Cissidium longum Darby, 2019

Darby, Michael, 2020, A revision of Cissidium Motschulsky (Coleoptera: Ptiliidae) with seventy seven new species, European Journal of Taxonomy 622, pp. 1-188 : 83-85

Cissidium longum Darby, 2019

Fig. 53

Material examined

Holotype

MALAYSIA • ♀; Sarawak, 4 th division, Gunung Mulu National Park ; May–Aug. 1978; P.M. Hammond and J.E. Marshall leg.; BM 1978-49; base camp, alluvial forest litter near laboratory; BMNH.

Supplementary description

The following description amplifies the type description of Darby (2019), in particular by adding more details of the meso- and metaventral characters, in order to conform with the entries in the present paper.

SIZE. Habitus ( Fig. 53A ), length 0.67 mm.

COLOUR. Yellow, shining, antennae, legs and pubescence yellow.

HEAD. Distance across eyes 0.20 mm; antennomeres III–XI, length 0.37 mm, III–IX length 0.22 mm, X–XI length 0.15 mm; mentum as Fig. 4A.

PRONOTUM. Length 0.19 mm, width 0.29 mm, with three or four foveae joining to form short longitudinal depressions on each side of the base, foveolate on disc and at sides; side margins strongly sinuate posteriorly, hind angles acute, wider than elytra, anterior angles rounded, bordered, the border not continued along the posterior margin, medial emargination opposite the scutellum sinuous ( Fig. 53B ).

ELYTRA. Length 0.43 mm, width 0.37 mm, basal third strongly foveolate.

MESOVENTRITE. Without pubescence, almost imperceptibly reticulate, medial projection of collar very small expanding to meet keel, mid-keel much reduced without anterior or posterior angles, tapering posteriorly to join keel, the junction marked by a series of ± six small raised bumps (possibly once setae bearing?); keel terminating past interruptions of mesocoxal margins; humeri toothed; mesoventral lateral margins long and straight then rectangular with rounded angles, without serrations ( Fig. 53C ).

METAVENTRITE. Length 0.13 mm, pubescent, width across spines 0.10 mm, posterior margin of mesocoxae serrate.

Remarks

This is the only species from Malaysia in this group which has angulate lateral margins to the mesoventrite.

Figures

Fig. 53. Cissidium longum Darby, 2019. A. Habitus. B. Pronotum, × 485. C. Mesoventrite showing median process of collar, mid-keel and keel, × 895.

Fig. 4. Menta and submenta. A. Cissidium petri Darby, 2015, × 1380. B. Cissidium tigrum Darby, 2015, × 1220. C. Cissidium amboroense Darby, 2015, × 1260. D. Cissidium losbanos sp. nov., × 1100. E. Cissidium triangulum Darby, 2019, × 650. F. Cissidium pilosellum sp. nov., × 1420.