Cheilosia

Meigen, 1822

Blacklets

Species Guides

4

Cheilosia is a large of hoverflies (Syrphidae) commonly known as blacklets. Most exhibit predominantly black or dull coloration without the bright patterns seen in many other hoverflies. It is one of the most species-diverse genera in the . Larval varies by species: some feed in plant stems, others in fungi, and several species have been developed as agents for plants.

Cheilosia by (c) Will Linnard, some rights reserved (CC BY), uploaded by Will Linnard. Used under a CC-BY license.Cheilosia by (c) Ben Armstrong, some rights reserved (CC BY), uploaded by Ben Armstrong. Used under a CC-BY license.Cheilosia rufipes by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Cheilosia: /kaɪˈloʊsiə/

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

Identification

Distinguished from other hoverfly by predominantly black or dull coloration lacking bright patterns. Cheilosia grossa specifically can be identified by orange tibiae, black , and furry appearance combined with early spring period.

Images

Appearance

Most are black or largely uncoloured, lacking the bright colours and patterns typical of many hoverfly species. Specific species such as Cheilosia grossa are described as large and fluffy with orange tibiae, black , and a furry appearance.

Habitat

varies by . Cheilosia grossa occurs in woodland rides and edges, heathlands, and damp meadows, particularly where thistles are abundant. Species used for inhabit areas with their plants (hawkweeds, Hieracium spp.).

Distribution

Records from Denmark, Norway, Sweden, Vermont (USA), and other US locations. Cheilosia grossa is distributed across the UK, Ireland, Northern and Central Europe. Some have been introduced or evaluated for introduction to New Zealand for .

Seasonality

Cheilosia grossa is active March-May, peaking late March-early April. Seasonality for other varies and is poorly documented for many.

Diet

of Cheilosia grossa visit willows (Salix caprea) and other early spring flowering plants including blackthorn, colt's-foot, and dandelion. Larvae are phytophagous, feeding on thistle roots and stems (Cirsium palustre, C. vulgare) or hawkweed roots and crowns (Hieracium spp.). Some have larvae that feed in fungi.

Host Associations

  • Cirsium palustre (marsh thistle) - larval Cheilosia grossa
  • Cirsium vulgare (spear thistle) - larval Cheilosia grossa
  • Salix caprea (goat willow) - food sourceCheilosia grossa
  • Hieracium spp. (hawkweeds) - larval C. urbana and C. psilophthalma

Life Cycle

Cheilosia grossa: females lay on early flowering thistle spikes in spring; larvae emerge within days and tunnel in thistle roots and stems; larvae exit roots in late August and overwinter as pupae in soil, emerging as the following spring. Other : larvae feed in plant stems or fungi; specific details vary by species and are unknown for many.

Behavior

Cheilosia grossa males hover at height over open ground and can form loose swarms at 2-6 metres above ground. tend to fly high, making them difficult to observe. Larval of thistles is indicated by sprouting of multiple stems and stunted plant growth.

Ecological Role

Phytophagous larvae act as herbivores on plants; serve as of early spring flowering plants. Some function as agents for plants.

Human Relevance

Cheilosia urbana and C. psilophthalma have been approved and released in New Zealand as agents for hawkweeds (Hieracium spp.).

Similar Taxa

  • Other hoverfly generaCheilosia lack the bright colours and patterns typical of many hoverfly species, appearing predominantly black or dull.

More Details

Species diversity

Cheilosia is one of the most -diverse of hoverflies, though the of many species remains little understood.

Larval habitat variation

Larval varies considerably: some feed in plant stems, others in fungi, with specific associations documented for only a minority of .

Sources and further reading