Bee heaven

Regular readers will know that from time to time I visit a family property on Hervey’s Range, in the hills about 40 minutes out of town. One of its outbuildings is a mud-brick pump-shed about two metres square with a corrugated iron roof. A big, old, rarely used pump takes up half the space on the dirt floor. [Update: photos of shed and the bushland around it added to flickr 1 Sept 2013].

Walking into the shed is like walking into a bee-hive. There’s a constant droning hum and constant movement of flying insects. The walls are pocked with dozens, hundreds, of holes which look like bullet holes but are in fact bees’ nests. The insects are not at all aggressive so one can stand there watching the activity and gradually make sense of it all – and take lots of photos, too, as I did last weekend (for the record, nearly 100 photos in just over half an hour). Many of the best are on my Flickr photostream but I’ve put one of each species here too, to see if I can make the connections between the different creatures living together.

(Clicking on a picture will take you to a bigger version as usual, but this time it will be on Flickr and there will be another picture of the same species adjacent.)

Three bees:

Blue-banded Bee, Amegilla sp., Apidae. By far the most numerous species in the pump-shed, and makers of the nesting holes. Most sources only mention Amegilla cingulata but Graeme Cocks notes that “there could be four species locally.”

After mating, female blue banded bees build a nest hole into soft sandstone or clay. Cells at the end contain an egg and food (pollen and nectar) for the larvae when it emerges. A single hole can actually be a complicated maze of tunnels. Although solitary, many blue banded bees may build their nest burrows in the same spot, close to one another, but it is not a colony [in the way a honey-bee hive is a colony]. … The eggs in each nest develop but remain sealed in their cells until the warm weather returns and they emerge as the next generation of adults. (Source: bluebandedbees.com)

Fire-tailed Resin Bee, Megachile mystaceana. About the same size as the Blue-banded Bee but there were only three or four around at any one time.

This Resin Bee female builds nest in existing cavity … (Source: Brisbane Insects)

Fire-Tailed Resin Bee (Megachile mystaceana) … is a great looking bee with a bright orange abdomen. … These bees will create a series of individual compartments (between about 8 and 12) within each hole and provision each compartment with pollen and nectar before sealing the end of the hole with a mix of resin and mud. (Source: nativebees.com)

Neon Cuckoo Bee, Thyreus nitidulus, Melectini, Apinae, Apidae. Much brighter than the Blue-banded Bee but a little smaller and far less numerous, with only one or two cruising around the shed. (A better photo is here.)

The female neon cuckoo bee seeks out the burrow nests of the blue-banded bee (Amegilla cingulata), and lays an egg into a partly completed brood cell while it is unguarded. The larval cuckoo bee then consumes the larder and later emerges from the cell. (Source: wikipedia)

The wasps:

Cuckoo Wasp. A beautiful metallic green wasp, much smaller than any of the bees at only 6-8mm long (i.e. not the more familiar bee-sized Cuckoo Wasp, Stilbum cyanurum, here although colours are very similar).

[Cuckoo wasps] are most diverse in desert regions of the world, as they are typically associated with solitary bee and wasp species, which are also most diverse in such areas. (Source: wikipedia)

On finding the eggs or the nest containing eggs of a suitable species, such as the Mud-dauber Wasp, the female cuckoo wasp lays an egg next to the egg of the host species. The cuckoo wasp’s egg hatches first and the larva eats the food that is stored for the Mud-dauber’s young. … (Source: Australian Museum)

Gasteruptiid wasp. A very slim wasp with a body length about 22mm, an ovipositor almost as long again, and long dangling hind legs. I only saw one of these, flying in from outside and hovering along the face of the wall looking for something or other.

Gasteruptiid females oviposit in the nests of solitary bees (Apidae) and wasps (Vespidae) , where the larvae are predator-inquilines, eating the host egg or larvae and consuming the pollen store. Adult gasteruptiids may be seen on flowers or hovering near bare ground, logs or trees. (Source: CSIRO)

Velvet Ant, Mutillidae (not a Cuckoo Wasp as I first thought). A beautiful, hairy, metallic blue-green wasp about the size of the Cuckoo Wasp at 6-8mm long. Male Velvet Ants, like this one, are winged; females are wingless (see CSIRO’s What Bug is That for more information).

Velvet Ant, Mutillidae, female. I saw this one scurrying around on the shed wall and couldn’t decide for a while whether it was an ant or a wasp.

Mutillids are ectoparasitoids, and can be found on bare ground, sandy areas, tree trunks and walls where they search for nests of Sphecidae, Crabrionidae, Vespidae and Apidae whose larvae or pupae they parasitise. (Source: CSIRO)

I don’t know the maker of this nest but I do know that it isn’t any of those above. A wasp (Eumeninae) has converted a bee’s nest to her own use by plugging the original entrance and fitting a narrow spout-like entry.

Other small wildlife:

Fly. This one species of fly was quite numerous. They spent most of their time resting on the shed wall, and they looked as though they were observing the bees and looking for chances to raid nests.

Their size and conformation reminds me of Tachinidae and the  Australasian/Oceanian Diptera Catalog notes that “The majority parasitize either larvae of Lepidoptera or larvae or adults of Coleoptera, but others attack adults of Hemiptera (Heteroptera), larvae of Hymenoptera (sawflies and social Vespoidea), or adults of various orthopteroid orders.” This is all quite speculative, however, since I’m not sure that my flies are Tachinidae, nor that Tachinidae do parasitise any of the bees nesting here.

Spiders. One abandoned huntsman exoskeleton (I can hardly call it a ‘shed skin’, can I?) and lots of small webs but not a great population of live spiders.

Ant-lion nymphs, in their volcano-shaped pits on the floor.

Why are they all there together?

In case you didn’t put the pieces of the puzzle together as you went along …

• The Blue-banded Bees are there simply because it was a great  place to make nests.
• The Fire-tailed Resin Bees are there because they like to re-use the Blue-banded Bees’ empty nest-holes.
• The Neon Cuckoo Bee is there in the hope it can drop an egg into the new nest of a Blue-banded Bee.
• The Cuckoo Wasp, Gasteruptiid wasp and Velvet Ants are there for much the same reason, although they may be parasitising the Fire-tailed Bees and/or the unknown maker of the nest with a spout entrance (the Gasteruptiid seems very interested in it here) as well as, or instead of, the Blue-banded Bees. Note that they can’t be planning to parasitise each other’s nests because none of them make their own nests.
• The flies may be there for the same reason, or maybe they just like to steal food from the bees.
• The spiders and ants just like a cool shady place to lie in wait for prey.

What a bee-hive!

Update 20.1.13: corrected identification of one photo, male Velvet Ant not Cuckoo Wasp.