Acrocera orbicula

(Fabricius, 1787)

Acrocera orbicula is a of small-headed fly in the Acroceridae. Its larvae are internal of spiders, with first-instar larvae () actively seeking or waiting in proximity to them. The species has been documented in parts of northern Europe including Denmark, Norway, and Sweden.

Pronunciation

How to pronounce Acrocera orbicula: //əˈkɹoʊsərə ɔːrˈbɪkjʊlə//

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Distribution

Denmark, Norway, and Sweden.

Host Associations

  • spiders - internal Larvae burrow through spider and attach to book lungs
  • mites - internal First-instar larvae described from mites (Acari) per Sferra 1986

Life Cycle

are laid in close proximity to . First-instar larvae () wait for or actively seek a host. Upon contact, larvae burrow through the spider's and attach to the book lungs, where they remain in for several months. Subsequent larval instars develop rapidly, consuming most of the liquid contents of the host. Larvae emerge posteriorly from the host, attach to spider silk for , and emerge in 7–10 days.

Behavior

First-instar larvae exhibit -seeking , either waiting for or actively searching for spider hosts. Larvae enter a prolonged of several months while attached to host book lungs before resuming development.

Ecological Role

Internal of spiders; regulator of arachnid .

More Details

Oviposition

Oviposition is specifically adapted to place near spider to facilitate larval .

Taxonomic note

The specific epithet 'orbicula' has been used in some sources, though the accepted spelling following Fabricius (1787) is 'orbicula'.

Sources and further reading