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.     

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 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.     

Pherbina mediterranea: immature stages,biology, phenology and distribution (Diptera: Sciomyzidae)

The egg, three larval instars, and puparium of Pherbina mediterranea are described. The duration of the various immature stages indicates that this specis is univoltine and spends the winter as quiescent larvae. The biology, phenology and geographical distribution are presented. The main features of the larvae are illustrated with scanning electron micrographs. A key to the adults of genus Pherbina is given.     

Notes on Simulium ovazzae Grenier and Mouchet (Diptera: Simuliidae) and river crabs (Malacostraca: Potamidae) and their association

Summary

Collections of crabs in the forest zone of West Cameroon produced three species—Potamonautes africanus, P. orthostylis and P. pobeguini. The P. africanus carried populations of immature Simulium ovazzae.

Analysis of crabs collected by hand and those collected in traps indicates very little overlap in the sizes of the crabs obtained by the two techniques. This problem is discussed.

The infestation rates of S. ovazzae on P. africanus were found to be highest on medium-sized crabs. The attachment sites of the S. ovazzae on the crabs were found to vary with both the size of the crab and the size of the Simulium larva.

The size distributions of S. ovazzae larvae on small crabs were found to be different from those on medium and large crabs. The characteristic deficiency of smaller larvae on medium and large crabs reported for other crab-phoretic species was also found with S. ovazzae but the smaller crabs showed a deficiency of larger larvae. A hypothesis is put forward to explain the dearth of larger larvae on the smaller crabs and the higher infestation rate on medium crabs.

S. ovazzae are shown to arrive on their hosts as single larvae carried by the current.

Six adult S. ovazzae were reared from pupae in the laboratory. Small numbers of presumed S. ovazzae biting man in Cameroon are reported.     

The Agromyzid genus Paraphytomyza Enderlein: new to the Oriental Region (Diptera)

Paraphytomyza jasmini sp. n. from India and P. loniceroides sp. n. from N.W. Pakistan are described, representing the first reared species in this genus known in the Oriental Region. P. kraussi (Sasakawa, 1963) from Papua New Guinea is formally transferred to Paraphytomyza as a new combination. The nomenclature, distribution and host range of Paraphytomyza are discussed.     

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.     

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.     

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.     

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.     

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.     

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.     

A synopsis of present knowledge of the Simuliidae (Diptera) of the Canary Islands,including keys to the larval and pupal stages

As human demands for water have become more intense in modern times, the Canary Islands have become a difficult environment for all the macroinvertebrate fauna dependent upon running water for their survival; few permanent streams remain. Investigations on the simuliid (blackfly) fauna have shown, however, that at least six species exist in the archipelago, but that one, the endemic Simulium paraloutetense, known only from one site now destroyed, is possibly extinct. The paper presents cumulated data on distribution and material obtained over the past 33 years (since aquatic-stage specimens from breeding sites were first collected) with the aim of providing a baseline against which future studies of the Canarian simuliid fauna can be assessed. Revised identification keys for larvae and pupae are given to aid such monitoring. Remarks concerning each species include notes on chromosomal data when these are available. Comments are included on some aspects of the lotic habitats and island colonization.     

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.     

Bionomics,behaviour and immature stages of Pelecotoma fennica (Paykull) (Coleoptera: Rhipiphoridae)

Ptilinus fuscus (Anobiidae) was confirmed as the host species of Pelecotoma fennica (Rhipiphoridae, Pelecotominae). Females of Pelecotoma oviposit into the wood infested by the host larvae. First-instar larvae are elongate, unsclerotized, very different from the triungulinid larvae known in other rhipiphorids. They search actively for the host larvae in the wood; no phoresy is involved in the life cycle. The first-instar larvae temporarily paralyse the host larva and enter its body, overwintering (some perhaps more than once) as an endoparasite. In the spring of the year of emergence, the endoparasite engorges enormously (without moulting) and develops a special sclerotized caudal structure which is then used for perforation of the host's integument. The larva undergoes a further four ectoparasitic instars. The fifth (i.e. fourth ectoparasitic) instar differs considerably from the preceding three, and is capable of boring through the wood to prepare the emergence gallery for the adult. Pupation occurs in the wood. The rate of parasitization may locally far exceed 50%. Superparasitization by the first-instar larvae is possible, but usually only 1 larva survives to the ectoparasitic stage. Larval morphology of Pelecotoma is described and illustrated. Additional data on bionomics and larval morphology are also presented for the genus Metoecus (Rhipiphorinae). Comparing the biology and larval morphology of Pelecotoma with other Rhipiphoridae, it is assumed that ancestral rhipiphorids may have been xylophilous Tenebrionoidea with predaceous or omnivorous larvae, and that the ‘triungulinid’ larvae and phoretic habits may not belong to the groundplan of the family Rhipiphoridae. The widespread opinion considering Rhipiphoridae closely related to the family Mordellidae is questioned.     

Description of the immature stages of Sigara (Tropocorixa) santiagiensis (Hungerford, 1928) (Insecta: Heteroptera: Corixidae)

The immature stages of Sigara santiagiensis are described and illustrated for the first time. The eggs of Sigara can be distinguished by the chorionic surface. The main characters separating the five nymphal instars of S. santiagiensis are: body and head lengths; body, head and eye widths; ocular index; numbers of transverse sulcations of the rostrum, setae on the inner surface of protibiotarsus, campaniform sensilla on posterior surface of protrochanter, spines on posteroventral surface of mesotibia and on tibial comb of metaleg, long, slender setae on posterodorsal surface of mesotarsus, spines and swimming hairs on anteroventral and posterodorsal surfaces of metatarsus; and grade of development of the wing pads. The body length, the chaetotaxy of the mesonotum, profemora and metafemora, protibiotarsus, metatibia, metatarsus and urosternites distinguish species or group of species of instars I and V of some of the species of the genus Sigara described up to now.