Hot Lips Bumble Bees and handedness (1 Viewer)

[Brian Stone]

A friend told me these observations today.

He has bumblebees feeding on Salvia microphylla 'Hot Lips'. They have to make a hole in the side of the flower to reach the nectar as they can't reach it from the front. The interesting thing is that every single flower on the plant in his garden has the hole on the right hand side.

His daughter, who lives nearby, has the same plant in the garden and every single flower on that has a hole in the left hand side of the flower.

It is clear that in many flowers it would have been easier to go in on the other side to that used. In fact in many cases it was very difficult to get access to the side chosen.

So what's going on here? Are these different species? Is it possible that the first bee to discover the source returns to the colony and communicates the location and somewhere in that is an instruction as to how to get at the nectar? Are entire colonies 'left/right handed'?

 

[Nikon Kid]

Brian
Maybe the bee that was giving the directions and instructions was dyslexic :h?:

 

[Wildwood]

Different species often have their own particular sequence for visiting flowers. On an inflorescence (flower spike/group) some move in an upwards spiral and some start at the top and work down. This applies to both short-tongue species, which have to 'rob' the nectar from the base if the flower if it is a deep one, or long-tongue species, which will approach the flower in the normal way and so pollinate it at the same time (Check out a field of broad beans and you'll be surprised how many flowers have been robbed - B. hortorum is the major pollinator of this crop as it is a long-tongued, long-headed species so can reach into the deep flowers and so pollinate too). This behaviour is thought to be related to efficiency in finding nectar.

The 'robbing' holes on the left/right side of single flowers may be just an extension of this behaviour. So if a bee approaches any given flower and robs the left side with success, and then repeats it on the next flower, it may then go on to approach the next flower from the same direction regardless whether access is harder or not. One group of robbed flowers may be the work of just one bee, or if another one comes along afterwards, it may just re-use the same holes, and so carry on the sequence.

Bees almost remind me of little automated robots sometimes, in that if one is spotted foraging on flowers, and you then go and capture it in a tube to examine it, it will obviously struggle to get out. If you then let it go again, it will often just fly straight back to the same flowers and continue foraging as if nothing has happened.