Why are these white dots appearing on my citrus and avocado trees and the leaves getting pale?

Question

My Orange and small avocado trees are becomming yellowish and have many dots on them, is this a deficiency of something or something else?

I checked the bottom of the leaves for any sort of plague but didn't see anything.

Click any image for full size

Answer 1

Looks like spider mites or a deficiency. Here's how to tell them apart:

• look on the underside of the leaf. Spider mites are visible to the eye but a magnifying glass will help. If you see whitish blobs clustered around the veins of the plant you have a small problem. If I'm right you have an extensive infestation and will see them all over the underside of the leaf. You might even see webbing between the axils of the leaf.
• on the top of the leaf you won't see much except for pinhole sized light spots where the spiders have sucked the plant juices out from the underside
• if it is a deficiency it is more common to see dark veins and light leaf material or spotting but you will not see webs or anything on the leaf. See this post for some pictures of citrus with a deficiency.

Control of spider mites on citrus is challenging in warm climates. Mix one teaspoon of soap to a quart of water, get a cloth and wipe the underside of each leaf. Rinse or spray with fresh water. Repeat at least twice at five day intervals to get the eggs.