What insects are attracted to light?

Insects are fascinating creatures that play essential roles in ecosystems around the world. While many insects are active during the day and rely on sunlight for navigation and survival, some species are attracted to artificial light sources at night. This phenomenon, known as phototaxis, can lead to insects congregating around outdoor lights, street lamps, and illuminated buildings, sometimes in large numbers. In this article, we’ll explore the reasons behind light attraction in insects and identify some common pests drawn to light.

Understanding Phototaxis:

Phototaxis refers to the movement of organisms in response to light stimuli. Insects exhibit various types of phototaxis, including positive phototaxis, where they are attracted to light sources, and negative phototaxis, where they are repelled by light. Positive phototaxis is particularly common among nocturnal insects, which use natural light sources such as the moon and stars for navigation. However, artificial light sources can disrupt this behaviour and make insects disoriented or attracted to artificial light sources.

Reasons for Light Attraction:

1. Navigation: Many nocturnal insects rely on celestial cues like the moon and stars to navigate and orient themselves in their environment. Artificial lights can disrupt these natural cues, causing insects to become disoriented and attracted to artificial light sources.
2. Feeding: Some insects attract light because they simulate natural food sources, such as flowers or insects. For example, moths may mistake artificial lights for flowers and fly towards them in search of nectar.
3. Mating: Insects use visual cues, including light, to locate potential mates. Artificial lights can act as mating signals, attracting male insects in search of females.
4. Escape Behavior: Insects may be attracted to light to escape predators or adverse environmental conditions. By flying towards light sources, insects may be attempting to flee from threats or seek refuge in illuminated areas.

Common Light-Loving Pests:

1. Moths are the most well-known example of insects attracted to light. These nocturnal insects are drawn to artificial lights, street lamps, and illuminated buildings, where they may gather in large numbers.
2. Beetles: Certain beetles, including June and Japanese beetles, are attracted to light and may be found congregating around outdoor lights and illuminated structures.
3. Flies: Various species of flies, such as houseflies, fruit flies, and blowflies, are attracted to light and may gather around indoor and outdoor light sources.
4. Mosquitoes: While mosquitoes are primarily active at dawn and dusk, some species are attracted to artificial lights at night. While not as commonly associated with light as other pests, mosquitoes may be drawn to illuminated areas searching for hosts.
5. Ants: Although not typically considered light-loving insects, certain species of ants, such as carpenter ants and pavement ants, may be attracted to outdoor lights and buildings, especially if they seek food or foraging opportunities.

Mitigating Light Attraction:

1. Use Yellow or Amber Lights: Yellow or amber-coloured lights are less attractive to insects than white or blue lights. Homeowners can minimise insect attraction by using light bulbs with warmer colour temperatures while providing illumination.
2. Install Motion-Activated Lights: Motion-activated lights only turn on when motion is detected, reducing the time that lights are illuminated and potentially attracting insects.
3. Position Lights Away from Entry Points: Position outdoor lights away from doors, windows, and other entry points to reduce the likelihood of insects entering buildings.
4. Clean Light Fixtures Regularly: Regularly clean outdoor light fixtures to remove debris, dead insects, and other organic matter that may attract pests.
5. Use Screens and Mesh: Install screens or mesh covers over outdoor lights to prevent insects from accessing the bulbs and congregating around the light source.