Symphyla (Gr. sym, together, + phylon,
tribe) are small (2 to 10 mm) and have
centipede-like bodies (Figure 20-3B). They live in humus, leaf mold, and
debris. Scutigerella (L. dim. of Scutigera)
are often pests on vegetables and
flowers, particularly in greenhouses.
They are soft bodied, with 14 segments,
12 of which bear legs and one a pair of spinnerets. The antennae are
long and unbranched. Only 160 species
have been described.
Symphylans are eyeless but have
sensory pits at the bases of the antennae.
The tracheal system is limited to a
pair of spiracles on the head and tracheal
tubes to anterior segments only.