Dimorphism: a difference in form, color, etc, between individuals of the same species, characterizing two distinct types: may be seasonal, sexual or geographic.
Dioptrate: an ocellate spot with the pupil divided by a transverse line.
Dioptric: with a transversely divided ocellus.
Diploglossata: an ordinal term proposed for Hemimeridae, because of the supposed presence of a second labial segment.
Diplogangliata: applied to the Arthropods.
Diplopteryga: Hymenoptera; wasps in which the wings are longitudinally folded when at rest.
Dipneumones: having two lungs (certain spiders).
Diptera: an ordinal term applied to insects having only one pair of wings (anterior): thorax agglutinate; mouth haustellate; transformations complete.
Dipterocecidium: a gall formed by a dipterous insect.
Dipterous: belonging to or having the characters of Diptera.
Direct: applied to metamorphosis = incomplete.
Directive coloration: directive marks or colors which tend to divert the attention of an enemy from more vital parts.
Discal: on or relating to the disc of any surface or structure.
Discal area: of a wing applies especially to the more central portion, or that area covered by the discal cell.
Discal bristles: Diptera; are inserted on the middle of the abdominal segments before the hind margin.
Discal cell: Lepidoptera; the large or median cell extending from the base of the wing toward the center: = radial cell (Comst.): in Diptera (Will.) = 1st medial 2 (Comst.): Odonata; = discoidal areolets, q.v.: Trichoptera, the cell between the forks of the radial sector, and separated from the 2d apical cell by a cross-vein.
Discal patch: in some male Hesperidae the oblique streak of specialized black scales on the disc of the primaries.
Discal vein: Lepidoptera; the cross-vein closing the discal or median cell extends from radius 5 to media 1.
Discocellular nervure or vein: Lepidoptera; = discal vein, q.v.
Discoidal: relating to the disc, or middle = discal.
Discoidal area: the middle area or field: Trichoptera; that area of the tegmina between the posterior or anal and the anterior or costal areas = d. field.
Discoidal areolets: Odonata; a varying number of rows of cells on the outer side of the triangle between the short sector (M 4 of Comst.) and the upper sector of the triangle (Cu 1 of Comst.) = post-triangular cells := discal cells.