Tetranychus urticae
Tiny arachnids that feed on plant cells, causing stippling and bronzing of leaves. Populations explode in hot, dry conditions.
Extremely small (1/50 inch), barely visible without magnification. Yellow, green, or red. Fine webbing on leaf undersides in heavy infestations.
Stippled, yellowed leaves. Bronze or rusty appearance. Fine webbing. Leaf drop. Reduced plant vigor and yield.
Many generations per year (as short as 5-7 days in hot weather). Overwinter as adults or eggs. Populations build rapidly in hot, dry conditions.
Maintain adequate irrigation. Avoid dusty conditions. Don't over-fertilize with nitrogen. Encourage predatory insects. Inspect plants regularly.