Publications for:

pest = Erysiphe heraclei
crop = Hedera (crop)

found 2 publications:

2015

First report of powdery mildew caused by Erysiphe heraclei on Hedera helix in China
Plant Disease (2015) 99 (6), p. 888A
publishers website - pestinfo wiki

2008

First report of powdery mildew incited by Erysiphe heraclei on English ivy (Hedera helix) in Italy
Plant Disease (2008) 92 (2), p. 313
publishers website - pestinfo wiki