Ivy Bee invasion in my polytunnel!

[BettinaD]

Hello - I'm a grower of cut flowers and currently have hundreds of ivy bees (Colletes hederae) in my polytunnel! This has never happened before so I'm just trying to figure out what to do with them/whether to do anything at all? I've read that they're not dangerous and I've been working in there quite happily alongside the bees but just wonder whether anyone has any information about them. They are very active on warm days, but don't seem to feed much. I haven't spotted any nesting site anywhere - apparently they like sandy soil and we have solid clay! Can they be collected somehow and brought outside? Any information would be gratefully received, thank you!

[DianeBees]

I'm afraid I don't know anything about Ivy Bees (Just googling them now)
How easily can they get out? What flowers are attracting them?
Sorry I can't be more helpful!

http://www.bwars.com/content/colletes-hederae-faqs

it forages almost exclusively at flowers of Ivy, and flies only from September to mid-November (ie during the flowering period of Ivy).

[BettinaD]

Hello @DianeBees - the doors of the tunnel are wide open so they could easily leave. Some of them seem to fly in and out but they're mainly sat on the metal structure of the tunnel, on the polythene sides and on the flowers (without feeding though!). I grow dahlias and zinnias in there, the zinnias do produce a lot of pollen but as mentioned, not much feeding going on. I might have a thorough look for a nesting site somewhere in the vicinity tomorrow - we have some raised beds so perhaps they made themselves at home in the compost in there? Just very strange that we never noticed them before and suddenly there's hundreds!

[Patrick]

Hi BettinaD

I had to google it too. Are there nest holes in the ground surface dotted about? Maybe areas out of the prevailing weather and in the warm with areas of bare soil uncovered by vegetation for excavating nests is exactly what they are after.

Its a stunning little bee, apparently considered harmless and a very interesting recent UK arrival (much as Tree Bumble bees) so I would enjoy their company whilst they are with you.

I wonder of they will exhibit the same seasonality if they are indeed living in a protected polytunnnel? You may be the first to find out..!

[BettinaD]

Hello Patrick - I've yet got to do a thorough investigation of the surrounding soil to see if there are any nest holes. It's a bit difficult at the moment, as the tunnel is full of very bushy plants so I can't actually see the soil very well. I'd be amazed if they have indeed made nests in there because we work in there every day and haven't noticed anything! It would also be a problem when it comes to re-planting time, as we have to lift the dahlias and plant other crops. But yes, definitely a very interesting time, and they are lovely little creatures!

[nealh]

Collete species like most of the various ground dwelling bees are solitary bees, they will each will have a separate nesting camber though may use the same main entrance tunnel to access the chambers Like Leafcutter & Mason bees will be quite harmless as we pose no threat to them. Life span is short and about 6- 8 weeks and they will have done the necessary to allow next years generation to prosper. Strength in numbers nesting close together to help to ward off predators.

If they are nesting in the poly tunnel it should be evident by many small holes in the soil or simply watching where & when they go to ground to locate where they are nesting.

Ivy is in bud but not seen any flowering just yet, could be they use the poly's for warmth and pollen from the flowers to furnish the larvae with food as the larval stage is very long.