Otiorhynchus sulcatus - these are creamy-white larvae,
about 1.5cm (half inch) long with brown heads. Rarely a problem
in the open, they mainly affect the soil in greenhouses.
They are not fussy eaters, they enjoy the roots, stems and leaves of
many plants. This causes the plants to wilt and die.
Unfortunately, they are becoming more common.
How to Treat Vine Weevil
The traditional treatment was to mix in gamma HCH dust into the
top layer of the soil. Maybe the weevils have become
immune to this or maybe it never worked very well. Either way,
it does little to deter these pests.
There is a relatively 'new' biological treatment available from some
garden centres - a nematode called 'Nemesis' which enjoys eating
the weevils. It does seem to make a real difference.
In the end, if your greenhouse soil is seriously infected, the best
solution is to remove the top 20 cm (9inches) of the soil and
replace it with new top soil.