Holoptic-eyes
Guides
Astatinae
Astatina wasps
Astatinae is a cosmopolitan subfamily of solitary wasps in the family Crabronidae, comprising approximately 14 species in North America and additional species across Europe and Asia. The subfamily includes two primary genera: Astata and Dryudella. Males are readily distinguished by their holoptic eyes—enormous compound eyes that meet at the top of the head—and exceptionally broad hind wings that enable rapid flight. Females are fossorial, constructing multi-celled nest burrows in soil or sand and provisioning them with paralyzed true bugs (Hemiptera) as food for their larvae.
Bibio abbreviatus
Bibio abbreviatus is a species of march fly in the family Bibionidae, first described by Loew in 1864. Adults emerge in spring and are known for forming large swarming aggregations. Males possess holoptic eyes that meet at the top of the head, while females have relatively small heads. The species belongs to a genus of decomposer flies whose larvae develop in soil.
Bibio articulatus
red-legged march fly
Bibio articulatus is a species of march fly in the family Bibionidae, commonly known as the red-legged march fly. It is distinguished by its dark exoskeleton ranging from black to deep red and its conspicuous red or orange legs. The species exhibits pronounced sexual dimorphism, particularly in eye size and body proportions. It is most active during spring months and is found primarily in the eastern United States.
Bibio femoratus
March fly, Lovebug
Bibio femoratus is a medium-sized fly in the family Bibionidae, commonly known as the March fly or lovebug in the southeastern United States. Adults are recognized by their black bodies with orange or red thorax and legs, and a diagnostic dark spot on the leading edge of the wing. The species forms conspicuous mating swarms in early spring, with pairs remaining coupled for extended periods. Larvae develop in soil and feed on decaying organic matter.
Bibio rufipes
March fly
Bibio rufipes is a species of march fly in the family Bibionidae. Adults emerge in spring, with males forming conspicuous swarms that blanket ground and low vegetation. Females possess fossorial adaptations including stout, downcurved spurs on the fore tibiae used to excavate soil for egg-laying. The species occurs across northern Europe including Norway and Sweden.
Chalcosyrphus chalybeus
violet leafwalker
Chalcosyrphus chalybeus, commonly known as the violet leafwalker, is a species of syrphid fly (flower fly) found in the northeastern United States and adjacent Canada. Adults are characterized by their all-black coloration with a distinctive steely blue or violet metallic sheen. Unlike many syrphid flies, this species shows a strong association with dead wood rather than flowers. The larvae develop in decaying wood as saprophages, while adults are known to visit flowers for nectar and pollen. Males possess holoptic (contiguous) eyes, a trait unusual among syrphid flies.
Chalcosyrphus nemorum
Dusky-banded Leafwalker
Chalcosyrphus nemorum is a common species of syrphid fly with a Palearctic and Nearctic distribution. Adults are medium-sized hoverflies with distinctive enlarged, swollen hind femora bearing ventral spines and curved hind tibiae—adaptations associated with their association with dead wood. The species exhibits sexual dimorphism, with males having holoptic (contiguous) eyes. Larvae develop under the bark of conifers (Larix, Pinus) and various hardwoods, where they function as saprophages in decaying wood. Adults are flower visitors, obtaining nectar and pollen from diverse plant species including white umbellifers, Caltha, Anemone nemorosa, and Ranunculus.
Dilophus arizonaensis
Dilophus arizonaensis is a species of march fly in the family Bibionidae, first described by Hardy in 1937. Like other members of the genus Dilophus, it is smaller and less robust than the related genus Bibio, often with reddish coloration. The genus is distinguished from Bibio by having a ring of shorter teeth on the front legs rather than long spurs. As with other bibionids, adults are short-lived and emerge in spring, with males forming swarms to attract mates. Larval stages feed on decaying organic matter in soil.
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 tingi
March fly
Dilophus tingi is a species of March fly in the family Bibionidae. Like other members of the genus Dilophus, it is likely smaller and less robust than the related genus Bibio, and frequently exhibits reddish coloration. March flies are spring-emerging dipterans known for their swarming behavior and fossorial egg-laying habits.
Dryudella
Dryudella is a genus of solitary digger wasps in the family Crabronidae, subfamily Astatinae, containing over 50 described species distributed across the Holarctic region. These small wasps (typically under 10 mm) are specialized predators of true bugs (Hemiptera), with females constructing nest burrows in sandy soils to provision their offspring. Males exhibit distinctive holoptic eyes that meet at the top of the head and possess broad hind wings that enable rapid flight from perches on twigs and stems. The genus shows sexual habitat segregation, with females typically in shaded nesting areas and males in sunny locations.
Dryudella caerulea
Dryudella caerulea is a solitary wasp in the family Crabronidae, subfamily Astatinae. It is one of approximately ten North American species in the genus Dryudella. Females are fossorial, excavating nest burrows in soil, and provision nests with paralyzed true bugs (Hemiptera) as food for their larvae. The species is found in arid habitats of western North America and Central America. Males possess holoptic eyes that meet at the top of the head and broader hind wings than females, adaptations associated with their rapid, darting flight behavior while perching on vegetation to detect mates and rivals.
Pipunculidae
Big-headed Flies
Pipunculidae is a family of flies (Diptera) commonly known as big-headed flies, distinguished by their large holoptic compound eyes that cover nearly the entire head. The family has a worldwide distribution with over 1,400 described species. Larvae develop as parasitoids almost exclusively in Auchenorrhyncha (leafhoppers, planthoppers, and cicadas), with the exception of the genus Nephrocerus, which parasitizes adult crane flies (Tipulidae). Molecular analysis indicates the family originated in the Maastrichtian age of the Late Cretaceous, with the oldest fossils dating to the Eocene. Some species are used as biological control agents in rice fields.