Cissidium arcuatum, 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 : 102-103

Cissidium arcuatum sp. nov.

urn:lsid:zoobank.org:act:990BE6BE-B990-4332-91A4-11B17CD39C1B

Figs 6D , 64

Etymology

Johnson ms name, presumed to be after the shape of the pronotal lateral margins.

Material examined

Holotype

VIETNAM • ♀; Tonkin, Hoabinh; A.de Cooman leg.; BM.1940-13; BMNH.

Paratype

VIETNAM • 1 ♀; same collection data as for holotype; mounted verso; MMUE,

Description

SIZE. Habitus ( Fig. 64A ), length 0.67 mm.

COLOUR. Dark brown, pubescence, legs and antennae yellow.

HEAD. With a shallow linear depression behind the eyes, width across eyes 0.21 mm; antennomeres III– XI length 0.36 mm, III–IX length 0.20 mm, X–XI length 0.16 mm; mentum as Fig. 4A.

PRONOTUM. Length 0.18 mm, width 0.30 mm, with scattered pubescence and two short linear depressions converging posteriorly to base at sides of emargination opposite scutellum; lateral margins rounded and then sinuate to obtuse hind angles, bordered, the border extending along the posterior margin to the medial emargination ( Fig. 64B ).

ELYTRA. Length 0.47 mm, width 0.39 mm, pubescent, shallowly foveolate, length of setae as pronotum.

MESOVENTRITE. Collar with wide medial area on the anterior margin without reticulation; medial extension of collar short, wide, coarsely sculpted; mid-keel parallel-sided with two concave insertions anteriorly, hind angles not reaching anterior margins of mesocoxal borders; keel with a series of ± eight setae broadest anteriorly then narrowing with slightly concave margins to a rounded tip at the interruption of the mesocoxal borders; mesoventral lateral margins serrate; humeri strongly toothed ( Fig. 64C ).

METAVENTRITE. Length 0.17 mm, width across spines 0.11 mm, with scattered setae, disc simple. Posterior margins of mesocoxal cavities not serrate.

WINGS. Macropterous.

GENITALIA. Female spermatheca Fig. 6D ; male aedeagus as Fig. 6 Fa–b, but length 0.10 mm.

Remarks

Distinguished from C. aristophanousi sp. nov. by the two elongate foveae on the pronotum.

Figures

Fig. 6. Figures to show genitalia types. – Spermathecae. A. Cissidium bilineatum sp. nov. B. Cissidium amboroense Darby, 2015. C. Cissidium sawadai Darby, 2015. D. Cissidium arcuatum sp. nov. E. Cissidium murphyi sp. nov. – Aedeagi. F. Cissidium petri Darby, 2015. G. Cissidium clareae sp. nov. H. Cissidium fraternum sp. nov. I. Cissidium tigrum Darby, 2015. J. Cissidium apterum sp. nov. K. Cissidium brachypterum sp. nov. L. Cissidium greensladei sp. nov. M. Cissidium kolombangaricum sp. nov. N. Cissidium mindanao sp. nov.

Fig. 64. Cissidium arcuatum sp. nov. A. Habitus. B. Pronotum, × 425. C. Mesoventrite showing median process of collar, mid-keel and keel, × 550.

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.