Leptidea gigantean (Leech, 1890)

Llorente-Bousquets, Jorge & Castro-Gerardino, Diana Jimena, 2018, Antennal ultrastructure of Leptidea Billberg, 1820 (Pieridae: Dismorphiinae: Leptideini) and its taxonomic implications, Zootaxa 4402 (3), pp. 401-442 : 430-432

Leptidea gigantean (Leech, 1890)

ANTENNAL CLUB ( Fig. 14a, b ): The antenna is claviform with a differentiated club, but less so than the other species of Leptidea , so it is similar to those of Dismorphiini. The scaleless club is 950 µm in length in the male and 1570 µm in the female. Compared to other species of Leptidea , there is a greater difference in the length of the club between the sexes. ANTENNOMERES ( Fig. 14 a–f): The number of scaleless antennomeres is six in the male and ten in the female; the distal two antennomeres are fused. This antennomere is cupuliform, although in females it is more elongated. Antennomeres are always wider than long, especially in the male, but the l:w ratio is much lower than in other scongeners, in which they are only slightly depressed. In the male the l:w ration is up to 1:3 and in the female it is 1:2. Its width is also constant, so there is no distal narrowing of the club. In the male, the antennomeres are “quasi- cylindrical,” and in the female they are doliform. In the female the scaled area covers one antennomere less on the ventral surface; in the male, the two surfaces have the same number of scaleless antennomeres.

SULCI AND PSEUDOSULCI ( Fig. 14e, f ). The male has 6 central and 8 lateral sulci, and the female has 9 central and 18 lateral. In the first scaleless antennomere of the male, there is a central sulcus as wide as the other sulci; these occupy almost half the length of the antennomeres (except the distal one) and are broad. In the 4th antennomere the sulci join and form a ventral-lateral-dorsal band. Of the species of Leptidea we examined, this is the only one where the male has a dorsal surface like the ventral; the lateral sulci occur toward the dorsal surface from the first antennomere whereas the female does not show this displacement. In the male, sulci have a continuous edge; they are horizontal semi-elliptic aggregates; and are sometimes semi-triangular and remarkably truncated. In the female, the first antennomere is partly scaled; it lacks sulci or pseudosulci; and there are some chaetic sensilla. In the others antennomeres, the sulci are very irregular and disaggregated and are accompanied by at least two pseudosulci; they are truncated by the distal margin of the antennomere and occupy less than half the length of the same. The lateral sulci are disaggregated from the second to the fourth antennomere and from the fifth, they are aggregated; they are very close to the distal margin of the antennomere but are not always truncated.

MICROTRICHIA ( Fig. 14 g–i). Microtrichia m1 and m2 are present. In the male, the st:m1 ratio of the central sulci is 1: 3 in the first four antennomeres and 1: 2 in the distal one. In the female, the ratio is 1:3.

TRICHOID SENSILLA ( Fig. 14g ). Theses sensilla average ca. 23 µm in length, with the surrounding cuticular ring partly attached to the m1. In the male, some sensilla have a differentiated base from the flagellum, which is darker and slightly ornate. In the female, the bases are smooth and some sensilla appear forked, with two apices. There are trichoid sensilla in the sulci and pseudosulci and sometimes outside of them, toward the lateral side, although they are very scarce.

CHAETIC SENSILLA ( Fig. 14g ). The chaetic sensilla average ca. 19 µm in length and are usually shorter than the trichoid sensilla. In the male, the sensilla of the basal antennomeres are longer (22 µm), narrower, and with a more acute apex. They do not always present a typical distribution or constant number in the antennomeres. They are scarce, and we observed two to six sensilla very close to the periphery of the sulci, and even within these, at the apex of the distal antennomere there are only four sensilla. In the female, on the lateral surface of the 2nd and 3rd antennomere, there are up to seven sensilla on the ventral surface; from the 4th antennomere, the number of sensilla is up to four. Unlike the male, the sensilla are not at the periphery or within the sulci. At the apex of the distal antennomere, they are rather scarce but are longer (27 µm).

BASICONIC SENSILLA ( Fig. 14h ). In this species the basiconic sensila average ca. 11 µm in length. They are distributed throughout the antennomere, outside the sulci.

AURICULATE SENSILLA ( Fig. 14i, j ). Theses sensilla are found in the edge of the sulci and even within the sulci in the female. A few have a bifurcated apex, and in females they may be trifurcate.

COELOCONIC SENSILLA ( Fig. 14k ). In the female we noticed the coeloconic sensilla near the lateral sulci.

OTHER SENSILLA. In the male we found only one campaniform sensillum near the basal area of the distal antennomere ( Fig. 14 l ).

Figures

FIGURE 14 (a–f). Antennal club and scaleless antennomeres in Leptidea gigantea. a. Antennal club ♂ (x90); b. Antennal club ♀ (x70); c. Distal antennomere ♂ (x400); d. Distal antennomere ♀ (x250); e. The fourth antennomere ♂ (x400); f. Sixth antennomere of the club in ♀ (x375).