Jugular sclerite: small sclerite in the membrane connecting the head with the thorax: see cervical sclerite.
Jugulum: that sclerite just behind the sub-mentum; =gula: that cavity of the posterior part of the head to which the neck is annexed: the lateral and under parts of the prothorax.
Jugum: in certain Lepidoptera and Trichoptera, a lobe or process at the base of primaries, overlapping secondaries and holding the two together in flight.
Katabolic: the destructive change from animal tissue to waste product: see anabolic.
Keel: an elevated ridge or carina.
Kermesinus: dark red, with much blue [purple lake].
Key: a tabular or other arrangement of species, genera or other classification according to characters that serve to identify them.
Kidney-shaped: like a kidney in outline; convex on one long side, concave on the other, the ends evenly and somewhat obtusely rounded: bean-shaped.
Knee: the point of junction of femur and tibia.