Psammoecus grandis Grouvelle, 1908

Karner, Michael, 2012, A revision of African Psammoecus (Coleoptera, Silvanidae) and descriptions of two new species from the collection of the Musée royal de l’Afrique centrale, European Journal of Taxonomy 17, pp. 1-31 : 16-18

Psammoecus grandis Grouvelle, 1908

( Fig. 7 )

Material examined

Holotype

♀: ‘Af. or. All. | Kwai. Weise’ [blue label, Grouvelle’s hand], ‘Type’ [Grouvelle’s hand], ‘Type’ [red label, printed], ‘MUSEUM PARIS | 1917 | Coll. GROUVELLE’ [blue label], ‘ Psammoecus | grandis | G. Grouv’ [Grouvelle’s hand] ( MNHN).

Other material

1 spm ‘COLL. MUS. CONGO | Ruanda: Gitarama, | 1850 m. terr. Nyanza, | P. Basilewsky I-1953 ’ ( MRAC). 1♂ ‘I.R.S.A.C.-Mus. Congo | Kivu: Terr. Lubero | 2.200 m. 2-XII-1951 | N. Leleup | (for mont. avec bamb.)’, ‘Récolté dans l’humus’ [blue label] ( MRAC). 1 spm ‘COLL. MUS. CONGO | Urundi: Kitega 1600- | 1700 m. 3/ 4-III-1953 | P. Basilewsky’ ( MKF). 4 spms ‘COLL. MUS. CONGO | Urundi: Bururi, 1800 - | 2000 m. 5/ 12-III-1953 | P. Basilewsky’ ( MRAC).

Differential diagnosis

Ps. grandis resembles Ps. longicornis Schaufuss, 1872 and Ps. lateralis ( Grouvelle, 1899) , but differs by the presence of small lateral teeth of pronotum. It differs from Ps. longicornis also by the very large and curved parameres with very short extensions.

Redescription

BODY. Slender, narrow, total length 3.4-4.2 mm ( Fig. 7A ), surface yellowish-brown, elytra with dark maculae of variable shape; some immature specimens only with a darkish macula in the posterior half of elytra, other specimens with posterior half of elytral suture and elytral maculae blackish-brown. 7 th to 10 th antennomere and apex of 6 th antennomere darkened, 11 th antennomere brighter than basis of antennae.

HEAD. With comparatively small eyes and broad, curved temples; width 0.80-0.89 mm, length 0.45- 0.48 mm; 1.71-1.85 times as wide as long. Eye length 0.23-0.25 mm, distance of inner margins 0.48- 0.56 mm. Puncturation on vertex irregular, pubescence composed of short, recumbent setae, directed anteriorly; microsculpture well defined, reticulate. Longitudinal impressions on vertex short, curved, almost attaining the anterior third of eyes. Antennae as in Fig. 7B , short, length 1.58-2.00 mm, 1 st antennomere very long and slender. Antennomere proportions of holotype as follows: 3.33: 1: 1.17: 1.5: 1.2: 1.7: 1: 1: 1.8: 1: 2.17.

PRONOTUM. Subquadrate, width 0.89-1.03 mm, length 0.75-0.90 mm, 1.14-1.23 times as wide as long. Surface uneven with flat impressions near the posterior margin close to the posterior angles as well as in the middle of the posterior margin. Less distinct impressions also close to the anterior margin, in some specimens also in the middle of the pronotal disc. Posterior angle with a very small group of teeth, lateral margins with four to five very short lateral teeth, posterior angle almost rudimentary. The holotype shows an asymmetrical tooth pattern with different numbers and location of lateral teeth on the two sides of the pronotum. Puncturation slightly coarser and denser than on vertex, pubescence as on vertex; microsculpture well defined, reticulate.

ELYTRA. Narrow, slender, length 2.10-2.67 mm, combined width 1.35-1.60 mm, 1.50-1.81 times as long as their combined width. Rows of punctures on the disc a little narrower than interstices. Pubescence rather flat, consisting of long setae. Microsculpture visible only in few specimens, very weak, reticulate.

PARAMERES. with broad base, narrowing and curving inwards toward apex ( Fig. 7C ).

Figures

Fig. 7. Psammoecus grandis Grouvelle, 1908. A. Habitus of holotype. B. Left antenna of holotype. C. parameres of specimen from Kivu. Scale line A, B: 1 mm; C: 0.2 mm.