Sandsitermes robustus (Holmgren) Holmgren, 2017

Cuezzo, Carolina, Cancello, Eliana M. & Carrijo, Tiago F., 2017, Sandsitermes gen. nov., a new nasute termite genus from South America (Isoptera, Termitidae, Nasutitermitinae), Zootaxa 4221 (5), pp. 562-574 : 571-572

Sandsitermes robustus (Holmgren) , new combination

Figs 1–23

Eutermes robustus Holmgren 1906: 67 –68 (soldier, fig. O; worker, fig. P). Syntypes: NHRS (soldiers and workers); type locality: Peru, Chaquimayo, Llinquipata [examined].

Eutermes robustus, Holmgren 1910: 283 –284 (soldier, fig. 56; worker).

Nasutitermes robustus, Snyder 1949: 295 (catalogue), new combination.

Nasutitermes robustus, Krishna et al. 2013: 1780 (catalogue).

Description of the imago caste and redescription of soldier and worker castes. Imago ( Figs 1–3 ). Head capsule covered with short fine decumbent hairs projecting toward front, few long erect setae, plus short scattered erect setae in front of ocelli and around fontanelle. Postclypeus with short hairs over surface, pair of erect bristles at posterior margin, and shorter decumbent bristles over anterior margin. Labrum covered with hairs, with three pairs of erect bristles at midline. Pronotum with erect bristles along lateral and posterior margins, and many fine decumbent bristles over its entire surface. Wing scales with some erect bristles and shorter decumbent bristles over entire surface. Meso- and metanotum with short decumbent bristles. Tergites with dense covering of short fine decumbent bristles, in addition to row of erect bristles on posterior margin, not visible in Fig. 3 . Sternites with long erect bristles and short decumbent bristles over entire surface. Head capsule chestnut brown with yellowish frontal marks. Postclypeus, antennal articles and legs yellowish, paler than head capsule. Labrum yellowish white. Thoracic nota yellowish brown with dark-brown margins. Tergites yellowish, sternites lighter-colored than tergites. Posterior region of meso- and metanotum with rugose surface, with two small protuberances slightly lighter-toned than posterior area. Range of measurements (mm) of two females and one male from MZUSP 8051: LH, 0.93– 1.13; WH, 1.00–1.10; OF, 0.38–0.50; DE, 0.48–0.50; LO, 0.15–0.18; WO, 0.11–0.13; EOD, 0.06–0.08; LP, 0.80– 0.83; WP, 1.13–1.20; LT, 1.78–1.93.

Soldier ( Figs 4–5 ). In dorsal view, head capsule varying from oval to rounded, widest at middle. Antenna with 13 articles: 1st largest; 2nd smallest; 3rd larger than 2nd and 4th but smaller than 1st; 2nd similar to 4th; 5th to apex, gradually increasing in size. Pronotum with anterior lobe rounded, not emarginate. Anterior lobe of pronotum less developed than posterior lobe, and forming angle of more than 90° between them. Head capsule with long erect bristles, four at base of nasus, plus two more on vertex, and scattered microscopic hairs over entire surface of head capsule. Postclypeus and labrum with microscopic hairs. Postmentum with bristles and short hairs. Nasus with four bristles, short hairs on apical third, and no microscopic hairs over surface. Anterior margin of anterior lobe of pronotum with short bristles, posterior margin of anterior lobe of pronotum with short hairs and noticeable very short hairs over pronotum surface. Meso- and metanotum with microscopic hairs over entire surface, no bristles or short hairs on posterior margin of thoracic nota. First abdominal tergite with two long thick erect bristles on middle posterior margin, very short hairs over lateral margins, and microscopic hairs over surface; remaining abdominal tergites equal but with four bristles instead of two. Sternites with thick erect bristles on posterior margin and many decumbent hairs of different sizes over surface. Procoxa with noticeably short microscopic hairs on upper surface. Head capsule yellow to light brown, with the nasus distinctly darker than head capsule. Thoracic nota yellow with darker margins. Tergites, sternites, antennal articles and legs whitish yellow. Range of measurements (mm) of 10 soldiers from MZUSP 8051; 6 from NHRS 16; 2 from NHRS 17: LH, 1.83–2.45; LHp, 1.13–1.55; HH, 0.75–1.03; WH, 1.05–1.53; LT, 1.35–1.75; WNs, 0.33–0.45; WP, 0.53–0.73.

Worker ( Figs 6–23 ). Short scattered hairs on frontal area of head and at least six long erect bristles on rear; postclypeus with two long erect bristles, some very short hairs over surface and short decumbent bristles on posterior margin; pro-, meso- and metanotum with short hairs on margins; tergites each with row of long bristles on posterior margin and many short bristles over surface. Mandibles ( Figs 12–14 ) and digestive tube ( Figs 15–23 ), see genus description. Measurements (mm) of workers from the type colony, NHRS 0 0 17. Type 2 worker: WH, 1.35, LT, 1.75; minor type 1 worker WH, 1.25, LT, 1.42; major type 1 worker, WH, 1.27, LT, 1.50.

Material examined. Syntypes: PERU. Chaquimayo, Cotype “ Eutermes ” N. Holmgren det., three soldiers and four workers , USNM Isoptera Type 059; Chaquimayo, Lat -13.4335, Long. -70.4112, N. Holmgren det., several soldier and workers, NHRS 0 0 16, NHRS 0 0 17. Other non-type material: Llinquipata, Lat. -13.4572, Long. - 70.3919, soldiers, NHRS (Sthlm 862/10). New records, with imago. PERU. Junín. San Ramón Valle de Chanchamayo, 830 m, 17.x.1956, W Weyrauch, Lat. -11.1232, Long. -75.3675 , MZUSP 8051 . New records, without imagoes. PERU . Chatarra forest , 26.v.2014, Lat. -10.51303, Long. -75.07276 UF (PU154.0) ; 8 km SW von Humbolt , 30.v.2014, Lat. -8.85449, Long. -75.11904, UF (PU751.0) ; 15 km W von Humbolt , 30.v.2014, Lat. - 8.84806, Long. -75.18536, UF (PU765.0, PU769.0) ; 76 km NE Tingo María , 30.v.2014, UF (PU791.0) ; 54 km NE Tingo María , 30.v.2014, Lat. -9.05222, Long. -75.57818, UF (PU835.0, PU836.0, PU837.0, PU839.0, PU840.0, PU841.0, PU850.0); Parque Nacional Tingo María , 31.v.2014, Lat. -9.37830, Long. -76.03231, UF (PU912.0).

Figures

FIGURES 1 – 3. Sandsitermes robustus gen. et comb. nov., female, MZUSP 8061: (1) head capsule and pronotum, profile view; (2) head capsule and pronotum, dorsal view; (3) meso- and metanotum, dorsal view. Scale bars 0.5 mm.

FIGURES 4 – 5. Sandsitermes robustus gen. et comb. nov., soldier, NHRS 0016: (4) head capsule, profile view; (5) head capsule, dorsal view. Scale bar 0.5 mm.

FIGURES 6 – 11. Sandsitermes robustus gen. et comb. nov., workers, MZUSP 8061: head capsule of type 2 worker (6) profile and (7) dorsal view; head capsule of major type 1 worker (8) profile and (9) dorsal view; head capsule of minor type 1 worker (10) profile and (11) dorsal view. Scale bar 0.5 mm.

FIGURES 12 – 14. Sandsitermes robustus gen. et comb. nov., worker mandibles, NHRS 0016: (12) type 2 in dorsal view; minor type 1 (13) in dorsal view and (14) molar region in frontal view. Scale bar 1 mm.

FIGURES 15 – 20. Sandsitermes robustus gen. et comb. nov., type 1 worker, in situ gut, NHRS 0016: (15) dorsal, (16) right, (17) ventral, and (18) left views; (19) right view without mesenteron; (20) mixed segment and Malpighian tubules. C, crop; G, gizzard; M, mesenteron; P 1, first proctodeal segment; P 2, enteric valve; P 3, paunch; P 4, colon; P 5, rectum. Scale bar 1 mm.

FIGURES 21 – 23. Sandsitermes robustus gen. et comb. nov., type 1 worker, UF PU 791.0: (21) enteric valve cushions arranged in two rings, arrow aligned with the axis of the valve and oriented from P 2 to paunch (P 3); (22) complete gizzard armature, large arrow indicating column and pulvillus I, and small arrows indicating columns and pulvilli II; (23) detail of the columnar belt with surface of folds I and II, ornamented with scales very difficult to see in the proximal area.