What characterizes a systemic pesticide?

A systemic pesticide is characterized by its ability to be absorbed by the plant or animal and then translocated throughout its tissues. This means that once the pesticide is taken up, it spreads within the organism, allowing it to affect pests that may not necessarily come into direct contact with the pesticide. This property is particularly beneficial for controlling pests that feed on plant tissues or that are hidden away, as the chemical remains effective even if the pests do not directly encounter the pesticide.

In contrast, the other characteristics do not apply to systemic pesticides. For instance, pesticides that must contact pests directly are typically contact pesticides, which only work on the pests they directly touch, without offering the extended efficacy that systemics provide. Similarly, systemic pesticides can remain effective for longer periods compared to those that are only effective for short durations, as they are distributed throughout the plant. Lastly, the characteristic of affecting only insects on the surface pertains to contact pesticides, which do not have the systemic qualities necessary for treating pests that reside within the plant or animal tissues.