Eutermes (Diversitermes) Holmgren 1912 : 60

Oliveira, Danilo Elias & Constantino, Reginaldo, 2016, A taxonomic revision of the neotropical termite genus Diversitermes (Isoptera: Termitidae: Nasutitermitinae), Zootaxa 4158 (2), pp. 221-245 : 223-227

Eutermes (Diversitermes) Holmgren 1912: 60

Nasutitermes (Diversitermes) : Snyder 1926: 35 [part] Diversitermes: Snyder 1949 [part]

Diversitermes: Mathews 1977: 179 [part]

Diversitermes: Krishna et al. 2013: 1568 [catalog, part] Type-species: Eutermes diversimiles Silvestri 1901 , designated by Snyder (1949: 306).

Imago ( Figs. 1–3 ). Head capsule elliptic in dorsal view, covered with numerous long hairs. Left mandible: cutting edge between M1 and M3 sinuous; M4 partially visible in the gap between M3 and MPr; tip hidden behind MPr; A and M1 about the same size in both mandibles. Right mandible: posterior margin of A, M1, and M2 about the same length; molar plate narrow (width about 2/5 its length), concave, irregularly shaped, with 6–7 transverse ridges; proximal ridge large and tooth-like, separated from the rest by a gap and orientated at an angle of about 45° relative to the other ridges; basal notch strongly developed, nearly a right angle. Fontanelle spot large and conspicuous, Yshaped, yellowish or light brown. Eyes medium-sized; ocelli well separated from eyes. Antenna with 15 articles. Head, pronotum, tergites and sternites covered with dense hairs and sparse bristles. Wings with short hairs on surface, more numerous on costal border and on apical region. Wings densely covered with asteroid micrasters on entire surface, and papilae on anterior and posterior margins ( Figs. 3 D–3F; also described by Roonwal et al. 1981). Each tibia with two apical spurs.

Soldier ( Figs. 4–6 ). Trimorphic. Nasus subcylindrical. Vestigial mandibles with distinct points. Antenna with 12–14 articles. Tibial spurs 2:2:2. Major soldier. Head capsule proportionally wide, elliptic or subrectangular, without constriction behind antennae. Top of head convex in profile. Pronotum approximately half the width of head. Femur with sparse hairs and a few bristles on inner margin; tibiae with numerous hairs, denser on distal region. Head capsule with two bristles on vertex and four bristles at the base of nasus, and numerous microscopic hairs ( Fig. 7 A, B, C, D). Nasus covered with dense short hairs and 4 longer ones at tip. Thorax and abdomen densely covered with microscopic hairs. Pronotum with 2–4 bristles on anterior margin; meso- and metanotum without bristles. Intermediate soldier. Head capsule in dorsal view with nearly parallel or slightly converging sides, and a moderate constriction near the middle. Pronotum approximately 2/3 the width of head. Top of head in profile slightly elevated behind antennae; nasus oriented anteriorly or slightly upturned. Pilosity similar to major soldier. Minor soldier. Head with a moderate to conspicuous constriction behind antennae; sides converging anteriorly. Pronotum approximately 2/3 the width of head. Latera head profile similar to intermediate soldier but with proportionally longer nasus. Head capsule with microscopic hairs similar to those of major soldier; nasus with scattered microscopic hairs and dense short hairs only on apical quarter.

Workers ( Fig. 8–9 ). Dimorphic. Head elliptic in dorsal view. Epicranial suture distinct. Legs and antennae short. Antennae with 14–15 articles; 3rd article sometimes incompletely divided. Pronotum with a few bristles on anterior margin and short hairs on posterior margin. Meso- and metanotum without bristles and with short hairs on posterior margin. Tergites with short hairs on surface and a row of bristles on posterior margin. Mandibles similar to those of imago, except for the wider molar plate ( Figs. 7 E, F). Two types of major workers workers are present. Type I with narrow pronotum and left mandible with a narrow gap between M3 and MPr; apical tooth shorter than M1; angle between A and M1 narrow; left mandible index 0.35–0.45 ( Fig. 9 B, E, H). Type II: slightly larger than type I, with wider pronotum; left mandible with a wide gap between M3 and MPr; apical tooth about the same length as M1; angle between A and M1 wider; left mandible index 0.45–0.5 ( Fig. 9 C, F, I). Minor workers rare, conspicuously smaller, with mandibles similar to those of major workers of type I ( Fig. 9 A, D, G).

Gut morphology ( Figs. 10–11 ). Gizzard and mesenteron of moderate size. Mixed segment very short. Malpighian tubules attached to the gut in two very close pairs near the junction of mesenteron and proctodeum, sometimes with a mesenteric swelling at the point of attachment. First proctodeal segment (P1) short and narrower than mesenteron, strongly curved near the enteric valve. Enteric valve conical and narrow; armature weak and divided into two rings ( Fig. 11 B). First ring extending into P1 and comprised of 6 elongate plates, weakly sclerotized, covered with small spines. Second ring located entirely in P2, comprised of 3 small plates alternating with 3 larger ones; small plates more elongate, finger-like, with 3–6 spines; larger plates wider and with 6 or more spines. Enteric valve short, conical, located posteriorly and inserted into a pouch of P3 (enteric valve seating) at the dorsal left or dorsal center side. P3 with an enteric valve seating, not lobed, attached to the rest of P3 by a strong annular sphincter.

Comparisons. Among all genera of Nasutitermitinae, only Diversitermes , Velocitermes , and Muelleritermes have trimorphic soldiers. The major soldier of Velocitermes has a constricted head, while in Diversitermes the head capsule of the major soldier is pear-shaped or elliptic, without a constriction. Soldiers of Muelleritermes have dense short hairs on head capsule while in Diversitermes they have microscopic hairs only. The head capsule of the intermediate soldier of Muelleritermes is not constricted. Workers of Muelleritermes are pale colored, with unpigmented heads. Workers of Diversitermes can be recognized by the strong annular sphincter between enteric valve seating and the rest of P3, by the Malpighian tubules attached to mesenteron in two pairs separated by a short distance, sometimes on a small mesenteric swelling. Imagoes are similar to those of Velocitermes and Muelleritermes .

Remarks. We do not have detailed information on the caste system of Diversitermes , but it is likely similar to that of Velocitermes spp. ( Haifig et al. 2012 and our own unpublished data). In V. heteropterus , large (major) workers are female of at least two instars: 3rd (similar to type I of Diversitermes ) and 4th (similar to type II of Diversitermes ). Minor workers are male and become soldiers.

Figures

FIGURE 1. Imagos of Diversitermes. From left to right: meso- and metanotum, pronotum, head in dorsal view, and head in profile. A – D, D. castaniceps; E – H, D. diversimiles. I – L, D. tiapuan, sp. n.

FIGURE 2. Imagos of Diversitermes. Top row: mandibles; bottom row: antennae. A and D, D. castaniceps; B and E, D. diversimiles; C and F, D. tiapuan, sp. n.

FIGURE 3. Imagos of Diversitermes. Top row: basal region of forewing; bottom row: wing microsculpturing. A and D, D. castaniceps; B and E, D. diversimiles; C and F, D. tiapuan, sp. n.

FIGURE 4. Major soldiers: thorax in dorsal view (left), head in dorsal view (center), and head in profile (right). A – C, Diversitermes castaniceps. D – I, D. diversimiles (two soldiers from different colonies showing size variation). J – L, D. tiapuan, sp. n. All figures in the same scale.

FIGURE 5. Intermediate soldiers: thorax in dorsal view (left), head in dorsal view (center), and head in profile (right). A – C, Diversitermes castaniceps; D – F, D. diversimiles. G – I, D. tiapuan, sp. n. All figures in the same scale.

FIGURE 6. Minor soldiers: thorax in dorsal view (left), head in dorsal view (center), and head in profile (right). A – C, Diversitermes castaniceps. D – I, D. diversimiles (two soldiers from different colonies showing size and color variation). J – L, D. tiapuan, sp. n. All figures in the same scale.

FIGURE 7. Scanning electron micrographs. A – B, head of the major soldier of Diversitermes tiapuan, sp. n; C – D, head of the major soldier of D. diversimiles. E – F, right mandible and molar plate of major worker (3 rd instar) of D. tiapuan, sp. n. Figs. A – D in the same scale. Soldier heads in Figs. B and D wrinkled due to drying.

FIGURE 8. Head of major workers in profile (top) and from dorsal view (bottom). A – B, Diversitermes castaniceps. C – D, Diversitermes diversimiles. E – F, Diversitermes tiapuan, sp. n. All figures in the same scale.

FIGURE 9. Mandibles of minor worker (left), major worker of type I (center), and major worker of type II (right). A – C, Diversitermes castaniceps. D – F, D. diversimiles. G – I, D. tiapuan, sp. n. All figures in the same scale.

FIGURE 10. Gut morphology of major worker in situ. Diversitermes castaniceps: A, ventral; B, right; C, dorsal; D, left; E, junction of P 2 and P 3; F, mixed segment; G, attachment of Malpighian tubules. Diversitermes diversimiles: H, ventral; I, right; J, dorsal; K, left; L – M, junction of P 2 and P 3; N, mixed segment; O, attachment of Malpighian tubules. Diversitermes tiapuan, sp. n.: P, ventral; Q, right; R, dorsal; S, left; T – U, junction of P 2 and P 3; V, mixed segment; X, attachment of Malpighian tubules.

FIGURE 11. Gizzard and enteric valve of major workers. A, gizzard armature of Diversitermes tiapuan, sp. n.; B, entire enteric valve armature of D. tiapuan, sp. n. C – E, spines on one plate the first ring of the enteric valve armature: C, D. castaniceps; D, D. diversimiles; E, D. tiapuan, sp. n. Scale bars in B – E: 0.1 mm.