From our perspective as Crassula plants, we are generally resilient and low-maintenance. However, our succulent, juicy leaves and stems, which we are so proud of, can unfortunately attract unwanted attention from various pests. An infestation is not just an inconvenience; it is a direct attack on our vitality, draining our precious moisture and nutrients. Early identification and treatment are crucial for our survival and continued growth.
To us, mealybugs are one of the most common and frustrating pests. They appear as small, cotton-like white masses nestled in our leaf axils, the undersides of our leaves, and even around our roots. Their piercing-sucking mouthparts pierce our skin to feed on our sap, weakening us significantly. This feeding causes our leaves to yellow, wilt, and potentially drop. They also excrete a sticky substance called honeydew, which can lead to the growth of sooty mold, further blocking our sunlight absorption.
Spider mites are tiny arachnids that are extremely difficult to see with the naked eye. The first sign we often show is a subtle stippling or speckling of light-colored dots on our leaves—this is where they have been feeding. As the infestation worsens, we may develop a fine, silky webbing, particularly between our stems and leaves. They thrive in hot, dry conditions, which are otherwise ideal for us, making them a persistent threat that causes our foliage to become bronzed and desiccated.
Scale insects attach themselves to our stems and the undersides of our leaves like small, immobile bumps. They can be brown, black, or tan and have a hard, protective shell that makes them difficult to dislodge. Like mealybugs, they are sap-suckers. Their feeding creates yellow spots on our leaves and causes them to lose their luster and vigor. A heavy infestation can stunt our growth and cause leaf drop, as we simply cannot sustain the constant drain on our resources.
While the adult flies are merely annoying, the real danger to us lies in their larvae. These tiny white worms live in the soil and feed on our delicate root hairs and organic matter. This damages our root systems, our primary means of absorbing water and nutrients. This damage manifests as poor growth, wilting despite adequate water, and a general lack of vitality. Overly moist soil is the primary cause, which is also detrimental to our roots, leading to rot.
For minor infestations, we respond well to being gently wiped with a cotton swab dipped in isopropyl alcohol. This directly dissolves the pests' protective coatings. A strong jet of water can also help dislodge mites and young scales. For more persistent problems, horticultural oils or insecticidal soaps are effective, as they smother the pests without causing us significant harm. It is critical to ensure complete coverage, especially on our leaf undersides. For fungus gnats, allowing our soil to dry out more thoroughly between waterings is the most effective treatment, killing the larvae and discouraging new eggs.
