Parena scutata (Alluaud, 1917)

Shi, Hongliang & Liang, Hongbin, 2023, Taxonomic revision of the genus Parena Motschulsky, 1860 (Coleoptera, Carabidae, Lebiini, Metallicina), Zootaxa 5286 (1), pp. 1-144 : 126

13. Parena scutata species group

This species group contains three species distributed in the Sub-Saharan African mainland and one species from Madagascar. This group is characterized by: postgenae without suborbital setae; elytra not metallic, uniformly reddish brown or with dark patches; elytral apices distinctly truncate, apical margin nearly straight, sutural angles more or less pointed, very faintly so in some species; elytra with or without microsculpture; antennomere 1 with the ventroapical seta only slightly shorter than the dorsoapical one; male genitalia with LL greater than LW, apex slightly bent dorsally; gonocoxite II of ovipositor quadrate, apex more or less emarginate.

This species group is most similar to the P. plagiata group in having postgenae without suborbital setae and a similar elytra color pattern (four species of these two groups have their elytra largely dark with a narrow red apical band). Although members of these two groups have similar external appearances, we divided them into different species groups based on differences in the following important aspects: shape of elytral apices, length of the apical setae of antennomere 1, and shape of the male genitalia and female ovipositor. Species of the P. scutata group have distinctly truncate elytral apices with the sutural angles more or less pointed, although very faint so in some species ( Figs 5B, 5C, 5D ). This character state is unique in the subgenus Parena , but presents in several species of the subgenus Crossoglossa . Moreover, in the P. scutata group, the ventroapical seta of antennomere 1 is only slightly shorter than the dorsoapical one ( Fig. 1D ), whereas, in all other species of this genus, the ventroapical seta is less than half the length of the dorsal-apical one ( Figs 1A, 1B, 1C ). In all studied species, the male genitalia and female ovipositor also have significant differences between these two groups. In the P. scutata group, the median lobe of aedeagus is slenderer and the apical lamella is much longer than in the P. plagiata group. In the P. scutata group, gonocoxite II of the ovipositor is nearly quadrate with its inner and outer margins equally in length, whereas in the P. plagiata group, gonocoxite II is strongly pointed near its inner apical angle with its inner margin much longer than the outer margin.

Figures

FIGURE 1. Antennae and mouthparts of Parena spp. A–D Line drawings of basal three antennomeres, view of lateral surface: A P. (Crossoglossa) cavipennis (Bates). B P. (Bothynoptera) malaisei (Andrewes). C P. (Parena) africana (Alluaud). D P. (Parena) ruficornis sp. n. E Antennomeres 7–11 of P. (Parena) nigrolineata (Chaudoir), showing the sensory pits on dorsal surface. F–G Labrum of P. (Crossoglossa) cavipennis (Bates), Beijing: F dorsal surface. G ventral surface. H Maxilla of P. (Crossoglossa) cavipennis (Bates), Beijing. Scale bars = 0.2mm.

FIGURE 5. Elytral apex (left) of Parena spp. A P. (Parena) africana (Alluaud), Cameroon. B P. (Parena) ruficornis sp. n., Central Africa, paratype. C P. (Parena) valeriae Facchini, holotype. D P. (Parena) madagascariensis (Alluaud), Madagascar. E P. (Bothynoptera) tesari (Jedlička), Taiwan. F P. (Bothynoptera) heteronycha sp. n., Laos, paratype. G P. (Bothynoptera) kurosai Habu, Japan. H P. (Bothynoptera) dorsigera (Schaum), Yunnan. I P. (Bothynoptera) dorsigera (Schaum), Beijing. J P. (Bothynoptera) dorsigera (Schaum), Japan. Scale bars = 0.5mm