symphylans

Symphyla, commonly known as symphylans, are a group of small, soil-dwelling myriapods classified in the class Symphyla within the subphylum Myriapoda of the phylum Arthropoda. They are among the earliest diverging myriapods and are distinct from true centipedes and millipedes. Most species are minute, less than several millimeters in length, with elongated bodies and numerous leg pairs arranged along the trunk. They typically appear pale white or translucent and have long antennae. Eyes are absent or scarcely developed in many species.

Symphylans inhabit moist soil, leaf litter, compost, and protected microhabitats in greenhouses and fields. They feed on decaying plant matter, fungi, and, in some cases, live plant roots, seedlings, or root hairs, which can make them agricultural pests under certain conditions. Predation and competition influence populations; they are often active at night or during cool, damp periods.

Females lay eggs in soil; hatchlings are small and resemble adults but with fewer leg pairs. Through successive molts, they add body segments and legs in a process known as anamorphosis. The development leads to sexually mature adults after several molts; some species may show varying life cycles depending on environment.

They are found worldwide, with higher diversity in temperate and subtropical regions. In horticulture and agriculture they may damage seedlings and young roots, especially in high-moisture soils, prompting management measures.

Taxonomic placement has varied historically, but current classification places symphylans as a class within Myriapoda. They are distinct from other myriapods by morphology and reproductive patterns.