Neotermescostaseca: a new termite from the coastal desert of Peru and the redescription of N.chilensis (Isoptera, Kalotermitidae)

Abstract The imago and soldier castes of a new Neotermes species, N.costaseca, are described. It is only the third termite species known from the Pacific coastal desert of Peru. Neotermescostasecasp. n. is compared with the allopatric Neotermeschilensis from the arid central and southern coastal plain of Chile.


Introduction
The coastal desert of Peru and Chile (Atacama) spans approximately 3,000 km from -5° to -27° latitude. Only two termite species are recorded from this region, Cryptotermes brevis (Walker) (widespread, Scheffrahn et al. 2009) and Amitermes lunae in the north (Trujillo, Peru;Scheffrahn and Huchet 2010). Another species in the genus Neotermes Holmgren, 1911, N. chilensis (Blanchard), extends northward to the steppe transition zone of the Atacama (Copiapo, Chile) and ranges southward along the coastal plain to Santa Cruz, Chile (Camousseight and Vera 2005). Herein, a new Neotermes species is described, N. costaseca, the third species of termite from the Peruvian coastal desert, and it is compared with the Chilean N. chilensis.

Materials and methods
Microphotographs were taken as multi-layer montages using a Leica M205C stereomicroscope controlled by Leica Application Suite version 3 software. Preserved specimens were taken from 85% ethanol and suspended in a pool of Purell® Hand Sanitizer to position the specimens on a transparent Petri dish background. Diagnosis. The imago of N. costaseca has larger eyes and ocelli than N. chilensis and the former possesses arolia. The soldier mandible of N. chilensis has much more pronounced basal humps than N. costaseca and the former has more protruding genal horns.
Description. Imago (Figs 1A-C, 2; Table 1). Head capsule and pronotum orangebrown. Compound eye nearly circular; ocellus yellowish orange, large, and roundly ellipsoid; nearly touching eye margin. Head vertex and frons slightly depressed, without rugosity; covered with dozens of long (0.25 mm), variously directed setae. Pronotum wider than head capsule; anterior margin evenly concave; anterior margin very weakly emarginate. Pronotum covered with shorter and many long (0.3 mm) setae, especially along lateral margins. Antennae with 17-22 articles, basal article relative lengths 1>2=3>4. Anterior margin of fore wing scale convex; margin lined with 12-15 setae. Fore wing with subcosta joining costal margin at ca. one-fifth of wing length from suture. Radius joining costal margin at two-fifths wing length; radial sector with ca. seven anterior branches. Median vein sclerotised and running very close to and parallel radial sector. Arolium present.
Comparisons. Although climatically isolated, some character overlap is possible with other neotropical Neotermes. A revision of Neotropical Neotermes is needed to identify diagnostic characters. The imago of N. costaseca has longer head and pronotal setae and larger eyes and ocelli than N. chilensis. Neotermes costaseca has an arolium which is lacking in N. chilensis. The soldier mandible of N. chilensis has much more pronounced basal humps, more sinuate marginal teeth, and more sharply curved apical teeth than N. costaseca. The anterolateral corners of N. chilensis constrict more than those of N. costaseca and, unlike N. costaseca, the genal horns of N. chilensis protrude. The pronotum of the N. chilensis soldier is crescent-shaped with that of N. costaseca resembles a bow tie. The soldier eye spot of N. costaseca is hyaline while that of N. chilensis is almost always pigmented. The soldier of N. castaneus differs from both N. costaseca and N. chilensis in having shorter, thicker mandibles with larger, more rounded basal humps.
The arid-adapted N. costaseca and N. chilensis are most comparable with non-Amazonian congenerics from Argentina (Torales et al. 2008), Bolivia, Paraguay, and southern Brazil (Krishna et al. 2013). Compared to N. chilensis, the soldiers of N. hirtellus (Silvestri), N. fulvescens (Silvestri), and N. modestus (Silvestri) all have more reduced madibular basal humps (Silvestri 1903). Compared to N. costaseca and N. chilensis, the N. hirtellus soldier has a shorter third antennal article relative to the second, the head converging toward the front, and the ocellus separated from eye (Costa Lima 1941). The imago and soldier of N. fulvescens are smaller, the imago lacks an arolium, and the solder mandibles are shorter and thicker than both N. chilensis and N. costaseca. The N. modestus soldier and imago are smaller than both N. chilensis and N. costaseca (Silvestri 1903). Compared to N. chilensis and N. costaseca, the imago wings of N. arthurimuelleri (Rosen) are more darkly pigmented, shorter (12 mm long), and the ocelli are more separated from the eye (Costa Lima 1942).  The N. glabriusculus Oliveira imago has smaller ocelli than both N. costaseca and N. chilensis and are more removed from the eye while the soldier dentition in the former is less robust and the tips are not as curved and have almost no basal humps (Oliveira 1979). The N. magnoculus (Snyder) imago is smaller (Snyder 1926) than N. chilesnsis and N. costaseca. The N. wagneri (Desneux) soldier has proportionally shorter mandibles and no enlargement of the third antennal article compared with N. chilesnsis and N. costaseca (Costa Lima 1941, 1942. Finally, the N. zanclus Oliveira soldier has a more elongated and sub rectangular head capsule (Oliveira 1979).
Biology. Neotermes costaseca colonies were collected from both dead branches attached to live trees and directly from sapwood within live trees (Fig. 4). Alates were present in October, but were not collected in June suggesting the latter as part of the likely flight season. The greater tergite separation and mottling in the queen depicted in Fig. 4A suggest that this queen is older than the queen in Fig. 4C   Figure 4. Live habitus photographs of Neotermes costaseca; A physogastric queen and pseudergate, colony 1 B soldier, colony 1 C various castes, colony 2 D exposed galleries of live tree from where colony 2 was removed. Figures 1D-F Description. Imago (Fig. 1D-F; Table 1). Head capsule and pronotum reddish brown. Anterodorsal margin of compound eye straight; ocellus yellowish orange, reniform; touching eye margin. Head vertex and frons slightly depressed, slightly rugose; covered with scattered short setae (0.15-0.2 mm) directed forward on head, variably directed on pronotum. Pronotum wider than head capsule; anterior margin evenly concave; anterior margin emarginate giving "bow tie" resemblance. Pronotum covered with short and medium-long (0.15-0.25 mm) setae. Anterior margin of fore wing scale convex; margin lined with 15-20 setae of same length. Arolium absent.
Material examined. Chile: La Serena, Road 5, Ovalle-Quebrada Seca intersection (-27.356, -70.659 Biology. Neotermes chilensis colonies were collected from fence posts, dead branches, and dead tree trunks. An alate was collected in mid-February suggesting a late summer flight season. Discussion. The lack of termite diversity in the Neotropical coastal desert can be attributed to its climate and geographical barriers of the Pacific Ocean and the Andes. The entire coast of Peru and much of the Chilean coast is arid, but profound aridity (≤ 20 mm/yr) begins near Pacasmayo, Peru, and extends southward to approximately Copiapo, Chile (Fig. 5, climate data from http://www.weatherbase.com/). Although hyperarid as a result of Humboldt Current cooling, this region is transected by many wooded riparian habitats fed by rain and snowmelt runoff from the Andes, providing food (wood) for only three termite species. With the addition of N. costaseca, there are now 27 Neotermes species (Krishna et al. 2013). With only N. costaseca and two other termite species known from the coastal desert of Peru and Chile, it is unlikely that N. costaseca will be found outside of this unique Neotropical biome.