Sand Fly

Sand flies belong to the subfamily Phlebotominae within the fly family Psychodidae, comprising several hundred species distributed across warm and tropical regions of the world. Despite their name, they are not restricted to sandy areas and are more accurately associated with humid, sheltered microhabitats regardless of soil type.

These are among the smallest blood-feeding flies, so small that they can pass through standard window screening. Their weak flight and habit of resting in cracks and crevices during the day make them easy to overlook until dusk, when they become active.

Sand flies are notable in the insect world for their unusual erect, V-shaped wing posture at rest, a feature that immediately distinguishes them from mosquitoes and most other small biting flies.

• Tiny body, only 2-3 mm long
• Densely hairy body and wings, giving a fuzzy appearance
• Wings held erect in a distinctive V-shape above the body at rest, unlike mosquitoes which fold wings flat
• Long, slender legs
• Pale tan to yellow-brown coloring
• Short, silent, hopping flight pattern rather than sustained flying
• Lookalikes: midges are less hairy and hold their wings flat rather than upright

Sand flies are found across tropical and subtropical regions worldwide, including the Mediterranean basin, Middle East, Africa, Asia, and Central and South America. Larvae develop in humid, organic-rich soil, animal burrows, tree hollows, leaf litter, and cracks in walls or rock. Adults are weak fliers and stay close to the ground and to their breeding sites, most active at dusk and after dark.

Females require a blood meal to develop eggs and feed on mammals, birds, and reptiles primarily at dusk and during the night, while males feed on plant sap and nectar. Sand flies move in short, low hops rather than sustained flight, and spend daylight hours resting in dark, humid crevices such as animal burrows, rock piles, or wall cracks. Larvae are terrestrial detritivores, living in moist organic soil rather than water.

Eggs are laid in moist, organic-rich soil or sheltered crevices. Larvae pass through four instars while feeding on organic debris in the soil, a process that can take several weeks. Pupation occurs attached to the substrate near the larval habitat, and adults emerge shortly after. A complete generation can take anywhere from a few weeks to a few months depending on temperature, with multiple generations possible in warm climates and larvae overwintering in cooler regions.