Small-headed Fly? - Turbopsebius diligens

Moved

Moved from Small-headed Flies.

… Dennis Haines, 18 August, 2010 - 12:47pm

Moved

Moved from ID Request.

… Carol Davis, 31 May, 2010 - 10:27am

and the spider looks to be

Misumena

… john and jane balaban, 31 May, 2010 - 10:20am

Thanks!

And the spider slowly dragged the poor fly to the underside of the flower so I couldn't steal it. It was quite the ordeal.

… Carol Davis, 31 May, 2010 - 10:26am

A cyclic situation here

...in that a spider is feeding on a fly whose larvae feed on spiders.

Maybe not exactly cyclic though, since the only currently known host spiders for T. diligens are Hololena curta and Rualena sp., which are funnel spiders of the family Agelenidae...very different from the crab spider family, Thomisidae.

… Aaron Schusteff, 13 July, 2013 - 9:24pm

Yes!

Acroceridae, possibly Ogcodes niger? I say that based on coloration only. Nice find, did you keep the specimen? Not sure if we need both images though.

… Chris Grinter, 30 May, 2010 - 11:20pm

Chris, I was thinking a femal

Chris, I was thinking a female Turbopsebius diligens based on the infuscated wings. It doesn't look like Ogcodes to me. Its something about the shape of the thorax and position of the head, also the abdomen doesn't look right.

… Dennis Haines, 16 August, 2010 - 11:12pm

Further details

...to tack down Dennis's thoughts above.

Wing venation diagrams for Turbopsebius and Ogcodes are given on pp.578-579 of McAlpine(1) and in Plates VII, VIII, XIV, and XV of Cole (1919) [large (13MB!) PDF here].

From those diagrams, the wing venation in this post is a good match for (female) Turbopsebius (= Opsebius in Cole), whereas the wing venation of Ogcodes is distinctly "open", and in particular lacks the forked R4/R5 clearly visible here.

Moreover, the anal vein meets the 6th vein to close the anal cell, which together with the west of the rockies location, indicates T. diligens per pg 395. of Sabrosky (1948).

… Aaron Schusteff, 13 January, 2012 - 12:12am

No.

The spider kept the specimen. I had no idea what it was until today. Feel free to get rid of one of the images. Thanks for the ID.

… Carol Davis, 30 May, 2010 - 11:26pm