Fundamentals of Entomology

STUDY OF INSECT ORDERS: PROTURA

• The proturans are minute whitish hexapods, 0.6 to 1.5 mm in length. The head is somewhat conical, and there are no eyes or antennae. The mouth parts do not bite, but are apparently used to scrape off food particles that are then mixed with saliva and sucked into the mouth.
• The first pair of legs is principally sensory in function and is carried in an elevated position like antennae. The tarsi are one-segmented. Styli are present on the first three abdominal segments. On hatching from the egg, the proturan abdomen consists of 9 segments.
• At each of the next three molts, segments are added anterior to the apical portion (the telson), so that the adult abdomen appears to have 12 segments (11 metameric segments and the apical telson). These hexapods live in the moist soil or humus, in leaf mold, under bark, and in decomposing logs.
• They feed on decomposing organic matter and fungal spores. They are found worldwide and approximately 200 species are known at present.

Important identification characteristics

a) Minute insects, with entognathous piercing mouth parts
b) Antennae and eyes are absent
c) Abdomen 11 segmented with a terminal telson, first 3 segments with a pair of small appendages called styli
d) Forelegs sensory and held above the head, like antennae
e) Metamorphosis slight, chiefly evident as an increase in number of abdominal segments following each moult (anamorphosis)
e.g. Eosentomon indicus