Tag Archives: Spider

Have you ever seen a fly catch a spider?

[update] – When I wrote this I thought the creature was a robber fly, now I think it’s a spider wasp.

Here’s something you don’t see every day, a large fly like creature walking along carrying a sizeable spider underneath it! Now that’s a prey reversal! A bit like seeing a huge rat hauling a dead cat somewhere.

The fly was black, about 4cm in length with long legs that allowed it to carry the spider underneath it and still walk easily. The one I saw was on a mission to get somewhere, it walked quickly over the pavement for about 4m and then climbed a wall before I lost it. It had wings but didn’t try to fly, maybe the spider was too heavy for it. The spider was slightly longer than the fly and looked bulkier, all the spiders legs were gone and it was being carried inverted with it’s abdomen towards the front of the fly.

I think this is a robber fly, it’s somehow caught a large spider and is hauling it off somwehere

Curious as to if this was normal I did some searching. The closest thing I could find that lives in the area is a robber fly. “Robber flies are large, bristly flies that catch their prey (usually other insects) mid-flight.” Robber flys are known to catch and eat spiders, the fly I saw didn’t have the same enlarged powerful chest as the robber fly photos on the articles. It looks like there is some variation between robber fly species so maybe it’s just a different species that I saw.

It was moving fast and I only had my phone on me so I found it hard to get a clear picture, but you can see the size of the spider compared to a garden hose and a house brick. The spider looked like a huntsman, I’m not sure how the fly would have killed it and removed it’s legs, or maybe it found the spider like that?

Fly hauling a large spider away somewhere
Fly hauling a large spider. Garden hose for scale, shame the subject is blury

Resources and references

Trying to work out how to catch a Funnel Web

[Update] – I thought these were Funnel Web spiders but now I’m pretty sure they are trapdoors, possibly the Sydney Brown Trap-door. See comments below.

As much as I hate to do it I recently killed a few large Funnel Web Trap-door Spiders that had taken up residence close to the house near where the kids play. I did it by pouring petrol down their holes until they came out, then squashed them. Not nice but when they’re that close I didn’t feel like I had a choice. They were big ones, it took 2 liters of petrol to get 2 to come out of their holes. I didn’t like killing them, and also didn’t like pouring that much fuel into the ground. It got me searching around for more info on Funnel Webs and how to deal with them.

As far as catching goes all that I could find was instructions on how to pop a jar over the top of them. Nothing on how to lure them out of their holes. From looking around I learned that stocks of Funnel Web anti venom is low because of low numbers of the spiders in captivity that are milked to produce the anti venom. The Australian Reptile park, where the anti venom is made, is making requests for anyone able to catch a live Funnel Web to drop them off. That’s cool, if I could only catch them then they could be put to some use.

Hoping to come up with something I researched a bit more about the spiders habits and diet. True to their name Funnel Webs live in holes in the ground often with a funnel shaped web at the opening. They lay fine web trip wires near the entrance then at night wait for any small creature to disturb the trip, then they pounce, subduing the prey with potent venom. In this way Funnel Webs eat insects, small lizards and frogs.

Late at night I visited another group of Funnel Web Trap-door holes out the front near to the street. It was Funnel Web Trap-door city, I counted about 30 individuals, mostly smaller but about 4 or 5 big ones, all sitting at the mouths of their holes waiting for dinner. I had a go at trying to get a few of the bigger ones out of their holes by lightly scraping a stick near the entrance. Some individuals pounced then quickly retreated back down the hole, others just retreated straight down the hole. There would be no way you could pop a jar over them.

Sydney Funnel Web Brown Trap-door Spider waiting in it’s hole for dinner to come by.
There were about 30 individuals in the small area under this tree, another smaller spider can be seen in it’s hole below the larger one

The next night I brought a bottle of water and emptied it down a hole hoping the spider would be flooded out, but again it just retreated down the hole.

I’m still scratching my head on what to do, I’m going to try the water in the hole again, but with more water. Hopefully it will come out enough to pop a jar over the top of it.

References and links