Solitary Bees

It has been more than a week without an update, basically because I was trying to get this blog back online in Internet Explorer (after fiddling with it too much)… so just time for a quick photo update of last weekend (no.3) before Easter began.

In the main box which had been put outside for me on the 2nd of April (as it was reliably warming up) I discovered that at least 8 of the earth-blocked plastic tube entrances had been unblocked in just the two days before I came back to the countryside. Until that point all the activity seen had been from the between bricks solitary bees (still going strong), and the overflow paper straws I had made late in the 2008 season when the box had filled up. I managed to take a few decent pictures of the males waiting for females to emerge…

It was also a good sign because I had started to get worried about how many of the tube cocoons were actually going to produce bees. I had estimated that possibly up to 80 might emerge from the box, but I wasn’t going to risk pulling the tubes out to count them (and the stress of the bees worried about things beyond their control). I had tried to learn my lessons from last year and adopt a total risk minimisation strategy.

The opaque plastic tubes

I created the box for the possibilities of filming the solitary bees in 2006. The next year, after feeling satisfied with the success of the experiment – all 30+ solitary bees cocoons had been emerged/produced – I lightly cleaned out the tubes and replaced those at the top with new clear ones. The films that followed of the squabbles between female bees became some of my favourites and have received up to 500 views on the tube. At the start of 2008 with worries about frosts, early emergences and bee deaths I removed the tubes and the cocoons (89) from them but I think the cold snap and stress of the removal caused a number of losses up to 30%, so I resolved to not touch the contents in 2009.

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Update 2010 provoked by Jerry’s comment : a major part of this loss was actually due to an error which I only just confirmed this year. In fact I thought all the cocoons should emerge at the same time and assumed that they were dead. It is in fact quite probable that in some of these ‘un-emerged’ were females that were delaying their emergence until temperatures are more stable. I say this because part of my 30% loss was due to me giving up on about 20 or so cocoons, placing them on a shelf in the barn workshop, only to find they were completely gone the next day. So I will never know the real cause – handling, frost or snacking animals. However, I have finally learned the art of patience.

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So it was a guesstimate this year as to how many female bees actually emerged from them, last year amongst the survivors there were about 14 females that emerged and flew off. This year I have no certainty of how many females have emerged – no idea of the success rate at this point – so I will only be able to count the females that are actively nest-building in a given moment in time. This ‘not knowing’ is a worry as it would be good to know that the the plastic tube project is part of the solution and not causing excessive problems.

I get the impression from the appearance of the plastic tubes and the opaque cells is that I will probably do well to properly clean and perhaps disinfect them so that any fungus (white cells), mites (if they exist) won’t carry on over to the next year. I tried to make one ‘inspection video’ (not sure it’s that good to show this) before setting the box out, but not a lot of light was able to be shed on whether it was a successful post-adult phase in terms of expanding the population.

This entry was posted on Thursday, April 16th, 2009 at 11:17 pm and is filed under 2009 emergence, bee emergence, learning curve, solitary bee males. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.