Caystrus marginiventris
Creators: name: Ahmad, I.
name: Zahid, M.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Pentatomidae
Caystrus
Caystrus marginiventris

description: C. marginiventris (St å l)
(Fig. 1)
Paramecus marginiventris,, Stål 1858: 435
Caystrus marginiventris, Stål 1861: 199.
Sciocoris marginiventris, Walker 1867: 177 Caystrus marginiventris Distant 1901: 26; Linnavuori 1972: 400-401; Ahmad et al. 2005: 1-4.
Colouration and general shape
Body ochraceous with brownish punctures; except brownish black eyes; ocelli pale; membrane hyaline.
Head
Distinctly broader than long; anteocular distance about equal to remainder of head; paraclypei much broad and long but not enclosing clypeus, postero-lateral margin strongly concave, terminating anteriorly infront of eyes with sub round lobe; apex of head smoothly rounded; antennae with basal segment slightly shorter than head apex, 2 nd segment shorter than 3 rd, 5 th longest, length of antennal segments I 0.6, II 1.1 (0.9-1.1), III 1.4 (1.4- 1.45), IV 1.6 (1.6-1.85), V 1.8, antennal formula 1<2<3<4<5; labium just reaching hind coxae, 2 nd segment longest, 4 th shortest, length of segments I 1.1 (1.1-1.2), II 1.35 (1.35-1.45), III 1.2 (1.2-1.3), IV 0.8 (0.8-0.9), labial formula 4<1<3<2; anteocular distance 0.9 (0.9-1.0); remainder of head 0.95 (0.95- 1.05); width of head 2.6; interocular distance 1.3(1.3-1.5); interocellar distance 0.8(0.8-0.9).
Thorax
Pronotum about 2.5x broader than long, anterior margin distinctly broader than head width across the eyes, anterior angles toothed, humeral angles subacutely produced, lateral margins sinuate, length of pronotum 2.4(2.4-2.7), width 6.0 (6.0-6.3); scutellum with subrounded apex, length of scutellum 4.65 (4.65-5.0), width 3.9 (3.9-4.0); metathoracic scent auricles (Fig. 1) with peritreme finger-like reaching ½ length of evaporatoria, apex round, anterior margin of peritreme slightly concave and posterior margin slightly convex, ostiole slit-like; distance base scutellum-apex clavus 3.6 (3.6- 3.8); apex clavus-apex corium 2.2 (2.2-2.4); apex corium-apex abdomen including membrane 1.8 (1.8-2.0); apex scutellum-apex abdomen including membrane 3.25(3.25-3.6).
Abdomen
Convex beneath; connexiva slightly exposed at repose; posterior margin of 7 th abdominal sternum concave, lateral margins slightly sinuate with acute angles; abdomen shorter than membrane of hemelytra. Total length 12.15 (12.15-13.35).
Male genitalia
Pygophore (Fig.1C) quadrangular, dorso-median surface slightly concave with a large plate-like process at inner lateral margins, lateral lobe narrowly produced, ventro-median surface bilobed; paramere (Fig. 1D) somewhat F-shaped, outer margin straight, humped near apex, apex of blade sharply truncate; aedeagus (Fig. 1E,F) with theca without thecal appendages, vesica large ventrally curved into sharply pointed apex, a pair of large ventro-lateral membranous conjunctival appendages, with sclerotized tip, dorso lateral membranous conjunctival appendages with large sclerotized bilobed plates.
Female genitalia
Female terminalia (Fig. 1G) with triangular, medium sized 1 st gonocoxae, inner and posterior margins sinuate, medially wide apart; 9 th paratergites flipper-like, large, not reaching beyond fused posterior margin of 8 th paratergites, later with posterior margin medially concave, 2 nd gonocoxae with posterior margin straight; posterior margin of proctiger concave; spermatheca (Fig. 1H) with balloon-like median dilation, proximally enclosed by a ring, proximal spermathecal duct about 4x in length of distal spermathecal duct, pump region tubular with sinuated lateral margins, bulb spherical with three finger-like processes.
Material examined
1male and 1 female Zair: Gandajika, Mayidi, leg Rev.P. Van.Eyen, J.Decelle, 1942, 3, 1959 “Coll. Mus. Tervuren”, deposited at Nat. Hist. Mus. Stockholm, Sweden.
Comparative note
C. marginiventris is isolated in this complex in having body ochraceous with brownish punctures, apical lobe of scutellum remarkably elongate and pointed at apex, body at least 12.15mm long, (12.15-13.35mm.) and dorso-median surface of pygophore shallowly concave and sinuate.
description: Published as part of Ahmad, I. & Zahid, M., 2009, Resurrections and redescriptions of Caystrus marginiventris (Stål), C. trivalis (Gerstaecker) and C. pseudobrunnescens Linnavuori (Hemiptera: Pentatomidae: Pentatominae), key to this complex and their cladistic relationships, pp. 305-312 in Pakistan Journal of Zoology 41 on pages 306-307