Aphids

Aphids are tiny, soft-bodied, sap-sucking insects that form colonies mainly on young leaves and shoots. Heavy infestations can cause leaves to curl and turn yellow, stunt growth, and result in the appearance of sticky honeydew. Some aphids transmit plant viruses, but small colonies are often kept in check by natural enemies. Plants should be monitored regularly, especially on the undersides of leaves, and action should be taken only after identifying the pest and assessing the extent of the problem.