raster (noun; plural
rastri; Latin
rastrum, rake): (
Arthropoda:
Insecta) A
complex of bare areas, hairs and spines on the
ventral surface of the last abdominal
segment, in front of the
anus in Scarabaeoidea; comprised of
septula,
palidium,
teges,
tegillum in some groups, and
campus in Coleoptera.