What Are the Little White Aphids on My Geraniums?

Aphids

• Aphids are small, pear-shaped, soft-bodied insects that suck the fluid from geranium leaves, flowers and stems. They have long mouthparts that pierce plant tissue and absorb the fluids. The various species of aphid are green, yellow, brown, red or black. White aphids have a secretion of waxy or wooly substance covering their body. All species have a pair of tube-like structures called cornicles growing from their hind end.

Geranium Growth

• Geraniums need at least four hours of direct sun each day to produce abundant flowers. They prefer well-draining soil rich in composted material. Geraniums need 17 nutrients from soil to grow and thrive. The soil should be allowed to dry out after each watering. Soggy soil conditions invite aphids and fungal problems. Aphids are most active when new growth begins in early spring.

Aphid Feeding Patterns

• Aphid populations increase rapidly. Adult aphids reproduce up to 12 times per day year-round. A newborn aphid becomes a reproducing adult in seven to 10 days. They feed in dense groups, often on the underside of geranium leaves. Plants should be checked frequently during spring’s growth period. Aphids feed most heavily when the temperature is between 65 and 80 degrees Fahrenheit.

Eradication

• Small aphid colonies on single leaves can be pruned off geranium plants. A strong stream of water from a hose nozzle washes aphids off outdoor geraniums. Natural predators for aphids include beneficial insects such as parasitic wasps, lacewings, syrphid flies and lady beetles. Beneficial insects are supported by a diversity of plant life in the garden. Geraniums are sprayed with insecticidal soap, neem oil or vegetable horticultural oil to control aphid infestations.