Round "stoppers" / "fillers" / not sure what they're called

[TD]

My kitchen fitters left a couple of large holes drilled in cupboards, probably for pipework that went elsewhere in the end. 20mm and 60mm. I want to fill or block them so insects can't invade the cupboards.

I foresaw some sort of plastic plugs that could fill the holes in, but I searched on Ebay, and apparently I don't know what to search for. Can someone give me a clue?

Alternative (cheap, easy, effective) ways of filling the holes are welcomed. I thought about taping some net over them as well but it's a bit Mickey Mouse.

[newshound]

If you can't find plugs I would just use white duct tape (2 strips for the 60 mm)

[Jeremy Nicoll - news posts]

Or a rectangular piece of white (if that's the inside colour of the carcasses) card or plywood or plastic-card glued over the hole...

[Dave Liquorice]

The fitters screwed up by making holes in the wrong place(s). Get them to source new panel(s) and replace at their cost.

[Dave Plowman (News)]

Why not get the fitters back to do the job properly?

I'd be tempted to replace the panels with new on a new kitchen. Anything else will look like a bodge.