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a-trichobothrium on sternite V of Spilostethus hospes (Lygaeidae: Lygaeinae); b-posterior two trichobothria on sternite VI of Lygaeosoma pusillum (Lygaeidae: Lygaeinae); c-anterior trichobothrium on sternite V of L. pusillum; d-the middle trichobothrium on sternite III of Heterogaster chinensis (Heterogastridae); e-anterior trichobothrium on sternite VI of Geocoris ochropterus (Geocoridae: Geocorinae); f-lateral trichobothrium of the posterior row on sternite VI Plinthisus maculatus (Rhyparochromidae: Plinthisinae); g-lateral trichobothrium on sternite VII of Arocatus rufi pes (Lygaeidae: Lygaeinae); h-posterior two trichobothria on sternite V of Drymus sylvaticus (Rhyparochromidae: Drymini); i-lateral trichobothrium on sternite IV of Trapezonotus arenarius elegantulus (Rhyparochromidae: Gonianotini); j-anterior trichobothrium on sternite V of T. a. elegantulus (Rhyparochromidae: Gonianotini), enlarged; k-three trichobothria on sternite III of Iphicrates spinicaput (Blissidae); l-part of Fig. 4k, enlarged. FL-fl uting of sensillum; LA-lamellae of bothrium; MTmicrotrichium of trichome; SR-fused simple rows of microtrichia; TM-trichome.
Source publication
Members of the clade Trichophora (Hemiptera: Heteroptera: Pentatomomorpha) have trichobothria on their abdominal sterna. There is no comparative study of the fine structure of abdominal trichobothria in the group and until now the trichobothria of their immatures were virtually unknown. The fine structure of the abdominal trichobothrial complex (=...
Contexts in source publication
Context 1
... A5: the bothrium is deeply recessed and it has a high rim; the wall of the cavity has transverse lamel- lae which are usually somewhat wavy or sparsely serrate (Fig. 4a-c). This type was recorded in the majority of the Lygaeinae studied (genera Lygaeus, Lygaeosoma, Spiloste- thus, ...
Context 2
... strong, central mechanoreceptive seta on the AT cor- responds to the structure called hair shaft by Gaffal (1976), trichobothrial seta by Weirauch (2003) or simply "hair" by Meßlinger (1987). It is generally circular in cross-section, straight or curved, not twisted and usually with grooves running its whole length (Fig. 4c, j). The base of the sensil- lum is subcylindrical (Fig. 3a) or slightly constricted (Fig. 3b). If the sensillum is constricted basally, the bothrium usually tends to be recessed. The diameter of the sensillum varied from 1.21 to 4.19 μm in the adult specimens ...
Context 3
... species have a diffuse trichome. In these species sparsely scattered microtrichia occur virtually all over the integument of the respective abdominal sternites and the density of the microtrichia gradually decreases with the distance from the trichobothrium, therefore the trichome is indistinctly delimited. In several cases diffuse trichomes extend over a large area of the abdominal venter. Diffuse trichomes occurred in some of the species of Blissidae, Colobathristidae, Lygaeidae: Lygaeinae and Rhyparochro- midae: Drymini studied (Fig. ...
Context 4
... T1: microtrichia are nearly uniform, distinctly sep- arate from each other (Fig. 4d-h), or at most fused basally, forming a simple linear series (Fig. 4i-j: SR) occurring only in the area immediately surrounding the bothrium or in other areas of the trichome. This type occurs in the ma- jority of the lygaeoid subgroups except for the few excep- tions listed ...
Context 5
... T1: microtrichia are nearly uniform, distinctly sep- arate from each other (Fig. 4d-h), or at most fused basally, forming a simple linear series (Fig. 4i-j: SR) occurring only in the area immediately surrounding the bothrium or in other areas of the trichome. This type occurs in the ma- jority of the lygaeoid subgroups except for the few excep- tions listed ...
Context 6
... Henry (1997a) claims that Larginae, Pyrrhocoridae, Colobathristidae and Lygaeinae lack a trichome (charac- ter 46: trichobothrial "pads"); based on the present study we conclude that all of the above mentioned taxa have trichomes (Figs 4a-c, j; 5g). A re-examination of the taxa studied by Henry (1997a) and a reconsideration of the character coding is ...
Context 7
... trichobothrium is frequently surrounded by a tri- cho me, an area of densely arranged microtrichia (MT) (Figs 4-5). Trichomes are present in all the species of the superfamily Pyrrhocoroidea and the majority of Lygae- oidea studied, whereas all members of Pentatomoidea, Co- reoidea and Idiostoloidea, and the lygaeoid families Oxy- carenidae, Piesmatidae, Cryptorhamphidae and Berytidae studied lack trichomes (Table ...
Context 8
... M2: microtrichia subcylindrical, with a very swol- len base, apical portion strongly curved, sharply tapering into a pointed tip (Figs 4k, l; 5g, h). This type was present in all the species of Pyrrhocoridae and Blissidae ...
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Citations
... A trichobothrium is a complex sensory organ, which usually consists of a long, slender mechanoreceptive seta (trich) that most often is longer than any surrounding pubescence and always tapers apically, and which is situated in a cuplike depression in the cuticle (bothrium) (Schuh, 1975, Nichols & Schuh, 1989Gao et al., 2017, Kment et al., 2019, Hemala et al., 2020, Taszakowski et al., 2020. The function of the trichobothria in Heteroptera is still unclear. ...
... Due to the fact that the number and arrangement of trichobothria are highly conservative, they are essential in diagnosing family-group taxa and phylogenetic studies based on morphology (Schaefer, 1975, Henry, 1997, Lis and Hohol-Kilinkiewicz, 2001, Grazia et al., 2008, Cassis and Schuh, 2012. The diversity of trichobothria locations on the body in various true bugs taxa could indicate that these sensilla have different origins (Schuh and Ç Stys, 1991;Gao et al., 2017). The occurrence of trichobothria in Heteroptera has been summarised, e.g. in papers by Gao et al. (2017), Hemala et al. (2020) and Taszakowski et al. (2020). ...
... The diversity of trichobothria locations on the body in various true bugs taxa could indicate that these sensilla have different origins (Schuh and Ç Stys, 1991;Gao et al., 2017). The occurrence of trichobothria in Heteroptera has been summarised, e.g. in papers by Gao et al. (2017), Hemala et al. (2020) and Taszakowski et al. (2020). ...
A trichobothrium is a complex sensory organ, which usually consists of a long, slender mechanoreceptive seta (trich), which is situated in a cuplike depression in the cuticle (bothrium). Nabidae (Hemiptera: Heteroptera: Cimicomorpha), also called damsel
bugs, are a relatively small family within which two subfamilies, Nabinae and Prostemmatinae, are distinguished. Trichobothria are present in the number of one to seven pairs located laterally on the scutellum of adult representatives of Prostemmatinae. This feature is commonly used to distinguish this subfamily from
Nabinae. Trichobothria are also found on the abdominal tergites of Prostemmatinae nymphs. Similar sensilla have been observed in adult representatives of Nabinae, but their homology has not yet been confirmed. During morphological studies on Nabidae,
conducted using scanning electron microscopy, we noticed sensilla resembling trichobothria on the heads of these insects. This discovery prompted us to examine the presence of these structures in damsel bugs more carefully. Imagines of fifteen species of both subfamilies were analysed using a scanning electron microscope. The results present data on the distribution and micromorphology of the trichobothria in damsel bugs. A pair of dorsal and ventral cephalic trichobothria were observed in all of the examined species of subfamily Nabinae. These sensilla were not found on the heads of Prostemmatinae. The results of studies on scutellar trichobothria confirmed the previously known data regarding their occurrence in Prostemmatinae. Moreover, our
research showed the presence of these sensory structures in all of the examined Nabinae species: one pair of trichobothria in Arachnocorini, Carthasini, Gorpini and Nabini, and two pairs in Stenonabini. The presence of abdominal trichobothria was shown in Nabini and Stenonabini. In the remaining studied tribes of Nabinae and in the subfamily Prostemmatinae, the presence of structures that could undoubtedly be considered abdominal trichobothria was not found.
... Only after L3 these setae transform into trichobothria, i.e. hair-like setae with a minutely spiculated base, including the SD1 on A9. In later instars these trichobothria are constituted by a long thin sensillum inserted in the center of a cuticular depression or cavity, which is similar to the bothrium of the Heteroptera (Hemiptera) trichobothria (Gao et al., 2017). The inner wall of this depression is densely covered with regular arranged spine-like outgrowths. ...
... The inner wall of this depression is densely covered with regular arranged spine-like outgrowths. Although the trichobothria seen here are similar to those of other groups, they lack of a dome-shaped elevated cuticular protuberance as in Heteroptera (Gao et al., 2017), Gryllidae (Orthoptera), Blattidae (Blattodea) (Keil, 1997), or Mygalomorphae (Araneae) (Guadanucci, 2012), and the outgrowth of the cavity is unique. Additional studies on the morphology of these setae across different subfamilies and tribes of Noctuidae will be needed to test their distribution, variation and possible evolutionary trends. ...
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Agrotis Ochsenheimer (Lepidoptera: Noctuidae) is a widespread, cosmopolitan genus, with 20 species occurring in South America. Two of those species are considered major pests of different crops, Agrotis ipsilon (Hufnagel) and A. robusta (Blanchard). The latter is often confused with A. malefida Guenée in the literature and, despite its economic importance, its immature stages have been only superficially described. Agrotis canities (Grote), although never regarded as a pest, is known to use some crops as hosts and is commonly captured in light traps. However, its immature stages are unknown, making the evaluation of its true economic importance difficult. In this study, we examine in detail the external morphology and ultrastructure of the egg, larva and pupa of A. robusta and A. canities using light and scanning electron microscopy. Furthermore, we provide an identification key for those four species including all immature stages and up-to-date maps of their distribution in South America. Finally, we discussed the application of immature stages morphology of Agrotis species in systematic and phylogenetic studies. Particularly, we examine the morphology of the trichobothria, or “tonosensillum”, through larval development and the progressive and differential development of abdominal legs in each species.
... Photomicrographs were done with Keyence VHX 5000 digital microscope, and Kern Optics OZL 466 stereoscopic microscope mounted with Kern Optics OCD 832 (5 MPix) microscope camera. Morphological terminology was adapted from Malipatil and Blackett (2013) (general morphology), Kment and Vilímová (2010) (metathoracic scent efferent apparatus), Slater (1977) (mesothoracic wing), Slater and Hurlbutt (1957) (metathoracic wing), and Gao et al. (2017) (abdominal trichobothria). Genitalia were dissected and macerated as described in Kóbor (2019a). ...
The geocorine (Hemiptera: Heteroptera: Lygaeoidea: Geocoridae) true bug genus Umbrageocoris Kóbor, 2019 is redefined based on new morphological information from newly acquired specimens. Two new species are described: U. boonei sp. nov. from continental Indomalaya and U. malipatili sp. nov. from Australia; two new combinations are proposed: U. elegantulus (Distant, 1904), comb. nov. , and U. woodwardi (Malipatil, 1994), comb. nov. (both transferred from Geocoris Fallén, 1814). Keys, diagnoses, and distribution data to the discussed species are provided. Hypotheses on the origin of Umbrageocoris and its relationship to other geocorine genera in the region are formulated. New country records: U. elegantulus (Papua New Guinea), U. maai maai (Thailand, Laos) and U. woodwardi (Papua New Guinea).
... On sternum VII anterior trichome absent, but posterior trichome with sensilla similar to those on V and VI. Bothria on sterna V-VII don't appear to be sunken below surface of cuticle (see Gao et al. 2017 for terminology). ...
A new species, Meschia brevirostris sp. nov. (Hemiptera: Heteroptera: Lygaeoidea: Meschiidae), is described from New Caledonia. Photographs and SEM micrographs of the male and female habitus, genital structures and selected morphological structures are presented.
... The description of immature of stink bugs has been growing over the years, from little detailed descriptions in the early 20 th century (e.g., Kirkaldy, 1907;Withmarsh, 1916;Miller, 1934), later improved with the use of drawings (e.g., Southwood, 1956;De Coursey and Essebaugh, 1962;Grazia et al., 1985;Bundy and McPherson, 2018) and digital photographs (e.g., Jones and Coppel, 1963;Schwertner et al., 2002;Zou et al., 2012;Matesco et al., 2014). From the 1970s, the access to new techniques for entomologists such as the scanning electron microscopy (SEM) (Friedrich et al., 2014) has enabled the study of structures yet underexplored, such as egg sculpturing (Ren, 1992;Matesco et al., 2009Matesco et al., , 2014, ESES of DAGs (Biasotto et al., 2013;Bottega et al., 2015;Bianchi et al., 2016), and the trichobothria (e.g., Vecchio et al., 1988;Schwertner et al., 2002;Brugnera et al., 2019), abdominal mechanoreceptive sensilla with importance in Heteroptera classification (Schaefer, 1975;Gao et al., 2017). ...
The Asopinae are known for their predatory behavior, differing from the phytophagous habits of most pentatomoids, feeding mostly on soft body insects such as larvae of Lepidoptera and Coleoptera. For this reason, asopines have been studied as biological controllers in integrated pest management programs. Notwithstanding their clear relevance, the general knowledge about Asopinae has important gaps, especially regarding immature. Thus, the importance of studying eggs and nymphs of true bugs (Heteroptera) is evident, contributing to understand their classification, biology, and evolution. In this perspective, we conducted a research about immature of predatory stink bugs, highlighting critical features for identification. We present: (1) a literature overview about eggs and nymphs of predatory stink bugs guided by selected categories; (2) images of females laying eggs of ten species and nymphs of thirty-four species, obtained on websites with a citizen science approach; (3) a comparative morphology of immature of six species reared under laboratory conditions, which we examined using light and scanning electron microscopy. We found a remarkable morphological diversity of both eggs and nymphs of Asopinae, revealing key features to establish diagnoses for identification and potential characters to phylogenetics,
such as the aero-micropylar processes and chorion scultpturing of the eggs; and the coloration, labium and abdominal plates morphology of nymphs. The results show that little is known about Asopinae immature considering the diversity of the group; however, information obtained by citizen science initiatives, for instance, can improve this knowledge.
... These phylogenetic results will have immense impact on our understanding of eutrichophoran morphology. For example, the resultant topology suggests open trichobothrium associated with the trichome (Gao et al., 2017;Hemala et al., 2020;Kment et al., 2019) as a synapomorphy of Eutrichophora, subsequently lost in Coreoidea (except for the Hyocephalidae) and in some Lygaeoidea lineages. ...
More than 95% of phytophagous true bug (Hemiptera: Heteroptera) species belong to four superfamilies: Miroidea (Cimicomorpha), Pentatomoidea, Coreoidea, and Lygaeoidea (all Pentatomomorpha). These iconic groups of highly diverse, overwhelmingly phytophagous insects include several economically prominent agricultural and silvicultural pest species, though their evolutionary history has not yet been well resolved. In particular, superfamily- and family-level phylogenetic relationships of these four lineages have remained controversial, and the divergence times of some crucial nodes for phytophagous true bugs have hitherto been little known, which hampers a better understanding of the evolutionary processes and patterns of phytophagous insects. In the present study, we used 150 species and concatenated nuclear and mitochondrial protein-coding genes and rRNA genes to infer the phylogenetic relationships within the Terheteroptera (Cimicomorpha + Pentatomomorpha) and estimated their divergence times. Our results support the monophyly of Cimicomorpha, Pentatomomorpha, Miroidea, Pentatomoidea, Pyrrhocoroidea, Coreoidea, and Lygaeoidea. The phylogenetic relationships across phytophagous lineages are largely congruent at deep nodes across the analyses based on different datasets and tree-reconstructing methods with just a few exceptions. Estimated divergence times and ancestral state reconstructions for feeding habit indicate that phytophagous true bugs explosively radiated in the Early Cretaceous-shortly after the angiosperm radiation-with the subsequent diversification of the most speciose clades (Mirinae, Pentatomidae, Coreinae, and Rhyparochromidae) in the Late Cretaceous.
... The description of immature of stink bugs has been growing over the years, from little detailed descriptions in the early 20 th century (e.g., Kirkaldy, 1907;Withmarsh, 1916;Miller, 1934), later improved with the use of drawings (e.g., Southwood, 1956;De Coursey and Essebaugh, 1962;Grazia et al., 1985;Bundy and McPherson, 2018) and digital photographs (e.g., Jones and Coppel, 1963;Schwertner et al., 2002;Zou et al., 2012;Matesco et al., 2014). From the 1970s, the access to new techniques for entomologists such as the scanning electron microscopy (SEM) (Friedrich et al., 2014) has enabled the study of structures yet underexplored, such as egg sculpturing (Ren, 1992;Matesco et al., 2009Matesco et al., , 2014, ESES of DAGs (Biasotto et al., 2013;Bottega et al., 2015;Bianchi et al., 2016), and the trichobothria (e.g., Vecchio et al., 1988;Schwertner et al., 2002;Brugnera et al., 2019), abdominal mechanoreceptive sensilla with importance in Heteroptera classification (Schaefer, 1975;Gao et al., 2017). ...
The Asopinae are known for their predatory behavior, differing from the phytophagous habits of most pentatomoids, feeding mostly on soft body insects such as larvae of Lepidoptera and Coleoptera. For this reason, asopines have been studied as biological controllers in integrated pest management programs. Notwithstanding their clear relevance, the general knowledge about Asopinae has important gaps, especially regarding immature. Thus, the importance of studying eggs and nymphs of true bugs (Heteroptera) is evident, contributing to understand their classification, biology, and evolution. In this perspective, we conducted a research about immature of predatory stink bugs, highlighting critical features for identification. We present: (1) a literature overview about eggs and nymphs of predatory stink bugs guided by selected categories; (2) images of females laying eggs of ten species and nymphs of thirty-four species, obtained on websites with a citizen science approach; (3) a comparative morphology of immature of six species reared under laboratory conditions, which we examined using light and scanning electron microscopy. We found a remarkable morphological diversity of both eggs and nymphs of Asopinae, revealing key features to establish diagnoses for identification and potential characters to phylogenetics, such as the aero-micropylar processes and chorion scultpturing of the eggs; and the coloration, labium and abdominal plates morphology of nymphs. The results show that little is known about Asopinae immature considering the diversity of the group; however, information obtained by citizen science initiatives, for instance, can improve this knowledge.
... Larvae (n = 461) were collected during field investigations and taken to the insect laboratory of Nanjing Forestry University. The highly ossified head capsules of the larvae were removed, cleaned, and fixed on a strip of adhesive tape (Gao et al. 2017). The head capsule width (HCW) and head capsule length (HCL) of each larva were measured under a Zeiss Discovery V20 stereomicroscope (Fig. 1). ...
Cinnamomum camphora (L.) J. Presl. (Laurales: Lauraceae) is widely cultivated as an important landscape tree species in many urban areas in South China, especially in Shanghai City. Pagiophloeus tsushimanus Morimoto has become a destructive insect pest of C . camphora plantations in Shanghai, but the biological and ecological traits of this pest remain largely unknown. In this study, we investigated the damage and life history and determined the larval instar of P . tsushimanus . The results indicated that P . tsushimanus is a monophagous weevil pest, and C . camphora is the unique host tree species. C . camphora plantations in all administrative districts of Shanghai have been seriously damaged by P . tsushimanus . Adults often aggregate for feeding on the tender bark of twigs and occasionally on newly emerged buds. After experiencing damage, the twigs shrink and crack and the buds will shrink. Adults tend to repeatedly mate and oviposit, and all females lay single eggs at a time. Eggs will be covered with a mixture of secretions and wood chips by female adults. Larvae (1st–2nd instar) feed on the phloem, while 3rd–5th instar can bore into the phloem and the cambium. Massive tunnels, including three shapes (inverted “L”, inverted “T”, and inverted “Z”), were observed in the trunk of each tree, and resulted in swelling of the outer bark. P . tsushimanus has one life cycle per year in Shanghai. Both adults and larvae (3rd–5th instar) overwinter from early November to early April. Adults overwinter in grooves on the underside of branches or at branch nodes, and larvae overwinter in tunnels. Five larval instars of P . tsushimanus were determined according to Dyar's and Crosby's rules. The biological traits and life history of P . tsushimanus have been identified and can provide guidance in terms of pest control and plantation management.
... A trichobothrium is a complex sensory organ, which usually consists of a long, slender mechanoreceptive seta (trich) that most often is longer than any surrounding pubescence and always tapers apically, which is situated in a cuplike depression in the cuticle (bothrium) (Schuh, 1975;Nichols and Schuh, 1989;Gao et al., 2017;Kment et al., 2019;Hemala et al., 2020). The function of the trichobothria in Heteroptera is unclear. ...
... The number and arrangement of trichobothria are highly conservative, and therefore they are important in the diagnostic of familygroup taxa and phylogenetic studies that are based on morphology (Schaefer, 1975;Henry, 1997;Lis and Hohol-Kilinkiewicz, 2001;Grazia et al., 2008;Cassis and Schuh, 2012). The diversity of the positions of trichobothria on the body in various taxa of Heteroptera could indicate that these sensilla have different origins (Schuh and Štys, 1991;Gao et al., 2017). In representatives of Gerromorpha, the trichobothria were located on the head, antennae and femora (Andersen, 1977;Schuh and Weirauch, 2020); in Nepomorpha on the labium (Brożek, 2013); in Leptopodomorpha on the head (Cobben, 1978); in Pentatomomorpha on the abdomen (Tullgren, 1918;Schaefer, 1966, Gao et al., 2017Kment et al., 2019;Hemala et al., 2020) and in Cimicomorpha on the head, antennae, scutellum, femora and abdomen (Carayon and Villiers, 1968;Schuh, 1975;Wygodzinsky and Lodhi, 1989;Schuh and Štys, 1991;Weirauch, 2003;Cassis and Schuh, 2012, Pluot-Sigwalt and Chérot, 2013, Schuh and Weirauch, 2020. ...
... The diversity of the positions of trichobothria on the body in various taxa of Heteroptera could indicate that these sensilla have different origins (Schuh and Štys, 1991;Gao et al., 2017). In representatives of Gerromorpha, the trichobothria were located on the head, antennae and femora (Andersen, 1977;Schuh and Weirauch, 2020); in Nepomorpha on the labium (Brożek, 2013); in Leptopodomorpha on the head (Cobben, 1978); in Pentatomomorpha on the abdomen (Tullgren, 1918;Schaefer, 1966, Gao et al., 2017Kment et al., 2019;Hemala et al., 2020) and in Cimicomorpha on the head, antennae, scutellum, femora and abdomen (Carayon and Villiers, 1968;Schuh, 1975;Wygodzinsky and Lodhi, 1989;Schuh and Štys, 1991;Weirauch, 2003;Cassis and Schuh, 2012, Pluot-Sigwalt and Chérot, 2013, Schuh and Weirauch, 2020. ...
A pair of ventral cephalic trichobothria was observed for the first time and so far the only one in a representative of single species of Miridae (Fulvius carayoni) in 2013. The purpose of our research was to verify the hypothesis that this is not an exception, but a characteristic feature of all plant bugs. Twenty-three representatives of all seven subfamilies of Miridae were examined using a scanning electron microscope. The results presents detailed data on the distribution and ultramorphology of the cephalic trichobothria in plant bugs. A pair of ventral cephalic trichobothria was observed in all of the examined species. Each trichobothrium of this pair is located laterally to the first article of the rostrum, on the gula (between the buccula and the antennal tubercle). Moreover, a pair of dorsal cephalic trichobothria was observed for the first time. They were found in nine species, located above the antennal tubercle, towards the center of the frons.
... They were attached to scanning electron microscopy (SEM) stubs using double-sided electric tape, and they were then sputtered with gold in a sputter coater (BAL-TEC SCD 005, Balzers, Switzerland). The structures were observed under the FEI Quanta 200 SEM operated at 15-20 kV (Gao et al., 2017). ...
Spiracles are the openings in the exoskeleton of insects through which air enters into the respiratory system that is formed by a series of tubes called tracheae. They are primarily located on the abdomen, but can also occur on the thorax, including the metathorax. An insect metathoracic spiracle is usually composed of an external opening and a more internal filter apparatus. We propose new terminology for these structures, and we explore the value in their use in taxonomic and phylogenetic studies within the true bug infraorder Pentatomomorpha, with emphasis on the superfamily Lygaeoidea (Insecta: Hemiptera: Heteroptera). These structures were studied using scanning electron microscopy. Two types of metathoracic spiracle external openings were recognized: a narrow opening (type N), which is slit-like; and a wide opening (type W), with internal fine structures located between the mesothoracic and metathoracic margins of the interpleural suture clearly visible. The filter apparatus in the Pentatomomorpha consists of modified mushroom bodies of the metathoracic scent gland evaporatorium, for which the term mycoid filter processes is proposed. Eight different types of mycoid filter processes, and an unmodified microsculpture type (a type with usual cuticular microsculpture and filter setae) can be found on the anterior or posterior margins of the metathoracic spiracle. We believe the wide opening (type W) to be the plesiomorphic character state in the Pentatomomorpha, with multiple, independent transformations leading to the narrow opening in Lygaeoidea. Considerable variability in the structure of the spiracle opening (in Lygaeoidea), and in the structure of the mycoid filter processes (in Pentatomomorpha) was detected. Overall, we found the morphology of these structures to be of limited value concerning the taxonomy or for determining phylogenetic relationships of the higher taxa (families) of Pentatomomorpha, but they may be useful as additional evidence for taxonomic and phylogenetic studies at the generic and perhaps the tribal levels.
