Coelopa vanduzeei : The Kelp Fly – The Race Rocks Taxonomy

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Kelp Flies eating at a would on an elephant seal photo by Ryan Murphy

They are scavengers on decaying vegetation and as shown here a blood meal from a marine mammal.

kelp flies are the most irritating (to humans) of the organisms that inhabit the islands, but then again they are an essential part of the ecosystem. They do not look like a house fly but are rather thinner and a lighter color. In the upper intertidal zone they lay their eggs in decaying algae where the larvae, when they hatch, eat the bacteria that is decomposing the algae. This is a saprophagous mode of nutrition. In this video they move rather quickly, but you can see several copulating at various times. On a calm day kelp flies are very bothersome, but when a breeze is blowing they stay low to the ground. Often when our boat is docked, they will manage to find their way into the cabin so one has to open the windows and flush them out or they keep on pestering us all the way back to the college. Even in November, they are still around in the winch house and other unheated buildings on the island.

Probably the most irritating insect to work around when on the island is the kelp fly. On a calm day in May or June these flies are very difficult to tolerate. They also like getting into buildings and often end up dead on the windowsills. 

Domain Eukarya
Kingdom Animalia
Phylum Arthropoda
Class Insecta
Order Diptera
Family Coelopidae
Genus Coelopa
Species vanduzeei
Common Name:Kelp Fly

pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams. Dec 2005- Ryan Murphy