Polyommatus Latreille

Munguira, Miguel L., Martín, José, García-Barros, Enrique, Shahbazian, Gayaneh & Cancela, Juan Pablo, 2015, Morphology and morphometry of Lycaenid eggs (Lepidoptera: Lycaenidae), Zootaxa 3937 (2), pp. 201-247 : 220-228

Genus Polyommatus Latreille

( Fig. 14 C–F and 15–18)

In Polyommatus icarus (Rottemburg) ( Fig. 14 C, D) the chorion structure is made up of a network of triangular or quadrangular cells with thick walls, without tubercles in the transition zone. The tubercle-aeropyle area has thick, blunt tubercles opening into aeropyles at the tip. The annular zone bears three series of cells with smooth surface and irregular chorionic ridges in their centre. The egg of P. e ros (Ochsenheimer) ( Fig. 14 E, F) has a very characteristic, fine structure, mainly made up of small quadrangular cells. The tubercles are blunt and not very prominent, they are found at the rib intersections of four or five cells. P. daphnis (Denis & Schiffermüller) ( Fig. 15 A, B) has a transition zone with irregular cells; the tubercle-aeropyle zone has cells with thick walls that congregate together in numbers of five to nine to form massive tubercles, with rounded ends and aeropyles on their top.

The five species traditionally grouped within the subgenus Agrodiaetus Hübner share very similar egg morphology ( Fig. 15 C–F and 16). These species are P. ripartii (Freyer) P. fulgens (Sagarra) P. fabressei (Oberthür) P. v i ol et a e (Gómez-Bustillo, Expósito & Martínez), and P. damon (Denis y Schiffermüller). In the network of cells that form the chorion structure the cell size increases when further away from the micropyle. The micropylar area is extremely reduced and the tubercle-aeropyle area is conspicuous with cells in groups of six or seven and very prominent tubercles with characteristic starry sections. Tubercles are up to 50 microns long and have aeropyles at the end. The cells from this area have fine walls that extend past the edges to reinforce the tubercles. P. amandus (Schneider) ( Fig. 17 A, B) shows a reduced transition zone; the tubercles of the tubercle-aeropyle zone are large and somewhat flattened and orientated towards the equator of the egg and not towards the micropyle. The tubercles have ridges that are extensions of the cell walls.

The species of the P. doryl as (Denis & Schiffermüller) group have a network of quadrangular cells whose angles are arranged to form short tubercles, crowned with aeropyles ( Fig. 17 C–F and 18A, B). The transition zone has thick cell walls with a rough surface and the annular zone inner cells with smooth walls. The micropylar rosette has four to six petals, each with a prominent outcrop next to the micropyle. In P. nivescens (Keferstein) the appearance of the reticulum is more regular than in P. golgus (Hübner) and P. d or y l as ( Munguira & Martín 1989).

The egg of P. escheri (Hübner) ( Fig. 18 C, D) has a wide and flattened transition zone, with rounded cell corners and an irregular pattern. The tubercle-aeropyle zone is garnished with large, star like tubercles resulting from the joining of cell walls. The cells have predominantly triangular form and they group together to form hexagons. The annular zone has several series of rounded cells with scattered spots in their inside and a smooth surface. Comparatively, Polyommatus thersites (Cantener) ( Fig. 18 E, F) has the chorion surface with a fine framework of quadrangular, irregular cells and in the tubercle-aeropyle zone small, flattened tubercles which open into aeropyles. The annular zone has only two or three series of cells which give way to the transition zone that shows cells gradually increasing in size.

Figures

FIGURE 14. Scanning electron microscope photographs of a general view of the egg and the detail of the annular zone of the eggs of Cyaniris semiargus (A, B), Polyommatus icarus (C, D), and P. e ro s (E, F). Scale bars 300 (A, C), 200 (E), 50 (B, D), and 20 Μm (F).

FIGURE 15. Scanning electron microscope photographs of a general view of the egg and the detail of the annular zone of the eggs of Polyommatus daphnis (A, B), P. ripartii (C, D), and P. fulgens (E, F). Scale bars 200 (A, C, E), 100 (D), and 20 Μm (B, F).

FIGURE 17. Scanning electron microscope photographs of a general view of the egg and the detail of the annular zone of the eggs of Polyommatus amandus (A, B), P. dorylas (C, D), and P. nivescens (E, F). Scale bars 200 (A, C, E) and 20 Μm (B, D, F).

FIGURE 18. Scanning electron microscope photographs of a general view of the egg and the detail of the annular zone of the eggs of Polyommatus golgus (A, B), P. escheri (C, D), and P. thersites (E, F). Scale bars 200 (A), 300 (C, E), 20 (B, F), and 50 Μm (D).