Sialis
Holarctic Alderflies
Species Guides
5- Sialis iola
- Sialis itasca
- Sialis mohri(alderfly)
- Sialis nevadensis
- Sialis rotunda(Alderfly)
Sialis is a of alderflies in the Sialidae, characterized by small, brown, heavy-bodied insects with forewings 10–20 mm long. The genus is distinguished from other Megaloptera by having fewer than fifteen square along the upper edge of the front wings. are and active in late spring. Larvae are aquatic that develop over two years before pupating in shoreline soil.
Pronunciation
How to pronounce Sialis: /ˈsaɪælɪs/
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Identification
Distinguished from other Megaloptera by the presence of fewer than fifteen square along the upper edge of the front wings; other Megaloptera have more than fifteen. Small size (10–20 mm forewing length), brown coloration, and heavy body are supporting characteristics. The wing cell pattern is the definitive diagnostic feature.
Images
Appearance
Small, mainly brown alderflies with a relatively heavy body. Forewings reach 10–20 mm in length. Females are usually larger than males. Wings display large forming a network, with the upper edge of the front wings consisting of nearly square cells. The Sialis is distinguished by having fewer than fifteen such square cells, whereas other Megaloptera possess more.
Habitat
Riparian environments. occur on vegetation near water bodies. Larvae inhabit aquatic environments initially, later burrowing into mud at depths up to 18 meters.
Distribution
Most of Europe. The has a Holarctic distribution pattern, with also recorded from Asia (Siberia, Korea, Japan region) based on species epithets in the literature.
Seasonality
fly from May to June. Larval development spans two years, with in the larval stage.
Diet
Larvae feed on insect larvae, worms, and small molluscs. feeding habits are not documented in available sources.
Life Cycle
Females deposit up to 2000 in groups of approximately 200 on leaves of shore plants. Hatching larvae fall directly into water. Larvae live in water initially, then burrow into mud at depths up to 18 meters. Development requires two years, with larvae . occurs on shore under soil.
Behavior
are . Females exhibit -laying on shore plant leaves. Larvae are predatory and undergo an aquatic-to-benthic transition during development.
Ecological Role
Larvae function as in aquatic and benthic , consuming insect larvae, worms, and small molluscs. They contribute to nutrient cycling in freshwater mud through their burrowing activity.
Similar Taxa
- Other Megaloptera generaOther Megaloptera possess more than fifteen square along the upper edge of the front wings, whereas Sialis has fewer than fifteen. This wing venation character is the primary distinguishing feature.
More Details
Species diversity
The includes at least eleven described , with Sialis lutaria (Linnaeus 1758) being the type species and most widely known. Several species were described by Vshivkova in 1985 from eastern Palearctic regions.