Affected tissue eventually turns brown, shrinks, and hardens. To manage leaf and flower gall, reduce humidity, avoid excessive leaf moisture, improve aeration through increased spacing, and pick off newly formed galls before they turn white. Fungicide applications are not effective. Rose aphids are only one of the several hundred aphids or plant lice that appear on various plants throughout Kentucky. Aphids are sucking insects and are capable of transmitting diseases to certain plants.
Aphids have a rather complicated life history.
At certain times, they lay eggs and other times they give birth to living young. They may also reproduce without mating, and under certain conditions are able to produce either males or females. Aphids will frequently alternate from one host to another. Since aphid numbers can build up rapidly, frequent monitoring is needed, especially when plants have succulent growth. Rose Black Spot Black spot is one of the most common diseases of roses.