Hoary: covered with a fine, white, silvery pubescence: pruinose q.v.
Holometabolous: having a complete transformation; with egg, larval, pupal and adult stages distinctly separated.
Holopneustic: having many pairs of open stigmata.
Holoptic: Diptera in which the eyes of male are contiguous between vertex and antennae: see dichoptic.
Holosericeus: with short, dense, silky hair, giving a satiny lustre.
Holotype: the unique type: = type; q.v.
Homelytra: elytra of similar or equal substance.
Homo: prefix = the same; similar.
Homochronic heredity: inheritance at corresponding periods of life.
Homochronous: changes in an organism which appear in the offspring at the same age at which they did in the parent.