prothorax

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Related to Prosternum: Propleuron

prothorax

[prō′thȯr‚aks]
(invertebrate zoology)
The first thoracic segment of an insect; bears the first pair of legs.
References in periodicals archive ?
5); prosternum longer than wide with lateral procoxal foveae (Fig.
Prosternum longer than wide, widest at midpoint of prosternum (Fig.
Diagnosis: Overall length 3-5 mm; wing veins without setulae; meron and proepisternal depression bare; prosternum with lateral setulae.
On mesonotum, asymmetrical absence of P2[alpha] (on 1 specimen); on prosternum, asymmetrical absence of A1 and P3 (1); on tergite II, asymmetrical absence of A4 (1), P2[alpha] (1), P4a (1); on tergite IV, symmetrical (7) or asymmetrical (1) absent of P3a; on tergite V, symmetrical (3) or asymmetrical (2) absent of P3a; on tergite VII, asymmetrical absence of A1 (1), A2 (1), P1 (1); on sternite I, asymmetrical absence of A2 (1); on sternite II, asymmetrical absence of A2 (2), P1a (1); on sternite III, asymmetrical absence of P2 (1); on sternite VI, presence of Pc (1); on sternite VII, asymmetrical absence of A2 and P3 (1); on sternite VIII, presence of five setae (1).
Prosternum without pores; meso- and metasterna with three or four closely adjacent median pores.
5 times as long as wide, sides curved, dorsal surface smooth; prosternal surface smooth, 3 setae (l elongate) at anterolateral angles and 2 short setae at posterolateral angles; prosternum trapezoidal, sides oblique, posterior margin straight, a pair of medial setae present posterior to posterior margin of presternum.
Thorax: Collar, pronorum, mesoscutum, and scutellum black, except pale orange on anterior margin of pronotum, lateral area to callus, and apex and short medial stripe on scutellum; prosternum cream; propleuron pale orange, blending to cream ventrally; mesosternum black; mesepisternum pale to dusky orange; mesepimeron cream; metepisternum cream with dark brown to black dorsally; mesothoracic spiracle and adjacent evaporative area and metepisternal scent gland evaporative area black, peritreme partially pale.
Prosternum (stn1) strongly sclerotized with a well-developed median ridge and transverse ridges; all prosternal setae absent.
2 times as long as posterior notopleural setae; notopleuron and lateral and ventral margins of scutellum with black hairs, prosternum, propleuron and anepimeron all with hairs, katepimeron bare, meron with row of setae; anterior and posterior spiracles dark brown, katepisternal setae 2+1.
3 times as long as posterior notopleural seta; notopleuron and lateral and ventral margins of scutellum with black hairs, ventral surface of distal part bare, prosternum, propleuron and anepimeron all with hairs, katepimeron bare, meron with row of setae; anterior and posterior spiracles dark brown, katepisternal setae 1+1.
Prosternum sunken, with posterior third in front of the area between fore legs produced into narrowed acute, tubercle; mesosternum and metasternum at midline with wide longitudinal furrow; metathoracic peritreme auriculiform; evaporating area poorly developed.
Rostrum reaching posterior margin of abdominal sternite III; rostral segment I reaching anterior margin of prosternum.