Bees under attack?

[JRsbugs]

My Megachiles are quite aggressive Stuart!

Some pics from last year as well as this year, comments under, showing with colour and faded hairs.

[eucera]

I'm not saying that Megachile are not aggressive, just that it is less obvious than Anthidium (clearly the champions at aggression)!

[E G]

Many thanks again for info and photos. Boy, am I learning a lot about bees. From the information given and some further research it certainly looks like it could be the megachile. Needless to say I haven't seen it again.

[Africa]

Originally Posted by eucera

Have you ever seen Anthidium kill anything? This is often repeated but I have never found a soul who has seen this (except the person who originally put the story about)

True eucera, I've never seen it myself. I've seen many attacks and in every case the bee/bumblebee was able to fly away. The study you refer to must be:
P. Wirtz, M. Szabados, H.Pethig, J.Plant : An extreme case of interspecific territoriality : male Anthidium manicatum (Hymenoptera, Megachilidae) wound and kill intruders. Ethology 78, 159-167.
I have not read it but is widely cited. As far as I know research from S German populations. I wouldn't be surprised if there are differences in aggresiveness between populations.

[crazylilthing]

Originally Posted by JRsbugs

My Megachiles are quite aggressive Stuart!

Interesting, especially as we have nettle-leaved bellflowers (wild campanulas) and Megachile nesting on two sites.

Is Megachile capable of killing rivals such as bumble-bees if there is a shortage of suitable nectar for nest-stocking?
Any instances of this?

[Africa]

I found a few photos of male M. willughbiella attacking bumblebees (B. hortorum) in the description it says they bite the bumbles with their large mandibles - and from the rear!)
Images of the bug Leaf-cutting Bee (Megachile willughbiella)

Images of the bug Leaf-cutting Bee (Megachile willughbiella)

I've given up on lupins though, I don't want a war with slugs (I know I will lose!) but I will try to get a large campanula patch next year.

[Africa]

Wait a minute! one of the photos is identical to yours Janet! are you wallaby1? no wonder you said your Megachiles were quite aggressive. Maybe is the hovering what makes Anthidium more obvious. The Megachiles use a ;sit-and-wait approach. I have never seen them attacking anything, but on the other hand, I don't have an attractive 'flower patch' for them. There is a garden nearby where I have seen males but they patrol lavender (none in my lavender though!). Do you know of any other favourite plants for leaf-cutters?

[JRsbugs]

Yes Africa, I am wallaby1, lol, found out! I don't post there any more though due to unacceptable photo usage policies. It was B. lucorum.

The Campanulas shouldn't be bothered by slugs but I don't have many slugs, I've picked them up and transprted them elsewhere over the years. I didn't notice the megachiles visiting the Lupins so much this year, but they didn't grow as well as usual. They do flower a little earlier though.

I have seen Megachiles on blue Geranium, and early in the season I saw one on Forget-me-nots. I guess Stuart will fill you in for other species.