Part 45

Dorsal scale: that part of the covering scale of the Diaspinae that lies above the insect, as opposed to the ventral scale, which lies below.

Dorsal space: in slug-caterpillars is the area between the sub-dorsal ridges.

Dorsal vessel: the heart; q.v.

Dorsi-meson: the middle of the upper surface.

Dorso-alar region: Diptera; between the transverse suture and the scutellum on one side and the root of the wing and the dorso-central region on the other.

Dorso-central bristles: Diptera; two or four longitudinal rows on the inner part of the dorsal.

Dorso-central region: Diptera; bounded by two imaginary lines drawn from the scutellar bridges forward, and coinciding with a space free from bristles that exists on the outer side of the dorsal rows and is often occupied by a dorsal thoracic stripe.

Dorso-humeral region: Diptera; bounded by the anterior end of thorax and transverse suture on two sides and by the dorsopleural suture and dorsocentral region on the two others.

Dorsolum: the mesoscutum.

Dorsopleural suture: Diptera; the lateral suture between dorsal and pleurum from the humeri through the base of the wing: separates the mesonotum from the pleura.

Dorso-ventral: in a line from the upper to the lower surface.

Dorsulum: the mesonotum before the scutellum, with the wing sockets: also, specifically, the meso-scutellum.

Dorsum: the upper surface: in Coleoptera; often confined to meso- and meta-thorax: Odonata; includes mesepisterna and meso- and meta-thoracic terga: Diptera; upper surface of thorax, limited by the dorsopleural sutures laterally, the scutellum posteriorly and the neck anteriorly: Lepidoptera; the lower or inner margin of the wing.

Draw-thread: the silk-producing gland.

Drone: in Hymenoptera; the male bee.

Duct: a channel, tube or canal for carrying a secretion from a gland to the point of discharge.

Ductus ejaculatorius: the single duct or tube formed by the union of the vasa deferentia from each side, through which the seminal fluid is ejected into the vagina.

Dufour's gland: that gland, in Hymenoptera, that secretes the alkaline portion of the poison carried by the sting.

Duodenum: the chylific ventricle; also applied to the first section of the digestive tract just behind entrance of malpighian tubules.

Dupion: a cocoon spun by two silk-worms together; also the coarse silk from such a cocoon.

Duplicate -us: double.

Duplicate-pectinate: having the branches of a bipectinated antenna alternately long and short.

Duple: double, or twice.

Durus: hard.

Dusky: somewhat darkened; pale fuscous.

E: as prefix, is privative and means without.

Ears: organs of hearing, as on the first tibiae or on the first abdominal segment of some Trichoptera.

Ebenine: black like ebony.