I have a lot of maggots in the skirting boards and stairs of my communal hallway in Devon. This has been going on for several weeks (councils are very slow to act), and now I have just discovered a caterpillar. Is the catepillar a grown up version of the maggots? Is it feeding off the maggots? What will the maggots become if not the caterpillar? And what will the caterpillar become?
I think the caterpillar is a yellow underwing. They often live underground feeding on plant roots but I don't know how it found its way into your house - maybe it's looked for somewhere to pupate.
The larvae look like bibionids (Bibio or Dilophus species). They often occur together in large numbers, in soil, but again I don't know why they'd be in your hallway
Thanks very much for your reply.
There are large structural problems with this building (I have a serious damp/mould problem - my bedroom is the otherside of this wall), and these maggots are a part of it.
I think they come up through this hole and then make their way through the corridor to other holes in the skirting board. They are always scattered all over the place after a good rain (which it's been doing a lot of recently!).
The caterpillar was found at that large hole pictured above. I'm relieved that the maggots aren't related to the caterpillar since I've killed hundreds of them.
I don't think either the larvae or the caterpillar are causing any damage, I think they're just a symptom of the structural problems you describe. However, their presence indicates that those problems are pretty bad. I don't claim to be an expert but I think bibionid larvae normally feed on decaying vegetation (although they will occasionally turn their attention to healthy roots) and I wonder if mould in / around the house is drawing them in. Is there dry rot?
Oh, yes, definitely a symptom. I didn't mean to imply they were the cause.
I've no idea how you tell if there is dry rot..? There are serious structural issues around damp/mould (my bedroom is unusable), but I'm stuck between a horrendous letting agent who won't do anything, and a ridiculously slow acting council.
Tell me, do you think there is the possibility that the maggots could work their way through to the other side of that wall, i.e. my bedroom?
Well, in your latest photo the end piece of skirtinmg board seems to be in a pretty bad state, which could well be some sort of rot. I wonder if the fungus causing the rot could be attracting the larvae, but that's just a suggestion. If there is wet rot or dry rot that might be a more urgent issue than the larvae.
I'm not entirely sure how the larvae are getting in to your hallway so it's difficult to say whether they might appear in your room. If they're just coming up from the ground below it would seem feasible. In my house ants seem able to appear both sides of the external walls but occasionally further in the house too.
Oh god... thanks for your advice. I hope the council acts soon! I don't want these things burrowing through to my flat!!!
There are a lot of problems with this building - rain comes in through the top part of that wall! Not to mention rising damp (according to the damp specialist that visited), and now these maggots. I wouldn't be surprised if there was some sort of fungus as well. Why not?! The more problems the merrier at this point..!