Spittlebug (genus Deois)

The genus Deois comprises several species of spittlebugs belonging to the family Cercopidae (order Hemiptera). These insects are recognized as major agricultural pests, particularly in the Neotropical regions, where they cause severe damage to pasture grasses and various graminaceous crops. Their impact on livestock productivity is globally significant.

These pests primarily target forage grasses, such as Brachiaria species, which are essential for cattle grazing. Additionally, they can cause substantial losses in sugarcane and rice production. By feeding on the xylem sap, Deois nymphs and adults deprive plants of water and nutrients, leading to rapid deterioration of the vegetation.

The life cycle of Deois is characterized by the presence of a nymphal stage that lives within protective spittle masses at the base of host plants. This foam serves as a barrier against desiccation and predators. Once they reach the adult stage, they become highly mobile, allowing for quick colonization of new fields and rapid population expansion during favorable weather conditions.

The economic damage caused by Deois is multifaceted. The feeding process induces phytotoxic reactions, resulting in leaf yellowing, stunting, and eventual necrosis of the foliage. In heavily infested areas, pasture biomass production drops significantly, forcing farmers to reduce cattle stocking rates and invest in expensive field restoration measures.

Managing Deois requires an Integrated Pest Management (IPM) approach. Strategies often include:

• Implementation of biological control using Metarhizium fungi.
• Adopting resistant grass varieties to reduce host suitability.
• Controlled grazing management and mechanical harvesting to disrupt the life cycle.

Chemical control remains an option but should be used judiciously to protect beneficial insects and environmental health. Monitoring populations through nymphs counting or adult density assessment is crucial for timely intervention. Long-term success depends on a combination of cultural practices that make the environment less conducive to nymphal survival.