Zoologischer Anzeiger 253 (2014) 236–258 Contents lists available at ScienceDirect Zoologischer Anzeiger journal homepage: www.elsevier.com/locate/jcz External thoracic scent efferent system of Scutelleridae (Hemiptera: Heteroptera) Shama Parveen a,* , Kamil Usmani b , Sucheta Khokhar c , Vilayanoor Venkataraman Ramamurthy a , Jitka Vilímová d a Division of Entomology, Indian Agricultural Research Institute, New Delhi 110012, India b Department of Zoology, Aligarh Muslim University, Aligarh 202002, India c Department of Entomology, C.C.S.H.U, Hisar 125004, India d Faculty of Science, Department of Zoology, Charles University, Vinicna 7, 128 44 Praha 2, Czech Republic article info Article history: Received 22 August 2013 Received in revised form 14 November 2013 Accepted 19 November 2013 Available online 28 December 2013 Corresponding Editor: Sven Bradler. Keywords: Scutelleridae Metathoracic scent glands Ostiole Peritreme Evaporatorium Microsculptures abstract The metathoracic scent glands in the Heteroptera produce defence secretions which are spread out- side the body through and by using the thoracic external scent efferent system. That complex system was studied in 18 species from 11 genera of four subfamilies, Elvisurinae, Eurygastrinae, Hoteinae and Scutellerinae of the family Scutelleridae (Pentatomoidea). The results have been compared with pub- lished data. The pattern of that system is more consistent at the level of genus, mostly very similar in the congeneric species, but mostly variable within higher taxonomic levels, tribes and subfamilies. Five types of the external scent efferent system are recognized within the family Scutelleridae, basic two of them in studied species: (i) peritreme well developed, covering large part of metapleuron, evaporatorium small, developed only on metapleuron, (ii) evaporatorium large, more conspicuous than moderate-sized to small peritreme, extending to mesopleuron as large structure. The results do not support a hypothesis that the system of structures associated externally with metathoracic scent glands is in correlation with type of a habitat. However, these structures are well usable as diagnostic characters for scutellerid genera (e.g. Cantao, Hyperonchus, Scutellera and Solenosthedium). © 2013 Elsevier GmbH. All rights reserved. 1. Introduction A specific pattern of scent glands including their unique efferent systems is considered autapomorphic feature for the Heteroptera within the Insecta (e.g. Wheeler et al., 1993; Schuh and Slater, 1995; Weirauch, 2006). These glands are primarily significant in a defence (Remold, 1962, 1963; Cobben, 1978; Staddon, 1979; Aldrich, 1988). Dorsoabdominal scent glands are basically developed in larvae and often persist to adulthood (e.g. summary in Weirauch, 2006 and Vilímová and Kutalová, 2012), however, metathoracic/metapleural scent glands (hereinafter just MTGs) are exclusively adult struc- tures (e.g. Staddon, 1979). The MTGs were first mentioned by Dufour (1833) as a source of repelent secretion in the heteropteran adults. Subsequently, Künckel d’Herculais (1866) described other scent glands in a quite different position, dorsally in the abdomen in larvae. Brindley (1930) was the first who use the structural details of the scent apparatus for the Heteroptera classification, * Corresponding author. Tel.: +91 011 25842042. E-mail addresses: shama parven@yahoo.co.in (S. Parveen), usmanikamil94@gmail.com (K. Usmani), suchetakhokhar@gmail.com (S. Khokhar), vvrento@gmail.com (V.V. Ramamurthy), vilim@natur.cuni.cz (J. Vilímová). and also tried to establish a phylogenetic relationships in some families. Cobben (1978) emphasized the importance of MTGs in a phylogenetic hypothesis of the Heteroptera, while Schaefer (1972) suggested that level of development of the external structures asso- ciated with MTGs is in a correlation with type of habit within trichophoran Heteroptera. The MTGs occupy a ventral position in the hind part of the metathorax, concealed dorsally by the abdominal nerves and gut. The glands themselves consist of differentiated epithelial cells forming units function as secretory structures. A secretion of them is emptying into a reservoir lined with a cuticular intima. Sometimes, also an accessory gland attached to the reservoir is developed, which apparently serves to deliver enzymatic prod- ucts important in a production of the final scent gland substances (Noirot and Quennedey, 1991). The metathoracic scent apparatus is divided to internal parts, i.e. proper glands with ductuli, reser- voir, lateral duct and its valvular apparatus and to thoracic scent efferent system composed from internal scent efferent system and external scent efferent system (details and summary of the ter- minology in Kment and Vilímová, 2010a). The external cuticular structures associated with the MTGs help in a rapid evaporation of the secretion along with protection of the individual itself from its toxicity (Remold, 1962, 1963; Staddon, 1979; Carver, 1990). The 0044-5231/$ – see front matter © 2013 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.jcz.2013.11.003