“Daddy long legs” are a common sight in many homes and gardens, their long, slender limbs often sparking curiosity about their delicate appearance and surprising resilience. This prompts questions about how they sustain themselves, especially when food is scarce. Understanding their survival mechanisms reveals insights into arthropod adaptations.
Understanding “Daddy Long Legs”
The common name “daddy long legs” refers to a few distinct types of creatures. Primarily, it describes two arachnids: harvestmen (Order Opiliones) and cellar spiders (Family Pholcidae), though it is also sometimes used for crane flies, which are insects. Harvestmen, unlike true spiders, have a fused, oval-shaped body and possess only two eyes. They also do not produce silk or venom.
Cellar spiders, however, are true spiders with two distinct body segments and can produce silk to build webs. They are also known to produce venom, though it is not harmful to humans. This article will focus on these two common arachnid types—harvestmen and cellar spiders—as they are most frequently encountered.
Survival Without Food
Harvestmen and cellar spiders can endure periods without sustenance. Spiders generally exhibit a low metabolic rate, allowing them to conserve energy efficiently when food is unavailable. They burn through energy reserves at a slower pace compared to animals with higher metabolic demands.
Durations vary by species and individual circumstances, but many spiders can survive for several weeks without a meal. Larger spiders, benefiting from greater energy reserves, may even last for months, with some reported to survive up to two years. This resilience is partly due to their ectothermic nature, meaning their body temperature and metabolic activity fluctuate with their environment, allowing them to reduce energy expenditure in cooler conditions.
Factors Affecting Resilience
Several factors influence how long harvestmen and cellar spiders can survive without food. Environmental conditions, particularly temperature, play a significant role. Lower temperatures can slow down an arthropod’s metabolic rate, extending its survival time by reducing energy consumption. Conversely, higher temperatures increase metabolism, shortening the time they can last without food.
Humidity is another environmental factor, as sufficient moisture reduces water loss, which is crucial for survival. Individual attributes also matter, including the creature’s age and overall health. Younger or less healthy individuals may have fewer energy reserves and a less efficient metabolism, limiting their starvation tolerance. The amount of fat and other stored nutrients from their last meal directly impacts their ability to survive starvation.
Their Natural Diet
Harvestmen are omnivores with a diverse diet, consuming small insects, decaying plant and animal matter, fungi, and sometimes even pollen. They grasp their food with mouthparts and tear it apart to consume it.
Cellar spiders are predatory arachnids, primarily feeding on insects, other spiders, and small invertebrates like ants. They use their webs to capture prey, which they then consume. When regular food sources are absent, both types rely on stored energy reserves, such as lipids, to sustain essential bodily functions.