prothorax

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Related to Prosternum: Propleuron

prothorax

(prō-thôr′ăks′)
n. pl. pro·thoraxes or pro·thoraces (-thôr′ə-sēz′)
The anterior division of the thorax of an insect, bearing the first pair of legs.

pro′tho·rac′ic (-thə-răs′ĭk) adj.

prothorax

the first thoracic segment in insects.
References in periodicals archive ?
Antennal style lacking long setae; prosternum small, disassociated from proepisternum and prothoracic coxae; alula moderately well developed 18
2A): Slightly surpassing posterior margin of prosternum, not reaching middle of mesosternum; segment I slightly longer than distance between buccula and pronotum; segment II slightly longer than segment I; segment III almost as long as segment I; segment IV 1.
The Biology of Coleoptera) states that the prosternum is always a median undivided sclerite, with lateral wings in front, abutting on the pleura or on the hypomeron, and narrowed between the coxa to form the prosternal process.
11 Prosternum bare; 3 or 4 pairs of postsutural dorsocentral setae; acrostichals 3:3, strongly developed; 1 species .
Venter: generally reddish to dark-reddish; pale to whitish on prosternum, extensive areas on propleura and abdominal sternites 3-7; mostly dense with semi-erect to erect golden yellow hairs.
Some characteristics are strikingly similar, such as the shape and size of the fastigium and the subgenital plate or the prothorax coloration, with distinct and bright lateral bands on the pronotum and on the median zone of the prosternum.
Prosternum glabrous and smooth, with row of moderately dense setae that covers mentum inserted on prosternal apical margin.
VENTRAL SURFACE: Ventral midline of prosternum lacking a carina; anterior half of mesosternum broadly domed, lacking tumescences, posterior half of mesosternum broadly depressed, hind margin deeply posteriorly concave, posterolateral angles slender, acute; metasternum triangular, strongly raised along longitudinal midline, anterior margin angulate, lateral margins strongly anteriorly convergent, posterior margin transversely truncate; space between middle and hind coxae distinctly less than diameter of coxae.
Pronotum yellowish translucent with grayish mark; prosternum quadrangular, wide, with ventrally protruding fore margin (arrow in Fig.
Pectoral canal on prosternum open behind and passing anterior margin of mesocoxae, rostrum not touching middle coxa, but ending in receptacle on mesosternum, mesosternal process cavernous, forming receptacle, receptacle at least as long as wide, its inner margin U-shaped; mesosternum truncate between middle coxae, width of mesosternum separating middle coxae wider than the dorsal apex of the rostrum (Fig.
Thorax: Black, almost entirely shining, prothoracic sclerites (except middle part of prosternum and postpronotal lobe) subshining, scutellum and mediotergite (= metanotum) densely tomentose.