Insect Calling Cards
Changes in leaf color or texture can signal an insect problem. Leaves may become spotted, speckled or yellowed when insects are present. Leaves might also become distorted or misshapen, often looking cupped or pinched. You may spot webbing draped along leaf undersides or where leaves attach to stems.
Some insects secrete a substance called honeydew, which makes leaves unusually shiny and sticky. Honeydew also encourages sooty mold to grow on leaves, creating black smudges. Often honeydew drips onto nearby surfaces, coating them with a sticky layer.
Look for insects lurking beneath leaves, clustered along new growth or boldly lodged where stems and leaves join. A 10-power magnifying glass can help shift suspicions into a confirmed diagnosis.
Which Insect Is the Culprit?
Certain symptoms indicate the arrival of specific insects. Use this guide to track down your invader.
AphidSmall green, yellow, black or white soft-bodied insects. Feeding produces honeydew and yellow and/or distorted leaves. Aphids reproduce quickly and can heavily infest a plant in a few days. Look for Aphids on new growth.
Spider MiteVery tiny (not even pinhead-size) creatures that thrive in hot, dry conditions. They cluster along leaf undersides or where leaves join stems. Feeding produces speckling on leaf surfaces, causing plants to look faded. Webbing occurs with heavy infestations and is likely the most easily detectible symptom. Hard to eradicate.
MealybugSmall, cotton-like insects are easily visible, occurring most often on stems or leaf undersides. Feeding produces honeydew and distorted growth. Hard to control when numbers are high. Isolate infested plants to limit insect spread.
ScaleStationary, sucking insects with shell-like coverings that typically gather on stems and leaf undersides, but can occur on leaf surfaces. Feeding produces distorted growth and honeydew. Hard to control.
WhiteflyThese insects resemble tiny white Moths and flutter around when infested plants are disturbed. They feed on leaf undersides, producing honeydew. Overall plant growth is stunted; leaves turn yellow and die.
How To Avoid Insect Problems
- Minimize insect infestations by following a few simple steps.
- Visually inspect plants each time you water.
- Clean plant leaves regularly; dust can shelter insects or eggs. Don't use a feather duster –it easily spreads insects or eggs. Wipe leaves with a damp sponge or spray plants with water.
- Provide ideal growing conditions. Nothing keeps insects at bay like a healthy plant.