DSCF0613

DSCF0613

Observation - DSCF0613 - UK and Ireland. Description: Something is attacking this geranium in my garden and killing off the leaves and flower stalks. It works it's way through the stem, causing wilt. It only attacks this geranium variety. Is it an insect or a fungus?

Something is attacking this geranium in my garden and killing off the leaves and flower stalks. It works it's way through the stem, causing wilt. It only attacks this geranium variety. Is it an insect or a fungus?