Mexican grasshopper

Taxonomic position. Sphenarium mexicanum is a species of grasshopper belonging to the order Orthoptera and the family Pyrgomorphidae. It is a well-known agricultural pest native to Mexico and Central America, frequently causing significant economic losses to farmers in these regions.

Host crops. This species is highly polyphagous, meaning it feeds on a wide variety of plant species. Its primary targets include corn (maize), beans, alfalfa, and a range of horticultural crops. In areas with high population densities, the grasshoppers can consume entire fields of crops, leading to total harvest failures.

Biology and life cycle. The life cycle of S. mexicanum is closely synchronized with the regional rainy season. Females deposit egg pods into the soil at the end of the rainy season. These eggs remain in diapause through the dry season, hatching only after the first rains arrive. The insects go through several nymphal stages before reaching adulthood.

Damage and economic impact. Both nymphs and adults are voracious herbivores. They feed on leaves, stems, and sometimes reproductive parts of the host plants, leading to severe defoliation. The resulting damage reduces the photosynthetic capacity of the plants, stunts growth, and can result in the complete destruction of economic crops if left unmanaged.

Control measures. Effective management of the Mexican grasshopper requires an integrated approach:

• Regular field monitoring to detect early-stage nymph populations.
• Application of chemical insecticides when populations exceed economic injury thresholds.
• Tillage practices that disturb soil where egg pods are located.
• Utilization of biological control agents, including entomopathogenic fungi and natural predators to keep populations in check.