Rose Mallow Season and Their Special Bee!

In Pavilion Park in Cape May Point, there is a simple dirt basketball court.

The ground is compacted, but loose and sandy enough for ground nesting bees to dig down and make homes for themselves.

And that is exactly what has happened! 

There are 50 - 100 holes, with bees flying, circling, 

digging and diving down.

Who are these bees? 

Why are they here?

After several calls, in an attempt to preserve their nesting site, I spoke with the naturalist from Cape May Point State Park, and he informed me that they are Rose Mallow Bees or Ptilothrix bombiformis.

They are solitary females, each creating their own nest, but in aggregate. The nests are not connected. Each bee provisions her own nest with pollen and nectar from just ONE type of plant, the Hibiscus, as they are specialist bees.

They are lazy bees and are cleptolectic, attempting to steal nesting sites of neighboring bees, which are typical of their Tribe Emphorini as mentioned in a published paper from Brazil: http://www.sea-entomologia.org/Publicaciones/PDF/BOLN45/281_288BSEA45Ptilothrix.pdf.

Here are 2 fighting over a hole:

They look like bumble bees, but they are not. They have a stout body, dense black hair, a yellow thorax and dark black abdomen with large folded wings, when not in flight. They also have prominent longer, hairier legs. Importantly, they do NOT sting!

They have a short life cycle, lasting about as long as the rose mallows' blooming period, from July to September. Swamp Rose Mallow (Hibiscus moscheutos), a native species to NJ, is a wetlands plant, with a 5 petaled colorful flower head and a spectacular sight to see in bloom.

I'm curious if this bee, also will feed from other Hibiscus varieties, such as Rose of Sharon (Hibiscus syriacus) and other Mallow varieties as listed here: (http://capemaywildlife.com/_templates/group_mallows.html) in the Cape May Point area or beyond?

For more information about these curious bees, visit the site: http://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/rosemallowbee.shtml

I hope the site will be protected, during their active season. I spoke with the Commissioner of Public Works at the Point, Robert Mullock, who knew about them, and who was happy to know I wasn't calling to ask to have them exterminated. I hope the area will be roped off and some signage will be installed to inform curious onlookers of this interesting bee.