Cactus Fly, not a Marsh Fly

Summer visitor to chapparal country in Southern California
First of all, I love your website. The variety of life on this planet is more fantastic than any other I’ve visited (at least in recent memory)! My wife and I have long wondered about a winged insect that shows up each year as the weather warms. It seems to like red wine; whenever we go in the backyard with a glass they seem to end up treating our glasses as their personal spa. Since it’s quite dark and looks a bit like the villains in the ‘Babylon 5’ TV series, we call them ‘Shadow Bugs’. They don’t seem harmful; at least they haven’t bitten us yet! We live on the edge of a rocky hill covered in chapparal (cactus, sage, and other desert shrubs). My wife grew up very near here, but in a more urban area and never saw one until we moved to our current house. I would estimate that this critter is between 3/4 of an inch and 1 inch long. In hopes that you can tell us what they are I’m enclosing two pictures. Thanks!
jeff fielding
orange, california

Hi Jeff,
After doing some research, we believe this to be a Marsh Fly in the genus Sepedon. We located some images on BugGuide that look very similar. Perhaps some expert will write in with an exact species.

Correction: Cactus Fly
Provided by Eric Eaton (09/23/2007)
The “marsh fly” is actually a “cactus fly” in the family Neriidae. Fantastic image! We could use it over at Bugguide, as this family is under-represented. Larvae of these insects develop in rotting cacti.

(09/23/2007) Maybe a Marsh Fly – not a marsh fly
Hi guys,
I enjoy the site. Your “Maybe a Marsh Fly” from 9/21/2007 is actually a Cactus Fly – Odontoloxozus longicornis. The larvae hang out in decaying cactus. Interesting that the adults like red wine, I’ll forced to experiment with that. Darn. Cheers,
Michael W.

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