Cissidium lucidulum, Darby, 2020

Darby, Michael, 2020, A revision of Cissidium Motschulsky (Coleoptera: Ptiliidae) with seventy seven new species, European Journal of Taxonomy 622, pp. 1-188 : 16-18

Cissidium lucidulum sp. nov.

urn:lsid:zoobank.org:act:A60A855C-4027-450F-A2B0-576BC746B873

Figs 5B , 11

Etymology

Johnson ms name. Named after the Latin adjective ‘ lucidus ’, meaning ‘bright, clear’ and referring to the dorsal surface.

Material examined

Holotype

SOLOMON ISLANDS • Guadalcanal, Mt. Austen , 4 Jul. 1966; no. 23371; P. Greenslade leg.; BMNH.

Description

SIZE. Habitus ( Fig. 11A ), length 0.52 mm.

COLOUR. Yellow brown, glabrous, shining.

HEAD. Without pubescence and with a shallow linear depression across the mid-point of the eyes, width across eyes 0.17 mm; antennomeres III–XI length 0.32 mm, III–IX length 0.17 mm, X–XI length 0.15 mm; mentum and prementum obscured.

PRONOTUM. Length 0.14 mm, width 0.24 mm, basal half with pair of well-defined oval, longitudinal foveae, one on each side of disc, separated by about a third of pronotal width, with similar but much smaller ones near pronotal hind angles, a further pair of more rounded foveae by the lateral margin angles, surface smooth and shining without foveolae; sides sharply angled, slightly widening posteriorly to almost rectangular hind angles, front angles rounded, conspicuously bordered, the border not continued along the basal margin, hind margin slightly wider than elytral base with a sinuous emargination before the scutellum ( Fig. 11B ).

ELYTRA. Length 0.35 mm, width 0.31 mm, surface smooth and shining, without foveolae. MESOVENTRITE. Collar with a median process onto the mid-keel; mid keel widenend anteriorly and posteriorly with carinae joining mesocoxae, sharply raised medially with a ridged top before junction with keel; keel parallel-sided, relatively broad between the mesocoxae ( Fig. 5B ); lateral margins angulate without serrations ( Fig. 11C ).

METAVENTRITE. Disc simple; posterior borders of mesocoxal cavities without serrations.

WINGS. Macropterous in both sexes.

Remarks

The sex of this unique specimen is unknown as the abdomen was unfortunately lost during preparation, but eye size suggests a female. The smallest species of the Solomon Islands and the only one to have a glabrous pronotum.

Figures

Fig. 5. Figures to show keel shapes. A. Cissidium bifoveolatum sp. nov., × 515. B. Cissidium lucidulum sp. nov., × 780. C. Cissidium scutellaris (Deane, 1931), × 1480. D. Cissidium tigrum Darby, 2015, × 840. E. Cissidium sawadai Darby, 2015, × 680. F. Cissidium lisae Darby, 2015, × 823.

Fig. 11. Cissidium lucidulum sp. nov. A. Habitus. B. Pronotum, × 670. C. Mesoventrite showing median process of collar, mid-keel, keel and angular lateral margin without serrations, × 690.