Caystrus brunnescens (Distant)

Ahmad, I. & Zahid, M., 2012, New characters with special reference to male and female genitalia providing the basis for phylogenetic relationship of Caystrine stink bug C. brunnescens Distant (Hemiptera: Pentaomidae) from Lower Niger, Pakistan J. Zool. 44, No. 4, pp. 1111-1115 : 1112-1113

Caystrus brunnescens (Distant)

( Fig. 1)

Agabotus brunnescens Distant 1884: 460 ; Letheiry and Severin, 1893: 112; Kirkaldy, 1909: 41; Schouteden, 1929: 60; Villiers, 1952: 304.

Caystrus brunnescens: Gillon, 1972: 290 , 321; Linnavuori, 1972; 400, 413; 1974: 402, 407; 1982; 76-77.

Colouration and general shape

Body light ochraceous with brownish punctures; eyes brownish; ocelli reddish; body oblong.

Head

Distinctly broader than long, anteocular distance slightly shorter than remainder of head, paraclypei broad and long enclosing clypeus, lateral margin sinuate, apex of head rounded; antennae with basal segment slightly shorter than head apex, second segment slightly shorter than third, fifth longest, length of antennal segments I. 0.50 (0.45- 0.50) II 0.90 (0.89-0.90) III 1.2 (0.95-1.2) IV 1.45 (1.25-1.45) V 1.8 (1.5-1.8), antennal formula 1<2<3<4<5; labium just reaching hind coxae, second longest, fourth shortest, length of segments I 0.8 (0.7-0.8) II 1.2 (1.1-1.2) III 1.1 (0.9-1.1) IV 0.70; labial formula 4<1<3<2 anteocular distance 0.75 (0.65-0.8), remainder of head 1.0 (0.9-1.05), width of head 2.25 (2.25-2.4); interocular distance 1.25 (1.25-1.40); interocellar distance 0.75 (0.75- 0.85).

Thorax

Pronotum distinctly less than 2.5x broader than long, anterior margin distinctly broader than head width, anterior angles toothed, humeral angles sub acutely produced, lateral margin distinctly sinuated, length 2.2 (2.0-2.6), width 5.2 (5.0-5.9); scutellum longer than broad with narrowed subacute apical lobe, length 4.15 (3.8-4.6), width 3.2 (3.0- 3.8); metathoracic scent gland ostiolar complex ( Fig. 1B) with peritreme thumb-like, anteriorly narrowed and posteriorly broad reaching less than half of evaporatoria, ostioles very much developed slit-like, anterior and posterior margin of peritreme distinctly sinuated; distance base scutellum–apex clavus 3.4 (3.0-3.6); apex clavus–apex corium 1.9 (1.8-2.2); apex corium–apex abdomen including membrane 1.5 (1.5-1.8), apex scutellum–apex abdomen including membrane 3.0 (2.9-3.4).

Abdomen

Convex beneath, connexiva exposed at repose, abdomen shorter than membrane of hemelytra; total length 11.1 (10.4-12.35)

Male genitalia

Pygophore ( Fig.1C) some what quadrangular, dorso median surface medially deeply concave with a large sclerotized process at inner lateral margin, lateral lobes narrowly truncately produced, ventromedian surface humped; paramere ( Fig. 1D) F-shaped, lateral margin almost straight, apex markedly truncated, inner process devoid of hairs; aedeagus ( Figs. 1 E-F) having theca without thecal appendage, vesica very large apex inwardly curved, a pair of bilobed ventro lateral membranous conjunctival appendage with sclerotized tips.

Female genitalia

Female terminalia ( Fig. 1G) with triangular shaped moderate first gonocoxae, inner and outer margins sinuated, slightly wide apart; ninth paratergites flipper-like large, slightly passing beyond fused posterior margin of eighth paratergites, later medially concave; second gonocoxae with posterior margin straight, posterior margin of proctiger markedly convex; spermatheca ( Fig. 1H) with balloon- like median dilation, median sclerotized duct proximally dilated, proximal spermathecal duct about 2x the distal spermathecal duct, pump region tubular with straight lateral margin, bulb oval with two moderate equal sized finger like processes.

Material examined Nigeria: S. Nigeria, one male and two female, Forebes , deposited at BMNH .

Other materials Two male and one female data same as above lodged at BMNH.

Comparative note

This species is most closely related to C. basalis and C. minor in having puncturing distinctly darker and scutellum narrow with a fine impunctate middle line but it can easily be separated from the same in having scutellum with apex acutely produced and paraclypei with apex truncated.