Rugitermes rufus Scheffrahn, 2020

Scheffrahn, Rudolf H. & Carrijo, Tiago F., 2020, Three new species of Rugitermes (Isoptera, Kalotermitidae) from Peru and Bolivia, ZooKeys 1000, pp. 31-44 : 31

Rugitermes rufus Scheffrahn sp. nov. Figures 4A, B , 5 , 6 ; Tables 1, 2

Diagnosis.

The coloration and size of the R. rufus imago easily distinguish it from all other species of Rugitermes . Rugitermes rufus is the only Rugitermes imago with a reddish-orange head capsule and dark brown coloration of the pronotum and remainder of the body. Rugitermes costaricensis (Snyder, 1929) and R. unicolor Snyder, 1952 imagos each have a yellow-brown head and yellow pronotum (with less contrast between coloration of head and pronotum in R. unicolor ). In all other Rugitermes , the imago head is black and the pronotum is yellow [ R. bicolor (Emerson, 1926), R. flavicinctus (Emerson, 1925), R. magninotus (Fig. 7 ), R. kirbyi (Snyder, 1926), R. nodulosus Oliveira, 1979, R. panamae (Snyder, 1925), and R. rugosus (Hagen, 1858)] or the head and pronotum are both black [( R. athertoni , R. laticollis , R. niger Oliveira, 1979, and R. occidentalis (Silvestri, 1901)]. The head width of the R. rufus imago is among the smallest: in range of R. flavicinctus (1.2 mm) and R. magninotus (1.25 mm). The soldier of R. rufus is smaller in all measurements compared with R. volcanensis . The antennal carina in R. rufus forms a smaller ovoid shelf of the gena and, in lateral oblique view, projects acutely from the frontal margin. In R. volcanensis , the shelf formed by the antennal carina is larger and, in the lateral oblique view, weakly projects above the frontal margin. The third antennal article of R. rufus is proportionally narrower and longer than that of R. volcanensis . See also diagnosis of R. aridus .

Type locality.

Bolivia, Amboró National Park, Refugio Los Volcanes, Santa Cruz District (Fig. 9B ).

Material examined.

Holotype. One female delate imago: Bolivia, Amboro National Park , hillside above Refugio Los Volcanes , Santa Cruz District (-18.119680, -63.608810) elev. 1402 m, 2 Jun. 2014, R. Scheffrahn et al., UFTC no. B01021 . Paratypes. Three soldiers, pseudergates, same colony sample as holotype. Five soldiers, pseudergates, Bolivia, Amboro National Park , forest surrounding Refugio Los Volcanes , Santa Cruz District (-18.1004, -63.5934) elev. 1374 m, 3 Jun. 2014, R. Scheffrahn et al., UFTC no. BO1055 . Four colonies, same locality as BO1055: three soldiers, pseudergates ( BO1061 ), four soldiers, pseudergates ( BO1062 ), two male dealate imagos, pseudergates ( BO1070 ).

Description.

Dealated imago (Figs 4A, B , 6 ). Head capsule reddish orange; pronotum, thorax, abdomen, and wing scales concolorous dark brown. Compound eye small; trapezoidal; with shorter straight margin below ocellus and more curved margin near gena. Ocellus ovoid, concolorous with interior of antennal socket; one-half diameter removed from eye margin. Head vertex and frons covered with about a dozen erect setae ca 0.15-mm-long; frons darker, with faint rugosity at frontal flange. Pronotum slightly wider than head capsule; anterior margin slightly incised; anterolateral corners nearly rectate, posterior margin narrowly concave; margins with few longer and many shorter setae. Pronotum interior pilosity congruent with vertex. Antennae with basal article relative lengths 1>2=3<4. Wing scale covered with about 20 setae of similar length and density as those on head and pronotum. Legs with femora light orange-brown; tibia much lighter. Arolium present. Measurements of three imagoes from two colonies are shown in Table 2 .

Soldier (Figs 5 , 6 ). Head capsule, in dorsal view, dark brown along margin of anteclypeus, anterolateral ridges, and antennal carinae grading to orange brown at frons, orange at mid-capsule and yellow at occiput; mandibles nearly black throughout. In ventral view, postmentum light orange-brown contrasting with light yellowish head capsule. Head capsule long, rectangular; lateral margins parallel, covered with a few setae except at occiput. Pronotum much wider than long; with a few long setae at margins and middle. Frontal flange and frons forming shallow furrow; angled 40° with plane of vertex. In dorsal view, antennal carina forms small ovoid shelf over the gena. In lateral oblique view, antennal carinae project acutely from the lateral margin of frons (Fig. 5C ). Antennal carinae and anterolateral ridges weakly rugose. The outer margin of each ridge form angle of ca 110° (Fig. 5B ). Eye spots large, narrowly oblique, barely lighter than head capsule. Third antennal article narrow at the base and longer than second and fourth article combined. Mandibles about one-half length of head capsule; tip curves about 60°; outer margin of mid-blade slightly curved, shallow hump at base. Measurements of 14 soldiers from four colonies are shown in Table 1 .

Distribution.

(Fig. 1 ). Amboró National Park, a transition of the Tucuman-Bolivian forest and the montane Chaco.

Etymology.

The species name " rufus " describes the unique reddish-orange coloration of the imago head.

Figures

Figure 1. Localities of the new Rugitermes species described herein.

Figure 4. Head and thorax of the Rugitermes rufus (A dorsal B lateral) and the R. volcanensis (C dorsal D lateral) imagos.

Figure 5. Head and pronotum of the Rugitermes rufus soldier A dorsal B right (arrow pointing to outer margin of anterolateral ridge) C lateral (arrow pointing to antennal carinae) D ventral.

Figure 6. Field habitus of the imago and soldiers of Rugitermes rufus.

Figure 7. Field habitus of the imagos and soldiers of Rugitermes magninotus from Peru (UFTC no. PU 222).

Figure 9. Biomes for new Rugitermes A R. aridus B R. rufus and R. volcanensis.