The term “daddy long legs” often sparks questions about their role in mosquito control. This belief suggests these long-legged creatures might be natural predators of mosquitoes. However, the name refers to several distinct organisms, and understanding their identities and habits is important to know if they truly contribute to reducing mosquito populations.
Understanding “Daddy Long Legs”
The informal name “daddy long legs” refers to at least three different arthropods.
One group is harvestmen (order Opiliones). These arachnids have a single, fused body segment, unlike spiders, which have two distinct body parts. Harvestmen lack venom glands and do not produce silk or webs.
Another creature commonly called “daddy long legs” is the cellar spider (family Pholcidae). These are true spiders with two body segments and typically possess eight eyes. Cellar spiders have very long, thin legs and are frequently found in basements where they spin irregular webs.
Finally, the term can also refer to crane flies (family Tipulidae). Crane flies are insects resembling oversized mosquitoes with long legs and narrow wings. Their appearance often leads to their mistaken identity as mosquito predators.
The Mosquito Question Answered
The various “daddy long legs” have different relationships with mosquitoes.
Harvestmen do not consume mosquitoes. They are primarily scavengers and opportunistic feeders, ingesting decaying plant and animal matter, fungi, or small insects.
Cellar spiders are predatory and can capture mosquitoes if these insects become entangled in their webs. While they prey on a variety of small insects and other spiders, they are not specialized mosquito predators. Their diet includes anything that gets caught in their webs, but they are not a primary solution for widespread mosquito control.
Adult crane flies do not eat mosquitoes. Many adult crane fly species have short lifespans and either do not feed or consume only nectar and pollen. Despite being known as “mosquito hawks,” adult crane flies are anatomically incapable of preying on mosquitoes. While some rare crane fly larvae may feed on mosquito larvae, this is not a common or significant dietary habit.
Their True Diets
The actual diets of these creatures highlight their distinct ecological roles.
Harvestmen are omnivorous, primarily consuming decaying organic material such as dead insects, plant matter, and fungi. They also scavenge on bird droppings and carrion, and some species may occasionally prey on small, soft-bodied insects. Unlike spiders, harvestmen can ingest solid food.
Cellar spiders are generalist predators, relying on their webs to trap a wide array of arthropods. Their diet includes various insects such as gnats, flies, and moths. Cellar spiders are known to prey on other spiders, sometimes even larger species, by ensnaring them in silk.
Adult crane flies generally have a limited diet, with many species not feeding during their brief adult stage, focusing on reproduction. Those that do feed typically consume nectar and pollen. The larvae of crane flies, often called “leatherjackets,” feed on decaying organic matter, plant roots, and grasses in moist soil environments.
Safety for Humans
These creatures pose minimal threat to humans.
Harvestmen are harmless, as they lack venom glands and fangs that could penetrate human skin. Despite an urban legend claiming they possess potent venom but cannot bite, this is false.
Cellar spiders possess venom and fangs, as they are true spiders. However, their fangs are very small, and their venom is not medically significant to humans. Bites are rare and typically result in only minor, localized irritation. The myth that they have highly toxic venom but fangs too short to bite is unsubstantiated.
Crane flies are harmless to humans. They do not bite or sting, and their mouthparts are not designed for such actions. Despite their resemblance to large mosquitoes, they do not feed on blood or transmit diseases.