dan_wrench's picture

Unknown eggs

Observed: 1st August 2007 By: dan_wrench
Natural Shropshire - Biodiversity Partnership
dan_wrench’s reputation in Invertebratesdan_wrench’s reputation in Invertebratesdan_wrench’s reputation in Invertebrates
IMG 5773
Description:

Invertebrate eggs on rush stem

Identifications
Species interactions

No interactions present.

Comments

Martin Harvey's picture

horsefly eggs

For comparison, see also my observation of unknown eggs at:
http://www.ispot.org.uk/node/1492

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Entomologist and biological recorder

dshubble's picture

Horsefly eggs

Ta for that - handy for comparison with the arrangement in Atylotus which has the eggs more or less perpendicular to the stem; Tabanus has them more angled and I suspect is indeed the genus in the linked observation.

Martin Harvey's picture

identification features

I don't have the RES handbook you mention, but in Stubbs and Drake, "British Soldierflies and their allies", they bunch together the three horsefly genera Atylotus, Hybomitra and Tabanus, saying that all three lay egg masses of three or four layers at an angle of 45-50 degrees to the substrate. They also say that the eggs are pale milky-white/yellow when first laid, soon darkening to dark grey or deep black.

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Entomologist and biological recorder

dshubble's picture

Horsefly eggs

Hi Martin,

Indeed - I've looked there too but there's just something about the 'jizz' of it, mainly the more perpendicular angle which still feels right for Atylotus... however, I've added a revised and more definite i.d. of Tabanidae to sit alongside the more speculative species-level one.

dan_wrench's picture

Golden Horsefly

Thanks for the ID. I've already made tentative arrangements for a return visit to the site with some proper dipterists... preferably with exposed arms to act as bait.

Dan Wrench
Biodiversity Officer - Shropshire
dan.wrench@shropshire.gov.uk
www.NaturalShropshire.org.uk
http://twitter.com/#!/ShropshireBAP

dshubble's picture

Golden Horsefly

Looking forward to seeing if I was right or not! Often worth checking if possible otherwise the rarities/scarcities don't get recorded.