Webspinners

Systematic position: Webspinners (genus Oligotoma) belong to the order Embioptera, family Oligotomidae. These insects are distinguished by their ability to produce silk using glands located on their forelegs, which they use to construct elaborate tunnel systems for protection and foraging.

Affected crops: While not primary agricultural pests, webspinners can cause damage to ornamental plants, shrubs, and trees in warm, humid climates. In greenhouse settings, they may feed on young shoots, bark, and root collars, often compromising the health of the host plant by covering them with their silk galleries.

Biology and life cycle: The life cycle consists of egg, nymph, and adult stages. Females are known for maternal care, guarding their eggs within silk-lined nests. Nymphs resemble miniature adults and live alongside them within the silk galleries. Their sedentary and hidden lifestyle makes them highly resistant to environmental fluctuations and natural predators.

Nature of damage and harm: Damage is caused primarily by mechanical feeding on the plant epidermis and tissues. The thick layers of silk can encircle stems, inhibiting growth and trapping moisture, which subsequently promotes the colonization of fungi and bacteria. Ornamental plants may lose their aesthetic value and suffer from stunted growth due to constant feeding pressure.

Control measures: Managing webspinner populations requires a strategy focused on structural and chemical intervention:

• Mechanical removal and clearing of silk webbing from tree bark and stems.
• Application of contact insecticides during peak adult activity periods to reduce population density.
• Maintaining proper ventilation in greenhouses to reduce humidity and discourage web construction.
• Regular monitoring of nursery stock to detect early signs of infestation before significant damage occurs.