Acta Zoologica 23. (1977)
1977 / 3-4. szám - STYS, P.: Revision of Symphylax (Heteroptera: Colobathristidae)
However, Ghauri (1968) has noted that specimens with faded humeral spots occur in S. tvallacei, and I have found individuals with humeral spots absent also in S. curvispina and S. picticollis. Consequently, absence of humeral spots is of no diagnostic value. There are minor specific differences in the shape and proportions of individual parts of the pronotum (and also in the distance between ocelli in relation to their distance from eyes). Though the basic biometrical characteristics of the pronotum are recorded for each taxon, I have not attempted to exploit them diagnostically, since the variation is extensive and sufficientlv large material has not been available for most species. Ghauri (1968) separates in his key Symphylax tvallacei from S. picticollis and S. musiphthora on the basis of the presence of alveoles all over the surface of the callar region of the pronotum, while in the other species the alveoles are said to be present at most in the middle of its anterior margin. After careful examination of my material I had to conclude that alveoles are present all over the callar region probably in all Symphylax species (including the lectotype of S. picticollisl), the degree of their visibility depending on the density of the tomentose cover, this being individually variable and dependent on the individual state of preservation of the examined specimen. Both Horváth (1912) and Ghauri (1968) distinguish Symphylax curvispina from the other species by its regularly curved scutellar spine, contrasting with a straight spine in the others. However, a large series of S. picticollis exhibits variation ranging from a straight vertical spine to moderately diagonal and strongly and regularly curved spine exceeding in this respect the situation encountered in S. curvispina. Hence also this character seems of no diagnostic value. b) Male genitalia. Two major structures furnish excellent diagnostic characters, the parameres and the hypandrium. The shape of parameres is species-specific, and the external view of the left paramere is shown for each species (Figs. 1, 3, 5, 7, 9, 11, 13, 15); the paramere is illustrated lying flat on the surface. The shape of the upper edge, degree of development and shape of anterior and posterior lobes (see Fig. 3 for terminology), and the shape of the posterodorsal angle of the latter are the most important characters. Also the shape of the paramere as seen in dorsal view (Figs. 2, 4, 6, 8, 10, 12, 14, 16) is species-specific and may be quite different even in subspecies of the same species (Figs. 4, 6); however, the utility of this character is reduced by obvious difficulties in achieving standard position for illustration. The parameres of all species conform to the same basic plan; the notable exception is Symphylax ghaurii with a greatly enlarged anterior lobe and lacking the posterior one. The posterodorsal margin of the pygophore is produced in a large, conspicuous, dorsally directed expansion set off from the pygophore proper by Acta Zoologica Academiae Scientiarum Hungaricae 23, 1977