Large marsh grasshopper

Systematic position and description: The large marsh grasshopper (Latin: Stethophyma grossum) is a member of the order Orthoptera and the family Acrididae. It is one of the largest grasshopper species in Europe. Adults typically display a striking olive-green color with distinctive yellow or red markings along the hind legs, which helps them camouflage effectively in dense, moisture-rich vegetation.

Crops damaged: This species is a polyphagous pest, meaning it feeds on a wide range of vegetation. It primarily targets wild grasses in meadows, pastures, and marshy areas. During outbreaks, it frequently migrates to adjacent agricultural fields, causing significant damage to cereal crops like wheat, barley, and oats, as well as vegetables and various forage crops planted near wet areas.

Biology and life cycle: The lifecycle of Stethophyma grossum involves incomplete metamorphosis (egg, nymph, adult). They overwinter in the egg stage, with eggs deposited in the soil or base of vegetation. Nymphs emerge in late spring or early summer. They undergo five molts before reaching the adult stage, requiring constant access to moist soil conditions for successful development.

Nature of damage and economic impact: The grasshoppers consume leaves, stems, and seed heads. Their feeding behavior is aggressive; they often strip the foliage entirely or chew through the base of the stems, leading to severe defoliation. In regions with high population densities, these insects can destroy large swaths of grassland, causing major economic losses for dairy and livestock farmers due to reduced hay yield.

Control measures: Integrated Pest Management (IPM) is essential for controlling large marsh grasshopper populations.

• Land drainage and water management to remove the preferred egg-laying sites.
• Mechanical cultivation, including plowing and discing of fallow land, to expose and destroy egg pods.
• Timely mowing of field borders and ditches to eliminate food sources for emerging nymphs.
• Application of chemical insecticides targeted at the early nymphal stages to prevent maturation.
• Biological control using natural predators and specialized entomopathogenic fungi.