Subgeneric assignment and synonymy of some southern Palaearctic species of Simulium (Diptera: Simuliidae)

Synopsis

Type-material has been studied of six southern Palaearctic species of Simulium Latreille hitherto inadequately known and the subgeneric assignment and synonymy of each established or verified. Four lectotypes are designated.     

The immature stages of Simulium speculiventre,type-species of Stilboplax Enderlein (Diptera: Simuliidae)

Synopsis

The previously unknown immature stages of Simulium speculiventre are described and figured, and a lectotype is designated for this species from the adult syntypes. S. speculiventre is assigned to the subgenus Eusimulium (new subgeneric combination) and the genus-group name Stilboplax Enderlein is sunk in synonymy with Eusimulium Roubaud (new synonym).     

On Simulium xanthinum,a curious yellow-bodied blackfly of the southwestern Palaearctic region (Diptera: Simuliidae)

An account is given of Simulium xanthinum, an unfamiliar simuliid of the southwestern Palaearctic area remarkable for its mainly bright orange-yellow adult and for the clear yellow-green colour of its larva when alive. The species is described in all life stages (except the unknown egg), and the name Simulium gaudi confirmed as a new synonym of S. xanthinum after examination of types and other material. The finding is reported of pupae and larvae in several limestone streams of Andalusia (southern Spain), notably in the headwaters of the Rio Guadalquivir. SEM examination of the heavily sculptured surface of the pupal gill seems to reveal the occurrence of rows of micropores, and this finding is briefly discussed for its bearing on current debate about the nature of the simuliid pupal gill plastron.     

The effect of elevation on the distribution of sibling species in the Simulium arcticum complex (Diptera: Simuliidae)

At least 5 sibling species and an additional 11 cytotypes of the Simulium arcticum complex occur in Montana. Consequently, this speciose complex might allow study of environmental correlates with genetic differentiation. We used conventional methods of collection and cytogenetic analysis to study 1128 male larvae of the Simulium arcticum complex at 15 sites within 5 drainages in western Montana to test the hypothesis that distribution of siblings is associated with elevation. We sampled at the mouth, at the headwaters, and at an intermediate site to span the range of elevations within each drainage. We restricted our analyses to the most abundant taxa of the S. arcticum complex within our study area and observed a statistically significant presence of S. apricarium at low-elevation sites. Simulium arcticum IIL-18 appeared more frequently than expected at high elevation sites. Simulium brevicercum and S. arcticum sensu strictu appeared to be distributed randomly. We suggest potential causal reasons for these distributions including differential use of habitats along these elevational gradients.     

Reproductive status and continuity of taxa of the Simulium arcticum complex (Diptera: Simuliidae) at the Clearwater River, Montana (2007, 2008, and 2009)

We made 27 collections over nine years at the Clearwater River and conducted preliminary cytogenetic analysis on 232 individuals of the Simulium arcticum complex there. Based on these preliminary findings, we analyzed an additional 1825 larvae from Clearwater collections in 2007, 2008, and 2009 to investigate the reproductive statuses of the two prevalent taxa of the complex there and to determine whether cytogenetic diversity and frequency of types were similar from year to year. We describe a cytotype new to science and a potentially derivative cytotype of S. arcticum sensu stricto. We also determine that these two taxa are present in similar frequencies from year to year and are in genetic equilibrium, suggesting that they are not reproductively isolated. This study constitutes the fourth positive test of our Geographic Distribution/Taxon Age hypothesis.     

A new species of Prosimulium Roubaud (Diptera:Simuliidae) from Rhodesia

Summary

A new species of Prosimulium from Rhodesia is described and placed in the damarense-group; this species-group is defined and keys are given for the identification of its three constituent species in larval, pupal and adult stages.     

The blackfly fauna of Majorca and other Balearic Islands (Diptera: Simuliidae)

Results are presented of a survey of the Simullidae of the Balearic Islands, an archipelago not previously studied for its blackfly fauna. Four morphospecies occur, none endemic, of which Prosimulium aculeatum is a rare species previously known only from Sardinia and Sicily, and Simulium cryophilum, S. velutinum and S. intermedium widespread in western Europe and North Africa.     

A supplement to the checklist of Chinese blackflies (Diptera: Simuliidae)

This work provides a summary of all simuliid species described or reported from China over the past 10 years. Text references pertaining to each additional species are accompanied by statements of the type localities, sexes and life stages described.     

Taxonomy and geography of the blackflies of the Canary Islands (Diptera: Simuliidae)

The Canary Islands provide a difficult habitat for Simuliidae because of the scarcity of running water for the early stages, but the archipelago currently supports a fauna of six species (one other species formerly present is considered extinct). Breeding is confined to three of the seven islands (Gomera, La Palma, Tenerife), but once occurred also in Gran Canaria, an island that now lacks flowing streams. The taxonomic and faunal conclusions are based on a study of all available specimens, including material of early stages and reared adult flies collected by the author and aided by cytological data from the larval polytene chromosomes of several species. Twenty-one nominal species have at some time or another been reported from the Canaries, but, following this revision, only seven are recognized in the fauna (most past records being erroneous and based on misidentifications or false assumptions of endemicity); full synonymies clarify the old records in relation to modern nomenclature. All species belong to Simulium Latreille s.l., and keys are given to them in adult, pupal and larval stages. Three species are endemic (two newly described) and the other four common to the Palaearctic mainland. Some remarks are included on simuliid colonization and extinction in the islands.     

A gynandromorph of Austrosimulium (Austrosimulium) australense (Schiner) from New Zealand (Diptera: Simuliidae)

Summary

A gynandromorph of Austrosimulium (Austrosimulium) australense (Schiner) is described. This individual had the head of a female, whereas the thorax and abdomen were a mosaic of male and female characters. The genitalia of both sexes were present, but only the female set was complete. Overall, the female characters of this specimen appeared to be more fully expressed than those of the male.     

The Simuliidae (Diptera) of the River Oder and its tributaries,with special reference to the re-appearance of Simulium (Schoenbaueria) nigrum (Meigen) in larger rivers in Central Europe

An investigation was carried out over a five-year period into the blackfly fauna of one of the most important rivers of the North-Central European lowlands, the Oder, together with its major tributaries (Nysa, Stobrawa, O?awa, Barycz, Bobr, Kroisa, Lausitzer Neisse, Warta, Notec), from its source in the Oder Hills to its mouth in the Baltic Sea. Thirteen species were found. The two dominant indicator species, Simulium (Simulium) reptans (Linnaeus) and Simulium (Schoenbaueria) nigrum (Meigen), develop populations of plague proportions within this catchment area. Blackflies of the subgenus Schoenbaueria Enderlein have not been found in Germany or Poland for more than 70 years. However, since 1997, the species S. (Sch.) nigrum was found in the River Oder in enormous numbers together with S. (S.) reptans, and in the vicinity of their breeding sites in Poland and eastern Germany both species are serious pests of man and grazing animals. Notes are given on the biology, distribution and habitat preferences of S. (Sch.) nigrum. The paper concludes with a comparison of the River Oder with some other Central European rivers in respect of its blackfly fauna, together with data on the phenology of the two indicator species.     

Notes on the Muscidae of New Guinea (Diptera)

Synopsis

The species of Muscidae described or subsequently recorded by Walker from New Guinea and adjacent islands are reviewed. Twenty-three species are treated: type-locations are stated, lectotypes designated where necessary, and generic assignments given. Two holotypes are considered lost, eight lectotypes are designated, and nine new combinations established.     

An investigation of the blackfly fauna of Andalusia,southern Spain (Diptera: Simuliidae)

A detailed account is provided of the blackfly (Simuliidae) fauna of Andalusia, southern Spain. The work is based on a study of 14204 specimens, of which 13733 were collected by the authors from a total of 137 positive sampling sites during prospections made mainly in early summer 1986 and in the spring seasons of 1994—1998. In all, 25 identified species and two possible species of uncertain identity are recorded. The topographical and climatic background is briefy described, data from previous literature and material from earlier collections are covered, a checklist of the blackflies of Spain and Portugal is provided, and the character of the simuliid fauna is discussed for areas within and outside Andalusia.     

Parasites of shore crabs in the genus Hemigrapsus (Decapoda: Brachyura: Varunidae) and their status in crabs geographically displaced: a review

Two brachyurans of the varunid genus Hemigrapsus from the northwestern Pacific Ocean have invaded coastal regions of the north Atlantic – Hemigrapsus takanoi (sibling species of Hemigrapsus penicillatus) and Hemigrapsus sanguineus in Europe and the latter in the USA. Parasites are known from these crabs in their native habitats, but except for an undescribed larval nematode, none has been found in those examined from their new locations. These parasites include metacercariae of eight species of microphallid trematode, the rhizocephalan barnacles Polyascus polygenea, Sacculina nigra and Sacculina senta, and the obligate gut-inhabiting mesomycetozoan Enteromyces callianassae (potential parasite). The following have been identified in four of the other eight Pacific crabs within the genus (Hemigrapsus nudus and Hemigrapsus oregonensis, northern hemisphere; Hemigrapsus crenulatus and Hemigrapsus sexdentatus, southern hemisphere), none of which have been geographically displaced: metacercariae of two microphallid trematodes; cystacanths of three acanthocephalans Profilicollis antarcticus, Profilicollis botulus and Profilicollis novaezelandensis; larval nematode Ascarophis sp.; nematomorph Nectonema zealandica; entoniscid isopod Portunion conformis; mesomycetozoan Taeniella carcini; and nemertean egg predator Carcinonemertes epialti. The likelihood of the displaced species of shore crabs being rejoined with their native parasites or their susceptibility to becoming infected by similar parasites in their new locations is discussed. In future global displacements of parasitized Hemigrapsus species it is possible that their most serious parasites, rhizocephalans and entoniscid isopods, may infect previously uninfected species. For example, the two eastern Pacific species of Hemigrapsus (H. nudus and H. oregonensis) may be vulnerable to the rhizocephalans and may in turn be a source of entoniscids transported elsewhere.     

Notes on some larval and pupal chironomids (Diptera) from Lake Kariba,Rhodesia

Summary

The effects of hydrolysable tannin and condensed tannin on the feeding of Schistocerca gregaria and Locusta migratoria are described. An attempt is made to explain the different effects of tannins in the presence of different nutrients. The ecological significance of these findings is discussed.