© Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at On some particular sclerotized structures associated with the vulvar area and the vestibulum in Orthotylinae and Phylinae (Heteroptera, Miridae)1 D. PLUOT-SIGWALT & A. MATOCQ Abstract: A review of the literature on mirid female genitalia, combined with new observations, shows that asymmetrical sclerotized structures occur in four tribes belonging to two mirid subfamilies: Or- thotylinae Orthotylini, and Phylinae Hallodapini, Leucophotopterini, Phylini. The structures are adja- cent to the vulva (Orthotylinae) and the vestibulum (Phylinae). In the latter case, the sclerotized struc- tures are directed towards the right side. In Orthotylinae, the vulvar area may be surrounded by com- plicated plates or lobes originating from the internal margin of the anterior gonapophyses (first valvu- lae). In Phylinae, the vestibulum may be strongly modified by sclerotization of some or most parts of its wall; in some Hallodapini (if not all), the sclerotized vestibulum bears a vesicular sac-like diverticulum. The sclerotized structures appear highly adaptive and related to the structure of the vesica (in Phyli- nae), of the parameres and probably also to the various spiculi of the conjunctiva (in Orthotylinae). Within Phylinae, size and shape of the sclerotized part of the vestibulum are closely correlated to size and shape of the vesica; thus, like the vesica, the vestibulum may be either short and relatively straight or C- or S-shaped, twisted with a complete loop, or not. In some cases, the vestibulum is modified into a highly specialized organ acting as a reinforced copulatory duct. The hypothesized functions of these documented sclerotized structures are: defence system for the female against potentially wounding by the male organ; a strengthening device for coupling, guidance and support of the vesica. Key words: adaptive trend, copulatory duct, female genitalia, gonapophyses, Heteroptera, Miridae, Or- thotylinae, Phylinae, vestibulum, vulva. Introduction Such genital differentiation has never been described elsewhere in the Orthotyli- A specific structure was recently discov- nae. In several major contributions involv- ered in the floor of the vagina of a new or- ing various orthotyline species, no particular thotyline species of Cyllecoris (C. ernsti MA- structure is mentioned: KULLENBERG (1947) TOCQ & PLUOT-SIGWALT 2006): an asym- in Cyllecoris [histrionius (L.)], Dryophilocoris, metrical stout tube-like body strongly scle- Orthotylus, Heterotoma; SLATER (1950) in rotized and pigmented, directed toward the various orthotyline species; DAVIS (1955) in right side and located below the ring scle- Lopidea; SOUTHWOOD (1953), SCUDDER rites near the vulvar area. This discovery led (1959), and EHANNO (1990a) in Orthotylus. us to survey the literature dealing with fe- However, several of these authors noticed male genitalia in Miridae to determine if some asymmetrical organization of the vul- other species possess comparable morpholo- var area or unusual sclerotized protuberance gy, or to find some data allowing to shed in this region (see KULLENBERG, DAVIS, light on this enigmatic female genital struc- EHANNO, loc. cit.). More recently, GAGNÉ ture. (1997) in Nesiomiris and SCHWARTZ (2004) Denisia 19, zugleich Kataloge th 1We are very pleased to dedicate this paper to our colleague and friend Ernst Heiss on the occasion of his 70 birth- der OÖ. Landesmuseen day. Neue Serie 50 (2006), 557–570 557 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at Figs 1-3: Orthotylinae Material and Methods Halticini, sclerotized areas observed Species examined: These were selected between the from subfamilies Orthotylinae and Phylinae gonapophyses 8 (gp8) at the level of the to confirm or add precision to literature da- vulva; ventral view; ta, and for comparison purpose. Hereinafter (1) Halticus luteicollis; we follow the classification proposed by (2) Pachytomella SCHUH (1995). About thirty species were parallela; (3) Dimorphocoris sp. examined, as follow: Scale bar = 0.1 mm. Orthotylinae. – Halticini: Dimorphocoris sp., Halticus luteicollis (PANZER 1804), Pachy- tomella parallela (MEYER-DÜR 1841). – Or- thotylini: Cyllecoris ernsti MATO CQ & PLUOT-SIGWALT 2006, C. histrionius (LIN- NAEUS 1767), Dryophilocoris luteus (HER- RICH-SCHAEFFER 1835), Mecomma ambulans ambulans (FALLÉN 1807), Orthotylus margin- alis REUTER 1883. Phylinae. – Hallodapini: Cremno- cephalus alpestris WAGNER 1941, C. matocqi in Melymacra mentioned and illustrated MAGNIEN 2000. – Phylini: Amblytylus brevi- strongly convoluted plates between the first collis FIEBER 1858, A. nasutus (KIRSCHBAUM valvulae. 1856), Anomalocornis peyreti COSTA & COU- In the Phylinae, however, several au- TURIER 2002, Atractotomus magnicornis (FAL- thors have described curious vaginal struc- LÉN 1807), A. mali (MEYER-DÜR 1843), A. tures, as a curved sclerotized duct, lateral kolenatii (FLOR 1860), Campylomma an- “tube“, or “ventral sac“, that should be anal- nulicorne (SIGNORET 1865), Criocoris sulci- ogous, if not homologous, to the structure cornis (KIRSCHBAUM 1856), Dasycapsus described in Cyllecoris: in the Phylini theryi POPPIUS 1912, Heterocapillus tigripes (MULSANT & REY 1852), Lopus decolor (FAL- (SCHMITZ 1976; HENRY & SCHUH 1979; LÉN 1807), Megalocoleus molliculus (FALLÉN SCHUH 1984; EYLES & SCHUH 2003), as well 1807), M. longirostris (FIEBER 1807), as in the Hallodapini (EHANNO 1990b; Phoenicocoris dissimilis (REUTER 1878), Pla- MAGNIEN 2000; WYNIGER 2006). Asymme- try is also often pointed out. In several giognathus arbustorum arbustorum (FABRICIUS 1794), Psallus perrisi (MULSANT & REY species, EYLES & SCHUH (2003) suggest that the sclerotized structures might be a guide 1852), Tuponia macedonica WAGNER 1957. and support for the long and looped phallus. Three tribes have not been investigated: Nichomachini in Orthotylinae; Leu- In the literature of female genitalia, cophoropterini and Pilophorini in Phylinae. most authors have focused on the vagina in dorsal view (roof of the genital chamber and Dissection, examination: Females are ring sclerites), and the posterior wall (main- dissected after KOH treatment following ly K-structures). Morphological data con- the recommendations of EHANNO (1990a). cerning other structures of the genitalia, in The genitalia are first examined entire un- particular the vulvar area and the floor of der a microscope, without coloration. the vagina, are scarce and dispersed. In this Thereafter, it is necessary to remove the go- paper, we attempt to summarize knowledge napophyses 9 (second valvulae) and the of the particular sclerotized structures found posterior wall if necessary, in order to see the in these areas, bringing together informa- vulvar area clearly at the base of the go- tion from the literature and original obser- napophyses 8 (first valvulae), the vestibu- vations of several previously unexamined lum and the floor of the vagina. The geni- species. This study provides a basis for fur- talia are then slightly stained with chlorazol ther research and draws attentions to genital black and examined again; further dissec- regions still poorly known. tion is performed if necessary. The genital 558 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at parts studied are best observed in ventral distinguish it clearly. It appears as part of the and caudal views. All illustrations were floor of the vagina (just below the ring scle- made from temporary slide mounts in lac- rites and the vermiform gland). It is often tophenol. connected to the sclerites linking the fibu- lae and the gonapophyses 8. Terminology: The terminology of the genital structures follows DUPUIS (1970) Tables 1 and 2 list all such structures in and EHANNO (1990a). the vulvar area and the vestibulum. In the literature, they are usually very succinctly Results described, sometimes only illustrated with- out comment. When pigmented (brownish- Localization and yellow to brown) and sclerotized, they are inventory of the structures obvious, and clearly visible through the membranous dorsal wall of the vagina. The literature survey showed that un- When unpigmented, they are inconspicuous usual features associated with the floor of and usually pass unnoticed. the vagina occur in certain tribes of at least two mirid subfamilies, the Orthotylinae 1) Miridae: Orthotylinae (Table 1) (Orthotylini: Table 1) and the Phylinae (Hallodapini, Leucophoropterini and Phyli- Halticini. No particular structure has ni: Table 2). As far as we know, comparable been described in this tribe, except some ap- features do not seem to occur in Orthotyli- parently common microsclerites or small nae Halticini or in other mirid groups; see sclerotized areas more or less distinctly de- for instance comparative studies concerning limited in the vulvar area between the go- several Mirinae (FONTES 1981, 1989, 1992a, napophyses 8 (CHÉROT et al. 2004) (Figs 1- 1992b; ROSENZWEIG 1997; SCHWARTZ & 3). Asymmetry was not observed. The floor FOOTTIT 1998) or the study of EHANNO of the vagina may have slightly sclerotized (1989) about Deraeocoris (Deraeocorinae). areas as described by EHANNO (1990c, 1991, Nevertheless unpublished data obtained by 1992). The vestibulum is not distinct, being F. Chérot (pers. comm.) strongly suggest apparently not (or weakly) sclerotized and that unusual features may occur in these unpigmented. subfamilies, and in others as well. Orthotylini. Various structures have The features discussed in the present