Introduction
Material and methods
General structure of the cydnid spermatheca. Definition and terminology
The spermatheca
The intermediate part (pars intermedialis) (spermathecal pump or pumping apparatus from several authors) is a modified segment of the spermathecal duct adjacent to the seminal receptacle. A diverticulum (tubular or sacciform) may be present - but rarely - at the base of the vas deferens (Fig. 4).
Vaginal structures associated with the spermatheca
Some functional aspects
Descriptions
- Amnestinae Hart
- Cephalocteinae Mulsant & Rey
- Cephalocteini Mulsant & Rey
- Scaptocorini Froeschner
- Cydninae Billberg
- Cydnini Billberg
- Geotomini Wagner
- Garsauriinae Froeschner
- Sehirinae Amyot & Serville
- Amaurocorini Wagner
- Sehirini Amyot & Serville
- Genera formerly included within Cydnidae: Dismegistus, Parastrachia, Thaumastella, Thyreocoris
Spermathecal opening simple, located medially on a certain area of the dorsal wall of the vagina where the. In the two species, the basal part of the canal changes into a long and wide membranous tubular segment; the cuticular intima, thick and soft, is concentrically folded and unpigmented. Spermathecal opening in the vagina simple, without special structure. Note: the basal part of the spermathecal duct could equally well be interpreted as a long dorsal sac of the vagina: compare its intima with that of the vaginal intima in Figure 11; both look very similar).
Intermediate part long and rather straight distally, cup-like enlarged at the level of the proximal flange. Duct with spherical dilatational invagination of various sizes (small to very large), differently pigmented; distal tube longer than proximal very short one; basal part of the latter may not be free (M. brunneus), connected to vaginal wall. The great dilatation is simple, without invaginated part of the tube; spermathecal opening in a small vaginal pouch containing two internal rod-like sclerites that are well pigmented, placed longitudinally and run parallel to each other (Fig. 45).
Canal with a large barrel-shaped dilatation-intussusception; cuticular wall of the latter slightly pigmented and half translucent half opaque, making external diagonally regular grooves or stripes; distal canal long and narrow; proximal canal wide and short. Spermathecal opening simple, wide, near a tubular structure lightly sclerotized and pigmented, running into the vaginal dorsal wall from the base of the spermathecal tube towards the common oviduct. Middle part straight, bounded by two well-developed flanges, the distal one slightly asymmetrical; flexible zone rather long in the middle of the segment.
Intermediate part: disc-shaped flange equal in size (Tritomegas), or distal flange asymmetric (Croscistethus); flexible area occupying the basal half of the segment. A pair of conspicuous annular sclerites (thick and pigmented) present; the presence of vaginal sacs (poorly differentiated) is suspected.
The different types of spermathecae recognized within the Cydnidae
The pentatomoid type of spermatheca
- A highly complex and characteristic intermediate part
- The ground plan of the pentatomoid spermatheca
Intermediate part bounded by two well-developed flanges, the distal one asymmetrical and perpendicular to the canal, the proximal one extending posteriorly along the canal; flexible area occupying the entire segment between the flanges; the septum and fretum are inconspicuous. Spermatic opening itself very simple in dorsal vaginal wall, strongly sclerotized and pigmented, (see description given by Schaefer et al., 1988). Ring sclerites are present as already shown by Schaefer et al. 1988); they are associated with a pair of well-developed lateral vaginal pouches, similar to those found in geotomine species (Fig. 1A).
Intermediate part rather short, bounded by a strong medium-sized proximal margin; distal flange absent; flexible zone in apical position, septum posteriorly; just behind the margin a short rigid segment connects the spermathecal duct. Only Jacobs (1989) mentioned the spongy structure of the receptacle in two other species of the genus, but did not provide detailed information about the vas deferens. The intermediate part is straight, bounded by two equally well-developed flanges; long flexible zone (about half the length of the intermediate part); septum and fretum present, undisturbed.
Duct with a large membranous basal dilatation invagination; invaginated part large, slightly sclerotized and pigmented, reaching only half the length of the dilated part; wall of dilatation very thin, transparent and regularly pleated; distal tube short, soft and. The Saldidae also have a pentatomoid-like spermatheca with an intermediate part often well bounded by a proximal flange (see Cobben and unpublished data of J. Carayon summarized by Péricart, 1990); nevertheless, one must emphasize that in Saldidae there is no flexible zone, and no septum or fretum (unpubl. data, to be verified). The plesiomorphic pentatomoid spermatheca probably consists of the following elements: a spherical or spherical apical receptacle; an intermediate part relatively short, well bounded by at least a proximal flange (never absent, but rare exceptions exist) and with a flexible zone and at least a septum; a canal simple, without differentiated part.
Types of spermathecae within Cydnidae: Description and comments
- The amaurocorine type
- The amnestine type
- The garsauriine type
- The “cydnoid” type
- The ochetostethan facies
- The cydnan facies
- The sehiran facies
- The scoparipan facies
- The adrisan facies
- The geotoman facies
Intermediate part not restricted posteriorly (proximal flange absent); distal flange present, restricted to one side of vessel; flexible zone present but very short;. Schematic drawings of the vessel and the intermediate part (pump apparatus) in several types (Figs. 67-69) and facial (Figs. 70-75) of spermathecae. A slight swelling present between the two main parts (solid/membranous) of the spermatic duct may be the posterior border of a possible intermediate part.
In this case, the long pigmented and rigid distal part of the canal should be considered as an intermediate part. Intermediate part flat; distal flange often greatly reduced (sometimes asymmetric or absent), positioned around base of receptacle; proximal moderately developed;. The Sehiran facies appears quite variable, but is constant if only the general features of the apical vessel and intermediate part are considered (Fig. 73).
Spermatic opening associated with numerous folds of the vaginal wall showing signs of pigmentation in some places. Nevertheless, the cuticular wall of the regularly grooved dilatation shows clear similarities with those observed in other facies (adrisan and geotoman facies). The spermathecal tube shows marked variations at the level of the dilatation (size, shape, pigmentation and sclerotization).
Spermathecal structures in Dismegistus, Parastrachia, Thaumastella and Thyreocoris
It is with some hesitation that we have included Hiverus hirtus in this group, despite the fact that the dilation of the spermatic duct in this species includes an intussusception. Nevertheless, the flat shape of the enormous expansion, the non-sclerotized structure of the latter and the characteristic spermathecal opening are characteristic features. On the other hand, the striated and fluted structure of the cuticular wall is shared by the dilatation with the geotomane facies.
Gampsotes parallelus appears to belong to the adrisanfacies despite the very slight enlargement (simple) of the spermathecal duct. Duct usually with a spherical or pyriform dilatation-invagination of different size (from small to very large) and colored (pigmentation, sclerotization); the wall of the dilatation always thick and striated; distal and proximal canal smooth and rather rigid. Spermathecal opening in folds and bends of the surrounding vaginal wall, but without sclerotization.
In the geotoman facies, the development of invagination is fully achieved, as in the Pentatomidae. However, the very thick striated expansion-invagination wall in Cydnidae is very characteristic and may be considered an autapomorphic condition. In particular, it possesses a strongly sclerotized structure at the base of the spermatic duct and shares with Ochetostethus a very long flexible zone.
Discussion and conclusions
Potential phylogenetic importance of the cydnid spermathecae in Cydnidae
- The current Cydnidae: A polyphyletic assemblage
- The “cydnoid” type: A diversity difficult to interpret
- The “cydnoid” type: Spermathecal characters difficult to evaluate
- Presumed synapomorphies linking “Cydnidae s. str.” and other Pentatomoidea
Nevertheless, the absence of the proximal canal and consequently the direct large opening into the vagina through the basal part of the dilation was never observed in other Pentatomoidea. Moreover, its appearance is not typically pentatomoidal due to the following features: the mushroom appearance of the flowerpot due to the invagination of the basal part (as far as we know, this peculiarity is only found in Pyrrhocoridae and rarely in Lygaeidae s.l.); the intermediate part quite short with a septum in the middle and a fretum absent (no narrowing of the lumen was observed at the level of the flange); the folded thin cuticular wall of the spermathecal duct. However, invagination of the spermathecal duct within the dilation does not occur in the Scutelleridae, except in Chrysocoris stallii (Wolff), as shown by Kumar (1962).
Several authors have already discussed spermatic characters in Pentatomoidea (Štys, 1964; Štys & Davidová, 1979; Gapud, 1991; Schaefer, 1993b). An expansion along the spermatic duct is also common in many families of Pentatomomorpha, but an expansion with an invaginated part of the duct is restricted to some Pentatomoidea: e.g., Pentatomidae (Gapud, 1991), Thyreocoridae (Štys & Davidová, 1979 present paper), Cyrto-coridae (Rolston & McDonald, 1979; Gapud, 1991), Aphylidae (McDonald, 1970); in these four families the wall of the great dilation is thin and membranous. The spermatic canal of the Cydninae Geotomini and Cephalocteinae indeed presents a character which may be considered unique within the Pentatomoidea, not having been found outside the Cydnidae, i.e., a thick-walled, striated enlargement including (in most cases) a intussusception of the canal.
Regarding the structure of the spermatheca and that of the vagina, it seems that "Cydnidae s. More specifically, the very distinctive features of the cuticular lining exhibiting internal striations or "gills" in the thick-walled expansion of the spermathecal duct, characteristic of most Cydnidae s. In the Canopidae, the spermatic duct also possesses a striated walled expansion thick (which includes intussusception) and the same internal "gills".
Taxonomic importance of the spermatheca in Cydnidae
Spermatheca and cydnid classification
We conclude that it is impossible to characterize the Cydnidae based on the spermatheca. 1964: The morphology of the Alydid abdomen with special reference to the genitalia and its bearing on classification (Heteroptera). 2000: The disc-like organ of the Lestoniidae (Heteroptera: Pentatomoidea), with comments on lestoniid relationships. Insect system.
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