Detonans: exploding: a sudden noise or a puff like an explosion. Detritus: rubbed off; a surface partly denuded. Deuterotoky: parthenogenetic reproduction when the progeny are male and female: see arrhenotoky and thelyotoky. Deutocerebral segment: =antennal segment; q.v. Deutocerebrum: the middle portion of the brain, formed by the ganglion of the 2d primary segment; also termed antennal or olfactory lobes from the parts it innervates. Deutoplasm: the yolk or food plasm of an ovum. Deutotergite: the secondary dorsal segment of the abdomen. Dextrad: extending or directed toward the right. Dextral: to the right of the median line. Dextro-caudad: extends obliquely between dextrad and caudad. Dextro-cephalad: extends obliquely between dextrad and cephalad. Di: as a prefix, = two. Diaphanous: semi-transparent; clear. Diaphragm: any thin dividing membrane; that thin membrane separating the cavity containing the heart from the rest of the body. Diarthrosis: any articulation that permits of motion. Diastole: that regular expansion of the heart that draws the blood inward: see systole. Dichaetae: a group of brachycerous Diptera with a proboscis consisting of two parts: Muscids, etc. Dichoptic: Diptera; eyes separated by front: not contiguous: see holoptic. Dichotomous: forked: dividing by pairs. Dichromatism: the possession of two color varieties. Dictyoptera: an ordinal term applied to the roaches: also more generally, to the Orthoptera. {Scanner's comment: Roaches are now classed as Dictyoptera, and Orthoptera are now classed as distinct from Dictyoptera} Didactyle -us: two-toed: with two tarsi of equal length. Didymus: double: geminate. Difformis: irregular in form or outline: not comparable; anomalous. Diffracted: bending in different directions. Diffuse: spreading out; without distinct edge or margin. Digestive tract: the alimentary canal as a whole: more specifically that portion behind the crop, in which assimilation takes place. Digitate: finger-like, or divided into finger-like processes. Digitiform: formed, shaped like or having the function of a finger. Digitules: appendages on the feet of Coccidae; in Lecanium, four knobbed hairs. Digitus: the terminal joint of the tarsus, bearing the claws: a small appendage attached to the lacinia of the maxilla; rarely present and probably tactile. Digoneutism: the power to produce two broods in one season. Dilatatus: Coleoptera a margin, when the sharp marginal edge extends beyond its usual limit: the base when the transverse diameter is much longer at one part. Dilated: widened, expanded. Dilation: an expansion or widening. Dilute: thinned out: applied to color means weak or pale. Dilution: much thinned out or diluted. Dimera: forms with two-jointed tarsi: specifically applied to some groups of Homoptera. Dimerous: having only two tarsal joints. Dimidiate -us: halved; extending half way around; applied to elytra when they cover only half the abdomen.