Cissidium

Darby, Michael, 2020, A revision of Cissidium Motschulsky (Coleoptera: Ptiliidae) with seventy seven new species, European Journal of Taxonomy 622, pp. 1-188 : 169-171

Key to species group 5

1. Pronotal sides rounded....................................................................................................................... 2 – Pronotal sides angulate ...................................................................................................................... 4

2. Pronotum base with a linear row of ten foveae in two pairs of five each, the medial two pairs being larger than the outer three pairs ......................................................................... C. modestum sp. nov.

– Foveae along pronotal base of the same size, more randomly arranged ........................................... 3

3. Pronotum base with ± seven foveae ...................................................................... C. upiense sp. nov. – Pronotum base with ± ten foveae.................................................................... C. sakaii Sawada, 2008 4. Head without a linear depression between the eyes .......................................................................... 5 – Head with a linear depression between the eyes ............................................... C. fraternum sp. nov.

5. Sides of mid-keel straight .................................................................... C. kolombangaricum sp. nov. – Sides of mid-keel concave ................................................................................................................ 6

6. Mid-keel short, anterior angles very wide .................................................. C. brachypterum sp. nov. – Mid keel anterior angles narrower..................................................................................................... 7

7. Mid keel shorter and wider .............................................................................. C. waginicum sp. nov. – Mid keel narrower................................................................................................. C. apterum sp. nov.

Cissidium apterum sp. nov.

urn:lsid:zoobank.org:act:0CF1B47A-22B0-45A8-AE70-F24D484C01C5

Figs 6J , 107

Etymology

Johnson ms name, named after the apterous male.

Material examined

Holotype

SOLOMON ISLANDS • ♂; Santa Ysobel, S.E., 1000 Ships Bay , opposite Lilihinia Is.; 20 Sep. 1965; forest litter; P.N. Lawrence leg.; BMNH.

Paratypes

SOLOMON ISLANDS • 1 ♀; Santa Ysobel, same collection data as for holotype; BMNH • 2 ♂♂, 2 ♀♀; NE Tatamba, Raja; 30 Sep. 1965; forest litter; P.N. Lawrence leg.; MMUE, BMNH • 1 ♂; E Central San Jorge Is. ; 24 Sep. 1965; forest litter; J.P. and P.N. Lawrence leg.; BMNH .

Description

SIZE. Habitus ( Fig. 101A ), length 0.63 mm.

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

HEAD. Without a clearly marked linear depression behind the eyes, width across eyes 0.22 mm; antennomeres III–XI length 0.36 mm, III–IX length 0.20 mm, X–XI length 0.16 mm.

PRONOTUM. Length 0.18 mm, width 0.32 mm, pubescent, base with a series of four or five foveae on each side, these two series separated by distinct space opposite scutellum and with a few scattered, rather large, somewhat irregular foveolae in basal half; side margins sharply angled, concave before rectangular hind angles, sinuous before obtuse anterior angles, strongly bordered, border effaced laterally on posterior margin ( Fig. 107B ).

ELYTRA. Length 0.47 mm, width 0.37 mm, pubescence as pronotum, basal third sparsely covered with large foveolae.

MESOVENTRITE. Medial extension of collar short, pointed; anterior margin of mid-keel wider than posterior, corners of posterior margin reaching anterior margins of mesocoxal borders; keel sharply raised anteriorly then almost parallel-sided to termination between mesocoxae; mesoventral lateral margins serrate in posterior half; humeri barely toothed, sloping posteriorly ( Fig. 107C ).

METAVENTRITE. Length 0.12 mm, width across spines 0.12 mm, with scattered setae, female disc simple, male disc depressed medially; posterior margins of mesocoxal cavities serrate.

WINGS. Male macropterous. Female apterous.

GENITALIA. Female spermatheca globular with small accessory knob. Male aedeagus with projecting hooked tip ( Fig. 6J ).

Remarks

Five of the ten species of Cissidium recorded from the Solomon Islands belong in this group and are difficult to separate on pronotal characters. The genitalia distinguish this species.

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. 107. Cissidium apterum sp. nov. A. Habitus. B. Pronotum, × 360. C. Mesoventrite showing median process of collar, mid-keel and keel, × 470.

Fig. 101. Cissidium reitteri (Matthews, 1889). A. Habitus. B. Pronotum, × 330. C. Mesoventrite showing median process of collar, mid-keel and keel, × 450.