Diptera Assemblages Research Articles

Landscape characteristics effects on Diptera assemblages and their relation with seasonal variations in urban green patches

ABSTRACTThe growth of cities results in the fragmentation of natural habitats, and the alteration of the remaining ones. The effects of landscape‐level drivers on arthropod assemblages in urban green spaces remain poorly understood. The aim of this study was to evaluate the effects of landscape characteristics in Diptera assemblages of urban green patches and their relation with seasonality in a southern hemisphere temperate city. Flies were sampled in urban green patches in Córdoba city, Argentina, in summer and winter of the same year. Landscape metrics derived from Sentinel 2 images were calculated at two levels of spatial heterogeneity hierarchy, at increasing buffer areas. We used generalized linear models to analyse the effects of landscape characteristics on family abundance and richness. Landscape and seasonal effects on Diptera family composition were also assessed. Abundance, richness and composition of dipteran assemblages were associated with the contrasting conditions of summer and winter, urban landscape fragmentation and the aggregation of vegetation patches. In general, fly assemblages were favoured by the aggregation of vegetation patches. The response of dipterans to landscape characteristics differed between seasons. The effects of landscape characteristics on Diptera assemblages' composition were stronger in winter. We concluded that landscape characteristics appear to have a bigger effect when environmental conditions are less favourable for these organisms. Our study provides further understanding of the effects landscape level drivers have on arthropods in green urban patches. This is particularly relevant if we wish to maintain and manage biodiversity through landscape planning.

Small Bait Traps May Not Accurately Reflect the Composition of Necrophagous Diptera Associated to Remains.

Simple SummaryFly families such as Calliphoridae and Muscidae contribute to the decomposition of cadavers and play an important role in courtroom proceedings, in part because of the clues they provide to help determine the time of death. In forensic entomology studies, they are often sampled using small bait traps containing a small amount of decomposing animal tissue. To determine whether the fly assemblages recovered by small bait traps are similar to those found on whole remains, we simultaneously documented the flies found on domestic pig carcasses and within small traps baited with pork liver. Results indicated that the fly assemblages found in the small bait traps and on the carcasses were different and reinforced the fact that caution should be exercised when data obtained from small bait traps are used in court.Small bait traps are beginning to emerge in forensic entomology as a new approach to sample early-colonizing necrophagous Diptera species while reducing the investment in time and energy in obtaining information. To test the hypothesis conveyed by the literature that these traps can be a substitute for whole carcasses, we simultaneously documented the Diptera assemblages visiting and colonizing domestic pig carcasses and small traps baited with pork liver. Results indicated that Diptera species occurrence and assemblage composition in the small bait traps and on the carcasses differed, while they were similar when comparing only the pig carcasses. These results are in agreement with the literature that examined insect colonization of other decaying substrates. Although small bait traps can be useful tools to document the communities of necrophagous Diptera in a given area, we stress that caution must be exercised when extending the data obtained by these traps to courtroom proceedings.

Temporal effects of cutting intensity on Diptera assemblages in eastern Borneo rainforest Indonesia

Abstract. Budiaman A, Haneda NF, Indahwati, Febrian D, Rahmah LN . 2020. Temporal effects of cutting intensity on Diptera assemblages in eastern Borneo rainforest Indonesia. Biodiversitas 21: 1074-1081. Studies on the effects of varying cutting intensity on the abundance and species richness of Diptera in tropical rainforest are limited, particularly in Southeast Asia region. The aim of the study was to assess the temporal effect of cutting intensity on Diptera community in tropical rainforest in the eastern Borneo rainforest, Indonesia, which was logged using the Indonesian Selective Cutting and Planting system. The field study was carried out in 2016. Responses of Diptera to the Indonesian Selective Cutting and Planting systems in the eastern Borneo rainforest, Indonesia were examined. We compared the abundance and morphospecies composition of Diptera before cutting and after cutting at three different treatments: low cutting intensity, medium cutting intensity and high cutting intensity. Diptera was collected using a malaise trap. Selective cutting of tropical rainforest altered biodiversity of Diptera. The abundance and morphospecies composition of Diptera were greater after cutting than before cutting at all cutting intensities. Our study showed that cutting intensity did not significantly affect the abundance and morphospecies composition of Diptera. Results of the study clearly indicated that the percentage of forest canopy cover could be a single predictor for abundance and morphospecies composition of Diptera in the natural rainforest of eastern Borneo, Indonesia.

Latitudinal patterns in phylogenetic and functional diversity of Diptera in temperate bogs

AbstractConservation of biodiversity is growing in interest, and wetlands are disappearing at an alarming rate, so understanding how communities are assembled and how interactions among species and ecosystems influence evolution is critical to the management of threatened habitats. We compared diversity and assemblages of peatland Diptera within and between ecoregions in Québec, Canada. We then determined the phylogenetic structure of peatland Diptera communities and how the structure differed with spatial scale (trap, site, ecoregion). Finally, we tested alpha and beta diversity along environmental and spatial gradients to determine which processes influence Diptera communities and diversity. Bogs across the three ecoregions support similar abundance, species richness, and functional diversity. We found that the major forces structuring Diptera assemblages in bogs across Québec are stochastic processes such as dispersal limitations. However, those random patterns change to clustering when anthropogenic disturbances modify the landscape. Assembly rules are mostly dictated by patch and landscape parameters specific to each ecoregion affecting dispersal and establishment between sites. Conservation of mobile organisms in habitats such as bogs will depend on conservation plans focusing on both patch quality and surrounding landscape, and that different conservation strategies need to be applied in different ecoregions.

Saproxylic Diptera assemblages in a temperate deciduous forest: implications for community assembly.

Saproxylic insects, those associated directly or indirectly with decaying wood for all or part of their life cycle, compose a large proportion of forest organisms. Flies (Diptera) are often the most abundant and species-rich group of insects in forest microhabitats, yet most work to date on saproxylic insect diversity and ecology has focused on beetles (Coleoptera). We compared saproxylic Diptera assemblages reared from two tree species (sugar maple and American beech) at two stages of decay (early/young and advanced/old) for a total of 20 logs in an eastern Canadian Nearctic old-growth forest. We found that communities are distinct within both species type and decay stage of wood. Early decay stage wood is more variable in community composition than later decay stage; however, as the age of the decaying wood increases, the abundance of Diptera increases significantly. Most indicator species are discernible in later decay stage and wood type. We venture to suggest that stochastic and deterministic processes may play a role in driving Diptera communities in temperate deciduous forests. To retain the highest saproxylic Diptera diversity in a forest, a variety of decaying wood types at different stages of decomposition is necessary.

The structure of carrion fly (Diptera) communities and conditions of their formation in towns of Northwestern Russia

The structure of the carrion-associated Diptera assemblages from five towns and a village in Northwestern Russia was investigated. The carrion fly complex comprises 13 species of 4 families: Calliphoridae, Sarcophagidae, Muscidae, and Fanniidae. The impact of the meteorological (wind speed, environment temperature, air humidity) and biotopic conditions (distance from water bodies and forests) on the composition of the carrion fly assemblages was analyzed. In all the study localities a chicken carcass was used as bait. Our data show that the community is uniform within Northwestern Russia and that its structure in different parts of the season mainly depends on the meteorological conditions and, to a lesser extent, on the biotopic environment.

Seasonal, Locality, and Habitat Variation in Assemblages of Carrion-Associated Diptera in Gauteng Province, South Africa

Seasonal, spatial, and habitat responses of carrion-associated Diptera assemblages can provide valuable information about the presence or absence of species and their relative abundance, and thereby enhance understanding of their responses to environmental variables and how this may have an impact on forensic investigations. Three different nature reserves (localities) within the Municipality of Tshwane, South Africa, were selected to determine whether species assemblages of carrion-feeding flies differ between seasons, localities, and habitat types. A total of 59,511 adult Diptera, identified to 35 species in eight different families, were collected using modified Redtop hanging traps, baited with liver and fish, during four seasons in three different habitat types. Species assemblages differed temporally, with season being the main factor determining species diversity and not locality or habitat. However, savanna and human-disturbed habitats supported a higher abundance and species richness than grassland habitats. Areas adjacent to the localities, such as large urban expanses in Dinokeng or agricultural holdings in Rietvlei, led to an increase in the abundance and mean species richness of carrion-associated Diptera, and in increased numbers of pest or invasive species such as Chrysomya megacephala (F.). Despite this, the overall species assemblages present in human-disturbed areas were very similar to those recorded in natural habitats.

Diversity patterns of aquatic specialists and generalists: contrasts among two spring-fen mesohabitats and nearby streams

AbstractHabitat specialists and generalists are known to differ in their width of environmental tolerance and their representation can vary along with the ecological contrast of habitats. In this study we explore factors shaping patterns of species richness and abundance of aquatic macroinvertebrate habitat specialists and generalists at isolated spring fens, separately for spring patch and spring brook mesohabitats at each site. We also examined habitat contrast of these unique island-like communities by the comparison of spring fen specialists and habitat generalists shared between the two spring fen mesohabitats and the nearest stream to each of 13 selects fen sites. Aquatic macroinvertebrates (Clitellata, Ephemeroptera, Plecoptera, Trichoptera, and Diptera) were investigated at 62 isolated spring fens, with 357 taxa identified in more than 172,000 individuals collected. We found that specialists experienced a stronger relation to local environmental conditions (i.e. the amount of dissolved oxygen and water conductivity) at both spring mesohabitats than generalists, primarily responding to fen habitat size. In contrast, responses of species abundances at spring patches and spring brooks differed as the abundances were controlled by the amount of oxygen in spring patches and by habitat size in spring brooks. Based on Trichoptera and Diptera assemblages we found a similar contrast between both spring fen sites and nearby streams. Our results suggest a higher resilience of specialist populations in well oxygenated sites and their competitive advantage over generalists at these sites, which stresses the importance to prevent any significant decrease of oxygenation (e.g., by eutrophication or drainage), especially in spring patches.

Aquatic Diptera (Insecta) assemblages in four sympatric Eryngium (Apiaceae) phytotelmata in flowering and senescent times

ABSTRACTThis study addresses how Diptera assemblages differ in four sympatric phytotelmata. The Eryngium species retain water in their axils forming a phytotelm and this situation leads to the speculation that dipteran assemblages may differ, mainly when the plants begin to grow and retain more water in their axils, and when becoming senescent. Diptera from Eryngium horridum, Eryngium stenophyllum, Eryngium aff. serra and Eryngium elegans were sampled. This study revealed that the Eryngium spp. are used by Diptera differentially and their populations show seasonal changes, with peaks in the autumn. Diptera were represented by immature stages belonging to six aquatic and seven semi-aquatic families. The most important were Chironomidae, Culicidae, Periscelididae and Ceratopogonidae. Two species of Chironomids were the most abundant. Culicidae, Periscelididae and Ceratopogonidae were more selective than Chironomidae. Saprophages were the most abundant where the fine detritus feeders were the dominant group. Periscelididae was the main free-swimming predator.

Environmental drivers of biotic traits and phenology patterns of Diptera assemblages in karst springs: The role of canopy uncovered

Springs are stable environments with constant abiotic factors and therefore of use in variety of ecological experiments. We investigated the influence of canopy coverage on abundance, diversity, phenology and feeding guilds among Diptera assemblages at two rheocrene karst springs located near each other. The springs differed by canopy coverage while physicochemical characteristics of the water were similar. We set six emergence traps for one year at each spring covering all available microhabitats proportionally. We hypothesized that canopy coverage will have a strong effect on assemblage composition of Diptera as well as on diversity, abundance, phenology and feeding guilds composition between sites and that it will have a stronger effect than microhabitat characteristics. Similarity of species composition among springs was only 37.5%, with 23 common species/taxa out of 74 species/taxa. Abundance of Diptera was 8.5× higher at the open canopy spring, while diversity and number of species/taxa was higher at closed canopy spring. Emergence started earlier at open canopy site and was prolonged even in winter months. The majority of species were detritus feeders followed by collectors and there was no substantial difference among sites. We conclude that at springs with similar water characteristics, canopy coverage is the main driver of Diptera assemblage structure, with water velocity as a complementary factor. Substrate and other physicochemical factors seem less important.

Estudio preliminar de los dípteros asociados a cebos de estiércol y carroña en un bosque serrano de Sierra de Minas, Uruguay

Se realizó un estudio preliminar sobre la estructura de los ensambles de dípteros coprófilos y necrófilos a nivel de familias, en un bosque serrano en Sierra de Minas, Uruguay. Asimismo se estableció la variación estacional de dicha estructura para ambos grupos de dípteros. Se realizaron muestreos mensuales durante un año, colocando durante una semana, seis trampas de caída, tres cebadas con estiércol vacuno y tres con hígado vacuno. Se recolectaron 3,142 individuos pertenecientes a 21 familias del Orden Diptera. Se registró por primera vez la familia Heleomyizidae en Uruguay. Las familias con mayor abundancia fueron Phoridae y Sphaeroceridae, representando el 58% del total de ejemplares recolectados. En las trampas con estiércol vacuno predominaron Sphaeroceridae (42%), Cecidomyiidae (14%) y Phoridae (12%). En las necrotrampas la familia más abundante fue Phoridae que representó el 59% del total de individuos, seguida de Drosophilidae (10%). Los dos ensambles presentaron el mismo patrón de variación estacional de la abundancia, con picos en otoño (marzo-abril) y en primavera (octubre-noviembre). La riqueza de familias del ensamble coprófilo fue mayor durante la primavera (octubre a diciembre) y en otoño (abril) mientras que el ensamble necrófilo presentó la mayor riqueza de familias solamente de octubre a noviembre. Este estudio constituye un primer paso en la generación de conocimientosacerca de la composición de las comunidades de dípteros en ambientes nativos en Uruguay.

Sarcosaprophagous Diptera assemblages in natural habitats in central Spain: spatial and seasonal changes in composition

The composition and spatial distribution of sarcosaprophagous Diptera assemblages were studied using carrion-baited traps along a bioclimatic gradient of natural habitats in central Spain throughout the different seasons during 1 year. Calliphoridae and Muscidae were the most abundant families, accounting for, respectively, 41.9% and 35.1% of all Diptera specimens collected. Other abundant families were Heleomyzidae (8.4%), Sarcophagidae (6.9%) and Piophilidae (5.1%). Fly assemblage compositions differed among bioclimatic levels, with Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) being the dominant species in mesomediterranean habitats, Muscina levida (Harris) (Diptera: Muscidae) the dominant species in supramediterranean habitats, and Prochyliza nigrimana (Meigen) (Diptera: Piophilidae) the dominant species in oromediterranean habitats. Differences in assemblage composition were also found among seasons. Thermophobic species such as Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) and some species of Heleomyzidae were well represented during autumn, winter and spring in the three bioclimatic levels sampled. By contrast, thermophilic species such as Ch. albiceps and Lucilia sericata (Meigen) (Diptera: Calliphoridae) and most Muscidae and Sarcophagidae species were more abundant during summer and in mesomediterranean habitats located at lower elevations. Knowledge of the preferences of some species for certain habitats may be of ecological and forensic value and may establish a starting point for further research.

Preimaginal stages of Diptera (excluding Chironomidae and Simuliidae) of mountain lakes, their inlets and outlets in the Tatra Mountains (Slovakia)

The occurrence of preimaginal stages of Diptera (excluding Chironomidae and Simuliidae) in the Tatra Mountain lakes, their inlets and outlets, and the influence of acidification on the presence of these taxa were assessed. At 21 sites, 18 Diptera taxa were recorded in 2000 and 2001. The most frequent were Dicranota sp. (73%), Pedicia (C.)rivosa (50%) and Wiedemannia sp. (14%). Diptera were ordinated by RDA; relationships between taxa and environmental variables were significantly determined by temperature and habitat characteristics (altitude, habitat, alkalinity, Ca2+, pH, temperature, conductivity). The RDA diagram confirmed the existence of four Diptera assemblage groups corresponding with four habitat types. Group 1 — alpine and subalpine oligotrophic lakes at higher altitudes threatened by acidification, with the acid tolerant taxa Tipula rufina, T. alpium, Dicranota sp. and Rhypholophus sp. Group 2 — subalpine oligotrophic lakes not threatened by acidification with the acid sensitive taxa Wiedemannia sp., Hemerodromia sp., Tipula (S.) benesignata, Orimarga sp., Chionea sp., Pedicia (C.) rivosa and Bazarella subneglecta which prefer higher temperature. Group 3 — subalpine oligotrophic lakes, with the acid sensitive species Berdeniella illiesi, which prefers cold water. Group 4 — outlets of submontane oligotrophic lakes with characteristic taxa Tricyphona sp. and Tipula goriziensis. Acidified alpine and subalpine Tatra lakes are situated mostly at higher altitudes (1705–2145 m. a.s.l.) and have specific taxonomic composition.

Diptera Community In The Littoral Zone Of A North East Arid Zone Lake (Lake Alau), Maiduguri, Borno State, Nigeria

Maiduguri, Nigeria, were studied between January and June 2002. Dipteran samples were collected every 2 weeks from five different stations. Five groups of diptera organisms simulidae, chironomidae, centrapogo nidae, culicidae and chaoboridae were found in analyzable numbers. The diptera assemblage was dominated by chaoboridae, followed by chironomidae with the percentage compositions of 30.01% and 23.01% respectively. Ceratopogonidae has the least percentage composition of 13.66%. Significant difference in family composition were found in the lake, with chaoboridae being dominant. Climatic regime and the season appear to be the important key factors controlling the distribution of diptera in the lake. Key Words: Diptera, Littoral zone, Lake Alau Bio-Research Vol.2(1) 2004: 67-74