Associate Certified Entomologist (ACE) Practice Exam

In which range can insects detect the electromagnetic spectrum, including ultraviolet light?

1. 200-400 nanometers

2. 300-650 nanometers

3. 400-700 nanometers

4. 500-800 nanometers

The correct answer is: 300-650 nanometers

Insects are known to have specialized sensory organs that allow them to perceive a range of electromagnetic wavelengths, particularly in the ultraviolet (UV) spectrum, which is not visible to the human eye. The correct range for insect vision and detection of UV light is approximately 200 to 400 nanometers. This range includes ultraviolet light, with many species having receptors that allow them to detect wavelengths as short as 200 nanometers. The choice that states 300 to 650 nanometers encompasses the visible light spectrum and some UV light, but it does not fully account for the entire range of UV sensitivity found in various insect species. Therefore, this answer fails to accurately reflect the breadth of an insect's ability to detect EM radiation. Conversely, other choices range from 400 to 700 nanometers or 500 to 800 nanometers, which primarily represents visible light and far into the near-infrared range—again, missing the significant capacity insects have for UV detection. Understanding the full EM range that insects can perceive is vital for applications in pest management and entomology research, especially considering how UV light influences behaviors such as navigation, foraging, and mating.