Texas FFA Nursery Landscape Practice Exam

Which of the following pests is considered microscopic?

1. Nematodes

2. Thrips

3. Aphids

4. Spider mites

The correct answer is: Nematodes

Nematodes are considered microscopic pests due to their small size, typically measuring between 0.5 to 2.5 millimeters in length. They are often not visible to the naked eye and require the use of a microscope for identification and study. Nematodes are soil-borne organisms that can be both beneficial and harmful to plants, with various species causing plant diseases by affecting roots or feeding on plant tissues. In contrast, thrips, aphids, and spider mites are larger and can be seen without magnification. Thrips are small, slender insects that can be seen with the naked eye but are typically still quite small. Aphids are soft-bodied, pear-shaped insects, also visible to the naked eye, known for their rapid reproduction. Spider mites are even larger and belong to the arachnid family; they can be seen with the naked eye but may not be easily identified without closer inspection. Hence, in the context of microscopic size, nematodes clearly stand out.