Beneficial Pollinator -American sand wasp

At the home of one of my neighbours in Metchosin where I place a mason bee box each year there is a patch of very sandy ground where there is a large colony of the Bembix Americana, the American Sand Wasp .  I noticed them on many of the plants in the garden also .

An interesting article appears in Wikipedia showing that these are also predators of other insects. I hope they don’t take our mason bees too.

“The Bembicini, or sand wasps, are a large tribe of bembecid wasps, comprising 20 genera. Bembicines are predators on various groups of insects.[1] The type of prey captured tends to be rather consistent within each genus, with flies (Diptera) being the most common type of prey taken. Nests are typically short, simple burrows, with a single enlarged chamber at the bottom which is stocked with freshly paralysed prey items for the developing wasp larva; the egg may sometimes be laid before the chamber is completely stocked. It is common for numerous females to excavate nests within a small area where the soil is suitable, creating large and sometimes very dense nesting aggregations, which tend to attract various species of parasitic flies and wasps, many of which are cleptoparasites; in some cases, the sand wasps prey on their own parasites (e.g.,[2]), a surprisingly rare phenomenon in the animal kingdom.[3] Although sand wasps are normally yellow and black, some are black and white with bright green eyes.

See my entry in iNaturalist

Houdini fly invasion


Two years ago I had never heard of the Houdini Fly.  However at that time  they were starting to  turn up in the Duncan area. This year I encountered them in several of my mason bee nest boxes I have placed on surrounding farms in the Metchosin area so they are a recent invading parasite for mason bee larvae production.

These are probably the most destructive parasites of mason bee colonies as they will eat through all the cocoons in a tube if allowed to remain through the fall and winter. The best solution is to clean out the mason bee incubating tubes as soon as possible, even as early as late August. It is important to leave those tubes that have not been sealed by then for a few more weeks in the bee house as later nesting leaf-cutter bees and other pollinating wasps and bees may still be working.

Not cleaning out your colonies early may lead to total cocoon production  failure.

See this link for other parasites of mason bees:
https://gfletcher.ca/category/mason-bees-and-phragmites_reed-grass-tubes/mason-bee-parasites/