How to find Cerceris fumipennis colonies
Locating Colony Habitat

Cerceris fumipennis occurs in suitable habitats from Florida to southern Ontario. Follow these steps:

Figure 1. Cerceris fumipennis nests at the Woodland Trails colony, Milton, Ontario, July 2007.

Figure 2. Cerceris fumipennis colony at Rondeau Provincial Park, Ontario, 2006. Figure 3. Cerceris fumipennis colony at Bronte Creek Provincial Park, Ontario, 2006.

 

Finding nests at the site

Figure 4 . Bee Wolf (Philanthus spp).
 
Figure 5 . Tachytes wasp (Tachytes spp).

After finding a promising colony habitat, you will need to locate the nests:

Figure 6 . Cerceris bicornuta (preys on weevils). Figure 7 . Digger-bee (clearing burrow entrance). Figure 8 . Tiger Beetle (Cicindela punctulata).

 

Confirming nest occupancy

To determine if the nest holes you have found are occupied by our wasp, try two tricks:

Figure 9 . Clear plastic cups over Cerceris fumipennis nests. Figure 10 . The nest of this female Cerceris fumipennis has been covered with a clear plastic cup.  An observer can now identify the beetle being carried by the wasp and then move the cup, letting the wasp pass into her nest with the beetle.

Marking nests

If the hole is empty place a clear plastic cup over the entrance with a stone on top to prevent the cup from blowing away (Fig. 21).  Check the cup every five minutes to see if a female is flying around it (Fig. 22) or buzzing inside it.  Do not leave the cups unattended for long periods, as wasps may over-heat and die on sunny days.  By catching the female you can easily identify the species.

Final Thoughts

Finding the first colony will be the hard part but once you have found one colony you will begin to notice them elsewhere. If the wasps are present, you will see them. If they are not conspicuous, then search elsewhere.

Once you have found some colonies you may want to go back and revisit a few of your earlier sites. It is easy to overlook small colonies on days when they are not active such as after a heavy rain. Revisiting possible sites a week later is a good idea.

To optimize efforts you will want to work around the following schedule. In Ontario, the wasps are active from about June 28th to September 5th. There is only a single brood in Ontario but in southern Florida the wasp has two broods with the first one becoming active in early April. Observations in both Ontario and Florida suggest that the wasps rarely forage before 9:30am and most females stop around 6:00pm; females spend the night in their burrows. The wasps are more active on sunny days than cloudy days.


A map of known cerceris colonies. View Cerceris fumipennis Colony Locations & Data in a larger map