Cassava thrips

The cassava thrips (Scirtothrips manihoti) is a significant insect pest belonging to the order Thysanoptera and the family Thripidae. This tiny insect is recognized as a serious threat in tropical agriculture, specifically targeting cassava crops, which serve as a primary food source in many regions.

The host plant for this species is primarily the cassava plant (Manihot esculenta). The pests preferentially attack the youngest leaves and the terminal shoots, where the tissues are most tender and rich in nutrients, making them highly susceptible to feeding damage.

The biological life cycle of Scirtothrips manihoti is relatively short, allowing for multiple generations per growing season. It consists of the egg, two larval stages, prepupa, pupa, and adult stages. The pupal stages often occur in the soil or within leaf litter, which complicates control efforts if not addressed properly.

Damage to the plant is characterized by stunting, crinkling, and chlorosis of the leaves. Severe infestations often lead to the death of terminal buds, forcing the plant to produce multiple side shoots, which results in stunted, bushy growth that significantly hinders the development of the storage roots.

Effective management strategies against cassava thrips include:

• Selection and planting of resistant or tolerant cassava cultivars.
• Implementation of proper sanitation practices to remove infested plant debris.
• Biological control through the conservation and introduction of natural predators like lacewings and predatory mites.
• Targeted application of systemic insecticides when populations reach economic injury levels.