Certified Arborist Practice Exam

A direct indication of the presence of an insect or disease:

1. Ovipositing

2. Nematodes

3. Bacteria

4. Phloem

The correct answer is: Ovipositing

Ovipositing refers to the act in which female insects lay their eggs, often on or within a host plant. This behavior is a direct indication of the presence of a specific insect population that may be targeting that plant. When ovipositing is observed, it signifies that the female is selecting that particular host for reproduction, typically because it provides a suitable environment for the larvae to develop. This can be an early warning sign for arborists, as it can indicate potential pest issues that may arise as the eggs hatch and larvae begin to feed on the plant. The presence of ovipositing is closely monitored because it can lead to further damage by the developing larvae, as well as ongoing population increases of the pest. In contrast, nematodes, bacteria, and phloem do not serve as direct indicators of insect presence. Nematodes are microscopic roundworms that can harm plants but do not indicate insect activity. Bacteria may cause plant diseases but do not signify insect presence specifically. Phloem is a critical part of a plant's vascular system for nutrient transport and is not an indicator of insect or disease presence.