jeremyr's picture

Siphona geniculata

Observed: 13th June 2013 By: jeremyrjeremyr’s reputation in Invertebratesjeremyr’s reputation in Invertebratesjeremyr’s reputation in Invertebratesjeremyr’s reputation in Invertebratesjeremyr’s reputation in Invertebrates
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segmented arista
Description:

4mm long, a parasite of Crane-fly larvae

Identifications
Species interactions

No interactions present.

Comments

jeremyr's picture

bristles

the median marginal bristles are on abdomen 1+2. This is another fly with jointed aristae

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jeremyr's picture

jointed arista

The arista has a very short 1st segment, a medium-length 2nd segment and a long 3rd one, although these are not keying features.

For another genus with an arista of three segments, see Triarthria:

http://www.ispot.org.uk/node/332962

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ChrisR's picture

The T1+2 marginal bristles

The T1+2 marginal bristles can't be relied upon - Belshaw was incorrect to say that only geniculata and setosa have them - they are also present in other species, namely cristata (rarely). Siphona geniculata is still the most likely identification (going by the large number of bristles below the last parafrontal bristle) but I couldn't be 100% sure unless I had seen the specimen.