[timdunn]

Hello,

Found one of my potato stems wilting tonight and thought it was probably blackleg. I pulled it out of the ground and found a larvae inside the stem. After a bit of detective work I think it may be the larvae of the Rosy Rustic moth. Anyone out there had a run in with these critters before and should I be concerned? Wiki link is here http://en.m.wikipedia.org/wiki/Hydraecia_micacea

 Thanks!

[mumofstig]

The only mention there's ever been on the forum is here -
http://chat.allotment-garden.org/index.php?topic=114732.msg1318825#msg1318825

so it seems quite rare, unless we've all just assumed the damage was always blackleg  Not much help I'm afraid 

[timdunn]

Thanks  interesting that it was less than a month ago. Have checked pics of the caterpillar and am almost certain that's what it is. Nothing else appears affected so perhaps it's just a one off/chance occurrence. 

[timdunn]

Just had another couple of tatties destroyed by the killer moth grub 

Here are some mugs shots:

[Yorkie]

Yuck! 

[timdunn]

Here's the mothership!

[mumofstig]

Shame your spuds are being attacked - I hope it doesn't become a common pest 

[timdunn]

It seems to be a fairly patchy spread and slow onset. I don't think it will have a huge effect on the crop as the potatoes are now flowering. I've probably lost only 1 or 2 full plants so far as the caterpillars seem to just stick to individual stems rather than marauding through the whole plant. I've seen these moths for years now but first time they've affected my tatties. Maybe more than usual survived the winter due to the mild conditions? Happier to deal with these than a dose of blight