Diplotrichus pilifrons Jordal, 2021

Jordal, Bjarte H., 2021, An integrated taxonomic revision of Diplotrichus (Coleoptera, Scolytinae) supports a Malagasy origin and single colonisation of South Africa, Zootaxa 5047 (2), pp. 101-122 : 108

Diplotrichus pilifrons Jordal , sp. nov.

(Figs, 15, 18, 21, 22)

urn:lsid:zoobank.org:act:7924E72C-BB15-4397-9D71-C4221276E7FC

Type material. Holotype female: South Africa, West Cape, Tsitsikamma, Storms River [ GIS: -33.964, 23.898], ex Trichocladus ellipticus 13 Nov. 2006, B. Jordal, leg. Allotype male and paratypes: same data as holotype (9); South Africa, West Cape, Knysna, Goudeveld [ GIS: -33.913, 23.948], ex Trichocladus ellipticus 13 Nov. 2006, B. Jordal, leg. (7) . Holotype, allotype and five paratypes in SAMC , eight paratypes in ZMUB , two in NHMW.

Diagnosis. Female frons lightly concave, entire surface covered by soft setae about half the length of setae on scapus, setae shorter in centre; antennal club with two distinct and angularly procurved sutures; elytral interstriae with regular row of erect spatulate setae separated in a row by the length of a seta or slightly less.

Description, female. Length 1.4–1.8 mm, 2.6–2.8 × as long as wide; colour dark brown. Frons lightly concave, entire surface covered by soft setae about half the length of seta on scapus, shorter setae near middle. Eyes separated above by 2.5–2.8 × the width.Antennal scapus triangular with setae as long as antennal club; the club with two angularly procurved sutures. Pronotum with distinct summit, asperities on anterior half; vestiture mixed hairlike, mainly on posterior half, and scale-like, mainly on anterior half. Elytral interstriae with regular rows of erect and narrowly spatulate setae separated within rows by their length or slightly less, closer on declivity. Protibiae with three apical denticles.

Etymology. Composed from the Latin noun pilus in plural, pili, meaning hairs, and the Latin noun frons, meaning forehead, referring to the setose frons in the females of this species.

Distribution and biology. South Africa. Collected in the Cape region, in the forests of Tsitsikamma, Knysna and Wilderness. Specimens were dissected from dead branches of Trichocladus ellipticus (Hamamelidaceae) and Maytenus acuminata (Celastraceae) , ranging from 3 to 10 cm in diameter. Mostly male-female pairs were found, with a few cases of bigamous tunnel systems. In one branch with older broods the females were alone with larvae. Broods ranged from 10 to 20 larvae in a Maytenus branch (n=20), while ranging from 25 to 42 larvae in an unknown tree branch (n=12). Females make longitudinal egg tunnels, while larvae make transverse feeding tunnels.

Remarks. Four of the South African Diplotrichus species are very similar to each other, the exception being D. widdringtoniae . Diplotrichus pilifrons is most similar to D. gracilis and is distinguished by the angular sutures in the antennal club, slightly shorter setae in the female frons, and by the slightly more spaced interstrial setae which are also has a more spatulate shape. Molecular data unambiguously separate these two species from each other and the other two South African species ( Fig. 7 ).

Figures

FIGURE 7. Maximum likelihood tree topology for Diplotrichus based on nucleotides from five gene fragments. Node support values from 100 bootstrap replicates are shown on branches.