Those of you who have followed this blog will know of my love and involvement with Horse Chestnut- or Conker- Trees. I have written before about the "blight" that has been effecting the leaves of these wonderful, majestic trees in recent years. This is caused by a leaf miner moth, Cameraria Ohridella. The caterpillars "mine" the leaves until they turn brown and die, giving the trees an early Autumn appearance. The trees normally recover from this but it can weaken their systems over the years.
Walking around Bath almost every single Chestnut I see- and there are many- has sadly been attacked by this hardworking grub. I get very emotional about this as, having planted many Conker trees myself, I regard them as my inheritance apart from regarding them as such exceptionally beautiful trees. Not only do they have fantastic, Matisse-like leaves but they also have those fantastic, candle like flowers.
I am therefore particularly distressed by a further disease which has been attacking these trees. This is "bleeding canker", a deadly bacteria caused by a fungus, Pseudomonas syringae pathovar aesculi, which results in sores in the trunk and limbs out of which ooze a black liquid gum. If this spreads in a continuous ring around the trunk it can destroy the tree. Also, branches can be weakened making the trees potentially dangerous to pedestrians, resulting in them being felled.
Another result of these diseases is a reduction in the harvest of conkers: where the ground beneath the trees is normally covered with these very special, shiny, tactile treasures, now you can find very few of them. Apparently the World Conker Championships- held in Ashton, Northamptonshire- have had problems supplying the 5,000 conkers need for the contest.