Welcome Gems!
I must confess that I've never heard of London Pride. Is that Saxifragas Umbrosa, as shown in the pic in the following link? I believe it's available in other colours as well.
Saxifragas Umbrosa
I looked up some information on vine weevils and found this rather wordy document on root/vine/black weevils that you may (or may not
) want to read. It does mention mainly nursery/container problems, as you were told, so I don't know, perhaps buying a contaminated nursery plant would have introduced it to your garden???
Root Weevils
The following info comes directly from my 'New Illustrated Guide to Gardening in Canada.' I hope it's of some help to you!
~ Vine Weevils~
Plants Affected:
Tuberous begonias, pot cyclamens, primroses, saxifrages (that's yours!
), and some other plants. Much damage is done to greehouse plants, but these pests also appear outdoors and are particularly serious on rhododendrons and azaleas, and on yews.
Symptoms and signs:
Small, white, fat, legless grubs that live in soil eat roots, tubers, and corms.
Danger period:
Most times of year. Grubs are usually noticed in winter and early spring.
Treatment:
Remove and destroy any grubs found when plants are repotted. Infested plants may be treated by working small amounts of Diazinon dust into soil or by applying soil drench of Diazinon or piperonyl butoxide. Paradichlorobenzene (moth cyrstals) placed among drainage crocks before potting will also protect susceptible plants. On outdoor shrubs, inspect plants carefully for chewed bark around base of stem and reject any showing signs.
Kim
