Broad bean beetle and enviromesh

[ChingfordHarry]

Hi

Like many of us, I get quite a few broad bean beetles. Not such a problem when I'm eating them as a green vegetable, but when they are dried it's more of a nuisance - those kept for seed don't last or grow as well, and although the beetle holes will allow a bit of oil or lemon juice into the bulk for extra flavour, they don't look so appetising, and not the kind of thing you would want to serve to guests...

I have read that enviromesh (or similar) might help keep the adults away during their laying season - but has anyone here actually tried this?

[ameno]

I don't grow broad beans, but if it's the same bean weevils that can affect other types of bean in storage, then I've found that they usually only hatch and then do damage in storage. Thus, the easiest way to deal with them is to freeze the beans for a couple of days as soon as they are fully dry (freezing before fully drying may damage the beans). This kills all of the eggs. Once you remove them from the freezer, they want laying out on trays again to make sure they are fully dry for a couple days (as the cold can cause condensation), before putting in your normal storage.
I have found that dry runner beans that I have previously frozen for several days will still germinate well, just as long as they were fully dry when they were frozen.

[ChingfordHarry]

Yes, as far as I know they're the same beetle - probably Bruchus rufimanus. As it happens, I do freeze my dried beans to kill pests like these, and it works a treat - for others who don't, your instructions are clear and comprehensive. Fortunately, the grubs tend to stick to the cotyledon so affected beans will (mostly) still germinate.

However, I've just shelled half a kilo of fresh green field beans and ~1/3 had beetle damage (small brown holes [smaller than the exit holes the adult beetles make]), surface markings and occasional grubs in the beans - so I'm more interested in trying to stop the blighters in the first place!

At the risk of changing the topic completely, I've noticed that "preppers" are very keen on oxygen absorbing sachets to kill grubs in their dried supplies - the idea being that the eggs and early stage larvae asphyxiate. Anyone here have any experience of these?