Identification
Aphids are small, soft-bodied insects ranging from 1 to 7 mm in length. They come in various colors, including green, black, yellow, and red, depending on the species. Aphids have pear-shaped bodies, long antennae, and two short tubes (cornicles) protruding from their backs. Some species develop wings when populations become overcrowded. They are found worldwide, thriving in temperate and tropical regions.
Lifecycle & Reproduction
Aphids have complex life cycles, often reproducing asexually through parthenogenesis, where females give birth to live young without mating. Under favorable conditions, a single aphid can produce dozens of offspring in a matter of days. In colder climates, they lay eggs to overwinter. Some species develop winged forms to migrate and colonize new plants.
Habits, Diet & Behavior
Aphids feed on plant sap using their piercing-sucking mouthparts. They prefer tender plant tissues, such as new leaves, stems, and flower buds. They excrete honeydew, a sugary substance that attracts ants and promotes sooty mold growth. Aphids are relatively immobile but can be carried by the wind or transported by ants, which protect them for their honeydew.
Where You’ll Find Them / Typical Locations
These pests infest a wide range of plants, including vegetables, fruit trees, ornamentals, and houseplants. They congregate on new growth, leaf undersides, and flower buds. Greenhouses, gardens, and agricultural fields are common infestation sites.
Threats & Danger
Aphids weaken plants by draining sap, leading to curled leaves, stunted growth, and reduced yields. They can transmit plant viruses, causing deformities and discoloration. Their honeydew secretion fosters fungal infections like sooty mold, further damaging plants. Severe infestations can cause plant decline or death, particularly in young or stressed plants.
Prevention
- Inspect new plants before introducing them to gardens or indoor spaces.
- Encourage natural predators such as ladybugs, lacewings, and parasitic wasps.
- Avoid excessive nitrogen fertilization, which promotes aphid population growth.
- Use row covers or netting to prevent infestations on vulnerable crops.
- Maintain plant health through proper watering and pruning to reduce susceptibility.
Signs of Infestation
- Curling, yellowing, or deformed leaves.
- Sticky honeydew residue on leaves and stems.
- Black sooty mold growth on plant surfaces.
- Clusters of small, soft-bodied insects on new growth.
- Presence of ants farming aphids for honeydew.
How to Get Rid of It
- Spray plants with a strong stream of water to dislodge aphids.
- Apply insecticidal soap or neem oil to affected areas.
- Introduce beneficial insects such as ladybugs and hoverflies.
- Use reflective mulch to deter aphids from settling on plants.
- Apply horticultural oils or pyrethrum-based insecticides for severe infestations.