Green-bellied stink bug threatens second-season corn productivity

Large-area corn cultivation, especially in the second crop, faces increasing challenges with the increasing incidence of pests. The green-bellied stink bug (Diceraeus melacanthus) stands out as one of the main entomological problems, causing significant damage, especially in the initial stages of plant development. In the last harvest, producers from several states reported significant losses due to attacks by this insect.

Characteristics and impact

First described in corn crops in Brazil in 1993, in Rio Brilhante (MS), the green-bellied stink bug has spread to several producing regions.

With a development cycle of around 29 days, this pest can complete up to four generations during the growing season. The insect uses its mouthparts to suck plant tissue, causing deformations in the leaves, reduction in plant size and, in more severe cases, death.

Damage is more intense in drought conditions, when plants have less capacity to recover.

Weeds and integrated management

The green-bellied stink bug has a close relationship with weeds, such as bitter grass (Digitaria insularis), trapoeraba (Commelina benghalensis) and mombaça grass (Panicum maximum). These plants provide shelter and food, facilitating the development of the insect's life cycle.

Studies carried out in Mato Grosso do Sul indicated a greater presence of bedbugs in areas with green weeds, highlighting the importance of controlling these species in pest management.

Among the management strategies, monitoring is essential. It is recommended to closely observe the bedbug population before and after planting the crop.

Spraying insecticides at the end of the soybean cycle, especially during desiccation for harvest, has been shown to be effective in reducing initial populations. However, it is essential to use products with adequate withdrawal periods.

Seed treatment and complementary strategies

Treatment of corn seeds with insecticides from the neonicotinoid group is an important preventive measure, especially in areas with low bed bug infestation.

In high infestation scenarios, this approach may not be sufficient, and complementary strategies may need to be adopted, such as “Plant and Apply” (PA). This technique consists of applying insecticides immediately after sowing corn, taking advantage of the movement of bugs caused by soil movement.

Spraying during the early stages of development, between V1 (one open leaf) and V5 (five open leaves), is also recommended. Seedling protection at these stages is crucial to minimize yield losses.

Studies indicate the effectiveness of natural biological control of the green-bellied stink bug by egg parasitoids, such as telenomus podisi, and adults, like Hexacladia smithii.

Pesticides registered for the control of Diceraeus melacanthus can be seen here.