Ruptitermes arboreus ( Emerson 1925 )

Acioli, Agno Nonato Serrão & Constantino, Reginaldo, 2015, A taxonomic revision of the neotropical termite genus Ruptitermes (Isoptera, Termitidae, Apicotermitinae), Zootaxa 4032 (5), pp. 451-492 : 457-459

Ruptitermes arboreus ( Emerson 1925)

Anoplotermes (Speculitermes) arboreus Emerson 1925: 427 (imago, fig. 81)

Speculitermes arboreus ; Snyder 1949: 110 (catalog, new combination)

Ruptitermes arboreus ; Mathews 1977: 100 (new combination); Constantino 1991: 195 –196 (imago, fig. 12); Krishna et al. 2013: 1408 (catalog, synonymy).

Imago ( Fig. 3 ). Head capsule very dark brown, with many long bristles and densely covered with short hairs, about 1/5 of the length of bristles. Eyes rounded, medium sized, bulging. Fontanelle oval, very large and convex, same color as head capsule. Ocelli small, distant from eyes. Frontal marks oval, depressed, a little paler than head capsule. Postclypeus brown, with many bristles and dense short hairs. Antenna light brown, much paler than postclypeus. Mandibles distinct from those of R. xanthochiton (see description of worker below). Pronotum about the same width as head; anterior margin nearly straight; lateral margins convex, converging posteriorly; brown, without pale spots along midline; with many bristles and dense short hairs. Scutum and scutellum brown, about the same color as pronotum; lateral margins of scutellum white. Pleural sclerites, coxa, and femur light brown; tibia light brown on proximal region, becoming yellow distally. Tergites brown, a little paler than pronotum; sternites paler than tergites. Measurements in Table 1 .

Worker ( Figs. 4 , 22 B, 23F–G, 24B–D). Head capsule rounded, dark brown, covered with many long and curved bristles and shorter hairs. Postclypeus strongly inflated, same color as head capsule, with many hairs and bristles of various sizes. Fontanelle large and wide, a little paler than head capsule. Frontal marks inconspicuous. Vestigial eyes conspicuous as white spots behind antennal sockets. Left mandible: A very short, M1 large; M3 larger than A, rounded; deep notch between M1 and M3; cutting edge between M1 and notch curved; molar tooth hidden under molar prominence. Right mandible: A very short; M1 large; M2 shorter than M1 and larger than A; molar plate large, concave, with faint ridges. Procoxa without spine-like bristles. Protibia long and thin. Thoracic nota light brown, with many long and curved bristles and hairs of variable size. Tergites light brown, a little pale than thoracic nota, covered with bristles and hairs of variable size. Dehiscent glands and crop size show two patterns: workers with small glands (hardly visible) have a very large crop, while workers with large glands have a small crop. Mixed segment very short; mesenteric lobe not inflated. Seating of enteric valve rounded, without diverticula (23F–G). Enteric valve very narrow; each ridge with a distinct, sclerotized spine near the center; surface of ridges reticulated with backwardly directed scales with serrated posterior fringes ( Figs. 24 B–D). Measurements in Table 2 .

R. xanthochiton 1.15–1.64 1.33–1.76 0.27–0.35 0.61–0.82 0.97–1.27 0.12–0.17 21

(1.38) (1.54) (0.30) (0.72) (1.06) (0.14)

Comparisons. The worker of R. arboreus is easily distinguished from all other species of the genus by their dark color, the presence of vestigial eyes, the long curved bristles on head, and the absence of spine-like bristles on the procoxa. Their mandibles and enteric valve are also distinct.

Distribution. Ruptitermes arboreus occurs mainly in primary rainforests in the Amazon region, with a few records in secondary vegetation ( Fig. 26 ).

Remarks. This species builds arboreal carton nests, which are small and may be located several meters above ground; they are connected to the ground by covered tunnels. The workers move rapidly and are very aggressive. They are dimorphic in relation to the development of the dehiscent glands. About half of the workers have large glands while the other half has poorly developed glands. This dimorphism suggests the presence of two specialized morphs, but little is known about their biology and behavior. They show some striking similarities with the workers of Constrictotermes spp: very similar mandibles (despite being phylogenetically distant) and a very large crop, which seem to be convergences resulting from similar foraging habits. Workers of Constrictotermes forage on the surface, scraping dead plant tissue, and carry their food in their crops ( Moura et al. 2006).

Type material examined. GUYANA: Guyana: Kartabo, 27.viii.1920, A.E. Emerson col., holotype imago and paratype workers ( AMNH).

Other material examined. BRAZIL: Amazonas: Manaus, 08.ix.1978, A.G. Bandeira col., workers (MPEG- 486). 14.vii.1983, R.L. Abreu col., workers (UnB-0370). Maraã, 28.x.1988, R. Constantino col., workers, queen (MPEG-2956, UnB-9927). Manaus, Reserva Ducke, 01.ix.1990, F.B. Apolinário col., workers (UnB-3634). 06.xi.1991, F.B. Apolinário col., workers ( INPA). 20.viii.1991, F.B. Apolinário col., workers ( INPA). 20.xi.1990, F.B. Apolinário col., workers ( INPA). Pará: Itaituba, Parque Nacional da Amazônia, 13.ii.2005, Y. Okada col., workers ( INPA). 22.viii.1978, A.G. Bandeira col., workers, queen (MPEG-0410, MPEG-411). Oriximiná, Porto Trombetas, 21.x.2000, A.N.S. Acioli col., workers ( INPA). Parauapebas, Serra dos Carajás, 10.xi.1983, A.G. Bandeira col., workers, queen (MPEG-1595). Rondônia: Ariquemes, Faz. Rancho Grande, 12.x.1993, D.H. Kistner col., workers (UnB-0558). Roraima: Boa Vista, 13.v.1977, A.G. Bandeira col., workers (MZSP-7639).

Figures

FIGURE 3. Imago of Ruptitermes arboreus (Emerson 1925). A, head in profile; B, head in dorsal view; C, pronotum in dorsal view; D, pterothorax in dorsal view.

FIGURE 4. Worker of Ruptitermes arboreus (Emerson 1925). A, habitus; B, protibia; C, procoxae; D, head in profile; E, head in dorsal view; F, mandibles.

FIGURE 22. Worker heads of Ruptitermes, showing pilosity. All figures in the same scale.

FIGURE 24. Enteric valve armature of workers of Ruptitermes. A, R. araujoi; B – D, R. arboreus; E – F, R. atyra; G, R. bandeirai; H – I, R. cangua; J – K, R. franciscoi. Scale bars = 0.1 mm.

FIGURE 26. Geographic range of Ruptitermes araujoi, sp. n., R. arboreus (Emerson 1925), and R. atyra, sp. n.

Tables

TABLE 2. Measurements of workers of Ruptitermes, range and mean (mm). WT: width of protibia; see other abbreviations in Table 1.

Species	LH	WH	LPc	WPc	LT	WT	n
R. araujoi	1.02–1.24 (1.16)	1.22–1.44 (1.37)	0.27–0.36 (0.29)	0.54–0.71 (0.66)	0.94–1.06 (1.00)	0.12–0.15 (0.13)	10
R. arboreus	0.82–0.91 (0.87)	0.91–1.06 (0.98)	0.18–0.27 (0.23)	0.49–0.58 (0.52)	0.94–1.18 (1.08)	0.09–0.11 (0.10)	15
R. atyra	1.34–1.62 (1.45)	1.58–1.88 (1.69)	0.27–0.34 (0.30)	0.64–0.76 (0.69)	1.24–1.46 (1.34)	0.12–0.16 (0.14)	10
R. bandeirai	0.57–0.67 (0.63)	0.74–0.79 (0.76)	0.12–0.20 (0.16)	0.32–0.40 (0.36)	0.49–0.62 (0.57)	0.11–0.12 (0.12)	10
R. cangua	1.36–1.47 (1.41)	1.62–1.71 (1.69)	0.27–0.29 (0.28)	0.64–0.82 (0.75)	1.15–1.24 (1.19)	0.15–0.17 (0.16)	10
R. franciscoi	0.94–1.10 (1.01)	1.14–1.30 (1.23)	0.20–0.32 (0.26)	0.48–0.56 (0.52)	0.80–0.95 (0.86)	0.10–0.15 (0.13)	10
R. kaapora	0.96–1.00 (0.99)	1.13–1.22 (1.18)	0.26–0.32 (0.31)	0.46–0.58 (0.53)	0.74–0.86 (0.81)	0.13–0.16 (0.15)	9
R. krishnai	1.00–1.10 (1.05)	1.18–1.24 (1.21)	0.19–0.24 (0.22)	0.47–0.58 (0.52)	0.86–0.92 (0.89)	0.10–0.15 (0.12)	10
R. maraca	0.82–1.04 (0.95)	0.94–1.21 (1.10)	0.21–0.29 (0.25)	0.43–0.55 (0.49)	0.63–0.95 (0.81)	0.09–0.14 (0.12)	24
R. piliceps	0.73–1.01 (0.85)	0.84–1.15 (1.00)	0.17–0.23 (0.19)	0.35–0.52 (0.46)	0.58–0.86 (0.72)	0.09–0.12 (0.10)	16
R. pitan	1.33–1.49 (1.42)	1.42–1.64 (1.54)	0.21–0.30 (0.26)	0.61–0.76 (0.69)	1.03–1.21 (1.13)	0.11–0.15 (0.12)	18
R. reconditus	0.82–1.03 (0.93)	1.00–1.27 (1.13)	0.21–0.27 (0.24)	0.46–0.58 (0.52)	0.76–0.94 (0.84)	0.09–0.12 (0.11)	21