Impatiens delight gardeners with their ease of care and flower color range. They grow in shady areas, enlivening places that would otherwise be bare. Another important charm impatiens offer is a rarity of problems. The plants aren't ordinarily prone to diseases and pests. To support this happy situation, gardeners should keep their impatiens in the environment they like, which keeps them healthy. When impatiens are afflicted, though, the bugs bothering them commonly include thrips, leafminers, aphids and spider mites. All suck the flesh from vegetation.
Thrps are slim, winged insects. Some thrips are actually beneficial to plants, eating other pests. Others, though, feast on the impatiens, sucking down plant matter from puncture wounds the thrips inflict. The results are scars or distortion of the vegetation. Thrips will feed on flowers, leaves or fruits.
Thrips range in color from dark to light. Identification is easier by looking at their wings, which are fringed. The damage to the impatiens may be seen before the bugs are visible.
Like thrips, leafminers puncture leaves and flowers to get their meal. The puncture wounds can give the plant a stippled or dotted appearance, the wounds looking like white dots. The larvae mine through leaves, these mines look like curving paths on the leaves. The damage leafminers do doesn't often cause the plant to die. The bugs look like small back and yellow flies.
Aphids reproduce quickly to form colonies on plants, which show aphid damage with yellow, curled and distorted leaves. They come in several colors, often green. They don't scatter when disturbed, which helps the gardener distinguish them from other pest colonies.
Another way to identify aphids is by the sweet excretions they make called honeydew. Ants love the stuff and encourage and protect aphids to get it. (Ladybugs, on the other hand, would rather feast on the aphids and are their natural predators.)
Spider mites, as their name might suggest, are not insects, but arachnids. They're very small, making colonies that you can see on the bottom of leaves as black dots that move. The colonies and individual mites can, like impatiens, live year-round, feeding by sucking out the insides of leaves. The leaves are stippled from the damage, sometimes turn dark, then yellow and fall. The mites can produce webbing.