Question
My two English Holly Bushes have developed small white powdery spores on the underside of the leaves. Some of the leaves have withered. Can you advise on the problem and advise a remedy. Thanks.

Answer
John,

The only insect or mite (my specialties) that might appear as white powdery spores are scale insects (see http://www.livingwithbugs.com/sca_ins.html for a picture). These insects often appear as white, cottony masses. If your leaves don't look like this then it is probably a disease such as powdery mildew. If you post a picture I may be able to give you a more definite answer.

Jack DeAngelis
http://www.livingwithbugs.com