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Summary A new species of fossil mermithid, Heydenius simulphilus sp. n. (Nematoda: Mermithidae), is described from two parasitic juvenile specimens adjacent to a male black fly (Diptera: Simuliidae) in Baltic amber. It is proposed that the nematodes emerged from their developmental sites in the haemocoel of the black fly host through a wound in the abdomen of the latter, as indicated by the release of a droplet of haemolymph and damaged cuticle. Various internal structures of the nematodes are identified and related to those found on extant developing mermithids. This is the first fossil record of mermithid parasitism of a black fly.

Simulioidea are extremely rare in the fossil record of the Mesozoic, when members of Culicomorpha originated. Based on numerous compressions from the Cretaceous of Asia (Khasurty and Baissa, Wester...

The Canadian Diptera fauna is updated. Numbers of species currently known from Canada, total Barcode Index Numbers (BINs), and estimated numbers of undescribed or unrecorded species are provided for each family. An overview of recent changes in the systematics and Canadian faunistics of major groups is provided as well as some general information on biology and life history. A total of 116 families and 9620 described species of Canadian Diptera are reported, representing more than a 36% increase in species numbers since the last comparable assessment by JF McAlpine et al. (1979). Almost 30,000 BINs have so far been obtained from flies in Canada. Estimates of additional number of species remaining to be documented in the country range from 5200 to 20,400.

A segregate of the so-called Australian ‘Paracnephia’ (Diptera: Simuliidae) is assigned to a new genus, Austrocnephia. The taxon is fully diagnosed and a key to constituent species presented. Two species-groups are recognized: the aurantiaca species-group, comprised of A. aurantiaca (Tonnoir 1925) and A. strenua (Mackerras & Mackerras 1950), and the tonnoiri species-group, comprised of A. fuscoflava (Mackerras & Mackerras 1948), A. orientalis (Mackerras & Mackerras 1950) and A. tonnoiri (Drummond 1931). Both species-groups are diagnosed and the included species fully redescribed. Detailed locality data is given, as is information about biology, when known. Brief comments are offered about the historical biogeography of Austrocnephia. A key to Australian simuliid genera is also provided.

Coalescent-based analyses have been recommended for species delimitation and tree reconstruction. Yet, despite recent advances in molecular methods, acquiring sufficient genetic data often precludes coalescent-based analyses in nonmodel organisms. We show that these methods are accessible to questions in nonmodel systems. Specifically, we use coalescent-based analyses to investigate evolutionary independence and relationships among chromosomally distinct members (sibling species) of a black fly (Diptera: Simuliidae) species complex. Our dataset consists of nuclear DNA (nuDNA) and mitochondrial DNA (mtDNA) markers – the former developed using the black fly transcriptome and available genomes from model relatives. We show that individual gene trees exhibit considerable discordance among one another and reveal little about potential species limits. Consistent species tree topologies are obtained from analyses of nuDNA, both with and without the inclusion of mtDNA data. Nodes on the tree receive robust support with the addition of mtDNA. Coalescent-based species validation approaches recognize all sibling species. However, unlike species tree analyses, the addition of mtDNA data does not improve or alter the results. Thus, analyses of nuDNA alone can validate sibling species. Contrary to these results, population genetic patterns of neutral diversity, within-locus recombination, and linkage disequilibrium suggest that sibling species represent a single species with high levels of nucleotide polymorphism, large effective population sizes, and extensive gene flow. Demographic patterns inferred from neutrality tests integrate seemingly disparate results by showing signatures of gene flow among structured populations that are expanding in size. Thus, admixture associated with geographic range expansions may be assimilating sibling species into a single genetic lineage.

Indirect impacts of climate change, mediated by new species interactions (including pathogens or parasites) will likely be key drivers of biodiversity reorganization. In addition, direct effects of extreme weather events remain understudied. Simultaneous investigation of the significance of ectoparasites on host populations and extreme weather events is lacking, especially in the Arctic. Here we document the consequences of recent black fly outbreaks and extreme precipitation events on the reproductive output of an arctic top predator, the peregrine falcon (Falco peregrinus tundrius) nesting at the northern range limit of ornithophilic black flies in Nunavut, Canada. Overall, black fly outbreaks and heavy rain reduced annual nestling survival by up to 30% and 50% respectively. High mortality caused by ectoparasites followed record-breaking spring snow precipitation, which likely increased stream discharge and nutrient runoff, two key parameters involved in growth and survival of black fly larvae. Using the RCP4.5 intermediate climate scenario run under the Canadian Global Climate Model, we anticipate a northward expansion of black fly distribution in Arctic regions. Our case study demonstrates that, in the context of climate change, extreme weather events can have substantial direct and indirect effects on reproductive output of an arctic top-predator population.

Protaustrosimulium n. gen. is described for four species: two previously named species from southeastern Australia—Paracnephia pilfreyi (Davies & Györkös 1988) and Paracnephia terebrans (Tonnoir 1925)—plus two newly described ones from the southwestern-most corner of Western Australia—Prot. amphorum n. sp. and Prot. opscurum n. sp. Molecular and morphological data suggest a close relationship between members of the new genus and Austrosimulium Tonnoir 1925. Monophyly of Protaustrosimulium is supported mainly by characters of adult females, as two of the four species are known only in that life stage. Two species groups are recognized: the pilfreyi-group for Prot. pilfreyi and Prot. amphorum, and the terebrans-group for Prot. terebrans and Prot. opscurum. The constituent species in each group are distributed vicariously in southeastern and southwestern Australia—a common biogeographical pattern in Australian simuliids.

Two species of Australian Simuliidae known only from adult females and currently assigned to "Paracnephia" are re-described, as are their now-known males and immature stages. Morphological character states of "Paracnephia" fergusoni (Tonnoir) and "P." fergusoni var. (Mackerras & Mackerras) reveal that they are markedly distinct from all other Australian species, and are here assigned to the new genus—Nothogreniera—the most plesiomorphic Gondwanan Australian simuliid. Structural variation among populations of N. fergusoni suggests that this entity comprises a species complex.

Moulton, John K., Currie, Douglas C., Craig, Douglas A. (2018): A New Genus, Ectemnoides, for Seven Species of Australian Gondwanan Simuliidae (Diptera) With Description of a Novel Form of Larval Attachment. Insect Systematics and Diversity 2 (4), No. 4: 1-54, DOI: 10.1093/isd/ixy009, URL: http://dx.doi.org/10.1093/isd/ixy009

Hybrid zones are windows into the speciation process, and their study can give clues into the maintenance and breakdown of species boundaries. Using both genetic and ecological tools, we investigate lineage diversification across a contact zone characterized by chromosome rearrangements. We show that black fly sibling species, Simulium arcticum sensu stricto (s.s.) and Simulium saxosum, lack genetic differentiation at both microsatellite and mtDNA loci in allopatry and sympatry, as well as exhibit high levels of gene flow and continuous chromosome variation in sympatry. Furthermore, hybrid frequencies at the contact zone are similar to those seen between races, rather than species. In contrast, S. arcticum s.s. and S. saxosum maintain ecological differences and distinct habitat associations - the contact zone situated at the margin of suitable habitat for each sibling species. Moreover, gene flow occurs only in a narrow band along an ecological transition. Except for the contact zone, S. arcticum s.s. and S. saxosum hybrids do not occur elsewhere within the sibling species' ranges. Although S. arcticum s.s. and S. saxosum maintain the potential to interbreed freely, we conclude that habitat associations and, perhaps, chromosome systems prevent expansion of ranges and assimilation of lineages.

Chromosome inversions may be involved in adaptation and speciation. We investigate ecological diversification among members of the Simulium arcticum species complex at different stages of chromosome divergence. Our analyses focus on two geographical scales. First, we assess ecological divergence of sibling species throughout North America using niche modelling methods. Then, using canonical correspondence analysis, we investigate habitat associations of sibling species and cytotypes in the northern Rocky Mountains ecoregion, where cytotypes tend to occur. Despite significant overlap in predicted distributions, all sibling species are ecologically unique. On the other hand, we discover various degrees of ecological divergence for cytotypes. Some cytotypes are ecologically distinct and perhaps are in their initial stages of incipient speciation. Other cytotypes are ecologically associated with one another or with particular sibling species. Thus, for members of the S. arcticum complex, ecological and chromosomal differences tend to develop early in lineage formation. Ecological distinctiveness of sibling species and cytotypes suggests that local adaptation may be involved in diversification of these chromosomal forms. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115, 13‐27.

With new material available of most stages of many known Australian Paracnephia, including new species, it is now clear that certain segregates warrant assignment to new genera. This applies to Paracnephia gladiator Moulton Adler, a Western Australia simuliid with numerous unique character states. The species is fully redescribed and assigned to Bunyipellum nov. gen. A diagnosis is provided and relationships discussed, as is historical biogeography. Bunyipellum appears to be more closely related to elements of the South American simuliid fauna than to any other Gondwanan Australian species.

The hitherto monotypic South American genus Paraustrosimulium Wygodzinsky & Coscarón is revised to accommodate two Australian species: Austrosimulium colboi Davies & Györkös and Paraustrosimulium obcidens n. sp. The generic diagnosis is updated and the eastern Australian species Paraustrosimulium colboi (Davies & Györkös) n. stat. is re-described, including the male for the first time. The Western, Australian sister species of P. colbo, namely P. obcidens Craig, Moulton Currie n. sp. is also fully described. The relationship of Paraustrosimulium to other simuliid genera is discussed, as are aspects of historical biogeography.

Arctic and subarctic environments are among the most inaccessible regions in the world, making biological surveys difficult to conduct. Thus, the insect fauna of these regions has remained inadequately surveyed. The aquatic insect orders Ephemeroptera, Plecoptera, and Trichoptera (EPTs) are particularly abundant and diverse at high latitudes, playing key roles in trophic chains where nutrients are scarce. However, particular aspects of their life cycle make them difficult to study. Specifically, species-level identification requires last-instar larvae or adults which, because they are short lived, are typically not available for all taxa during a particular collecting event. With the initial goal of surveying the biodiversity of these insect groups, we sampled ca.10,000 EPT specimens from 12 locations across northern Canada over two years. Approximately 800 of these were subsequently selected for COI DNA barcoding. Overall, we identified 155 EPT species (58 Ephemeroptera, 41 Plecoptera, 56 Trichoptera) based on a 2% divergence criterion. Compared to other similar studies on EPTs we found higher (particularly among the Plecoptera and Ephemeroptera) and more even diversity, potentially reflecting environmental differences in sampling localities. We further assessed phylogeographic divergence patterns among seven species, finding that eastern and western populations diverged during the Pleistocene Epoch (

A geometric morphometric analysis was conducted on wing-vein landmarks on exemplar species of the family Simuliidae of the following genera: Parasimulium, Gymnopais, Twinnia, Helodon, Prosimulium, Greniera, Stegopterna, Tlalocomyia, Cnephia, Ectemnia, Metacnephia, Austrosimulium, and Simulium. Generalized least squares superimposition was performed on landmarks, followed by a principal component analysis on resulting Procrustes distances. Patterns of shape change along the principal component axes were visualized using the thin-plate spline. The analysis revealed wing shape diversity through (1) the insertion points of the subcosta and R1, resulting in the terminus of the costa exhibiting a trend towards a more apical position on the wing, and (2) the insertion point of the humeral cross vein, resulting in the anterior branch of the media exhibiting a trend toward a more basal position on the wing. Canonical variates analysis of Procrustes distances successfully assigned all exemplar species into their a priori taxonomic groupings. The diversity in wing shape reveals a trend towards decreased length of basal radial cell and increased costalization of anterior wing veins in the evolutionary transition from plesiomorphic prosimuliines to more derived simuliines. The functional significance of these evolutionary transitions is discussed. © 2013 The Linnean Society of London

We investigated species limits and phylogenetic relationships among chromosomally distinct North American members of the Simulium malyschevi species-group. Maximum parsimony and Bayesian analyses were conducted based on 12S, COII, cyt b and ITS-1 gene sequences. In terms of species limits, monophyly was highly supported for each chromosomally and morphologically distinct taxon analysed (S. decimatum, S. defoliarti, S. malyschevi, and S. murmanum). In contrast, support for monophyly of morphologically homogeneous S. arcticum complex members was significant only in one case (S. saxosum) and not the other (S. negativum). Considering the overall topology, three principal conclusions were drawn: (i) the status of S. subvariegatum as a member of the S. malyschevi species-group remains uncertain. This species either was excluded from the malyschevi-group or formed a sister group with S. malyschevi at the base of the tree; (ii) although S. murmanum and S. decimatum branch after S. malyschevi, the position of the two species relative to each other remains unresolved; and (iii) the structurally homogeneous S. arcticum species complex was not monophyletic due to the inclusion of S. defoliarti. Further investigation may warrant changes to current malyschevi-group classification. Molecular datasets alone may be insufficient for resolving relationships among particular lineages of black flies.

Rapid and recent lineage radiations pose challenges to systematists. Using members of the highly diverseSimulium arcticumMalloch complex, we tested whether the cytochromecoxidase subunit I (COI) barcoding gene can differentiate black fly sibling species. Members of theS. arcticumcomplex were monophyletic in relation to two morphospecies and two cryptic species of theSimulium malyscheviDorogostaiskyet al.andSimulium noelleriFriederichs species-groups, respectively. Of fiveS. arcticumsibling species analysed, onlySimulium negativumAdleret al.was monophyletic. No other members of the complex could be distinguished using COI barcodes. The inability to resolveS. arcticumsibling species resulted because (1) haplotypes were shared between species and (2) the distribution of interspecific genetic distances completely overlapped the range of variation within species. Potential sources of incongruence between barcode data and species boundaries include imperfect taxonomy, inadequate genetic information, incomplete lineage sorting, and/or introgressive hybridization. We ruled out imperfect taxonomy because chromosomal, ecological, and distributional evidence support the validity ofS. arcticumsibling species. Therefore, current nomenclature should be maintained pending further study. We conclude that one or more of the latter three sources of incongruence could be responsible for the lack of reciprocal monophyly among species of theS. arcticumcomplex.

Arctic and subarctic environments are among the most inaccessible regions in the world, making biological surveys difficult to conduct. Thus, the insect fauna of these regions has remained inadequately surveyed. The aquatic insect orders Ephemeroptera, Plecoptera, and Trichoptera (EPTs) are particularly abundant and diverse at high latitudes, playing key roles in trophic chains where nutrients are scarce. However, particular aspects of their life cycle make them difficult to study. Specifically, species-level identification requires last-instar larvae or adults which, because they are short lived, are typically not available for all taxa during a particular collecting event. With the initial goal of surveying the biodiversity of these insect groups, we sampled ca.10,000 EPT specimens from 12 locations across northern Canada over two years. Approximately 800 of these were subsequently selected for COI DNA barcoding. Overall, we identified 155 EPT species (58 Ephemeroptera, 41 Plecoptera, 56 Trichoptera) based on a 2% divergence criterion. Compared to other similar studies on EPTs we found higher (particularly among the Plecoptera and Ephemeroptera) and more even diversity, potentially reflecting environmental differences in sampling localities. We further assessed phylogeographic divergence patterns among seven species, finding that eastern and western populations diverged during the Pleistocene Epoch (

A new species of black fly, Simulium (Inaequalium) marins (Diptera: Simuliidae), is described based on the male, female, pupa and larva. This new species was collected from two localities: a small stream on the Pico dos Marins, a high mountain with granite outcrops in Piquete County, state of São Paulo, and in a small stream in the Serra dos Orgãos National Park, state of Rio de Janeiro, Brazil.

Black flies are a worldwide family of nematocerous Diptera whose immature stages are confined to running waters. They are key organisms in both aquatic and terrestrial ecosystems, but are perhaps best known for the bloodsucking habits of adult females. Attacks by black flies are responsible for reduced tourism, deaths in wild and domestic birds and mammals, and transmission of parasitic diseases to hosts, including humans. About 2,000 nominal species are currently recognized; however, certain geographical regions remain inadequately surveyed. Furthermore, studies of the giant polytene chromosomes of larvae reveal that many morphologically recognized species actually consist of two or more structurally indistinguishable (yet reproductively isolated) sibling species. Calculations derived from the best-known regional fauna—the Nearctic Region—reveal that the actual number of World black fly species exceeds 3,000.

Les conflits sexuels peuvent favoriser le developpement au cours de l'evolution de caracteres sexuels antagonistes qui servent durant les interactions de l'accouplement. Un des cas les plus remarques de l'elaboration de caracteres morphologiques chez le mâle s'observe chez les patineurs du genre Rheumatobates Bergroth (Hemiptera: Gerridae). La signification fonctionnelle des modifications bizarres des appendices dans ce groupe reste inconnue. Nous traitons ici principalement d'une des especes les plus developpes a ce titre, R. rileyi Bergroth. Des observations et des experiences nous servent a determiner la sequence generale du comportement d'accouplement, le role des femelles dans l'issue des interactions sexuelles et la signification fonctionnelle des appendices fortement modifies du mâle. Nous placons ces caracteres sur un arbre phyletique reconnu du genre afin de determiner leur patron d'evolution. Les mâles harcellent les femelles a repetition et les femelles reagissent en s'eloignant en patinant; cependant, si le mâle reussit a l'attraper, il se produit une echauffouree pre-copulatoire. La dynamique de l'echauffouree determine le succes de la tentative d'accouplement. Les echauffourees courtes menent normalement a l'accouplement, alors que les echauffourees prolongees se terminent generalement par la separation du couple. Apres une courte periode de copulation, le mâle retire ses organes genitaux et debarque de la femelle. Les femelles qui ont ete tenues a l'ecart des mâles pendant un certain temps sont moins reticentes a l'accouplement. Durant l'echauffouree pre-copulatoire, les antennes des mâles servent a entourer la tete de la femelle et les pattes posterieures sont utilisees pour soulever les pattes posterieures de la femelles au-dessus de la surface de l'eau. Ni les antennes, ni les pattes posterieures ne servent durant la copulation; elles ne sont donc pas impliquees dans la cour associee a l'accouplement. En reliant ces caracteristiques a la phylogenie, on observe de multiples origines independantes et un pattem d'escalade (16 origines et 7 pertes). Nous concluons que ces caracteres bizarres des mâles sont des caracteres sexuels antagonistes et qu'ils sont apparus a plusieurs reprises chez ce genre.

Leptocerid caddisflies have a wide variety of case forms, and therefore it might seem difficult to establish behavioral homologies at the family or generic levels. We videotaped case building in representatives of 9 genera in 8 leptocerid tribes and compared their behavior to 32 other caddisfly genera in 11 families to determine if family-specific behaviors could be identified. We also constructed a behavioral phylogeny of the 8 leptocerine genera and compared this phylogeny to an existing morphological phylogeny. Four unreversed and 1 reversed behavioral synapomorphies supported the monophyly of the Leptoceridae even though case shape varies among the genera. An analysis of 9 intergeneric behavioral characters produced 1 most parsimonious tree (length 11; consistency index: 1.00; retention index: 1.00) that differed from the morphological phylogeny in the placement of 2 genera. Six character states were homologous relative to the morphological data, 5 of which supported 2 nodes that were previous...

Many animals engage in elaborate behavioural sequences in order to build structures. The ‘end-products’ (e.g., nests of birds, cases of caddisflies) of these behaviours have occasionally been used either to infer details of building behaviour or to infer that structures similar in appearance are constructed by similar behavioural sequences. However, behavioural information can be extrapolated from end-products only if there is congruence between the end-product structure and the animal's movements. Case building behaviour was studied in caddisflies (Trichoptera) to examine the relationship between end-products and behaviour. We found examples of taxa that built similar structures using different behavioural patterns, and taxa that built different structures using similar behaviours, regardless of whether these taxa were closely or distantly related. These findings question the reliability of behavioural inferences based solely on details of their associated end-products and suggest that end-product structure should be removed from the definition of animal behaviour.

Comparative analyses of populations at different stages of divergence can yield insights into the process of speciation. We assess population structure, gene flow, and maternal ancestry at five locations containing sympatric members of the Simulium arcticum complex at different stages of chromosome divergence. We analyze both nuclear and mitochondrial DNA markers, including 11 microsatellite loci, as well as COI, COII, cytb, and ND4 gene sequences. Simulium negativum, representing the later stages of divergence, shows both nuclear and mitochondrial differentiation when compared with allopatric and sympatric chromosomal forms, as well as both low contemporary and historical gene flow in sympatry. At intermediate stages of chromosome divergence, populations differ at nuclear, but not mitochondrial, loci in allopatry and sympatry. In one comparison of intermediate stage chromosomal forms (S. arcticum sensu stricto and S. apricarium), populations demonstrate low contemporary, but higher historical, gene flow in sympatry. In a second sympatric comparison (S. arcticum s. s. and S. brevicercum), both contemporary and historical gene flow are high. All analyses of sympatric populations at the earliest stages of chromosome divergence demonstrate panmixia; yet, some nuclear differentiation in allopatry is apparent. These findings suggest that molecular divergence is tracking chromosome divergence along a chromosomally-defined continuum of speciation in black flies.

Aim With six new species of subgenus Inseliellum Rubtsov recently described, a revised reconstructed phylogeny based on morphology is required. Geological history of islands where Inseliellum occurs, plus a cladistic analysis and hydrological considerations, provide the basis for a reconstructed geographical history of the species. Location Inseliellum is widely distributed and occurs in Micronesia, Cook Islands and Polynesia. A single specimen is known from Tonga Islands. Methods Maximum parsimony criteria using PAUP*, plus cytological information, were used to arrive at a preferred phylogenic reconstruction. Island ages of the hot spot archipelagoes involved are well known. The phylogeny was then compared with the palaeogeology. Information on evolution of running water habitats as islands age was incorporated into the biogeography. Results Cladistic analysis of forty of the forty-eight known Inseliellum species with Simulium (Nevermannia) neornatipes Dumbleton from New Caledonia and S. (Hebridosimulium) laciniatum Edwards from Fiji as outgroups, shows basal species and clades to be on widely separated older islands. In the Society Islands basal species are widely spread. Derived species, with morphological adaptations to deal with specialized habitats, are on younger islands (e.g. Tahiti), where a major species radiation has taken place. The reconstructed phylogeny indicates dispersal back to older islands, with minor subsequent species radiation. Main conclusions Palaeogeological evidence provides a basis for postulating that Inseliellum entered the western Pacific area some 20 Ma, with the possibility that it rafted eastwards on proto-Tonga Islands to the edge of southern-central Pacific. Older Cook Islands were present at that time. Movement into the Marquesas Islands was not earlier than 6 Ma and into the Society Islands perhaps 8–10 Ma. Basal species with generalized habitat requirements would have found suitable habitats (inferred from hydrological postulates) on leaves in the original, small shaded streams. With erosion and valley development, in particular on Tahiti, species radiated into specialized habitats such as cascades. Rich seston and high velocity probably drove reduction of filtering fans in some clades. With collapse of the caldera and formation of large rivers at c. 0.9 Ma, S. exasperans Craig and S. tahitiense Edwards adapted to deep, swiftly flowing water, all indicative that specialized habitat availability drove species radiation in Inseliellum. In the Society Islands, dispersal of derived species back to the oldest western islands was not possible because erosion has removed suitable habitats.

Higher level phylogenetic analyses rarely include behavioural data, predominantly because such groups sel - dom have complex behaviours that are susceptible to analysis. Even when broad groups do share a complex behaviour, there is skepticism about the appropriateness of using behavioural traits in higher level phylogenetic analyses. The Integripalpia is a suborder of caddisflies and is an appropriate group to investigate the use of behaviour in higher level analyses because all larvae use a complex suite of behaviours to build portable cases. A thorough investigation of case- building in 10 families (19 exemplar genera) yielded 24 behavioural characters. A parsimony analysis produced 87 equally parsimonious trees (length = 56 steps, consistency index (CI) = 0.84, retention index (RI) = 0.88) that sup - ported the monophyly of the integripalpian families, except for the Limnephilidae. Interfamilial relationships, although resolved, were not well supported with behaviour. Certain interfamilial relationships have also been difficult to establish reliably with morphological information, indicating a need for more characters (e.g., molecular) at this taxonomic level. This study indicates that if taxa share a complex behaviour (e.g., case building), then regardless of taxonomic level, one is likely to find shared derived behavioural characters that are useful for phylogeny reconstruction. Resume : Les analyses phylogenetiques de niveau superieur tiennent rarement compte de donnees comportementales, probablement parce que les groupes concernes ont rarement des comportements complexes analysables. Meme lorsque des groupes elargis ont des comportements complexes semblables, il persiste un doute quant a la pertinence d'utiliser des caracteres comportementaux lors d'analyses phylogenetiques de niveau superieur. Les Integripalpia, un sous-ordre des trichopteres, constituent un groupe approprie a l'etude de la pertinence des caracteres comportementaux dans l'analyse de niveau superieur, parce que toutes les larves utilisent une serie complexe de comportements pour construire leurs fourreaux mobiles. La construction des fourreaux a fait l'objet d'une etude approfondie chez 10 familles (19 genres representatifs); les resultats ont mis en evidence 24 caracteres comportementaux. Une analyse basee sur le principe de parcimonie a permis d'obtenir 87 arbres equivalents (longueur 56 etapes, indice de coherence (CI) = 0,84, indice de retention (RI) = 0,88) qui corroborent le monophyletisme des familles d'Integripalpia, a l'exception des Limnephilidae. Les relations entre familles, bien que resolues, ne sont pas corroborees de facon certaine par les donnees comportemen- tales. Certaines relations entre familles ont ete difficiles a etablir sur la base des donnees morphologiques, ce qui sou- ligne la necessite de tenir compte d'un plus grand nombre de caracteres (e.g., moleculaires) a ce niveau taxonomique. Cette etude indique que, si des taxons possedent un comportement complexe commun (e.g., la construction de fourreaux), alors, independamment du niveau taxonomique, ils ont probablement des caracteres comportementaux derives communs utilisables pour reconstituer leur phylogenie. (Traduit par la Redaction) 1854

We document a shift in roosting behavior of Great Horned Owls (Bubo virginianus) from winter and late spring to summer. During summer, Great Horned Owls roosted near the ground or exposed on open ground, whereas they chose concealed perches at mid-canopy level for the rest of the year as typical for forest owls. This shift of roosting behavior coincided with the emergence of ornithophilic black flies, which transmit avian malaria (Leucocytozoon spp.). The shift in roosting behavior was consistent with measurements of parasite exposure at different habitat positions. Black fly activity was highest at mid-canopy level, and almost no black flies were active on open ground. Ground-roosting was not caused by poorly developed flying capability of juveniles, because solitarily-roosting adult owls showed the same behavioral shift in a second year of study. Black flies and avian malaria are widely distributed, and the effect of the vertical distribution of these parasites in forests on roosting, nesting, and foraging of sylvatic birds deserves further study.

Black fly feeding alone and in concert with Leucocytozoon spp. infection caused mortality in fledgling great horned owls (Bubo virginianus) in the Yukon, Canada 1990 to 1991. These mortalities occurred during a year of food shortage corresponding with a decline in the population of snowshoe hare (Lepus americanus), the main prey for great horned owls. We hypothesize an interaction between food availability and the consequences of host-parasite interactions.

Eleven polymorphic microsatellite loci were isolated and developed from the black fly, Simulium negativum, a member of the Simulium arcticum sibling species complex. The observed heterozygosity of the 11 loci ranged from 0.03 to 0.83. The number of alleles per locus ranged from 8 to 19. Significant linkage disequilibria were encountered only for the primer pairs BF7-1 with BF7-5 and BF6-32 with BF7-16. Presumably, these microsatellite loci can be used to study genetic structure within the entire S. arcticum complex.

DNA barcoding has gained increased recognition as a molecular tool for species identification in various groups of organisms. In this preliminary study, we tested the efficacy of a 615-bp fragment of the cytochrome c oxidase I (COI) as a DNA barcode in the medically important family Simuliidae, or black flies. A total of 65 (25%) morphologically distinct species and sibling species in species complexes of the 255 recognized Nearctic black fly species were used to create a preliminary barcode profile for the family. Genetic divergence among congeners averaged 14.93% (range 2.83–15.33%), whereas intraspecific genetic divergence between morphologically distinct species averaged 0.72% (range 0–3.84%). DNA barcodes correctly identified nearly 100% of the morphologically distinct species (87% of the total sampled taxa), whereas in species complexes (13% of the sampled taxa) maximum values of divergence were comparatively higher (max. 4.58–6.5%), indicating cryptic diversity. The existence of sibling species in Prosimulium travisi and P. neomacropyga was also demonstrated, thus confirming previous cytological evidence about the existence of such cryptic diversity in these two taxa. We conclude that DNA barcoding is an effective method for species identification and discovery of cryptic diversity in black flies.

Mitochondrial based phylogenetic reconstructions often show deviations from species-level monophyly. We used the Simulium arcticum species complex (Diptera: Simuliidae) as a model system for interpreting non-monophyly in light of chromosomal data supporting species status of siblings. For cytogenetic identification of morphologically indistinguishable black fly sibling species, larvae must be preserved in Carnoy's solution, a fixative known to degrade DNA. Consequently, we reconstructed phylogenetic relationships based on 12S, COII, cyt b, and ITS-1 gene sequences obtained from larvae sampled from presumed taxon-pure localities. As species composition at 'taxon-pure' sites may have changed at the time of sampling, we performed a second study that aimed to: (1) assess phylogenetic relationships among cytologically verified members of the S. arcticum species complex using COI and COII gene sequences; (2) determine whether useable genetic information could be gleaned from Carnoy's fixed specimens; and (3) determine the extent to which Carnoy's fixative degrades DNA over time. We consistently obtained genetic data from material stored in Carnoy's solution for two to three months. Genetic analysis of samples fixed in Carnoy's solution for up to six years indicates that larvae preserved for a maximum of five years can provide useable information for molecular analysis. Our preliminary and cytologically confirmed phylogenetic analyses demonstrate that mitochondrial DNA fails to resolve species-level monophyly of chromosomally distinct S. arcticum taxa. As results of analyses based on cytologically verified larvae mirror those of our preliminary study, we rule out imperfect taxonomy as the reason for species-level non-monophyly. Although we cannot confidently reject either inadequate phylogenetic information or incomplete lineage sorting as the cause of non-monophyly, the sharing of alleles between sympatric siblings suggests introgressive hybridization between taxa. We conclude that the patterns present in the S. arcticum phylogeny likely represent the initial stages of chromosome based sibling speciation.

Sixteen species, of which 13 are new, in the subgenus Hebridosimulium Grenier & Rageau are now known. Fiji has only Simulium laciniatum, which is widely distributed on five islands. Tahiti has only one species, the enigmatic S. anatolicum. The remaining species are in Vanuatu and known from nine islands, ranging the full length and breadth of the archipelago. Hebridosimulium species are divided among two species groups. The callipygium species group is characterized, in part, by a smooth posterior abdomen in the larvae, and all but one species possess dorsal tubercles on the larval abdomen. Simulium callipygium is the type species, with the tuberculate species in a subgroup comprised of S. banksi, S. johnfrumi, S. pankumuense, and S. tuberculum. The second species group has larvae with the posteroventral abdomen markedly expanded, and all species lack dorsal tubercles. Constituents of the steatopygium species group are S. anatolicum, S. jolyi, S. laciniatum, S. lucyae, S. paradisium, S. steatopygium, S. subparadisium, S. supercilium, and S. undulatum. Two other species of this group, S. adsonense and S. spiroi, of which larvae have markedly pigmented heads, are assigned to the adsonense species subgroup. A chromosome map for Hebridosimulium is established for the first time.

The taxonomy of the genus Crozetia Davies (Diptera: Simuliidae) is reviewed. Apart from the eggs, all stages of Crozetia crozetensis (Womersley) and Cr. seguyi Beaucournu-Saguez and Vernon, are fully redescribed with only claws and genitalia detailed for the female of Cr. crozetensis. A phylogenetic analysis of the Simuliidae indicates that Crozetia is the sister group of all other members of the extant Simuliini, in agreement with current molecular evidence. Palaeogeological evidence on the age of the Crozet Islands is equivocal, but a very late Cretaceous to early Eocene age (79-54 Mya) is most likely, hence the presence of simuliids on this archipelago is not the result of vicariance from Gondwanaland. Method of dispersal to the Crozet Archipelago may have been via wind or possibly vectored by birds from Africa, as suggested by presence of a basal tooth on the adult female claw. Morphometric analysis of larvae of Cr. seguyi indicates seven instars which is typical for the Simuliidae.

A new species of black fly, Stegopterna diplomutata n. sp. (Diptera: Simuliidae) is described and illustrated. This species is most closely related to Stegopterna mutata (Malloch, 1914), with which it has long been confused. The two species are most easily distinguished based on the presence or absence of males; St. diplomutata is a diploid bisexual species that possesses males, whereas St. mutata is a triploid parthenogenetic species that lacks males. The two species are otherwise not distinguishable except through examination of their larval polytene chromosomes. Observations are provided about the evolution of triploidy in Stegopterna.