The common name “daddy long legs” is ambiguous, referring to at least three different arthropods, which often causes confusion. The term lacks the scientific precision to describe a single species. To understand what the young look like, it is necessary to identify which creature is being discussed. This article will clarify the identity of the three common “daddy long legs” and then focus on the juvenile form most frequently associated with the name: the harvestman.
Defining the Three “Daddy Long Legs”
The three creatures commonly called “daddy long legs” belong to separate biological classes. The first is the Crane Fly (Tipulidae), a true insect with six legs and wings. Next are the Cellar Spiders (Pholcidae), which are true spiders with eight legs and two distinct body segments separated by a narrow waist. Finally, there are Harvestmen (Opiliones), which are arachnids like spiders, but differ significantly in anatomy.
Harvestmen have eight legs, but their two body segments are broadly fused, giving them the appearance of a single, oval body. Unlike spiders, they lack venom and the ability to produce silk. Because the term “daddy long legs” is most commonly applied to the Harvestman, the focus for describing the young will be on the juvenile Harvestman.
The Appearance of Juvenile Harvestmen
The newly hatched Harvestman strongly resembles a miniature version of the adult, a development known as incomplete metamorphosis. Immediately upon hatching, juveniles are extremely small; their fused, oval body is often no larger than a pinhead. Their eight legs are slender and remarkably long in proportion to their tiny body, giving them a characteristic gangly appearance.
The body of a young Harvestman is typically pale, often translucent white or light gray, before significant pigmentation develops. This initial paleness gradually gives way to the dull shades of brown, gray, or black common in adult species. Like the adults, the juvenile possesses a single pair of eyes situated on a small raised bump, or ocularium, on top of the body. Their small size and light coloration allow them to remain cryptic in the shaded, moist environments where they are found.
Distinguishing Juvenile Harvestmen from Adults
The primary difference between a juvenile and an adult Harvestman is size, as they grow through a series of molts. The young Harvestman must shed its rigid outer exoskeleton multiple times, typically six to eight times, before reaching full adult size. Each time the exoskeleton is shed, the Harvestman emerges slightly larger, and its soft new skin gradually hardens.
Over these developmental stages, the body gains mass, and the legs, while still long, appear less fragile relative to the animal’s overall size. The coloration also deepens, transitioning from the initial pale hue to the cryptic browns and blacks of the mature Harvestman. This molting process allows for growth, but the fundamental body plan—fused body segments and eight legs—remains unchanged. These changes are gradual, resulting in a steady increase in size and darkening of features until the animal reaches its full adult dimensions, which range from 3 to 10 millimeters in body length.