A new Cervinotaptera species from northern Madagascar (Hemiptera, Heteroptera, Aradidae)

Abstract A new species, Cervinotapteratomhenryi, sp. n. (Hemiptera: Heteroptera: Aradidae: Mezirinae), from Montagne d’Ambre National Park in northern Madagascar is described and illustrated. The newly described species is compared with the only other known species, Cervinotapteraguilberti Heiss & Marchal, 2012.


Introduction
The first comprehensive studies on Aradidae of Madagascar and adjacent islands were provided by Ludvík Hoberlandt (1957Hoberlandt ( , 1963. In the last two decades Ernst Heiss published several taxonomic papers, describing many new genera and species, and summarized all published works in a catalogue (Heiss 2012). Most recently, two new genera and five new species of aradids were published , Heiss and Marchal 2012, Heiss and Baňař 2013, Baňař et al. 2016, Baňař and Heiss 2018.
The genus Cervinotaptera Heiss & Marchal, 2012 (Hemiptera: Heteroptera: Aradidae: Mezirinae) was erected for the apterous species Cervinotaptera guilberti Heiss & Marchal, 2012 from northern Madagascar (Heiss and Marchal 2012). During the expeditions of the first author in January 2015 and January 2016 to Montagne d'Ambre National Park in northern Madagascar, twelve specimens of a new species of Cervinotaptera were collected. The species is described in this paper.

Materials and methods
The body surface of most apterous, litter-living aradids is frequently covered by a layer of incrustations, which obscure body structures and intersegmental boundaries ( Figure  1C). It was therefore necessary to clean the specimens before examination. In this case, we used a combination of mechanical cleaning in distilled water with common detergent and short treatment in 10% KOH.
The term "dorsal ocular index" refers to the ratio of the minimum interocular distance to the maximum width of the eye; it is best calculated if measured as: (twice minimum interocular distance) / (maximum width across eyes, minus minimum interocular distance).
Color photographs of the newly described species were taken with a Leica MSV266 camera. Scanning electron micrographs of a gold-coated specimen were taken using a JEOL 6380 LV scanning electron microscope.
Measurements were taken using a SZP 11 ZOOM stereoscopic microscope with an eyepiece micrometer. Label data are cited verbatim, including potential errors, using a slash (/) to separate lines on the label; different labels are mentioned and indicated by a double slash (// Head ( Figures 2C-D, 4A-B) with longitudinal furrows and ridges and few globular tubercles on dorsal and lateral faces, numerous and more conspicuous on ventral face; wider than long, width : length ratio 1.25 in male, 1.21 in female; clypeus reaching nearly middle of antennal segment I, antenniferous lobes short, slightly shorter than clypeus; antennae long, 1.92 times as long as width of head in male, 1.95 times in female, segment I slightly bent at base, thickest, segment II thinner and shortest, segment III thinnest and longest, segment IV fusiform, antennal formula (longest segment first): III:I=IV:II. Eyes very small, globular, slightly stalked, ocular index 4.72 in male, 4.60 in female. Labium very short, hardly reaching two thirds of head length.  Pronotum 2.37 times as long as wide across lateral tubercles in both sexes; anterior lobe with two pairs of lateral tubercles ( Figures 2E, 4G), posterior lobe smooth at middle, lateral lobes each with four finger-like processes, posterior margin convex with two small tubercles directed posteriorly. Pronotum separated from mesonotum by deep and wide furrow.
Mesonotum fused to metanotum, fusion lines only partly visible, posteriorly with conspicuous median elevation bearing two semicircular tubercles. Posterior margin with two deep pits connected with very deep and broad median depression on metanotum.
Metanotum ( Figure 3B). Fused to mesonotum and mtg I+II, with rectangular median depression on anterior margin. Fused mtg I+II with deep median pit anteriorly, posteriorly with prominent median elevation, lateral parts with two (1+1) round elevations. Posterior margin of mtg I+II almost straight, clearly delimited from tergal plate by conspicuous furrow.
Abdomen. Tergal plate ( Figure 3A) shorter than wide, ratio width to length 1.31 in male, 1.43 in female. Scent gland scars visible on posterior margins of mtg III and IV only. Deltg II+III fused to elongate triangular sclerite ( Figure 3C), bearing two pairs of finger-like processes, inner process directed upwards, outer process strictly lateral. Deltg III-VII well separated from each other, bearing pair of processes similar to those on deltg II+III, shorter on deltg VI and VII. Vltg VII of male with posteriorly directed glabrous finger-like projections. Spiracles on ventral laterally produced tubercles decreasing in size from vltg II-VII, visible from above, those of paratergites VIII terminal. Metathoracic scent gland with long curved evaporatorium and additional ovate evaporatorium laterally of anterior coxae.
Female. General body structures similar in both sexes, female larger and wider. Etymology. Dedicated to our dear colleague and friend Thomas J. Henry, eminent student of the Heteroptera.
Collecting circumstances. All known specimens were collected by sifting mountain evergreen rain forest leaf litter in Montagne d'Ambre National Park ( Figure 6A-B) in northern Madagascar. Sifted samples were extracted in a Winkler apparatus during two or three days and were mixed several times daily. Cervinotaptera tomhenryi sp. n. shared the microhabitat with the recently described carventine aradid Comorocoris estherineae Baňař & Heiss, 2018; the largest parts of the type series of both species were extracted from the same samples during the expedition of 2015.

Discussion
Apterous Aradidae in stable tropical habitats of Madagascar tend to develop curious abdominal structures such as forked lateral expansions on the thorax and abdomen (Chlonocoris Usinger & Matsuda, 1959), ovate callosities and nodules (Comorocoris Heiss, 1985) or finger-like projections of different size (Cervinotaptera) and, in Mezirinae, show a remarkable development of unusual structures of metathoracic (Ambohitantelya Heiss & Baňař, 2013) and even prothoracic scent-gland evaporatoria. The adaptive value of these unusual structures and their importance in aradid classification are unknown and require further investigation.