Red spider mites are a common concern for gardeners and indoor plant enthusiasts. These microscopic organisms can quickly spread, leading to visible damage on various plants. This article aims to clarify common misunderstandings about these creatures and their impact on plants.
Understanding Red Spider Mites
Red spider mites, despite their common name, are not insects but are classified as arachnids, placing them in the same group as spiders and ticks. The most common species, Tetranychus urticae, is also known as the two-spotted spider mite. These mites are incredibly small, typically measuring less than 1 millimeter in length.
Their color can vary, often appearing yellowish-green with two dark spots on their backs for most of the year. However, during cooler months or when populations become dense, they can turn an orange-red color, which contributes to their common name. A distinguishing characteristic of a significant red spider mite infestation is the production of fine, silken webbing, which they use to move between plant parts. These mites feed by piercing plant cells with their specialized mouthparts and sucking out sap, making them significant plant pests.
Do Red Spider Mites Bite Humans?
Red spider mites do not bite humans. Their mouthparts are adapted for piercing plant cells and extracting sap, not for penetrating human skin or consuming blood. These mouthparts, often described as needle-like stylets, are designed to access the internal fluids of plants.
They pose no direct biting threat to people. Any perceived “bites” on human skin are likely from other sources, such as different types of mites or insects, or skin irritations from contact with infested plants. While handling heavily infested plants, some individuals might experience mild skin irritation, but this is typically due to contact with the mites’ silk, waste, or disturbed plant hairs, rather than a bite from the mite itself.
Recognizing and Managing Infestations
Red spider mites damage plants by feeding on their sap, leading to noticeable symptoms. Early signs of an infestation include fine, pale mottling or stippling on the upper surface of leaves. As the infestation progresses, leaves may turn yellow or bronze, become shriveled, and eventually drop prematurely. Characteristic fine webbing becomes more apparent with larger populations, often found on the undersides of leaves and between stems.
Managing red spider mite infestations often involves non-chemical approaches, especially for houseplants or garden plants. Since they thrive in warm, dry conditions, increasing humidity around plants can deter them. This can be achieved by misting plants or placing them on trays filled with pebbles and water.
Physically wiping leaves with a damp cloth can remove mites and their eggs. For more extensive infestations, insecticidal soaps or neem oil can be applied, as these organic options work by smothering the mites or disrupting their life cycle. Introducing natural predators, such as predatory mites, can also be an effective biological control for larger outbreaks.