Black Field Earwig – Economic Considerations
- Understand the potential yield losses associated with black field earwig feeding damage
- Assess the cost and benefits of taking preventative action
- Compare the costs, benefits, and risk of management against doing nothing or delaying treatment
- Consider the potential costs of further treatment
- Ignore all previous treatment costs in assessing current management options
- Undertake a “what if” scenario analysis to see what impact changing variables such as grain price and season have on the profits
- Consider using integrated pest management system and include a resistance management strategy into your spray/baiting program to reduce the chance of black field cricket and other non-target insects becoming resistant.
- Understand the potential yield losses and subsequent impact on profit (i.e yield loss x $/t).
- Black field earwig eats germinating seed and seedling roots resulting in poor establishment. Monitor the pest from planting until establishment and take action if there are more than 50 earwigs in 20 germinating seed baits. It is necessary to weigh up the cost of replant vs leaving a patchy plant stand which will be dependant on how late in the season it is and the moisture profile of the crop.
- Assess the costs and benefits of taking preventative action
- Compare the costs, benefits, and risks of each management option against doing nothing or delaying treatment
- What are the likely outcomes of each management option? When the result of treatment is unknown consider the most likely (expected), as well as the worst and best results from each treatment option.
- When calculating the cost of non-treatment assess the potential risk of yield losses.
- Compare the costs ensuring you allow for the possibility of further treatment.
- Selection of insecticide/bait may be influenced by the opportunities to control other insects.
- Consider choosing a treatment option where the expected return is sufficient to offset its risk of the treatment. We all have different attitudes to risk when making decisions. The probability (risk) of outcomes can be affected in terms of responsiveness (efficacy), application rates, products, application methods and climatic conditions. The economic calculator can assist with this decision.
- Ignore all previous treatment costs in your assessment in assessing current management options
- Costs associated with previous treatments should be ignored as they can’t be recovered. They are “sunk costs”. i.e. even if the current treatment results in the crop not breaking even, provided the additional benefit of the treatment is greater than the cost of treatment, then net return from treatment is still better than doing nothing about it.
Include a resistance management strategy into your program to reduce the chance of black field earwigs and other non-target pests becoming resistant.