Fly family diversity shows evidence of livestock grazing pressure in Mongolia (Insecta: Diptera)

Members of the insect order Diptera respond differentially to environmental changes and may play an important role in understanding the effects that livestock grazing disturbances have on biodiversity. Here we examine how increasing grazing pressures on the Mongolian steppe affect Diptera diversity and abundance. Using 2334 yellow pan traps, we sampled a total of 132 sites over four years to collect 17,348 flies. We compared fly diversity and abundance at five levels of livestock grazing. We observed that fly family diversity decreased in heavily grazed sites and that diptera communities at sites with intense grazing have proportionally higher prevalence of taxa from the families Muscidae, Sepsidae, Ephydridae, Chloropidae, and Tachinidae, two of which are often associated with animal waste. Chironomidae, Ceratopogonidae, Sarcophagidae, and Sciaridae are most prevalent at sites with very little or no grazing, and Anthomyiidae, Calliphoridae, Carnidae, Cecidomyiidae, Dolichopodidae, Empididae, Scatopsidae and Sphaeroceridae are most often encountered at sites with intermediate amounts of grazing. Observing changes in a few guilds of fly families at different grazing levels is beneficial in understanding human effects on fly diversity.     

Does biogeographical history matter? Diversity and distribution of lotic midges (Diptera: Chironomidae) in the Australian Wet Tropics

Abstract We examined broad scale patterns of diversity and distribution of lotic Chironomidae (Diptera) within the Wet Tropics bioregion of northern Queensland, Australia. Field surveys across broad latitudinal and altitudinal gradients within the Wet Tropics revealed a fauna of 87 species‐level taxa in 49 genera comprising three main elements: a small genuinely tropical fraction, and larger cosmopolitan and Gondwanan components. The latter group originated when Australia, as part of the ancient Gondwana supercontinent, was situated over Antarctic latitudes with a cooler, wetter climate than today. In the Wet Tropics, cool Gondwanan taxa occurred predominantly in upland and shaded lowland sites, but no species appeared narrowly temperature restricted, and there was no faunal zonation with altitude. Most chironomid species occurred at all latitudes within the Wet Tropics, with no evidence for an enduring effect of the historical rainforest contractions on current‐day distribution patterns. These findings contrast with those for aquatic faunas elsewhere in the world and for the terrestrial Wet Tropics fauna. We relate this to the generally broad environmental tolerances of Australian chironomids, and comment on why the latitudinal diversity gradient does not apply to the Australian chironomid fauna.     

Dipteran predators of Simuliid blackflies: a worldwide review

Haematophagous female blackflies (Diptera: Simuliidae) are serious biting pests and obligate vectors of vertebrate pathogens, namely filarial Dirofilaria, Mansonella, Onchocerca and protozoal Leucocytozoon. Immature stages of Simuliidae inhabit lotic waterways, the sessile larvae filter-feeding and often forming a large proportion of the benthic biomass, usually aggregated in well-oxygenated sections of streams, rivers, waterfalls and spillways. Simuliid control practices depend on larvicidal chemicals, biological products (bacteria, nematodes) and environmental modification. The potential use of predators for biological control of Simuliidae has not been exploited. Predators of Simuliidae include examples of at least 12 families of Diptera and other predaceous arthropods (Crustacea and insects: Coleoptera, Odonata, Plecoptera, Trichoptera), invertebrates (notably Turbellaria), as well as browsing fish. Diptera impacting upon simuliid populations comprise mainly Chironomidae, Empididae and Muscidae, although several other families (Asilidae, Dolichopodidae, Phoridae, Drosophilidae, Scathophagidae) play a significant role as predators. Details of predator and prey species and life stages are presented, by zoogeographical region, including the prevalence of cannibalism among Simuliidae.     

Revision of the Australian Gagrellinae (Arachnida: Opiliones: Sclerosomatidae), with a description of a new species

A new species of the Indo-Australian Gagrellinae (Arachnida: Opiliones: Sclerosomatidae), Gagrella cauricrepa , is described from the Iron Range, Cape York Peninsula, Queensland, Australia. This represents the first definite indigenous Australian record of Sclerosomatidae, though the family has previously been known from Papua New Guinea and the Solomon Islands. The previous record of Zaleptus marmoratus Roewer 1910 from the Australian fauna is regarded as currently unconfirmable.     

An estimation of the natural value of dune habitats using Empidoidea (Diptera)

The dune landscape along the Belgian coast was evaluated on the basis of its Empidoidea fauna by investigating the faunal composition in different habitat types. The sites selected for sampling were marram dunes, dune grassland, dune slack, scrubby vegetations and three different dune woodlands. White water traps at soil surface level were used to sample five sites from the end of April until November 1989, and four sites from April to August 1992. Data on the most abundant Dolichopodidae, Empididae and Hybotidae were analysed by means of the following multivariate analyses: detrended correspondence analysis (DCA), canonical correspondence analysis (CCA) and two-way indicator species analysis (TWINSPAN). Most sites showed a distinctive species composition, and several species were confined to particular habitat types. Empidoid communities from canopied and open habitats showed the largest contrasts during 1989. Six environmental variables were measured in July and August 1992, and correlations indicated that aerial humidity and, to a lesser extent, soil moisture were probably the main factors explaining dolichopodid distributions. In Empididae, on the contrary, the presence of canopy by scrub or trees appeared to be important for the occurrence of many species. Thus species diversity and abundance increased from dry to humid sites in dolichopodids and from open to canopied sites in empidids. On the other hand, canopied sites appeared to function as home-bases from which certain empidid species colonized more sun-exposed areas. With the Dolichopodidae it was possible to examine the recorded distribution of all species throughout Belgium. Nearly 75% of the dolichpodids appeared to be typical lowland species and in eight species, largest Belgian populations were established in the dune region. Moreover, seven species could be considered as true coastal species as they were almost entirely restricted to this region. These results clearly stress that not merely the coastal dunes themselves but the full diversity of the associated habitats needs to be maintained in order to protect the characteristic dune empidoid communities.     

Effect of methyl salicylate on behavioral responses of insects in a forest park

Attractiveness of methyl salicylate to arthropods in natural populations was studied in a park reserve. During the observation period, representatives of several families of Diptera (the leaf-mining Agromyzidae, the predatory Hybotidae, Dolichopodidae and Empididae), parasitic micro-Hymenoptera (Mymaridae, Pteromalidae, Eulophidae, and Aphelinidae), and phytophagous bugs (Heteroptera) were recorded. Significant attractiveness of methyl salicylate to parasitic micro-Hymenoptera and dance flies (Empididae) was demonstrated. Our data confirm the possibility of attracting beneficial arthropods with methyl salicylate.     

The spermatozoon of three species of Phlebotomus (Phlebotominae) and the acrosomal evolution in nematoceran dipterans

In this paper the spermatozoon of the dipteran Phlebotomus is described. This sperm shows a “9+9+0” flagellar pattern and an acrosomal complex, including a vesicular acrosome and a perforatorium. This last model seems to be the most primitive in Diptera, having in almost all families a simple acrosome, devoid of perforatorium. To substantiate this view, the acrosomes in Trichoceridae, Ceratopogonidae, Tipulidae, Chironomidae, Mycetophilidae and Culicidae are described. The evolutionary trends of the dipteran acrosome are compared with those of the flagellum. The 2 organelles seem to have followed different evolutionary pathways.These results suggest Psychodidae to be a well-defined family, and Phlebotominae, which is highly divergent, possibly belonging to a different family.     

Book Reviews

Book reviewed in this article: Robert Boyd and Peter J. Richerson. The Origin and Evolution of Cultures Zohl dé Ishtar. Holding Yawulyu: White Culture and Black Women's Law Donald Denoon. A Trial Separation: Australia and the Decolonisation of Papua New Guinea Sarah F. Green. Notes from the Balkans: Locating Marginality and Ambiguity on the Greek‐Albanian Border Holger Jebens. Pathways to Heaven: Contesting Mainline and Fundamentalist Christianity in Papua New Guinea Verena Keck. Social Discord and Bodily Disorders: Healing among the Yupno of Papua New Guinea Hotze Lont. Juggling Money: Financial Self‐help Organizations and Social Security in Yogyakarta Fiona Magowan and Karl Neuenfeldt (eds). Landscapes of Indigenous Performance: Music, Song and Dance of the Torres Strait and Arnhem Land David McKnight. Of Marriage, Violence and Sorcery: The Quest for Power in Northern Queensland B. J. Parker and L. Rodseth (eds). Untaming the Frontier in Anthropology, Archaeology and History Alexei Yurchak. Everything Was Forever, Until It Was No More     

The fauna of the exposed zone of Øvre Heimdalsvatn: Methods, sampling stations and general results

Twenty stations were sampled monthly during the Ice free period (June-September) in 1972. Emergence traps, emptied daily, were also employed. The major macroinvertebrates in the exposed zone were Ephemeroptera, Gammarus lacustris , Trichoptera, Chironomidae, Plecoptera and Coleoptera, and these constituted over 90% of total numbers. Densities of G. lacustris , Ephemeroptera, Tipulidae and Plecoptera showed a positive correlation with detritus. No significant relationship was found for the other taxa. Nearly 70% of the fauna emerged, and did so during the period from June to September. Chironomidae, Ephemeroptera, Plecoptera, Trichoptera and Tipulidae accounted for nearly all emergence and their total average annual emergence was 372 cal m⁻². Of this total, Chironomidae constituted 28%, Ephemeroptera 28%, Plecoptera and Trichoptera 15% each and Tipulidae 4%.     

Helminth communities of pademelons, Thylogale stigmatica and T. thetis from eastern Australia and Papua New Guinea

Gastrointestinal helminths were collected from pademelons of the genus Thylogale (Marsupialia: Macropodidae) in eastern Australia and Papua New Guinea. Examined were 12 Thylogale stigmatica stigmatica and 13 T. s. wilcoxi, the latter subdivided into eight specimens from the northern limit of their distribution and five from southern areas, all from eastern Queensland, Australia, one T. s. oriomo from Papua New Guinea and ten T. thetis from southeastern Queensland and northern New South Wales, Australia. Six species of cestodes and 40 species of nematodes were found. The helminth community of T. s. stigmatica was similar to that found in northern specimens of T. s. wilcoxi, while differences from the helminth community present in southern T. s. wilcoxi could be accounted for by parasites acquired from sympatric T. thetis. Thylogale thetis harboured a community of helminths distinct from but related to that in T. stigmatica. The evidence suggests that all subspecies of T. stigmatica examined share a common helminth community, but that in areas of sympatry, T. stigmatica and T. thetis share some of their parasites.     

Aphis clerodendri Matsumura (Hemiptera: Aphididae), attendant ants (Hymenoptera: Formicidae) and associates on Clerodendrum (Verbenaceae) in Australia

Abstract Aphis clerodendri Matsumura is newly recorded from Australia and is known from the Northern Territory, on islands in Torres Strait, and in rainforest in northern Queensland and New South Wales. It induces the formation of leaf pseudogalls on native species of Clerodendrum and is commonly attended by ants, which penetrate and may polydomously nest in the galls. Previously known only from eastern Asia, A. clerodendri can now be classified as native to Australia and Australasian in natural distribution. The species is also newly recorded from Papua New Guinea and Vietnam.     

Mosquito host-feeding patterns and implications for Japanese encephalitis virus transmission in northern Australia and Papua New Guinea

Japanese encephalitis (JE) virus spread to northern Australia during the 1990s, transmitted by Culex annulirostris Skuse and other mosquitoes (Diptera: Culicidae). To determine the relative importance of various hosts for potential vectors of JE virus, we investigated the host-feeding patterns of mosquitoes in northern Australia and Western Province of Papua New Guinea, with particular attention to pigs, Sus scrofa L. - the main amplifying host of JE virus in South-east Asia. Mosquitoes were collected by CDC light traps baited with dry ice and 1-octen-3-ol, run 16.00-08.00 hours, mostly set away from human habitations, if possible in places frequented by feral pigs. Bloodmeals of 2569 mosquitoes, representing 15 species, were identified by gel diffusion assay. All species had fed mostly on mammals: only <10% of bloodmeals were from birds. The predominant species was Cx. annulirostris (88%), with relatively few (4.4%) bloodmeals obtained from humans. From all 12 locations sampled, the mean proportion of Cx. annulirostris fed on pigs (9.1%) was considerably lower than fed on other animals (90.9%). Highest rates of pig-fed mosquitoes (>30%) were trapped where domestic pigs were kept close to human habitation. From seven of eight locations on the Australian mainland, the majority of Cx. annulirostris had obtained their bloodmeals from marsupials, probably the Agile wallaby Macropus agilis (Gould). Overall proportions of mosquito bloodmeals identified as marsupial were 60% from the Gulf Plains region of Australia, 78% from the Cape York Peninsula and 64% from the Daru area of Papua New Guinea. Thus, despite the abundance of feral pigs in northern Australia, our findings suggest that marsupials divert host-seeking Cx. annulirostris away from pigs. As marsupials are poor JE virus hosts, the prevalence of marsupials may impede the establishment of JE virus in Australia.     

Population structure, mitochondrial polyphyly and the repeated loss of human biting ability in anopheline mosquitoes from the southwest Pacific

Australia and New Guinea contain high levels of endemism and biodiversity, yet there have been few evaluations of population‐level genetic diversity in fauna occurring throughout the Australo‐Papuan region. Using extensive geographical sampling, we examined and compared the phylogenetic relationships, phylogeography and population structure of Anopheles farauti, An. hinesorum and An. irenicus throughout their ranges in the southwest Pacific using mitochondrial (mtDNA COI) and nuclear (ribosomal protein S9 and ribosomal DNA ITS2) loci. Phylogenetic analyses suggest that the ability to utilize humans as hosts has been lost repeatedly, coincident with independent colonizations of the Solomon Islands. As some of the species under investigation transmit malaria in the region, this is a medically important finding. Maximum likelihood and Bayesian phylogenetic analyses of nuclear loci also showed that the three species are monophyletic. However, putative introgression of An. hinesorum mtDNA onto a nuclear background of An. farauti was evident in populations from Queensland, Torres Strait and southern New Guinea. Haplotype networks and pairwise F_ST values show that there is significant genetic structure within New Guinea and Australia in both An. farauti and An. hinesorum, consistent with a long‐term history of low gene flow among populations.     

A curious coincidence: mosquito biodiversity and the limits of the Japanese encephalitis virus in Australasia

Background  

The mosquito Culex annulirostris Skuse (Diptera: Culicidae) is the major vector of endemic arboviruses in Australia and is also responsible for the establishment of the Japanese encephalitis virus (JEV) in southern Papua New Guinea (PNG) as well as its incursions into northern Australia. Papua New Guinea and mainland Australia are separated by a small stretch of water, the Torres Strait, and its islands. While there has been regular JEV activity on these islands, JEV has not established on mainland Australia despite an abundance of Cx. annulirostris and porcine amplifying hosts. Despite the public health significance of this mosquito and the fact that its adults show overlapping morphology with close relative Cx. palpalis Taylor, its evolution and genetic structure remain undetermined. We address a hypothesis that there is significant genetic diversity in Cx. annulirostris and that the identification of this diversity will shed light on the paradox that JEV can cycle on an island 70 km from mainland Australia while not establishing in Australia itself.     

The dipteran sperm tail: ultrastructural characteristics and phylogenetic considerations

The sperm tail from representatives of several families of Diptera has been examined by high resolution electron microscopy and a computer analysis that improved the visualization of recorded patterns. A considerable variability in sperm tail structure is found within Diptera, and is actually greater than that of any other insect order. The 'generalized insect sperm axoneme'. which is characterized as a 9+9+2 axoneme and by the accessory microtubules having 16 protofilaments, was found only in some dipterans; these are members of Mycetophilidae. From this fact we conclude that Mycetophilidae is likely to be the most primitive extant dipteran group. Another mycetophilid, Boletina , was seen to have accessory tubules with 15 protofilaments as have members of families Dixidae, Chironomidae, Culicidae, and Bibionidae. The last two families have spermatozoa of a type designated as 9+9+'1' there is a central rod rather than two microtubules. We regard this 9+9+'1'pattern with 15 protofilaments to represent a synapomorphic feature. Representatives of the neatoceran families Tipulidae and Trichoceridae have accessory tubules with 13 protofilaments as do examined members of several brachyceran families. Brachycera is hence likely to be derived from the vicinity of the tipulid family. The intertubular material is small in Mycetophilidae and most nematoceran groups, whereas in Tipulidae and Brachycera it is enlarged; here it bridges the space between the accessory tubules and contains various inclusions.     

Courtship in long-legged flies (Diptera: Dolichopodidae): function and evolution of signals

Analyzing the courtship behavior of long-legged flies (Diptera:Dolichopodidae), we focus on the evolutionary development ofcourtship signals. Long-legged flies may serve as a model forthis evolutionary process, because males of some species presentsexually dimorphic badges during courtship, whereas others donot exhibit such conspicuous signals but present lavish courtshipbehavior, including dynamic flight maneuvers. A comparison ofthese two groups within a single taxonomic family provides insightinto the evolution of courtship signals and the correspondingbehavior. Males of the closely related Empididae do not possesssuch badges. Within the super-family Empidoidea, we proposean evolutionary shift from dynamically courting and mating onthe wing (in Empididae) to courting and mating on ground (inDolichopodidae), accompanied by signaling through badge-waving.By comparing previously published data and observations on courtshipbehavior in Dolichopodidae, we present the hypothesis that thelatter replaced the former energetically expensive behavioras a case of automimicry and sensory trap.     

Two new species and a new Australian record of Bactrocera Macquart (Diptera: Tephritidae: Dacinae) from northern Queensland, Torres Strait and Papua New Guinea

Abstract  Bactrocera (Bactrocera) speewahensis Fay & Hancock sp. n. is described from northern Queensland and B. (B.) torresiae Huxham & Hancock sp. n. is described from Boigu, Saibai and Dauan islands in Torres Strait and southern Papua New Guinea. Bactrocera (B.) nigrovittata Drew is newly recorded from Australia. All records are of male flies responding to chemical lures.     

Littoral sand zoobenthos and its relation to organic pollution in Lake Nemi (Central Italy)

Summary The results of a study on the littoral sand zoobenthos in the polluted Lake Nemi are reported and the role of this community in the evaluation of water quality in lakes is discussed. The fauna was composed of 65 taxa belonging to 15 zoological groups. Oligochaeta were dominant, followed by Diptera: Chironomidae, Crustacea and nematoda. Oligochaeta, including 21 taxa, had the maximum percentage occurrence in the discharge zones, with prevalence of species (Potamothrix heuscheri, Limnodrilus hoffmeisteri, Nais elinguis) very tolerant to organic enrichment. On the contrary, Chironomidae showed a depletion in the same zones, where we also observed the absence of Tanytarsini, typical of oligo-mesotrophic conditions, and the exclusive presence of Diptera: Psychodidae, considered as indicators of pollution. The community structure is related to the pollutional status at the sampling points, in a similar way as can be observed in profundal macrobenthos.     

Herbivorous arthropods on bracken (Pteridium aquilinum (L.) Khun) in Australia compared with elsewhere

Abstract The herbivorous arthropod fauna of bracken fern (Pteridium aquilinum (L.) Khun), at a site near Sydney, Australia, is described and compared with previously reported bracken faunas in other geographic regions. Monthly sampling over 18 months found 17 species of herbivorous arthropods (15 insect and two mite species) from five orders. At the ordinal level, the mixture differed substantially from the bracken faunas of sites in Britain and Papua New Guinea. Notable was the presence of Thysanoptera and Acari, and the absence of Coleoptera and Hymenoptera. The mixtures of orders/families represented in the site bracken faunas in Britain, and less so in Australia, resembled those in the pool of herbivorous arthropods in those regions. Further, the mixture of orders on bracken was more similar to the mixture of orders on other ferns than to the mixture of orders among herbivorous insects on all plants; such similarity was not evident at family level. Compared with sites in other regions, the Sydney site had an abundance of pinna-sucking species and a dearth of mining species. Differences between regions in feeding niches most occupied tended to correspond with the differences in orders represented. Not all features of the fauna of bracken near Sydney reflected differences in the general herbivorous arthropod fauna of Australia compared with other regions, or differences between the herbivore faunas of ferns and seed plants. Its composition must be attributed in part to stochastic aspects of the speciation of herbivorous arthropods onto host plants.     

Responses of benthic macroinvertebrate communities to altitude and geology in tributaries of the Sepik River (Papua New Guinea): the influence of taxonomic resolution on the detection of environmental gradients

1. Benthic macroinvertebrate communities were sampled in 30 tributary streams at altitudes from sea level to about 3000 m draining three geologically distinct regions within the catchment of the Sepik River, Papua New Guinea. The fauna of this near‐pristine river has been little studied, and the impacts of ongoing and anticipated human impacts on the Sepik are uncertain. 2. Data on community composition were analysed at different levels of taxonomic resolution (species or morphospecies versus family) to compare their responses to environmental variables such as altitude and geology (reflected in water chemistry), and to indicate their potential utility for the detection of environmental change. 3. A total of 183 000 macroinvertebrates representing 250 species were collected, predominantly insects (232 species and >99% of individuals). The fauna was co‐dominated by Diptera (42% of individuals; 32 morphospecies, mainly Orthocladiinae, Simuliidae and Chironominae) and Ephemeroptera (36%; 48 species), although the Trichoptera showed the highest species (67) and family (13) richness, with Coleoptera ranked third (43 species). Naucoridae (Heteroptera) and Crambidae: Acentropinae (Lepidoptera), each represented by 13 species, were distinctive faunal elements. Mayflies were represented by only four families, one consisting of a single species. 4. Multivariate analysis of the species‐level data set revealed that community composition was influenced by geological region, but the effect was largely due to altitude as most streams in one region (the Central Highlands) were at higher elevations (>800 m) than streams in the other two regions (<500 m). However, altitude had no direct effect on species richness. A secondary influence of current speed and a subsidiary effect of water chemistry (pH and N‐NO₃) on community composition were also detected. Naucorid bugs showed evidence of altitudinal zonation and some species replacement, plus a tendency for certain genera to be associated with highland or lowland streams. 5. Analysis of the family‐level data set failed to uncover strong effects of any environmental variable, either individually or in combination, although some sensitivity to altitude plus slope was detected. 6. These findings suggest that attempts to use macroinvertebrates to detect environmental change in New Guinea streams will require species‐level monitoring of community composition.