The term “daddy long legs” frequently leads to confusion regarding their reproductive habits, particularly whether they lay eggs. This common name is applied to multiple types of arachnids, each with distinct biological characteristics and methods of reproduction. Understanding which creature is being discussed clarifies their egg-laying behaviors and maternal care.
Understanding “Daddy Long Legs”
The popular name “daddy long legs” typically refers to two different groups of arachnids: harvestmen (Order Opiliones) and cellar spiders (Family Pholcidae). Harvestmen are not true spiders, despite their similar appearance. They possess a fused, oval-shaped body that appears as a single segment, unlike spiders which have two distinct body segments. Harvestmen also lack venom glands and silk-producing spinnerets, meaning they do not spin webs.
In contrast, cellar spiders are true spiders. They exhibit the characteristic two-part body, consisting of a cephalothorax and an abdomen, often separated by a narrow “waist.” Cellar spiders have fangs and silk glands, which they use to construct irregular, messy webs, commonly found in corners of homes. While both groups share the trait of long, slender legs, these fundamental anatomical and behavioral differences set them apart.
Egg-Laying in Harvestmen
Harvestmen reproduce by laying eggs, typically in protected, moist environments. Females use a specialized organ called an ovipositor to deposit their eggs. These eggs are usually laid in clusters within damp soil, under rocks, beneath logs, or in crevices. A single batch can contain up to 120 spherical eggs, often white, yellow, or pale green, measuring about 0.5 to 1.0 mm in diameter.
Egg-laying for many harvestman species occurs in late summer to early autumn, with the eggs commonly overwintering and hatching in the following spring. Parental care after egg deposition is generally minimal or absent. While some species of harvestmen have males that guard the eggs, this behavior is not universal across all species.
Egg-Laying in Cellar Spiders
Cellar spiders also lay eggs, but their method involves the creation of a silk egg sac. After fertilization, the female encases her eggs in a thin, silken cloak. This egg sac is then carried by the female using her chelicerae, or mouthparts.
Each egg sac can contain a varying number of eggs, typically ranging from 10 to 60. The female often holds this sac continuously until the eggs hatch, which can take approximately 17 to 24 days. Once the spiderlings emerge, they may remain on the mother’s body for a short period before dispersing into the web.
Spotting the Difference
Distinguishing between harvestmen and cellar spiders can be achieved by observing their body structure and web-building habits. Harvestmen have a single, fused body segment, unlike cellar spiders which have two distinct body segments. Cellar spiders build irregular, tangled webs, while harvestmen do not produce silk. Furthermore, if you observe an arachnid carrying a spherical, silk-wrapped bundle, it is almost certainly a female cellar spider with her egg sac.