Summary: The aphid can be a serious threat to rose gardens. Summer temperatures create the perfect environment for aphid reproduction.
Aphids have unusual life cycles allowing them to build up very large populations in relatively short periods. Most aphids over-winter as fertilized eggs glued to stems or other parts of plants. Aphid nymphs hatch from these eggs to become wingless females. The females can reproduce without mating and eggs are held within their bodies until they hatch. Young aphids are born alive, quickly mature and begin to reproduce in the same manner. This pattern continues for as long as conditions are favorable. A dozen or more generations are typical in warm climates.
***image1***Aphids are almost always found on the new growth of rose plants. They tend to come out in full force in mid-summer when there hasn't been much rain. They suck the juices out of the roses, causing leaves to curl and disfigure.
The best aphid control is healthy plants that have received adequate amounts of water. If the rain hasn't come and ladybugs haven't done their job, then you need to stop the aphids before they take over. Insecticidal soaps will kill most soft bodied insects by suffocating them. You need to apply it a couple of times right before sunset. Then, two days later go out and spray any aphids that escaped your first spray. If you miss one the population will rebound in a matter of days.
Another quick way to get rid of aphids is to have your pest control company treat the roses with a low toxicity insecticide treatment. It's very effective and it won't hurt any flowers or ornamental shrubs. Ask to make sure they provide that specific service.