Which cleptoparasite killed the leafcutter bee larva?
Around this particular nest box, used by leafcutter bees, I filmed 7 different solitary bee parasites. There are several suspects that killed the bee larva, though some can be eliminated from the investigation!
Monodontomerus wasps, Pteromalus wasps, Chaetodactylus osmiae pollen mites and Cacoxenus indagator fly are all not guilty! I watched a female Coelioxys cuckoo bee enter this cavity and marked where the cell was she entered on the glass viewing window.
I was lucky with my timings as when I opened this cell it was pure good luck to find the formidable mandibles of the Coelioxys cuckoo bee larvae. It hatches before its host and is ‘unarmed’ feeding on the pollen nectar mix.
As it develops through its larval stages, The Journal of Apicultural Research states that it grows a strong mandible, which it uses to crush the egg, or kill its host or other Coelioxys larvae in the same cell. You can clearly see the fang like mandibles in the video. It can open them very wide which is useful when searching for its victim(s) in the dark.
The gruesome looking mandibles drop off after the ‘deed’ is done as they would prove almost useless when eating the nectar/pollen mixture. It therefore gets rid of the evidence! The lava becomes ‘unarmed’ once again, finishing its development inside the leafcutter bee cell. A leafcutter bee larva mandibles could not be used to kill another larva. They are better equipped to eat and drink the pollen/nectar mix, which contains much more fluid nectar than that of a red mason bee cell.
You may find this popular article about leafcutter bees interesting
A great visual guide for the identification of British Coelioxys Bees by the Amateur Entomological Society can be downloaded here
For more information on the above named species go to Bees Wasps and Ants Recording Society BWARS
For info and link to buy an excellent book Field Guide to the Bees of Great Britain and Ireland by Steven Falk
An extremely useful resource supports this book by a special web site feature within Steve Falk’s Flickr web site which furnishes extra photos and other useful resources to assist with identification.
Filmed using my award winning solitary bee observation nest box which made the film possible
Hi, I have found a cigar shaped “nest” about 6 inches long , stuck up underneath my garden parasol. Half of it fell down when I opened the umbrella and I have had to take the other bit down . Will the bee return to it if I just put it in a box underneath the umbrella or what shall I do with it ? Put it in the shed or something ? Does it need to hang upside down ?
Aw shame! She will not find them now. Keep it level if possible and try not to move it too much as the eggs/larvae are very delicate. Keep in a warm place out of sun.Then leave them there! If they are still alive contact me in October for more info! HTH George
Hi I bought a red mason bee nest box, it looks like the mason bee hasn’t had a good year but I have evidence of a leafcutter Bee and living larvae. I need to remove them so I can reuse the tubes nxt year. There are also nectar packages along with larvae. I have placed them in a small tin together with nectar, will they find their way to it? These may seem silly questions but I’m not all clued up on bees at the moment. Thanks
Anna, I have seen your photos. Leave the bees inside the paper tubes and do not open any more cells exposing the larvae. Put them in a mouse proof container inside an outdoor shed etc then contact me in the spring. HTH Cheers, George Ps You need a much better bee home!
I have a bee house and have 7 off sealed tubed. However today i have noticed 2 of them seem to have been opened. Do any solitary bees hatch the same year as sealed up. Or has some predatory pest opened them up to get at the larva.
Many thanks
Hi Joseph, difficult to say, as I have had several over the years and the small hole has usually been in the middle of the mud wall and the larvae have been fine in some cases and predates in others. I don’t know the design of your box which may make it difficult to see into the tubes….I can see in all of mine which helps 😊
Hi, I have a fairly young bird of paradise plant which I recently put outside to get some summer sun. Then today I noticed a leaf cutter bee taking leaves into a hole she’d burrowed into the soil in the pot. As this is an indoor plant sooner or later it should come back indoors but I don’t want to have the bees hatching out indoors. I think the plant will be ok in the greenhouse over winter but will this be ok for the bees? When do they normally hatch out by the way? Thanks for your help. Alyson
The bees wont hatch until next year so hopefully the green house should be fine. Cheers, George
Hi George
I have several leaf cutter bees in my nest box this year. Is there anything I can do to help them hatch successfully. I know with Mason Bees people harvest the cocoons, but what about leafcutters?
Hi. Last year several leafcutter bees nested in a pot in my greenhouse. This year there are more. I have to leave the door open for them as they seem incapable for finding their way out of the windows! Do bees return to the place from which they hatch?
Some do Belinda, some find new sites. Cheers George
Hi George, we have a few leafcutters starting to use our hotel at the moment. I’ve noticed that a couple of chambers have been laid and fully capped off, but the next day another leafcutter has come along and gradually cleared out the entire freshly laid chamber (even though there are plenty of empty holes still available).
I’m assuming it’s a different bee doing the dismantling, rather than the original nest maker destroying her own hardwork. Appears that they are acting very competitively for ‘prime real-estate’?? I have not found any literature detailing this behaviour yet. Do you know if this is common? Many thanks.
Probably Megachile ligniseca. https://www.bwars.com/bee/megachilidae/megachile-ligniseca
I have filmed them doing this.
Cheers George