I cooked salmon for dinner tonight. I filleted the fish myself and decided to run a little experiment before I started the barbeque. I put the carcass outside (on the top of my wooden compost box) to attract some flies to photograph (see blog #6 Macro photographs of flesh (Sarcophagidae) and blow (Calliphoridae) flies feeding on salmon carcass for more of an explanation). But this time, just out of curiosity, I timed how long it took for the different species to find the fish.
The first insects to show up were a couple of yellowjacket wasps (Vespula sp.). These critters arrived in less than two minutes and immediately started to work on the fish. It’s fascinating to watch wasps work: they would chew on the fish for 30 seconds or so, until they had a little ball of fish that they would carry off to their nest. The following are some photos of these little beats at work.
Blow flies (Calliphoridae) arrived at the eight minute mark, a full six minutes after the wasps. These are gorgeous little flies as you can see from the photo below.
Flesh flies (Sarcophagidae) didn’t start to arrive until 20 minutes had passed. Such sluggards! I wasn’t able to get any good photos of these flies because the wasps kept chasing them away. Interestingly the wasps pretty much ignored the blow flies.
After 30 minutes I wrapped up my little project and discarded the carcass. But a few small pieces of fish remained behind, which the wasps continued to chew on. At this point they wouldn’t let any flies land and feed. However, one enterprising little ant slipped up from below—apparently unnoticed by the wasps.
The technical stuff:
Camera: Olympus E-620 digital SLR
Lens: Zuiko 35mm macro
Settings: manual exposure (F16 @ 1/125 sec)
Lighting: Olympus RF-11 ring flash (TTL)