Sphenarium purpurascens

Taxonomic classification. Sphenarium purpurascens belongs to the order Orthoptera and the family Pyrgomorphidae. This grasshopper species is native to high-altitude regions of Mexico and Central America, where it has evolved to thrive in specific climatic conditions, often becoming a significant agricultural pest.

Affected crops. This species is a polyphagous pest, known for its ability to damage a wide variety of cultivated and wild plants. It poses a serious threat to maize (corn), beans, alfalfa, and various vegetable crops. The grasshoppers feed voraciously on both foliage and stems, often leading to severe defoliation of the crops.

Biology and life cycle. The life cycle of Sphenarium purpurascens is highly dependent on the alternation between dry and rainy seasons. Eggs are laid in the soil and undergo a period of diapause during the dry season. Once the rainy season begins, the eggs hatch, and the nymphs proceed through five instars before reaching the adult stage, at which point they become most destructive.

Character of damage. The damage caused by these insects is characterized by large, irregular holes in leaves, which can escalate to complete stripping of plant tissues. High population densities result in total destruction of young fields. The loss of leaf area significantly inhibits photosynthesis, leading to stunted growth and reduced yields in surviving plants.

Control measures. Integrated Pest Management (IPM) is essential for controlling this grasshopper. Effective strategies include

• mechanical soil cultivation to destroy egg pods;
• keeping field borders free of weeds that host the pest;
• applying registered insecticides targeted at early-stage nymphs to prevent massive outbreaks.