Limbodessus, Guignot, 1939

Surbakti, Suriani, Balke, Michael & Hendrich, Lars, 2023, Limbodessus moni sp. nov., a new high altitudinal diving beetle from the Grasberg in West Papua, Indonesia (Coleoptera: Dytiscidae, Bidessini), Zootaxa 5319 (3), pp. 413-420 : 420

Modified key to species of Limbodessus from New Guinea (after Balke et al. 2015; see also Hendrich et al. 2020)

1. Base of elytral epipleuron with raised transverse carina delineating a basal pit (see fig. 36 in Balke et al. 2015) (widespread in Australasian region; ventral aspect as in fig. 28, with metaventrite and metacoxa rather smooth; male genital as in figs 32, 33, 35).................................................................. Limbodessus compactus (Clark, 1862) - Base of elytral epipleuron without raised transverse carina delineating a basal pit (see fig. 38 in Balke et al. 2015)....... 2

2. Elytral plicae distinct, beetles testaceous or yellowish........................................................ 3

- Elytral plicae absent or at most only short and slightly curved inwards, 1/10 length of elytra, beetles brown to blackish..... 4

3. Larger species (TL=2.6–3.0 mm), mainly yellowish without distinct markings on elytra, metacoxa and metaventrite covered with few larger punctures. Short range endemic of Baliem Valley of Papua .... Limbodessus baliem Balke & Hendrich, 2015

- Smaller species (TL=2.0– 2.05 mm), mainly yellowish with distinct markings on elytra, metacoxa and metaventrite covered with numerous larger punctures. Endemic to island of Waigeo........ Limbodessus skalei Hendrich, Surbakti & Balke 2020

4. Larger species (TL=2.6–3.0 mm), median lobe ( Fig. 3A, B ). Females with strongly enlarged antennomeres forming a conspicuous club ( Fig. 1D ). Only known from high altitude grassland of range north of Sugapa, Papua ................................................................................ Limbodessus alexanderi Balke & Hendrich, 2015

- Smaller species (TL= 2.25–2.7 mm), median lobe ( Fig. 2A, B ). Females with only slightly enlarged antennomeres 4–11 ( Fig. 1B ). Only known from high altitude grassland of Carstenz Pyramid area..................... Limbodessus moni sp. nov.

Figures

FIGURE 1. A) Limbodessus moni sp. nov., holotype, male; B) L. moni sp. nov., female; C) L. alexanderi, male; D) L. alexanderi, female (Scale bars = 1 mm).

FIGURE 2. Limbodessus moni sp. nov., median lobe of aedeagus in ventral (A) and lateral view (B); left paramere, view on inner side (C) and right paramere, view on outer side (D). Scale bar = 0.2 mm.

FIGURE 3. Limbodessus alexanderi, median lobe of aedeagus in ventral (A) and lateral view (B); left paramere, view on inner side (C) and right paramere, view on outer side (D). Scale bar = 0.2 mm.