Hypanartia dione disjuncta

Llorente-Bousquets, Jorge, Nieves-Uribe, Sandra & Flores-Gallardo, Adrián, 2023, Exochorion in the tribe Nymphalini (Lepidoptera: Nymphalidae): the genus Hypanartia Hübner, [1821] and comparison with related genera, Zootaxa 5330 (2), pp. 151-200 : 170

Hypanartia dione disjuncta ( Plates 12 , 13 ) (n=26).

The chorion is 923 µm long and 1010 µm wide; the ratio of length/width is 0.9 and width/length is 1.1; the greatest amplitude is at the equatorial third. The base is convex and approximately 1.5 times broader than the apex, which is convex to semi-flat; the chorion is semi-ovoid ( Plates 12 , 13 , Figs. A). It exhibits 10 to 12 ridges made up of colonnades with narrow beams, which run from the edge of the apical region to the base ( Plate 12 , Fig. A-i, Plate 13 , Fig. A); the columns extend above the chorion from the apical region to the equator and, from this point, they barely protrude from the surface ( Plate 12 , Fig. A-ii, Plate 13 , Fig. A). For each ridge, there are at least 40 columns with plinths protruding slightly sideways from the rail, but without noticeable ribs between ridges until the prebase ( Plate 13 , Fig. A). Sections of the chorion without ribs have a smooth texture ( Plate 13 , Figs. A, C). Both the rail and the plinths have well-defined grooves ( Plate 13 , Fig. B); the rail is very subtle and barely noticeable in the intercolumnar spaces ( Plate 13 , Fig. B). The capitals of the columns are joined by a beam with marked depressions in the areas with aeropyles ( Plate 13 , Fig. B), which number 48 to 52 along the ridge ( Plate 13 , Fig. A). A thin, smooth wall can be seen surrounding the colonnades from the equator to the apical region; it is slightly thinner at the intercolumnar spaces ( Plate 12 , Fig. A-iii, Plate 13 , Fig. B). The columns become shorter from the equatorial third to the basal fifth ( Plates 12 , 13 , Fig. A), where only the beam can be seen ( Plate 13 , Figs. A, C). The prebase has a slightly rough texture, and five to seven ‘ribs’ can be seen between the ridges ( Plate 12 , Fig. A-iv, Plate 13 , Fig. C), which are barely raised and lack a thickened and conspicuous structure. In apical view, neither ribs nor ridge projections are visible beyond the transition zone ( Plate 12 , Fig. B-v, Plate 13 Fig. D). There are no ribs joining the ridges at their most apical section ( Plate 12 , Fig. B-v, Plate 13 , Fig. D). The most apical portion of the ridge lacks aeropyles ( Plate 13 , Fig. D). The three zones that can be distinguished in apical view—micropylar, perimicropylar, and transition—exhibit an incipient rough texture ( Plate 13 , Figs. D-F). The perimicropylar region exhibits an irregular wreath of 13 four- to seven-sided leaves that form an irregular semi-ring. All the leaves are well defined, but three of them lack a thickened external wall, with only a relief ( Plate 13 , Fig. E). In some leaves closest to the transition zone, there are projections at their vertices that have the same thickness as the walls, but they do not form a polygon ( Plate 13 , Fig. E). The micropylar rosette has seven straight-sided petals with sharp vertices, that are either pentagonal or hexagonal. They are well anchored to the central polygon. A pair of leaves from the wreath are near the petals but are not attached to the central polygon ( Plate 13 , Fig. F). Four micropylar openings are present that coincide with the vertices of the central rhomboidal polygon, which is at the same visual level as the petals ( Plate 13 , Fig. F). The outer walls of the petals are slightly thicker than the lateral ones. Color N 00 A 30 M 00.

Figures

PLATE 12. Chorion of Hypanartia dione disjunct. A. Lateral view; B. Apical view. i=ridges in colonnade; ii=apical columns longer than equatorial ones; iii=intercolumnar spacing; iv=basal ribs; v=projections of the ridges in the transition zone.

PLATE 13. Photographs of the chorion of Hypanartia dione disjuncta under the SEM. A Lateral view.; B. Detail of the colonnades; C. Basal region; D. Apical view; E. Perimicropylar region; F. Micropyle.