Atherix

Meigen, 1803

ibis flies

Species Guides

Atherix lantha(watersnipe fly)
Atherix pachypus(watersnipe fly)
Atherix variegata(watersnipe fly)

Atherix is a of 'ibis flies' in the Athericidae, a small family closely related to Rhagionidae (snipe flies). occur across most of Europe and the . are medium-sized flies; larvae are aquatic . Females of some species exhibit distinctive clustering , forming dense on bridge undersides where are deposited.

Atherix by (c) George Mitchell, some rights reserved (CC BY), uploaded by George Mitchell. Used under a CC-BY license.

Atherix by (c) nevwright, some rights reserved (CC BY), uploaded by nevwright. Used under a CC-BY license.

Pronunciation

How to pronounce Atherix: //ˈæθəˌrɪks//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Habitat

Aquatic environments, particularly running water including rivers and streams. often found near water sources. Females of some deposit on man-made structures such as bridge undersides.

Distribution

Present across most of Europe and the Nearctic ecozone. Specific records from Fennoscandia (Finland, Sweden, Norway), Denmark, and Colombia (Chocó). In Fennoscandia, distribution is primarily northern and eastern with recent western extensions in northern Sweden.

Seasonality

of Atherix lantha in Quebec are on the wing from mid-May to late June. First-instar larvae appear in June, with rapid growth through summer.

Diet

Larvae are predatory. Atherix lantha larvae are piercing-sucking that feed on aquatic including heptageniid mayflies, hyalellid amphipods, and hydropsychid . Prey vulnerability varies with predator and prey size.

Life Cycle

Atherix lantha has a with five larval instars. First-instar larvae appear in June; most reach fourth instar by September. occurs mainly in the fifth instar. Full-grown larvae leave water in May to pupate on banks. Larval development in Atherix ibis appears to last two years.

Behavior

Females of some form dense or 'cones' on the undersides of bridges, attaching to masses. In Atherix lantha, approximately 61,000 dead females have been observed attached to egg clusters under a single bridge. Upon hatching, larvae fall into the water below.

Ecological Role

Larvae function as in aquatic , potentially influencing of mayflies, amphipods, and .

Human Relevance

Female on bridge structures are conspicuous and have been used as a survey method for detecting presence. No significant economic or medical importance documented.

Similar Taxa

Rhagionidae (snipe flies) Athericidae was historically grouped with or confused with Rhagionidae due to morphological similarity; Athericidae now recognized as distinct family

More Details

Female aggregation behavior

The mass clustering of dead females on bridge structures is a distinctive trait of at least Atherix ibis and Atherix lantha. These are used as a detection method in distribution surveys.

Growth pattern

Larval growth in Atherix lantha follows Dyar's law of constant growth rate between instars (rate = 1.31), except between the first two instars where the rate is higher (1.41).