MDARD Michigan Core Pesticide Applicator Practice Exam

What is the key difference between systemic and contact pesticides?

1. Contact pesticides require ingestion

2. Systemic pesticides distribute internally

3. Contact pesticides are always more effective

4. Systemic pesticides are only for crop use

The correct answer is: Systemic pesticides distribute internally

The key difference between systemic and contact pesticides lies in how they interact with plants and pests. Systemic pesticides are designed to be absorbed by plants and distributed throughout their tissues. This absorption allows the pesticide to affect pests that feed on the plant, even if they do not come into direct contact with the chemical at the moment of application. When a pest consumes parts of the plant treated with a systemic pesticide, it can be effectively targeted, providing a more thorough means of pest control. In contrast, options such as those suggesting contact pesticides require ingestion or are always more effective do not accurately capture the nature of contact pesticides. Contact pesticides act on pests only when they come into direct contact with them, requiring no absorption into plant tissues. Likewise, systemic pesticides are not limited solely to crop use, as they can also be applied in ornamental and turf applications, making that option misleading as well. Therefore, the defining characteristic of systemic pesticides is their capacity to be absorbed and distributed within the plant, allowing for effective pest control beyond just direct contact.