tipula (Sivatipula) from China,with redescription of T. (S.) parvauricula and a key to all known species of the Oriental Region (Diptera,Tipulidae, Tipula)

Species of Tipula (Sivatipula) biprocessa sp. n. from Guangxi, China is described and illustrated as new in the subgenus Tipula (Sivatipula) Alexander, 1964. Tipula (Sivatipula) parvauricula Alexander, 1941 is redescribed and illustrated based on additional morphological characters. Semen pump of this subgenus is discussed. A key to all described species in this group is compiled.     

A new species of the brown lacewing genus Zachobiella Banks from China (Neuroptera,Hemerobiidae) with a key to species

The genus Zachobiella Banks, 1920 is reviewed and a new species Zachobiella yunanica sp. n. described from China. All species found in China are redescribed, and Zachobiella submarginata Esben-Petersen, 1929 is recorded from China for the first time. A key to the adults of Zachobiella is provided.     

Taxonomic revision of the Kimmeridgian (Upper Jurassic) genusMesosimoceras (Ammonoidea) and institution of the new genusPresimoceras (Ammonitina,Idoceratinae)

Presimoceras is a new genus of Idoceratinae. The biostratigraphical range ofPresimoceras is limited to theStrombecki, Divisum and lower part of theAcanthicum Zone within the Kimmeridgian (in the Southern European sense). The genusMesosimoceras (Idoceratinae) was instituted by Spath (1925), withSimoceras cavouri Gemmellaro as type species; this genus is here emended with the institution ofPresimoceras n. gen. The species groupcavouri-risgoviense is preserved in the emended genusMesosimoceras, while the groupherbichiludovicii-teres is accommodated inPresimoceras on account of the radical and numerous differences and the stratigraphical gap betweenMesosimoceras andPresimoceras. As type species of the new genusAmmonites nodulatus Quenstedt is designated. The new genus is here subdivided into three groups of species:herbichi, ludovicii andteres. Phylogenetically,Presimoceras is derived fromPassendorferia, Mesosimoceras fromNebrodites.     

A Contribution to our Knowledge of the Mermithidae (Nematoda)

The genera of the insect parasitic nematode family Mermithidae axe reviewed, and 16 of them axe redescribed and illustrated. Information is given on methods of rearing adult mermithid specimens and on host specificity. The four types of merrnithid life cycles axe described in detail. One figure shows the variety of insects parasitized by merrnithids and the location and size of the nematode within the insect. Several mermithid eggs are illustrated, and their usefulness in identification is discussed.Taxonomically, the primary emphasis is on the adult stages of the merrnithJds with larval and egg characteristics supplementaxy. An emended family diagnosis is given. Merrnis subnigrescens is considered a synonym of M. nigrescens, and M. tahitiensis is synonymized with M. mirabilis. Hydromermis contorta is accepted, leaving the genus Paramermis in an uncertain position. Study of the Steiner collections of Limnornermis bathybia indicates that Limnornerrnis is accepted as a valid genus. The adults of Agamermis decaudata are descried and illustrated for the first time. The genus Gastromermis is limited to the long single-spiculed forms, as it is now apparent that five or more genera have ventrally shifted mouth orifices. Amphirnermis tinyi n. sp. is described from damselflies from Louisiana. The genus Lanceimermis is accepted, and three species in this genus are illustrated. The taxon Reesimermis nielseni has been accepted for this important parasite of more than 20 mosquito species. This nematode previously has been referred to as Romanomermis sp. Romanomermis iyengari is transferred to the genus Reesirnermis. Diximermis peterseni n. gen., n. sp., from anopheline mosquitoes, is described and iUustrated. The adults of Agamomermis culicis which parasitize Aedes sollicitans, are described for the first time, and the species placed in a new genus, Perutilimermis. The new genus Neornesornermis is proposed for Mesomermis flumenalis Welch, 1962. Several problems on mermithid morphology and taxonomy are discussed. Type material is established for some of the taxa.     

Phylogeny of Salsoleae s.l. (Chenopodiaceae) based on DNA sequence data from ITS, psbB–psbH, and rbcL, with emphasis on taxa of northwestern China

To reconstruct phylogeny and verify the monophyly of major subgroups, a total of 52 species representing almost all species of Salsoleae s.l. in China were sampled, with analysis based on three molecular markers (nrDNA ITS, cpDNA psbB–psbH and rbcL), using maximum parsimony, maximum likelihood, and Bayesian inference methods. Our molecular evidence provides strong support for the following: (1) Camphorosmeae is nested within Salsoleae s.l. instead of the previously suggested sister relationship. (2) Tribe Salsoleae s.l. is monophyletic and is composed of three monophyletic subunits, Caroxyloneae, the Kali clade, and Salsoleae s.str. (3) Climacoptera is separated from Salsola s.l. It does not form a monophyletic group but is split into two monophyletic parts, Climacoptera I and Climacoptera II. (4) Halogeton is clearly polyphyletic, as are Anabasis and the genus Salsola s.l. (5) Caroxylon, Haloxylon, Kali, and Petrosimonia are well-supported monophyletic genera. Additional evidence is needed regarding the monophyly of Halimocnemis, which remains unclear.