Ornamental and Turf Pesticide Applicators Practice Exam

When is the optimal time to apply insecticides against soft scale insects?

1. During the egg stage

2. In late fall

3. During the crawler stage

4. In early spring

The correct answer is: During the crawler stage

The optimal time to apply insecticides against soft scale insects is during the crawler stage. This stage occurs when the newly hatched scale insects emerge and are mobile, making them more vulnerable to insecticides. At this point, they have not yet settled into their feeding sites and are still unprotected by the waxy coatings that later develop as they mature. Targeting the crawlers ensures that the treatment is most effective, as it maximizes the chance of controlling the population before they begin to establish themselves and reproduce. While applying insecticides during other stages may have some effect, they are generally less effective. For example, treating during the egg stage wouldn't control the pests effectively since the eggs are protected and not susceptible. Late fall is also less ideal because many scale insects could already be in their overwintering stage, reducing the effectiveness of treatments. Early spring could be useful, but it would be after the crawlers emerge, missing the peak vulnerability of the pest. Therefore, targeting the crawler stage is the most strategic timing for effective treatment against soft scale infestations.