Bombyliidae Research Articles

Review of the Oriental and Palaearctic bee fly genus Euchariomyia Bigot (Diptera: Bombyliidae: Bombyliinae).

The bee fly genus Euchariomyia Bigot is reviewed and new records from the Oriental Region are given. Five names (for four species-level taxa) have been associated with species in the genus. Examinations of types, as well as homotypic and topotypic specimens, shows all five names to belong to a highly variable single species, Euchariomyia dives Bigot. The following species are here shown to be the same as Euchariomyia dives Bigot: Bombylius pulchellus Wulp, 1880, Bombylius scintillans Brunetti, 1909, and Bombylius brunettii Senior-White, 1922, n. syn. The genus is known primarily from the southern and eastern Oriental Region and ranges into the Palaearctic in eastern China. We extend the distribution of the genus with new records in the southeastern Oriental Region [Indonesia (Sumatra), Laos, Peninsular Malaysia, and Vietnam].

Revision of the Australian bee fly genus Eusurbus (Bombyliidae, Bombyliinae), and description of Zentamyia gen. nov.

We review the endemic Australian bee fly genusEusurbusRoberts (Bombyliidae, Bombyliinae) and recognize two described species and three new species. The monotypic genusBromoglycisHull is identified as a new junior synonym ofEusurbus. Another species,E. nigracinctusRoberts, is designated as the type species of a new genusZentamyiagen. nov. This new genus is similar toEusurbusbased on several combined external characters including two-segmented palp, one-segmented flagellomere, open anal cell and cellr5, and the cellbrmuch longer than cellbm. However,Zentamyiagen. nov. has a more flattened scutum, and the apex of the flagellum is tapered. Moreover, the male genitalia are very different fromEusurbus, the male epandrium is narrow and long, and its posterolateral margin has a cluster of dense hairs; the female lacks a sand chamber, and the sperm pump is long and strong. A morphological phylogeny toEusurbusspecies is provided.

Description of a new species of Thevenetimyia (Diptera: Bombyliidae)from Madagascar, with a revised checklist of Madagascan bee fly fauna.

Madagascar is an island known for its richness of endemic species, including flies. Only eight genera of bee flies (Bombyliidae), including 17 described species (the majority of which are in the subfamily Anthracinae), are known from Madagascar. Here we describe a new species of Bombyliidae from Madagascar, Thevenetimyia spinosavus Maass & Bertone sp. nov. This fly represents the first record of the genus Thevenetimyia from Madagascar and the second species recorded in the Afrotropical Region. A revised checklist of Bombyliidae in Madagascar is provided, along with an appendix of associated literature. The known bee fly species likely represent only a fraction of the true diversity on the island, which has been relatively well sampled through extensive Malaise trapping of flies in Madagascar over the past decade.

Challenging the definition of the subfamily Usiinae: Phthiraxini, an unusual new tribe of bee flies (Diptera: Bombyliidae), based on Phthiraxia bowdeni gen. and sp. nov. from Western Australia

AbstractA new genus Phthiraxia gen. nov. (Usiinae: Phthiriini) is described from a remote region of Western Australia based on a male and a female specimen collected 35 years ago. The pair represent a single new species Phthiraxia bowdeni sp. nov. Two important characteristics of this new genus, however, challenge the definition of the subfamily Usiinae: the clypeus does not reach the base of antennae, and the palp is two‐segmented. Moreover, Phthiraxia gen. nov. has two other features: the wing vein M2 present, shared by all members of Phthiriini, and flagellum with subapical shallow sulcus containing a style, differentiating it from Phthiriini with a deep apical sulcus, and Usiini with a deep subapical sulcus. Results of a morphological phylogenetic analysis show that the new genus belongs to a lineage that is sister to the remaining members of the subfamily. Therefore, a monotypic new tribe, Phthiraxini tribus nov., is described to accommodate Phthiraxia gen. nov. A key to the Australian genera of Usiinae is provided. We reevaluate the syapomorphies of the Usiinae in light of the new tribe.

Life-Long Radar Tracking of Bumblebees.

Insect pollinators such as bumblebees play a vital role in many ecosystems, so it is important to understand their foraging movements on a landscape scale. We used harmonic radar to record the natural foraging behaviour of Bombus terrestris audax workers over their entire foraging career. Every flight ever made outside the nest by four foragers was recorded. Our data reveal where the bees flew and how their behaviour changed with experience, at an unprecedented level of detail. We identified how each bee’s flights fit into two categories—which we named exploration and exploitation flights—examining the differences between the two types of flight and how their occurrence changed over the course of the bees’ foraging careers. Exploitation of learned resources takes place during efficient, straight trips, usually to a single foraging location, and is seldom combined with exploration of other areas. Exploration of the landscape typically occurs in the first few flights made by each bee, but our data show that further exploration flights can be made throughout the bee’s foraging career. Bees showed striking levels of variation in how they explored their environment, their fidelity to particular patches, ratio of exploration to exploitation, duration and frequency of their foraging bouts. One bee developed a straight route to a forage patch within four flights and followed this route exclusively for six days before abandoning it entirely for a closer location; this second location had not been visited since her first exploratory flight nine days prior. Another bee made only rare exploitation flights and continued to explore widely throughout its life; two other bees showed more frequent switches between exploration and exploitation. Our data shed light on the way bumblebees balance exploration of the environment with exploitation of resources and reveal extreme levels of variation between individuals.

First record of Bombylisoma Rondani (Diptera: Bombyliidae) from Chinaand an identification key to the Chinese genera of Bombyliinae.

Bombylisoma Rondani is a genus of bee flies belonging to the subfamily Bombyliinae (Hull, 1973). It is easily identified by the following characters: Head usually as broad as thorax; hind-margin of eyes indented; wings often small, narrowed at base with at least alula reduced; hind femora often without macrochaetae; body usually more elongate even narrow conical or cylindrical, macrochaetae usually weak often hair-like especially those posterior to the wings; cell r₅ open, pulvilli well-developed; male terminalia with gonocoxite without prominent crest; parameral sheath, bearing paired horn-like outgrowths (Greathead & Evenhuis, 2001). Bombylisoma includes two known species from the Oriental Region: B. ghorpadei Kapoor & Agarwal, 1979 and B. resplendens Brunetti, 1909 (Evenhuis & Greathead, 2015). No species has previously been reported from China. Recently, one specimen of Bombylisoma collected from Yunnan was found in the Bernice Pauahi Bishop Museum. In the present paper this species, B. resplendens Brunetti, is redescribed and this represents the first record of the genus from China. A key to the genera of the Bombyliinae from China is presented.

Timeless standards for species delimitation.

Recently a new species of bombyliid fly, Marleyimyia xylocopae, was described by Marshall & Evenhuis (2015) based on two photographs taken during fieldwork in the Republic of South Africa. This species has no preserved holotype. The paper generated some buzz, especially among dipterists, because in most cases photographs taken in the field provide insufficient information for properly diagnosing and documenting species of Diptera.

FAMILY BOMBYLIIDAE.

Bombyliidae is one of the largest Diptera families with more than 4,500 recognized species worldwide. Their species vary from robust to thin, and may be small to large (2-20mm) and looks like bees or wasps. They also present great variation in color. Adults can often be seen either resting and sunning themselves on trails, rocks or twigs or feeding on flowering plants as they are nectar feeders. All reared bee flies are predators or parasitoids of arthropods. The Colombian fauna of bombyliids comprises at the moment 22 species, and 12 genera, of which, six are endemic species. Nonetheless, this number may be much higher, as Colombia is a megadiverse country and there are not many specimens of this family deposited in collections all over the world.

A new genus and species of micro bee fly from the Earliest Eocene French amber(Diptera: Mythicomyiidae: Psiloderoidinae).

Mythicomyiidae, or micro bee flies, are tiny flies (0.5-5.0 mm) that are found throughout most parts of the world except the highest altitudes and latitudes (Greathead & Evenhuis 2001). Including all extinct and extant taxa, the Mythicomyiidae currently comprise more than 380 valid taxonomic species distributed among 30 genera. The subfamily Psiloderoidinae is especially well represented among the fossil Mythicomyiidae by seven Cretaceous or Cenozoic genera. We here describe a new genus and a new species of this subfamily based on fossils from the Earliest Eocene of Oise (France). A Psiloderoidinae, Proplatypygus matilei Nel & DePloëg, 2004, is already described in this amber. Another mythicomyiid, Eurodoliopteryx inexpectatus Nel, 2006, is the most frequent bombylioid in this amber (Nel & DePloëg, 2004; Nel, 2006).

Electromagnetic radiation of mobile telecommunication antennas affects the abundance and composition of wild pollinators

The exponential increase of mobile telephony has led to a pronounced increase in electromagnetic fields in the environment that may affect pollinator communities and threaten pollination as a key ecosystem service. Previous studies conducted on model species under laboratory conditions have shown negative effects of electromagnetic radiation (EMR) on reproductive success, development, and navigation of insects. However, the potential effects that widespread mobile telecommunication antennas have on wild pollinator communities outside the laboratory microcosm are still unknown. Here we studied the effects of EMR from telecommunication antennas on key wild pollinator groups (wild bees, hoverflies, bee flies, remaining flies, beetles, butterflies, and wasps). We measured EMR at 4 distances (50, 100, 200 and 400 m) from 10 antennas (5 on Limnos Island and 5 on Lesvos Island, eastern Mediterranean, Greece), and correlated EMR values with insect abundance and richness (the latter only for wild bees and hoverflies). All pollinator groups except butterflies were affected by EMR. In both islands, beetle, wasp, and hoverfly abundance decreased with EMR, whereas the abundance of underground-nesting wild bees and bee flies unexpectedly increased with EMR. The effect of EMR on the abundance of remaining flies differed between islands. With respect to species richness, EMR only tended to have a negative effect on hoverflies in Limnos. As EMR affected the abundance of several insect guilds negatively, and changed the composition of wild pollinators in natural habitats, it might also have additional ecological and economic impacts on the maintenance of wild plant diversity, crop production and human welfare.

Effects of grazing intensity on pollinator abundance and diversity, and on pollination services

1. Pollinating insects provide important ecosystem services and are influenced by the intensity of grazing. Based on the Intermediate Disturbance Hypothesis (IDH), pollinator diversity is expected to peak at intermediate grazing intensities. However, this hump‐shaped relationship is rarely found.2. The effect of grazing intensity was tested on flower cover, on the abundance and richness of bees, hoverflies and bee flies, and on pollination services to early‐flowering bee‐pollinated Asphodelus ramosus L. For that, we used data on 11 plant–pollinator phryganic communities from Lesvos Island (Greece) widely differing in grazing intensities.3. Flower abundance and richness showed hump‐shaped relationships with grazing intensity. Grazing affected the abundance and richness of bees and hoverflies directly and also indirectly, through changes in the flower community. Grazing influenced directly the richness but not the abundance of bee flies. Overall, pollinator abundance and richness showed hump‐shaped relationships with grazing intensity, but variations in strength (hoverfly abundance) and direction (bee community) of the effect appeared along the season. Early in the season, grazing increased bee abundance but decreased richness, resulting in increased pollen limitation in A. ramosus.4. The effects of grazing on pollinators vary with the intensity of the disturbance, generally supporting the IDH, and the timing of land‐use activities may influence pollination services. Management strategies should include moderate grazing levels to preserve overall diversity in this area, however, the conservation of particular early bee or bee‐pollinated species may benefit from reduced grazing in early spring.

Natural History ofTetrapedia diversipes(Hymenoptera: Apidae) in an Atlantic Semideciduous Forest Remnant Surrounded by Coffee Crops,Coffea arabica(Rubiaceae)

Exotic plants can alter habitat composition and reduce the diversity of pollinators by competing with native species for resources. In a forest fragment surrounded by coffee crops, Coffea arabica L. (Rubiaceae), in southeastern Brazil, the life history of the oil-collecting bee Tetrapedia diversipes Klug (Apidae) was studied. Besides providing data on the phenology, nesting biology, and natural enemies of this bee species, we aimed to investigate if the intense mass flowering of coffee trees would attract T . diversipes specimens rather than native plants in bloom. As T. diversipes females nest in preexisting cavities, we displayed in the study site two types of trap-nests: bamboo canes and 5.8- by 0.6-cm black cardboard tubes. The trap-nests were inspected once a month from June 2011 to May 2013 and 494 nests were collected. Tetrapedia diversipes is a multivoltine species. Prepupal diapause occurred in nests collected at the end of the hot and wet season and during the cold and dry season. Nests were attacked by 14 species of natural enemies, and the most abundant species were the cuckoo bee Coelioxoides waltheriae Ducke (Apidae); the bee fly Anthrax oedipus F. (Bombyliidae); and the beetle Nemognatha cf. plaumanni Borchmann (Meloidae). Despite the mass flowering of coffee trees, pollen grains of C . arabica were not found in the pollen analysis. Our study reveals that even in the presence of an abundant source of floral resources of exotic origin, the studied population of T . diversipes preferred to use the native plant species to obtain the necessary resources for their survival.

Absorbing incident ultraviolet light decreases landings by Diptera and Hymenoptera on floweringChamaesyce albomarginata(Torr. & A. Gray) Small (Euphorbiaceae)

The reliance of insects on ultraviolet (UV) light in nature is not well known, despite a general understanding of how insects detect UV. Chamaesyce albomarginata (Torr. & A. Gray) Small is a mat-forming euphorb common in southwestern deserts that produces small, flower-like cyathia. The plant's small size, flatness, and abundant insect visitors enabled experimentally testing the dependence of flies, bees, and wasps flying to the plant on UV light. Most insects landing on plants were minute bombyliid flies in Mythicomyia Coquillet, 1893 and Nexus Hall & Evenhuis, 1987, andrenid bees in Perdita Smith, 1853, and sphecid wasps in Solierella Spinola, 1851. Ultraviolet light is absorbed by leaves on C. albomarginata, reflected slightly more by cyathia, and moderately reflected by surrounding substrate. Decreasing UV contrast between plants and surrounding substrate by covering substrate with clear UV-absorbing film, compared with clear UV-transmitting vinyl, did not affect numbers of insects landing on plants. Placing the same film approximately 20 cm above plants and surrounding substrate decreased numbers of insects landing by 68% compared with the vinyl. Diptera and Hymenoptera responded similarly by flying beneath the UV-absorbing film and approaching plants less frequently. Absorbing UV from incident light illuminating plants appeared to eliminate a visual cue used by insects for locating flowering plants. The most likely visual cue eliminated was the pattern of polarized UV in skylight.

Five new records of bee flies (Bombyliidae, Diptera) from Saudi Arabia with zoogeographical remarks.

Five bee-fly species (Bombyliidae, Diptera) have been listed in this paper as new to the Kingdom of Saudi Arabia. Four of the recorded species have been identified to the level of species, namely: Bombomyia discoidea (Fabricius, 1794), Spogostylum candidum (Sack, 1909), Exoprosopa linearis Bezzi, 1924, and Exoprosopa minos (Meigen, 1804), while the fifth one only to genus, Desmatoneura sp. The species have been collected from Al-Baha and Asir Provinces in the south-western part of the Kingdom. One of the four identified species, Exoprosopa linearis, has an Afrotropical affinity, and another two, Spogostylum candidum and Bombomyia discoidea, have considerable Afrotropical distributions, and this result agrees to some extent with studies considering these parts of the Arabian Peninsula, including Al-Baha and Asir Provinces, having Afrotropical influences and may be included in the Afrotropical Region rather than in the Palaearctic Region or the Eremic zone.

Summertime blues

A successful honey bee forager tells her nestmates the location of good nectar and pollen with the waggle dance, a symbolic language that communicates a distance and direction. Because bees are adept at scouting out profitable forage and are very sensitive to energetic reward, we can use the distance that bees communicate via waggle dances as a proxy for forage availability, where the further the bees fly, the less forage can be found locally. Previously we demonstrated that bees fly furthest in the summer compared with spring or autumn to bring back forage that is not necessarily of better quality. Here we show that August is also the month when significantly more foragers return with empty crops (P = 7.63e-06). This provides additional support that summer may represent a seasonal foraging challenge for honey bees.

The Role of Pollinator-Mediated Selection in the Divergence of Floral Traits between Two Closely Related Plant Species

Premise of research. Selection on floral traits by pollinators is expected to play a key role in the diversification of floral phenotypes and the maintenance of species boundaries in sympatry. However, relatively few studies have tested the generality of these assumptions in natural systems, and fewer still have examined multiple phenotypes to better understand which ones are most important to pollinators.Methodology. We created F2 hybrids between two sympatric species of dioecious Silene to segregate groups of floral characteristics from their associated pollination syndromes. Arrays of hybrid female plants were placed among natural field populations, where we observed native pollinators (diurnal and crepuscular) in order to address which individual traits or groups of traits influenced pollinator visitation, seed set, or predation. Pollinator visits included bees, bee flies, butterflies, and moths, including the mutualist nursery pollinator/seed predator Hadena bicruris.Pivotal results. Regardless of ti...

Zoogeographical affinities and faunal relationships of bee flies (Diptera: Bombyliidae) in Egypt

The distributions of 229 beefly (Diptera: Bombyliidae) species across the eight Egyptian ecological zones, together with their faunal affinities to the main zoogeographical regions, were used to test the suggestion of Holt et al. (2013) that the SaharoArabian is a distinct region rather than a subregion of the Palaearctic. All Egyptian ecological zones but one have greater affiliation to the Palaearctic and SaharoArabian than to the Afrotropical region; the Gebel Elba ecological zone, the southeastern triangle of Egypt, has greater affinities with the Afrotropics. Affinities to the Saharo-Arabian region were not different from those to the Palaearctic. From its bombyliid fauna, therefore, the Saharo-Arabian region is so closely allied to the Palaearctic as to constitute merely a subregion of it. Sinai shows a high level of endemism reflecting its isolation from other parts of Egypt.

Nesting ecology of Megachile (Chrysosarus) catamarcensis Schrottky (Hymenoptera: Megachilidae), a Prosopis-specialist bee

SummaryNests of the leafcutting bee Megachile (Chrysosarus) catamarcensis Schrottky (Hymenoptera: Megachilidae) were obtained during a 24 month trap-nesting programme in a xeric forest in the Province of La Pampa, Argentina. Nests were constructed in December and January; females made an average of 4.0 ± 2.2 cells, and used mud with flower petals and/or leaf pieces to build their nests. Provisions of cells were practically pure pollen mass of Proposis caldenia. Adult emergence showed a unimodal pattern, suggesting a univoltine life cycle. However, two individuals that emerged a month after the traps were collected indicate the existence of a small early-summer generation. This could indicate that M. catamarcensis, in some years (warmer) or in some populations (at lower latitudes), could exhibit a bivoltine life cycle. Approximately 15.3 % of all offspring failed to complete development to the adult stage, and an additional 13.9 % were killed by natural enemies. These included diverse parasitic wasps (Chrysididae, Sapygidae, and Leucospidae), a cleptoparasite bee (Megachilidae: Coelioxys), and a bee fly (Bombyliidae: Antrhax).

Biology of the Geophyte,Triteleia ixioidessubsp.anilina(Themidaceae), In Coniferous Forests of Butte County, California

The life cycle of the widespread, cormous geophyte, Triteleia ixioides (W. T. Aiton) Greene subsp. anilina (Greene) L. W. Lenz (Themidaceae) was studied in the field over several years in coniferous forest sites in Butte County, CA. All sites, ranging from 1383 to 1774 meters in elevation, have a Mediterranean climate and loamy soils above Tuscan mudflow substrate. Flowering scape height, corm weight, and corm depth varied significantly. Old corms decreased in dry weight throughout the winter, as shoots, roots, and new corms grew. By spring, each old corm had produced a leaf and a flowering scape, was depleted of stored food, and had a new “replacement corm” (without roots) already developed on top of it. Fruit set varied from 38.5% to 89.1%, with significant differences among populations sampled in different years and sites. Seed set was low (overall mean 38.4%), but varied significantly among years and sites, ranging from 26.4% to 56.3%. Plants are partially self-compatible. Soil moisture was not limiting to seed set, nor was pollen vectors, except on cold days. The most important pollinator was a bee fly (Bombylius facialis, Bombyliidae), although native bees provided some pollination at higher sites. Ten-minute observation periods, during bee fly activity, showed up to 15 visits to plants in a square meter. Percent seed germination was high (88–100%), with germination after the first rains and seedling growth continuing during the cold months. Seedlings produced single leaves up to 60.4 mm long, and corms averaged 1.6 ± 0.1 mm wide at one site. Contractile roots, produced lateral to the primary roots, averaged 16.13 ± 1.00 cm long. Shrinking and wrinkling at the upper part of the contractile root pulled the newly formed corm deeper in the soil. Study of contractile roots in Triteleia and other geophytes may help illustrate adaptation to summer drought in Mediterranean California.

Evaluation of Inflorescence Visitors as Pollinators of <I>Echinacea angustifolia</I> (Asteraceae): Comparison of Techniques

Inflorescences (heads or capitula) of the putative self-incompatible species, purple coneflower (Echinacea angustifolia (DC) Cronq. (Asteraceae)), were visited by insects representing the Coleoptera, Diptera, Hymenoptera, and Lepidoptera, in accordance with a generalist pollination syndrome. Measurement of the effectiveness of insect species as pollinators was accomplished by permitting solitary visits to receptive, central disc florets of virgin (previously bagged) heads. Four parameters were quantified: total stigmatic pollen load and proportion of pollen grains germinated, numbers of pollen tubes at style bases, and percentages of total receptive florets that had retracted (shrivelled) styles. Quantifying total and germinated pollen grains proved ineffective, partly owing to the tendency of self-pollen to initiate pollen tubes. The most effective pollinators were Apidae, especially bumble bees (Bombus spp.) and the European honey bee (Apis mellifera L.) (mean: 39 - 61% of styles retracted). Other noteworthy pollinators were cloudless sulfur butterflies (Phoebis sennae L.--Pieridae; mean 47% of style bases with pollen tubes), golden blister beetles (Epicauta ferruginea Say--Meloidae; 44%), and grasshopper bee flies (Systoechus vulgaris Loew--Bombyliidae; 22%). Sunflower leafcutter bees (Megachile pugnata Say) were less effective (4% of styles retracted). Promisingly, analysis of the proportion of retracted styles provided similar results to the established technique of pollen-tube quantification, but had the significant advantages of being completed more rapidly, without a microscope, and in the field. The quantitative technique of retracted-style analysis appears well suited for prompt measurement of inflorescence-visiting insects as pollinators of many asteraceans.