Explanation of Names
Ptiliidae Erichson 1845
Greek ptilon 'feather' (refers to the feather-like hind wings)
Living in close confinement of the soil, their wings are reduced to thin, feathery appendages.
(1)Numbers
3 subfamilies, with ~120 spp. in 27 genera in our area, 550 described spp. in ~70 genera worldwide; significant numbers of undescribed taxa have been collected
(2)(3)
Overview of our faunaTaxa not yet in the guide are marked (*); classification follows(4)
Family PTILIIDAE
Size
the smallest known beetles, most species being under 1 mm, and the smallest known being 0.35 mm
Identification
minute size, hindwings with feathery filamentous fringe of hairs (usually hidden beneath elytra in live individuals, and often protruding beyond elytra in pinned museum specimens)
Many species exhibit striking polymorphism, in which each sex is represented by two forms
(5):
1. a normal morph with well-developed eyes, wings, and body pigmentation
2. a vestigial morph in which eyes, wings, and body pigmentation are reduced or lacking
The vestigial morph is the more abundant form, comprising 90% or more of all individuals
Range
Widely distributed in temperate and tropical regions of the world
Habitat
moist organic materials, incl. leaf-litter, decaying wood, compost, treeholes, fungi, seaweed, dung, under bark, etc.
(5)Food
larvae and adults feed on molds and fungi
Life Cycle
Reproduction occurs continuously under favorable conditions; larvae often are found together with both teneral and fully-hardened adults at different times of the year; only a single egg (nearly half the female body length) is accommodated and matured in the abdomen at a time. Many spp. produce females from unfertilized eggs (thelytokous parthenogenesis), in which case populations may be female-only
(5)