Wiseana jocosa

Systematic position: Wiseana jocosa belongs to the order Lepidoptera, family Hepialidae. This moth species is primarily recognized as a significant pest in New Zealand, often referred to as a type of ghost moth or subterranean caterpillar, which impacts grasslands and pastoral systems.

Target crops: The species primarily attacks pasture grasses and forage crops. It has a preference for a wide range of monocots and legumes used for livestock feed. In regions with high population density, it can cause severe degradation of improved pastures and productive forage fields.

Biology and life cycle: The life cycle comprises egg, larval, pupal, and adult stages. Adult moths emerge at night to mate and lay eggs across the pasture surface. Larvae construct vertical tunnels in the soil, which serve as their primary shelter. They remain subterranean during the day and emerge at night to graze on the surrounding vegetation.

Damage patterns and economic impact: The damage is caused by larvae cutting off stems of grasses and clovers at the soil level. This feeding habit creates patches of dead or thinning vegetation in fields. Severe infestations lead to significant loss of dry matter production, which directly impacts the carrying capacity of farms and reduces overall pasture quality.

Control measures: Management strategies focus on an integrated pest management approach. Key methods include:

• Monitoring adult flights with pheromone or light traps to predict larval activity.
• Maintaining vigorous pasture growth through optimal fertilizer application.
• Using biological controls, such as entomopathogenic fungi, to target larvae in their tunnels.
• Strategic grazing management to minimize suitable egg-laying sites for female moths.