Buxus problem

JoeX

I have a buxus topiary ball - or the remnants of one. I’m suspecting box tree caterpillar as I can see wispy webbing…so burn it?

amancalledgeorge

There are pheromone based treatments/deterrents but I'd just say replace them with something that won't be a maintenance hog. I've made the switch to yew and small leaved euonymus and haven't regretted it one bit. 

Fairygirl

Some Hebes are also a great alternative - there are plenty which are small leaved, and work well if you want a globe. Buxifolia, is very similar to box. Clue's in the title 
I've used them in the past for that effect, and there's one called Margaret which is nice. A bonus of flowers too.
The only problem is that they can suffer in very cold winters, and they don't always appreciate being harshly pruned.  A lot depends on your climate though. 

JoeX

Is my diagnosis correct, and is fire better than garden waste?

Fairygirl

It probably is @JoeX, assuming you can do that, but it's not something we really have here, so I'm not sure   

amancalledgeorge

If it's a green waste municipal bin it would be fine. Otherwise if you can burn then, then why not. 

Athelas

I have Euonymus japonicus 'Green Spire' as a topiary ball, quite happy with that, though the leaves are somewhat larger than box. Euonymus japonicus 'Jean Hugues' could be another option. 

I also have Hebe 'Green Globe', very pretty. There's also Pittosporum tenuifolium 'Golf Ball' to consider, if you are after a replacement round green shrub.