© Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at Description of a new genus with larviform females from Mauritius (Heteroptera, Enicocephalidae), with discussion of thoracic and abdominal morphology1 P. Sˇ TYS & P. BA NAˇ Rˇ Abstract: A new monotypic genus of Enicocephalomorpha (Enicocephalidae, Enicocephalinae), Heis- saptera janaki nov.gen. et nov.sp., from Mauritius is established based on neotenously apterous females collected in litter of a mountain forest. The new genus belongs to a clade including genera with lateral Y-shaped and medial ⊥-shaped impressions (or their vestiges) on the midlobe of pronotum. Anatomy of exoskeleton of thorax is described in detail. Pterothoracic segments are fused in notal and sternal re- gions. The rudiments of larval forewing and hindwing pads are retained as small non-articulating lobes. Relationships of the new genus, occurrence of aptery in Enicocephalidae and neotenous aptery in the Heteroptera are summarized, and morphology of prothorax is discussed; the “proepimeral lobes” are identified as regions of notal rather than pleural origins. Metapostnotum and first abdominal medioter- gite are modified as parts of a unique basiabdominal vibrational organ; presence of a vibrational basiab- dominal system is synapomorphic for the Heteroptera. Key words: Enicocephalidae, Enicocephalomorpha, Heissaptera janaki, Heteroptera, Mauritius, mor- phology, neotenous aptery, nov.gen. et nov.sp., taxonomy. Introduction genus, is discussed within the context of the Enicocephalomorpha and/or Heteroptera. In this paper we describe a new genus and species of Enicocephalidae, Enico- The neotenous nature of the females of cephalinae, from Mauritius. The genus is a new genus provided a great opportunity to represented by neotenously apterous females study their external anatomy, which is, par- ticularly in the thoracic region, admittedly and fifth instar larvae of both sexes. Judging modified by aptery but in other respects from the condition of wing pads in larvae, more plesiomorphic than that of macropter- the unknown adult males are macropterous. ous forms owing to being closer to that of Similar sexually dimorphic situation (and the larva. The major advantage of the apter- the apterous condition as such) was previ- ous anatomy for study of the thorax is the ously known in the Enicocephalinae only in retention of normal lateral and vertical po- the American genus Hymenocoris (WY- sition of pleural elements, while these are GODZINSKY & SCHMIDT 1991). However, it strongly diagonal, partly shifted dorsad and is to be expected that flightless females will difficult to identify in macropterous enico- eventually be discovered in those subfami- cephalids (an analogy with dragonflies is not lies and genera of the Aenictopecheidae and inappropriate). The opportunity has been Enicocephalidae which are based on males fully utilized in the descriptive part of this only and abound in Western Palaearctic, paper, but is discussed in detail for the pro- Arabian peninsula and the Oriental region. thoracic notum and pleuron, and for wing All this, as well as relationship of the new rudiments only, while the other important Denisia 19, zugleich Kataloge 1Dedicated to Ernst Heiss, one of our best hemipterological friends, admired for accuracy of his work, broadness of his der OÖ. Landesmuseen interests and charismatic personality. Neue Serie 50 (2006), 681–695 681 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at 1 2 3 4 Figs 1-4: Heissaptera janaki nov.sp., holotype, female. (1) Total view (total length 5.6 mm) (2) Head, lateral view (3) Pronotum and pterothorax, dorsal view (4) Pronotum and pterothorax, lateral view. structural aspects with bearing on the mor- studied on more extensive and disposable phology of Enicocephalomorpha and Het- material, which we expect to receive, and eroptera as a whole (such as pterothoracic some only in connection with the study of fusions, position of scent gland openings larvae, which we do not include in the pres- and basiabdominal vibrational organ) are ent paper. We are not sure whether the two just mentioned and others (structure of ab- sympatric and syntopic females available are domen and terminalia) omitted from the really conspecific and whether to ascribe the discussion entirely. There are several rea- small but numerous differences (none affect- sons for that. Some of the structures must be ing the gross morphology) between them to 682 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at infraspecific variation or to interspecific dif- ferences. For this reason we based the de- scription, photographs and illustrations on the holotype only, and excluded the other material from the type series. We were surprised not so much by the discovery of a new genus and species but rather by the number and importance of new structural information which could be extracted from a limited material. Enicocephalidae: Enicocephalinae Heissaptera nov.gen. Type species. Heissaptera janaki nov.sp. by present designation. Etymology. Named after Ernst Heiss, an eminent heteropterist, + apterous = wing- less (from Gk. a = not + pteron = wing); gender feminine. Diagnosis. Females neotenously apter- ous. Head strongly elongate, preocular part long, antennifers remote from eyes, the lat- ter continuously facetted, postocular lobe delimited by a deep constriction, ocelli ab- sent; dorsal surface of head nearly bare, ven- tral with long pilosity. Antennae thin, terete. Pronotum of three distinct lobes; the midlobe with sublateral Y-shaped impres- sions interrupting its hind margin, the mesal branch of Y terminating in a deep pit; hind- lobe short, its posterior margin straight. Mesonotum and metanotum with short, projecting, non-articulating forewing and and hindtibia with two apical combs each. Figs 5-8: Heissaptera janaki nov.sp., holotype, female, all anterior view. (5-7) hindwing pads, respectively; mesonotum (Males winged as inferred from fifth larval Right foreleg (8) Left foreleg (5) Total view with a transverse, bulge shaped scutellum, instar, the latter with ocellar spots both in (bristle comb not illustrated); scale bar 0.5 metanotum with lateral spinous projections, males and females.) mm (6) Apex of tibia and tarsus (7-8) Inner mesopostnotum medially fused with metan- claw (6-8) hairs omitted. Differential diagnosis. There are only six otum. Mesosternum and metasternum genera of Enicocephalidae obligatorily broadly fused, the intersegmental sulcus apterous or with apterous females (all keyed lost. Metapostnotum, abdominal terga 1, 2 ˇ and ventrite 1 strongly modified owing to by STYS 2002b). Heissaptera differs from all presumed presence of basiabdominal vibra- of them by (1) wing rudiments developed as tional organ. Mediotergites 1 and 2 free. projecting lobes (rather than absent or rep- Abdomen with numerous setigerous tuber- resented by tubercles), (2) presence of medi- cles, membranous, laterotergites delimited al ⊥-shaped and sublateral Y-shaped impres- mainly by a system of sclerites. Tarsal formu- sions on the midlobe of pronotum (absent in la 1-2-2. Fore coxae and trochanters with- others), and (3) unique type of apicitibial out particulars, fore tibia once compressed, armature of foretibia (as far as known). This apicitibial armature of seven spiniform se- is true also for females of an American genus tae, the most dorsal one strongly curved, di- Hymenocoris UHLER 1892, the only enico- rected towards the cluster of straight ones; cephaline sharing with Heissaptera the sexu- foretarsus with two, proximal, curved, spini- ally dimorphic female aptery; moreover, Hy- form setae and two distal platelets. Midtibia menocoris females lack wing rudiments, their 683 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at Etymology. Named after Jiˇrí Janák, Czech coleopterist, collector of the species. General facies (Fig. 1) similar to Phthi- rocorinae, Monteithostolini. Elongate, ro- bust, apterous, larviform; outlines of all supracoxalia visible in dorsal view. Head, thorax and extremities strongly, abdomen weakly, sclerotized. Measurements of the holotype (in mm, L = length; W = width). Total L – 5.60; head: anterior lobe L – 0.80, posterior lobe L – 0.43, W – 0.51, distance eye-apex of an- tennifer – 0.44, diatone (max. W across eyes) – 0.48, min. interocular distance dorsal – 0.35, ventral – 0.35, eye L – 0.13; labium: total L – 0.82; antenna: segment 1 L – 0.28, segment 2 L – 0.70, segment 3 L – 0.67, seg- ment 4 L – 0.64; pronotum: total L (max.) – 0.87, collum L (median) – 0.22, max. W – 0.64, midlobe L (median) – 0.51, max. W – 1.02, hindlobe L (median) – 0.14, max. W – Figs 9-15: Heissaptera janaki nov.sp., “proepimeral lobes”(= proepimera partim by holotype, female, right foreleg (9) 0.88; foreleg: forefemur L – 1.28, max. W – WYGODZINSKY & SCHMIDT 1991) fuse mutu- Trochanter and basis of femur (cleared, 1.28, foretibia L – 1.13, max. W – 0.37; mi- ally behind the forecoxae, and the forefemur vestiture omitted except for coxal guard dleg: midfemur L – 0.95, max. W – 0.20, is provided with a basidorsal process. seta), anterior view (10) Condylar midtibia L – 1.04, max. W – 0.12, midtarsus trochanteral organ, anterior view (11) Anterior trochanteral organ, anterior view Only two specimens of Oncylocotis (Vin- L (without claw) – 0.35, max. W – 0.07; (12) Trochanter, posterior view (13) sonicoris) mauriciensis (VILLIERS 1969), both hindleg: hindfemur L – 1.33, max. W – 0.33, Posterior trochanteral organ, posterior