Cacoxenus indagator flies & bee mites: the main parasites of solitary bees
On the subject of solitary bee parasites I just wanted to share some of my experience through some pictures I took; of some of the mites that I found in my paper tubes and Cacoxenus indagator a fly parasite, so you get to see what they look like up close. Writing this was inspired by seeing the videos of disinfecting solitary bee cocoons.
When I first saw evidence of mites in my plastic tube bee observation box in June 2008, I didn’t know what had happened. Successful cells normally showed the silhouettes of an oval cocoon (vaguely visible in image with labels #4 & 5), however the cell containing mites looked to me as if a developing bee inside it had sneezed (as if having a bizarre hayfever) which had spread the pollen onto the walls of the tube. Hope you can see what I mean in the first picture (labelled #3)
On peeling open my paper tubes at the end of last year I got a real close-up of them. I would need to film this with a macro-video camera, but it was kind of spooky the way something invisible was slithering/crawling in amongst the digested/sneezed pollen dust. In this second image we see this ‘dust’ very clearly (labelled A).
What you may also notice in the middle of this image are the three larvae. These are from Cacoxenus indagator fly which I saw many times at the entrances to my tubes and tunnels. They look like fruit flies, and I have to say that I wasn’t very charitable to them.
Here’s a picture of two of them that I had photographed quite unwittingly in 2007 before I really knew what they were. The red-eyed little devils were apparently conversing amongst themselves, clearly pretending they were up to nothing sinister.
I would guess that about nearly ten percent of my tunnels were infected with their larvae when I open up the tubes at the end of last year. So I cleaned them out manually to ensure a minimum amount of infection this year.
Finding their presence in such quantities underlined the fact to me that I should not leave any tunnels with them in (if I really want to maximise my population’s potential), nor should I put drilled bee blocks in place without paper inserts that I can remove at the end of the season. I have decided that any reeds and tunnels that I have bee unable to disinfect (because I was afraid of damaging the cocoons), will be placed in a different part of the garden.
Here’s a video I took last year on my YouTube channel where we actually get a brief glimpse of a pesky fly snooping around (@40 secs hovering bottom right).
…and finally an even more interesting moment, this last video where we see a solitary bee female doing some spring cleaning of a tunnel of my bee observation box. It wasn’t till afterwards that I realised that I had recorded her tugging out an old empty cocoon (@35s & 48 seconds) and returning to the same tube. Oh yes, and there’s also another pesky Cacoxenus indagator glimpsed at the bottom of the shot hovering just underneath the box @30s.
February 2nd, 2010 at 1:01 am
[...] Mason Bees and other native bees « Solitary bee expansion project – cascades Cacoxenus indagator flies & bee mites – parasites of solitary bees [...]
February 3rd, 2010 at 2:49 am
The non-condo population can bring the mites, but essentially any visitor that comes to the condo that has picked up mites (Chaetodactylus sp.) whilst visiting flowers, or during mating can introduce them to the condo. The mites consume the pollen/nectar pillow which competes with the developing larva within each cell. The trays are cleaned with a stiff brush, either wire or plastic etc. We don’t use bleach or “cook” the trays to kill the mites as this can warp the trays.
Yes, please pass on, but hopefully you’ll give us credit. That’s why we put this up on the net. We’ve had professionals over the years essentially steal our ideas/inventions and claim that it’s theirs. Not a biggy, but quite annoying on a personal level. This way, we can point to Youtube for evidence when we actually put it “out there”. We’ve been using it for years.
Our Hutchings Peek-a-Boo trays really revolutionized my research when I did counts of egg-laying efficiency over the Spring and Summer. I could document how many eggs were laid over time that way. Extracted cocoons were placed individually in test tubes in the exact position that were originally in the channel which when emerged, I could be guaranteed of a sex determination to prove scientifically. This was specifically helpful in showing the most efficient length of channel for this species of bee for female progeny that were laid down, and I could free the bees from the tubes so no mortality for science. I wrote a paper but have yet to publish it. Many years old now and wish I could get someone else to take up the thesis. If interested, I could send to you in its unfinished state complete with graphs.
Gord
February 22nd, 2010 at 10:41 pm
Hey Paul,
Just remembered about this little article I wrote for out gardening centre here in Victoria. Thought it might bee interesting for you perhaps?
Anyways, here it is at: http://www.compost.bc.ca/newsandevents/newsletters/The%20Latest%20Dirt%20Fall%202008.pdf
Cheers,
Gord
March 7th, 2010 at 4:20 am
Waiting for your next excellent post on solitary bees. Wonderful blog!
Can’t wait for my cocoons and bee tubes I ordered from a supplier to arrive in a couple of weeks.
Setting my best friend up with some too- she’s a half mile away. More bees better!