Not another bee photo

I was surprised to see a "bee" on my domino cactus flower early this morning because these cactus flowers are white and open at night which means that they are pollinated by moths.

Taking a closer look, I realised my mistake: the proboscis was working very busily lapping up the pollen, which is not something that bees do. The legs are also long and slender, which gives it away that this is actually a Drone fly, Eristalis tenax.

Hover flies feed on nectar and pollen and they are harmless but mimic bees because bees can sting and are avoided by certain predators.

This strategy doesn't save them from all predators, my garden is full of Robber flies who would probably attack and feed on hover flies too. Below is a robber fly feeding on a soldier fly. Soldier flies mimic wasps and that was a bad strategy here as robber flies have no qualms about attacking wasps either.

Adult Hover flies have a genteel diet of nectar and pollen but like all flies, the larval stage involves a maggot. I didn't realise that their larvae live in mud and stagnant water and has a breathing tube. Oddly enough, I was watching some hoverfly maggots the other day in a bucket that had collected rainwater without knowing what I was looking at. I forgot about their presence in the bucket when I later tipped the water out because I saw mosquito larvae in it.

Although people always go on about declining honeybee populations, they don't spare a thought for the many fly species such as these who are also flower pollinators. Some bee mimic flies are also very important aphid predators and very useful in the vegetable garden.

The Domino cactus doesn't set seed, meaning either that there are no suitable insect pollinators around or that they aren't self-fertile. I'll be curious to see if the fly's visit changes that