Well not sure how far in the nest goes ,never thought about putting bin bag over them.I was a bit concerned about fire as they are so near the hive.Might try the bin bag if l can get near them. Thanks for the reply.
I had the same problem last year in my garden stone wall, tried for weeks to kill the little b******s, couldnt get rid of them all, couldn't dismantle the wall,wouldn't risk chemicals, powders etc in case they went into my hives, maybe a little bit drastic but in desperation , i blocked as many entrances as i could find (With an old ripped up t shirt) then i GASSED them with the bbq gas bottle........SORTED.
just hoped nobody walked past smoking or i would have been rebuilding the wall after i collected it from next door
right top dog of the killing of anything his on line, hedgerow pete
lets ask a few more questions and put a couple of ideas your way,
first up stop using petrol only use parafin or diesel a bucket ( 4 litres) poured onto in to and around the nest a litre at a time will soak into the paper the nest is made from and will burn very quick and cleanly
do it at night when everyone is at home bees and wasps and there will be no problems
other ideas pour dry wall paper paste into cracks in wall where there entrance is and then get the hose pipe to blow it inside the nest
dismantle wall and use fly spray
heres a sick one all wasp nests have only one entrance exit so find it and seal it with the largest glass bowl posible make sure it is sealed on the edges the wasps will not try to make another entrance as they can still see day light but the nest will starve in four weeks,
chemicals, i love the smell of toxins in the morning !!
try these wasps love meat as well as sugar so put a table spoon of dog/cat food inside a wasp trap that will placed next to the hive that will kill off loads
get a can of wasp net destroying foam and a large piece of carpet from a skip . spray nest then cover up wall with carpet
bees will not rob a wasp nest but by september you will have no alive bees because the wasps will kill them all for the grubs
if that little lot is not enough try this final one
get ,buy ,rob, borrow a home wall paper striper steamer . put the pad at the end of the hose into the nest entrance and then cover the wall up with every thing , news papers , carpet, blankets , dust sheets and then start steaming i would surgest three lots of water and to steam for three hours
and finaly whos this find a fisher man tell him he can have the grubs for free and they will come and deal with it for you instead wasp grub is worth a fourtune to a match fisher man