Swarming-behavior
Guides
Baetis bicaudatus
small minnow mayfly
Baetis bicaudatus is a small minnow mayfly in the family Baetidae, described by Dodds in 1923. It inhabits streams across western North America from Alaska to the southwestern United States and northern Canada. The species is bivoltine, producing two generations annually, with distinct summer and winter generations that differ in size and susceptibility to parasitism. Adults exhibit characteristic mayfly behavior including swarming mating aggregations, while nymphs are important grazers on periphyton in stream ecosystems.
Bibio albipennis
White-winged March Fly
Bibio albipennis, the White-winged March Fly, is a species of march fly in the family Bibionidae native to North America. Adults are most commonly observed in spring, with males forming conspicuous swarms to attract mates. The species is widespread across the continent and is one of approximately 37 currently recognized Bibio species north of Mexico. Like other bibionids, it plays a role in nutrient cycling through larval feeding on decaying organic matter.
Bibio holtii
Bibio holtii is a species of March fly described by McAtee in 1922. It belongs to the family Bibionidae, a group characterized by males with large holoptic eyes and females with small heads relative to body size. The species exhibits a Holarctic distribution pattern, occurring across the northern hemisphere. Like other Bibio species, adults are typically active in spring and form conspicuous swarms.
Bibio superfluus
Garden Maggot
Bibio superfluus, commonly known as the Garden Maggot, is a species of march fly in the family Bibionidae. Adults are active in spring, with males forming conspicuous swarms that attract females for mating. The species exhibits strong sexual dimorphism in head structure. Larvae develop in soil where they feed on decaying organic matter and plant roots.
Dilophus orbatus
March fly
Dilophus orbatus is a species of March fly in the family Bibionidae, first described by Thomas Say in 1823. The species exhibits pronounced sexual dimorphism in multiple traits: females are larger with black wings and smaller eyes, while males are smaller with transparent wings and large, nearly conjoined compound eyes that dominate the head. Adults typically emerge in spring. Like other Bibionidae, the larvae are soil-dwelling and feed on decaying organic matter.
Dilophus spinipes
Dilophus spinipes is a species of march fly in the family Bibionidae, first described by Thomas Say in 1823. The genus Dilophus is distinguished from the related genus Bibio by having a ring of shorter teeth on the forelegs rather than long spurs. Members of this genus are typically smaller and less robust than Bibio, often with reddish coloration. Like other bibionids, adults are short-lived and emerge in large numbers during spring months.
Fannia canicularis
Lesser House Fly, Little House Fly
Fannia canicularis, the lesser house fly, is a small dipteran (3.5–6 mm) widespread in association with human habitation and livestock facilities. It is distinguished by its habit of circling in the centers of rooms and its slender build with a straight median wing vein. The species is a significant pest in poultry operations, where larvae develop in accumulated manure. Males exhibit complex swarming behavior in shaded, enclosed sites, performing aerial chases controlled by precise visual-motor mechanisms. Among Fanniidae, this species is most frequently associated with myiasis.
Platypezidae
Flat-footed Flies
Platypezidae is a family of small true flies (Diptera) comprising over 250 species worldwide. Adults are commonly known as flat-footed flies due to their characteristically modified tarsal segments, particularly in males. The family is primarily associated with woodland habitats where larvae develop as fungivores. Adults exhibit distinctive swarming behavior for mating and are frequently observed performing rapid, erratic movements on vegetation. The family was formerly broader in circumscription, with Opetiidae and some genera now placed in Atelestidae removed based on phylogenetic evidence.
Polyphemus pediculus
Polyphemus pediculus is a predatory freshwater cladoceran crustacean in the family Polyphemidae. It is distributed throughout the Northern Hemisphere but exhibits significant genetic structuring, representing at least nine largely allopatric cryptic species rather than a truly cosmopolitan population. The species displays complex reproductive behavior involving both parthenogenetic and gamogenetic (sexual) phases, with pronounced seasonal and daily rhythms in swarming activity.
Rhamphomyia
dance flies
Rhamphomyia is a large genus of dance flies (Empididae) comprising over 600 species arranged in 8 subgenera. The genus exhibits remarkable diversity in mating systems, including sex-role reversal where females compete for mates and males provide nuptial gifts. Several species display elaborate visual ornaments used in courtship, such as inflatable abdominal sacs and modified leg scales. The genus has a cosmopolitan distribution with particular diversity in the Holarctic region, including specialized radiations in arctic tundra environments.
Sylvicola
wood gnats, window gnats, window midges, window flies
Sylvicola is a genus of wood gnats in the family Anisopodidae containing over 80 described species. The genus is widely distributed across the western Palaearctic, with some species introduced to North America and oceanic islands. Adults are active year-round in temperate regions and are frequently observed indoors near windows, earning them the common name 'window gnats.' The most thoroughly documented species, S. cinctus, serves as a representative for understanding genus-level traits.
Tabanus calens
Devoted Horse Fly
Tabanus calens is a species of horse fly in the family Tabanidae. It is distributed across Canada and the United States. Two subspecies are recognized: T. c. calens and T. c. giganteus. Males of this species exhibit distinctive hovering and swarming behavior.