Jolanta Brożek

The phylogenetic information carried by a new set of morphological characters in planthoppers: the internal mouthpart structures and test in the Cixiidae model (Hemiptera: Fulgoromorpha)

Internal morphological structures of Cixiidae mouthparts are described and compared in various representatives of the Cixiidae and several other representatives of hemipterans. The morphological study shows that the mouthpart structures have not evolved uniformly and reveals the great disparity of these structures. Particularly, the connecting system of the mouthparts, localisation of salivary canal and shape of the mandibular and maxillar stylets provide together a new set of 17 new characters. A parsimonious analysis to evaluate the phylogenetic interest carried by these 17 selected characters shows that mouthpart structures have not evolved anarchically, but that they indeed carry some phylogenetic information that will be useful to be included in further morphological phylogenetic analysis.

Comparative Analysis and Systematic Mapping of the Labial Sensilla in the Nepomorpha (Heteroptera: Insecta)

The present study provides new data concerning the morphology and distribution of the labial sensilla of 55 species of 12 nepomorphan families (Heteroptera: Nepomorpha) using the scanning electron microscope. On the labial tip, three morphologically distinct types of chemosensilla have been identified: two types of papillae sensilla and one type of peg-in-pit sensilla. Twenty-one morphologically distinct types of the mechanosensilla as well as two types of the trichoid sensilla (contact-chemoreceptive sensillum) have been identified on all labial segments in representatives of subfamilies. In Nepomorpha, morphological ground plan of the labial sensory structures is represented by an apical sensory field with 10–13 pairs of papillae sensilla and the peg-in-pit ones placed more laterally; numerous trichoid sensilla are placed on the IV segment; the chaetica sensilla are present and placed in groups or rows distributed along the labium near the labial groove on the dorsal side, and also several chaetica sensilla are unevenly scattered on the surface of that segment; the cupola and peg sensilla are numerous and evenly scattered on the fourth labial segment; the prioprerecptive sensilla, one pair is positioned on the dorsal side and on the fourth segment of the labium. The new apomorphical characters have been established for the labial sensilla in the Nepomorpha.

Phylogenetic signals from Nepomorpha (Insecta: Hemiptera: Heteroptera) mouthparts: stylets bundle, sense organs, and labial segments.

The present study is a cladistic analysis of morphological characters focusing on the file of the mandible, the apices of the maxillae, the rupturing device on the maxillae, the internal structures of the mouthparts, and the external morphology of the labial segments as well as the distribution of labial sensilla in true water bugs (Hemiptera: Heteroptera, infraorder Nepomorpha). The study is based on data referring to sixty-two species representing all nepomorphan families (Heteroptera), together with one outgroup species representing the infraorders Gerromorpha (Mesoveliidae). The morphological data matrix consists of forty-eight characters. The present hypothesis supports the monophyly of the Nepomorpha and the monophyly of all families. The new modification in the systematic classification has been proposed: ((Nepidae + Belostomatidae), (Diaprepocoridae + Corixidae + Micronectidae), (Ochteridae + Gelastocoridae), Aphelocheiridae, Potamocoridae, Naucoridae, Notonectidae, and (Pleidae + Helotrephidae)).

Morphological study of the antennal sensilla in Gerromorpha (Insecta: Hemiptera: Heteroptera)

The external morphology and distribution of the antennal sensilla of 21 species from five families of semiaquatic bugs (Gerromorpha) were examined using scanning electron microscopy. Nine main types were distinguished based on their morphological structure: sensilla trichoidea, sensilla chaetica, sensilla leaflike, sensilla campaniformia, sensilla coeloconica, sensilla ampullacea, sensilla basiconica, sensilla placoidea and sensilla bell-mouthed. The specific morphological structure of one type of sensilla (bell-mouthed sensilla) was observed only in Aquarius paludum. Several subtypes of sensilla are described, differentiated by number, location and type of sensillum characteristic for each examined taxon. The present study provides new data about the morphology and distribution of the antennal sensilla in Gerromorpha.

Deliberations on the External Morphology and Modification of the Labial Segments in the Nepomorpha (Heteroptera: Insecta) with Notes on the Phylogenetic Characteristics

The present study provides new data concerning the external morphology of the labial segments of 46 species from nine Nepomorpha families using the scanning electron microscope. The labial segments are described in detail and images of their structures are presented for the systematic groups. Subsequent segments of the labium (I, II, III, and IV) are shaped similarly in all investigated taxa but carry individual characters in some (sub-)families. Five morphologically distinct forms of the apical plate and five intercalary sclerites have been identified. Additionally, three types of the articulation on the dorsal side between the third and second segments are interpreted as the new characters. The presence of the midventral condyle on the distal edge of the first segment and the third segment has been reanalyzed. New position of the midventral condyle on the proximal edge of the fourth labial segment has been distinguished in several groups. The new set of characters has been estimated from the plesiomorphic taxa of the Nepoidea (Nepidae and Belostomatidae) and subsequently through the more advanced taxa in the relation to the outgroup (Gerromorpha). The evaluation of these characters has revealed twenty-seven new apomorphies for the labium in the Nepomorpha.

Morphological diversity of the labial sensilla of phytophagous and predatory Pentatomidae (Hemiptera: Heteroptera), with reference to their possible functions

Sensory structure on the labial surface of five genera of Pentatomidae (Hemiptera: Heteroptera) belonging to two subfamilies i.e. Asopinae and Pentatominae have been studied using Scanning Electron Microscopy. Three representatives of the subfamily Pentatominae (phytophagous)-Dolycoris indicus (Stal), Plautia crossota (Dallas) and Piezodorus hybneri (Gmelin) and two of Asopinae (predatory)-Perillus bioculatus (Fabricius) and Eocanthecona furcellata (Wolff) were studied to morphologically characterize and compare the sensory structures present on the labium. Six types of labial sensilla were found on their labial tip and surface. The labial sensilla identified were sensilla peg (SP), basiconica (SB), campaniformia (SCa), chaetica (SCh), styloconica (SStc) and trichodea (ST). Their possible functions were discussed relating to morphology and location. A new form of sensilla basiconica was also observed in D. indicus. Sensilla styloconica were restricted only to the predatory pentatomid bugs. Cuticular projections (Cpr) on the sensorial region of the studied pentatomids were also observed along with labial cuticular pores.

External traces of segmentation of the labium in the Corixoidea (Hemiptera: Heteroptera: Nepomorpha).

This paper describes the labium in ten representatives of the Corixoidea (Corixidae, Micronectidae and Diaprepocoridae), using scanning electron microscopy. Several new morphological details provide evidence for the external segmentation of the labium of the Corixoidea. The presence of the ventral condyle articulation (cv) is homologous to the condyle of the third segment of the labium in other nepomorphan species, the ventral lobe (vl) is homologous to the second and third segments of the labium, whereas the presence of the latero-ventral plate (lvp) near the apices is homologous to a part of the fourth segment of the labium in the other nepomorphan species. Moreover, the lower apical lobe (apl) and the pair of the sub-oval plates of the apex (ax) are homologous to the apex structures of the labium in other nepomorphans. The slit is a visible boundary between the second and third labial segments on the ventral side only in the Diaprepocoridae. The indication of the homological structural elements of the labium is a new achievement in comparison to earlier descriptions of this organ in several corixoid species. This supports the finding that traces of segmentation have been morphologically preserved in the labium of the Corixoidea, contrary to other previous studies describing the labium as unsegmented. A modified labium of the Corixoidea confirms an assumption about the evolutionary origins of this organ, which posits that it is homologous to the labium of other nepomorphan species.