Symphylans

Symphyla

Classification

Phylum: Arthropoda
Subphylum: Myriapoda
Class: Symphyla

Pronunciation

How to pronounce Symphyla: /ˈsɪmfɪlə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Summary

Symphyla, or garden symphylans, are small, soil-dwelling myriapods that play a significant role in soil ecosystems while also posing a potential threat to agriculture as pests, especially in cultivated soils. The classification includes about 200 species worldwide, primarily herbivorous or detritivorous.

Physical Characteristics

Small, cryptic myriapods without eyes and pigment, generally 2 to 10 mm long, with a soft body divided into head and trunk. The head has long, segmented antennae and three pairs of mouthparts. The trunk comprises 15–24 segments, protected by overlapping dorsal plates. Typically, adult symphylans have twelve pairs of legs.

Identification Tips

Symphylans can be distinguished from similar arthropods by their small size, lack of eyes, presence of long segmented antennae, and the specific arrangement of their body segments and legs. Scutigerellidae have larger dorsal tergites, while Scolopendrellidae have reduced and pointed tergites.

Habitat

Soil, especially the upper 12-15 cm, under stones, in decaying wood, and other moist places.

Distribution

All continents except Antarctica.

Diet

Primarily herbivores and detritus feeders consuming decaying vegetation, roots, and fungi. Some species have predatory or saprophagous diets.

Life Cycle

Symphylans undergo hemianamorphosis, where immature individuals hatch with six pairs of legs and add one pair per molt until reaching adulthood with usually twelve pairs of legs. They can live up to four years and molt throughout their life.

Reproduction

Symphylans do not copulate. The male deposits 150 to 450 packages of sperm (spermatophores) which the female collects in her mouth and later lays eggs in groups of eight to twelve.

Ecosystem Role

They play a role in soil health by contributing to detritus breakdown and nutrient cycling, but can also be pests in agricultural settings by damaging roots and seeds.

Economic Impact

May damage crops, especially in greenhouse settings and other cultivated environments. Known pests include Scutigerella immaculata and some Hanseniella species.

Evolution

Symphyla are believed to have diverged from other lineages before the end of the Mesozoic Era, with a poorly known fossil record consisting of five species. Morphological studies suggest they are related to millipedes and pauropods rather than centipedes, but molecular studies have shown conflicting results.

Misconceptions

Despite their common name 'garden centipedes,' symphylans are not closely related to centipedes and differ significantly in behavior and ecology.