Biserrate: doubly saw-toothed; with a saw tooth on each side of each antennal joint.
Bisetose -ous: with two bristle-like or setaceous appendages.
Bisinuate: a margin or line with two sinuations or incisions.
Bituberculate: with two distinct tubercles.
Biuncinnate: with two hooks.
Bivalve -ed: applied to mouth parts consisting of two parts or valves united to form a tube.
Bivittate: with two longitudinal stripes or vittae.
Blade: of maxilla, see lacinia.
Blastem: a nucleated protoplasmic layer preceding the blastoderm.
Blastoderm: the germinal membrane from which the organs of the embryo are formed.