Eurema albula ceciliana, Haghenbeck F., Garcia, Haghenbeck C. & Turrent, 2021

Nieves-Uribe, Sandra, Llorente-Bousquets, Jorge & Flores-Gallardo, Adrián, 2025, Exochorionic morphology in two species of white Eurema (Pieridae: Coliadinae) and its taxonomic contrast on Euremina proposals, Zootaxa 5621 (1), pp. 111-130 : 120-130

Eurema albula ceciliana

( Fig 4 A , Figs. 5–6 A – C ). Chorion 1484 µm long and 376 wide; 4 times longer than the maximum width at the equator ( Fig. 4 A ), and approximate w/l ratio of 1/4 (h=20). Color N 00 A 10 M 00. Semifusiform but somewhat oblong, with convex base and apex; the basal region is almost twice as wide as the apical ( Fig. 4 A ). The micropyle, with no distinguishable micropylar openings, is depressed and very irregular pentagonal with curved vertices and edges. It is and surrounded by a rosette with not very pointed five petals ( Fig. 5 A ); all with thick external walls and with thinner lateral ones in those closer to the micropylar polygon ( Fig. 5 A – i, B ). The perimicropylar region has an irregular wreath with a defined semi-ring of 16 foils with slightly curved vertices and four to five irregular sides ( Fig. 5 B ). The lateral walls of the foils—although thick—are diffuse, mainly in those closer to the rosette ( Fig. 5 B ). The walls of petals and foils have almost the same thickness as the rest of the exochorionic grid ( Fig. 5 A – C ). The lumen of the foils closest to the apical polygons is the only one with a slightly rough texture ( Fig. 5 B ). After the wreath there is no transition zone ( Fig. 5 B – C ), but wide irregular quadrangular or pentagonal apical polygons with aeropyles at their vertices ( Fig. 5 C , Fig. 6 A ). A rough texture forms a micro-grid relief ( Fig. 6 A – i ) more conspicuous towards the equatorial third ( Fig. 5 C – ii). The aeropyles are semicircular or elliptical ( Fig. 5 C , Fig. 6 A ) with an individual arrangement that concurs with the vertices of the polygons —confluence between axes and ribs ( Fig. 5 C ). There are 10–11 aeropyles at vertices aligned in an apex-equator direction ( Fig. 5 C ). Towards the equator, there are 22–23 almost straight axes in lateral view ( 40–43 in total), with fusions and bifurcations in any region of the chorion ( Fig. 4 A ); there are 61–72 ribs, mostly straight, with some diagonal ones throughout the exochorion ( Fig. 4 A ). The axes and the diagonal ribs protrude from the chorionic wall in great relief and are slightly thicker than the straight ribs and micro-grid, which remain in the same visual plane ( Fig. 6 B ). Since the ribs and the micro-grid are almost the same thickness, it is difficult to differentiate them by sight or by staining ( Fig. 4 A , Fig. 6 B ). The macro-grid is mostly quadrangular or irregularly rectangular ( Fig. 6 B ); almost all polygons are the same size, although the apical ones are narrower than the rest ( Fig. 4 A ). The micro-grid is composed of 4–6 rectangular polygons, but with gently curved vertices ( Fig. 6 B ). No texture is recorded in the lumen of the micro-grid ( Fig. 6 B ). Both grids maintain their thickness from pole to pole and become thinner towards the prebase, mainly the macro-grid ( Fig. 6 C ). In the prebasal area, the macro and micro-grid are blurred and the base shows only a slightly rough texture ( Fig. 6 C ). Basal aeropyles are not observed ( Fig. 6 C ).

Eurema albula ceciliana :

México: Oaxaca: Pluma Hidalgo, Finca Aurora-San Isidro ( 15°56’30” N, 96°29’13” W), 1170 msnm, 25-VIII-2008, J. Llorente (ABD-107); Candelaria Loxicha, El Azulillo ( 15°53’25” N, 96°29’27” W), 380 msnm, 03-VII-2011, J. Llorente (ABD-223, ABD-224) .

Figures

FIGURE 4. Chirographs in lateral view of the subspecies of Eurema albula. A. E. a. ceciliana; B. E. a. celata; C. E. a. marginella; D. E. a. sinoe; E. E. a. albula (Detail of its micro-grid on the right).

FIGURE 5. Photographs of the chorion of Eurema albula ceciliana (A–C) and E. a. celata (D–F) under SEM. A–D. Micropyle; B–E. Micropylar region; C–F. Apex. i, iii. Subtle anchorage in micropylar rosette; ii. Micro-grid texture in apical polygons; iv. Absence of wall in wreath foils; v. Conspicuous micro-grid in apical polygons.

FIGURE 6. Photographs of the chorion of Eurema albula caeciliana (A–C) and E. a. celata (D–F) under SEM.A–D.Aeropyles; B–E. Grids at the equator; C–F. Base. i. Incipient micro-grid in apical polygon.