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!
March 13th, 2010 at 6:56 pm
Thanks Gord and Omie.
Gord – that’s a very good little article you wrote there. I would be interested to hear more about why you put color dots on the surface – is that for you or the bees to keep track of the trays? Feel free to tell us if/when you start running your courses on Mason bee keeping – would be glad to help you publicise.
Omie – let us know how your bees get on… would also be glad to hear you talk about you and your friends efforts in starting up. You can even write a little piece if you want, and if you have no other place to put it online, I would be honoured if you would like to share it here. I will also be putting a Forum in place here wery soon if you want to share and pose more questions.
Cheers, Paul.
March 17th, 2010 at 2:45 pm
Hi there Paul
Just a a note to say how lovely to find a blog about solitary bees!!I am an artist and will be having a small show in London in June to promote interest in these delightful and rather neglected little bees. I am actually in the USA for a while and was initially researching USA bees for a commission and had some wonderful Osmia species sent to me by an orchard bee specialist, O cornifrons, O lignaria which they call BOB’s here and the beautiful little O aglia. I keep a blog about it all and have just added you to my Solitary Bee Links page.. I know you are in France but think all you have to say is very relevant to the UK.
I will also follow you on twitter but I am a bit new to it! I seem to be getting quite a bit of support and encouragement in trying to get solitary bees a bit better known and appreciated. I will follow your progress this year and blog about it. I have in fact just redrawn the O rufa, not on the blog yet but can send you a copy ..
March 17th, 2010 at 7:55 pm
Thanks Valerie,
It is great to hear from another fan of solitary bees – they need our help, above all in finding suitable accommodation. I will certainly take a look at your blog and at least, link back to the pages when I get another post up. Having carried out a brief scan of it (am at day job), I am very very impressed. I look forward to looking at your work in detail.
If you are also a facebooker and fancy join the “Campaign for solitary bees” or tell your friends about it, we are launching our manifesto very soon.
Cheers, Paul.
March 22nd, 2010 at 12:54 am
Hi Paul,
You asked about colours on the outside of the trays – it serves two purposes, although mostly for the dumb humans that watch the bees. Yes, it is a stair-falling-down system as well as a minor bee orientation ploy, but mostly the former for us to make sure we put back in the same order. Imagine if you showed up at your flat and someone had shifted the floors all around? Bees kinda’ like to know exactly where they left off instead of depending on their own scent.
It’s kinda’ far away from me where you are but my next class is March 27 at the Victoria Compost Centre. My Fall cleaning classes aren’t until November 20 (http://www.compost.bc.ca/learn/communityeducation.htm).
Thought you might like to see some of the bee discussions that go on around Vancouver/Seattle/Victoria on GardenWeb (http://www.gardenweb.com/). I’ve been contributing wherever I can. Some “experts” like to spar about what they think they know without doing much in the way of scientific methodology.
Thanks for the inspiration.
Cheers, Gord
May 9th, 2010 at 10:37 pm
Thanks for that info Gord
Judging by my bee behaviour when they come back to the tunnels, on further reflection I think any markers that help them identify the tunnel or section they are working on is actually useful.
I hope your classes are well attended – happy to have your link to them on here – would love to see how they go if you make another video or two.
Sorry I was very slow in coming back to you on your blog – I was changing jobs right in the middle of the bee season – and I note you have decided to pull it off-line. I would be happy to give you what help I can now I have more time on my hands when you set up another one.
May 15th, 2010 at 2:20 pm
I’ve been squishing those cacoxenus indagator flies when I get a chance. They are pretty lazy and easy to splat. Next year I will create a hatchery for the coccoons which I will clean with sand to get rid of the mites.
May 16th, 2010 at 9:51 pm
Haha – yes, they are pretty lazy and easy to squish jo0ls!
I have the impression that out of earshot of humans they are very polite – saying “good morning – lovely sunny day for a flight” as the mason bee emerges.
Sometimes I think I can also hear a barely audible whistling as they pretend to be looking at something else when the mason bee female returns.
However we know what they’re up to.
This morning (16th May) I had a weird experience in respect of this. Whilst watching my bees on the ladder one of the last remaining Osmia cornuta females emerged from a paper tube with something attached to her back leg. She then flew directly sideways towards me and hovered by my left ear. The ‘thing’ dropped from her leg and landed on my shoulder. It was the body of a dead parasitic fly. An entirely micro-weird moment.
I will be cleaning the cocoons in the late autumn before they become young adults and with the reflex to become stressed. Good luck with the rest of your population this year. Do come back and tell us more about them.
Regards, Paul.
May 19th, 2010 at 11:42 pm
Well, here’s a video showing my boxes, and the local birds…
http://www.youtube.com/user/jo0ls#p/u/6/yLvIfY-BSws
May 22nd, 2010 at 3:15 pm
Thanks for sharing jo0ls… it’s interesting those birds are really taking advantage of the solitary bees – but it’ll all naturally rebalance out in the end; it’s what ecosystems and food chains are all about.