Pub Date : 2025-11-26DOI: 10.1016/j.asd.2025.101495
Sunjie Chen , Shaohua Dong , Congnan Cen , Kai Sun , Xiaoping Yu
Hox genes encode a group of highly conserved transcription factors that play crucial roles in determine regional identity along the anterior-posterior axis in insects. Early studies identified Hox genes as spatially restricted regulators responsible for the proper development of insect body segments and appendages. Over the past two decades, investigations across a wide range of insect species have further demonstrated that Hox genes also regulate the development of distinct specialized structures and contribute to the formation of the nervous system. Substantial evidence suggests that Hox genes not only preserve the fundamental body plan but also contribute to the evolutionary diversification of morphology in insects. This review summarizes the research to date on Hox genes in insects, including their genomic organization, expression patterns, regulatory mechanisms, and functional roles, and highlights their significance in the morphological evolution of insects.
{"title":"Role of Hox genes in insect development and evolution","authors":"Sunjie Chen , Shaohua Dong , Congnan Cen , Kai Sun , Xiaoping Yu","doi":"10.1016/j.asd.2025.101495","DOIUrl":"10.1016/j.asd.2025.101495","url":null,"abstract":"<div><div>Hox genes encode a group of highly conserved transcription factors that play crucial roles in determine regional identity along the anterior-posterior axis in insects. Early studies identified Hox genes as spatially restricted regulators responsible for the proper development of insect body segments and appendages. Over the past two decades, investigations across a wide range of insect species have further demonstrated that Hox genes also regulate the development of distinct specialized structures and contribute to the formation of the nervous system. Substantial evidence suggests that Hox genes not only preserve the fundamental body plan but also contribute to the evolutionary diversification of morphology in insects. This review summarizes the research to date on Hox genes in insects, including their genomic organization, expression patterns, regulatory mechanisms, and functional roles, and highlights their significance in the morphological evolution of insects.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"90 ","pages":"Article 101495"},"PeriodicalIF":1.3,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145594784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.asd.2025.101494
Victor Benno Meyer-Rochow , Steffen Harzsch
{"title":"Introduction to the Special Issue on “Bioluminescence in Arthropods”","authors":"Victor Benno Meyer-Rochow , Steffen Harzsch","doi":"10.1016/j.asd.2025.101494","DOIUrl":"10.1016/j.asd.2025.101494","url":null,"abstract":"","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"90 ","pages":"Article 101494"},"PeriodicalIF":1.3,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145594783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.asd.2025.101492
Chu Wang , Fu-Ya Chung , Chung-Chi Lin , Johan Billen
The male subgenital plate gland was discovered by Janet in 1902, but has never been described in detail. We studied this gland in Solenopsis geminata and Solenopsis invicta using light and electron microscopy and are able to show the original section image of Janet. The unpaired gland is very large and occurs underneath the subgenital plate (= sternite 9). It is made up by over 1500 spherical to polygonal class-3 secretory cells of which the accompanying duct cells open through the ventral part of the genital chamber. Ultrastructural examination does not allow to speculate on the nature of the secretion and the gland function, although its prominent size should indicate an important role in the reproductive biology of fire ant males. We also screened serial sections through the paired valves of the external male genitalia (gonopods, volsella and penites) in search for gland cells, but did not find any exocrine tissue.
{"title":"Morphology of the subgenital plate gland in Solenopsis males (Hymenoptera, Formicidae)","authors":"Chu Wang , Fu-Ya Chung , Chung-Chi Lin , Johan Billen","doi":"10.1016/j.asd.2025.101492","DOIUrl":"10.1016/j.asd.2025.101492","url":null,"abstract":"<div><div>The male subgenital plate gland was discovered by Janet in 1902, but has never been described in detail. We studied this gland in <em>Solenopsis geminata</em> and <em>Solenopsis invicta</em> using light and electron microscopy and are able to show the original section image of Janet. The unpaired gland is very large and occurs underneath the subgenital plate (= sternite 9). It is made up by over 1500 spherical to polygonal class-3 secretory cells of which the accompanying duct cells open through the ventral part of the genital chamber. Ultrastructural examination does not allow to speculate on the nature of the secretion and the gland function, although its prominent size should indicate an important role in the reproductive biology of fire ant males. We also screened serial sections through the paired valves of the external male genitalia (gonopods, volsella and penites) in search for gland cells, but did not find any exocrine tissue.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101492"},"PeriodicalIF":1.3,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145395349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Insect egg glue plays a crucial role in adhering eggs together and to the substrate, thus providing them protection and stability. In most insect species, the glue is secreted by the accessory glands in the female reproductive tract, known as ‘colleterial glands’. However, in Nezara viridula L. (Hemiptera: Pentatomidae), these glands are absent, leaving its production site unclear. Through light microscopy, Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM), a distinct glue layer was identified between the follicular cells and the mature eggs in the vitellarium region, extending to the pedicel region of the ovariole. Ultrastructural analysis revealed that follicular cells contained numerous glue-filled vesicles, indicating that they actively secrete the egg glue via microvilli. During oviposition, the barrel-shaped eggs are laid in clutches with glue at their bottom and lateral sides. The glue subsequently hardens to form a cement-like layer that secures the eggs to the substrate. This glue adapts to the surface, faithfully replicating its features. N. viridula eggs show chorion decorations with conical projections and aero-micropylar processes along the circumference of the operculum. Mushroom-shaped structures are present around the aero-micropylar processes, making this area unwettable. The aero-micropylar processes vary in number and have porous texture with the opening for sperm entry in the apical part. This study, together with further investigations aiming to characterize the mechanical and chemical properties of the egg glue of N. viridula, enhances our understanding of the reproductive biology of this harmful insect and can have practical implications for pest control strategies and innovations in materials science.
{"title":"Egg glue secretion and chorion morphology of the Southern Green Stinkbug Nezara viridula L. (Hemiptera: Pentatomidae)","authors":"Asmita Baral , Silvana Piersanti , Gianandrea Salerno , Stanislav Gorb , Manuela Rebora","doi":"10.1016/j.asd.2025.101493","DOIUrl":"10.1016/j.asd.2025.101493","url":null,"abstract":"<div><div>Insect egg glue plays a crucial role in adhering eggs together and to the substrate, thus providing them protection and stability. In most insect species, the glue is secreted by the accessory glands in the female reproductive tract, known as ‘colleterial glands’. However, in <em>Nezara viridula</em> L. (Hemiptera: Pentatomidae), these glands are absent, leaving its production site unclear. Through light microscopy, Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM), a distinct glue layer was identified between the follicular cells and the mature eggs in the vitellarium region, extending to the pedicel region of the ovariole. Ultrastructural analysis revealed that follicular cells contained numerous glue-filled vesicles, indicating that they actively secrete the egg glue via microvilli. During oviposition, the barrel-shaped eggs are laid in clutches with glue at their bottom and lateral sides. The glue subsequently hardens to form a cement-like layer that secures the eggs to the substrate. This glue adapts to the surface, faithfully replicating its features. <em>N. viridula</em> eggs show chorion decorations with conical projections and aero-micropylar processes along the circumference of the operculum. Mushroom-shaped structures are present around the aero-micropylar processes, making this area unwettable. The aero-micropylar processes vary in number and have porous texture with the opening for sperm entry in the apical part. This study, together with further investigations aiming to characterize the mechanical and chemical properties of the egg glue of <em>N. viridula,</em> enhances our understanding of the reproductive biology of this harmful insect and can have practical implications for pest control strategies and innovations in materials science.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101493"},"PeriodicalIF":1.3,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.asd.2025.101490
Brendon E. Boudinot , Rolf G. Beutel , Michael Weingardt , Thomas van de Kamp , Jörg U. Hammel , Di Li , Adrian Richter , Benjamin Wipfler
The organization of the hexapod head remains a cornerstone problem in arthropod systematics, central to segmental homology, character definition, higher-level phylogeny, and functional and evolutionary morphology. Recently, Nel et al. (2025) proposed an alternative interpretation of insect head segmentation that departs markedly from established anatomical and comparative frameworks. We evaluate the internal consistency and external coherence of that hypothesis using their model groups, broader taxonomic samples, prior studies (including crustaceomorph Pancrustacea) and our own investigations. We identify multiple implausible anatomical interpretations and logical contradictions in their reconstruction. Our reanalysis, supported by microtomographic imaging (μ- and SR-μ-CT), shows that the proposed revision lacks empirical foundation (e.g. Psocodea), does not meet its own definitions (e.g. Neuropteroidea), misidentifies homologs (e.g. Coleoptera, Formicidae), and is unsupported by fossil or developmental evidence. Consequently, the new theory yields unreliable homology statements and obscures groundplan conditions and character polarities of the hexapod head. We therefore reject the hypothesis that “intercalate” and “promandible” sclerites existed in the groundplan of Hexapoda, and the assumed plesiomorphy of dicondyly. Our findings clarify relationships among major head sclerites, endoskeletal elements, and the head capsule's strengthening ridges, underscoring the need for comprehensive anatomy, broad sampling, and logical rigor in resolving arthropod head evolution.
{"title":"The insect head rewound: Clarifications to the groundplan of Hexapoda (Pancrustacea)","authors":"Brendon E. Boudinot , Rolf G. Beutel , Michael Weingardt , Thomas van de Kamp , Jörg U. Hammel , Di Li , Adrian Richter , Benjamin Wipfler","doi":"10.1016/j.asd.2025.101490","DOIUrl":"10.1016/j.asd.2025.101490","url":null,"abstract":"<div><div>The organization of the hexapod head remains a cornerstone problem in arthropod systematics, central to segmental homology, character definition, higher-level phylogeny, and functional and evolutionary morphology. Recently, Nel et al. (2025) proposed an alternative interpretation of insect head segmentation that departs markedly from established anatomical and comparative frameworks. We evaluate the internal consistency and external coherence of that hypothesis using their model groups, broader taxonomic samples, prior studies (including crustaceomorph Pancrustacea) and our own investigations. We identify multiple implausible anatomical interpretations and logical contradictions in their reconstruction. Our reanalysis, supported by microtomographic imaging (μ- and SR-μ-CT), shows that the proposed revision lacks empirical foundation (<em>e.g.</em> Psocodea), does not meet its own definitions (<em>e.g.</em> Neuropteroidea), misidentifies homologs (<em>e.g.</em> Coleoptera, Formicidae), and is unsupported by fossil or developmental evidence. Consequently, the new theory yields unreliable homology statements and obscures groundplan conditions and character polarities of the hexapod head. We therefore reject the hypothesis that “intercalate” and “promandible” sclerites existed in the groundplan of Hexapoda, and the assumed plesiomorphy of dicondyly. Our findings clarify relationships among major head sclerites, endoskeletal elements, and the head capsule's strengthening ridges, underscoring the need for comprehensive anatomy, broad sampling, and logical rigor in resolving arthropod head evolution.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101490"},"PeriodicalIF":1.3,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145402980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.asd.2025.101487
Andrijana Andrić , Andrea Aracil , Ruslan Mishustin , Grigory Popov , Santos Rojo , Snežana Radenković , Ante Vujić , Celeste Pérez-Bañón
The immature stages of hoverfly genus Merodon Meigen (Diptera: Syrphidae) are mostly understudied, with only about 6 % of species currently having published larva and/or puparium descriptions. The available information on breeding and oviposition sites and host-plants of these phytophagous larvae is also very limited. The aim of the present study is to expand upon this knowledge by introducing the first data on preimaginal stages of Merodon mishustini Popov, 2020 (belonging to the M. constans species group, M. albifrons lineage) reared from the bulbs of Galanthus spp. (Amaryllidaceae) in Turkey. The morphology of larvae and puparia is analyzed using stereomicroscope and scanning electron microscope and detailed illustrated descriptions of the main characters are presented. Variability within the species group and lineage, as well as the importance of the potential diagnostic characters as taxonomic tools for delimitation within the genus are discussed. The present study confirms the need for both more Merodon species and more specimens in different developmental stages to be examined and compared in order to arrive at better supported conclusions.
{"title":"New data on the morphology of the immature stages of Merodon mishustini as a contribution to the knowledge of the genus Merodon Meigen (Diptera: Syrphidae)","authors":"Andrijana Andrić , Andrea Aracil , Ruslan Mishustin , Grigory Popov , Santos Rojo , Snežana Radenković , Ante Vujić , Celeste Pérez-Bañón","doi":"10.1016/j.asd.2025.101487","DOIUrl":"10.1016/j.asd.2025.101487","url":null,"abstract":"<div><div>The immature stages of hoverfly genus <em>Merodon</em> Meigen (Diptera: Syrphidae) are mostly understudied, with only about 6 % of species currently having published larva and/or puparium descriptions. The available information on breeding and oviposition sites and host-plants of these phytophagous larvae is also very limited. The aim of the present study is to expand upon this knowledge by introducing the first data on preimaginal stages of <em>Merodon mishustini</em> Popov, 2020 (belonging to the <em>M. constans</em> species group, <em>M. albifrons</em> lineage) reared from the bulbs of <em>Galanthus</em> spp. (Amaryllidaceae) in Turkey. The morphology of larvae and puparia is analyzed using stereomicroscope and scanning electron microscope and detailed illustrated descriptions of the main characters are presented. Variability within the species group and lineage, as well as the importance of the potential diagnostic characters as taxonomic tools for delimitation within the genus are discussed. The present study confirms the need for both more <em>Merodon</em> species and more specimens in different developmental stages to be examined and compared in order to arrive at better supported conclusions.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101487"},"PeriodicalIF":1.3,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145467024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.asd.2025.101491
Giuseppe Camerini
This paper reports the results of field observations on the biology and behavior of the firefly Luciola pedemontana (Coleoptera Lampyridae). Sexual communication in L. pedemontana is based on flashing signals emitted by males, which actively fly in search of flightless females. The research aimed to assess the phenology of the reproductive season and the diurnal rhythms of male courtship flights, as well as the synchronisation of these flights with the photoperiod. The research was carried out (years 2003, 2004, 2009 and 2014) in a study area located in the Italian Apennines (Northern Italy - 314 m above sea level). Following the start of the reproductive season, the number of flying males was measured weekly. Males were counted while walking at a normal pace along a transect. The number of flying males was recorded every 30 min from 10 pm to midnight, as well as the time of their first appearance. Illuminance at dusk was measured using a lux meter. Courtship activity was observed in June and July. The maximum number of flying males engaged in courtship was recorded around mid-June. Males started flying on average 32.75 min after sunset, when illuminance dropped below 0.2 lux. Male flight peaked in the early part of the night (10.00 pm/11.00 pm), then a decline was observed and male flight ceased after midnight. The duration of the interflash interval was found to be inversely proportional to air temperature.
{"title":"Corrigendum to: “Observations on Luciola pedemontana (Coleoptera Lampyridae) male courtship” [Arthropod Struct. Develop. 86 (2025) 101426]","authors":"Giuseppe Camerini","doi":"10.1016/j.asd.2025.101491","DOIUrl":"10.1016/j.asd.2025.101491","url":null,"abstract":"<div><div>This paper reports the results of field observations on the biology and behavior of the firefly <em>Luciola pedemontana</em> (Coleoptera Lampyridae). Sexual communication in <em>L. pedemontana</em> is based on flashing signals emitted by males, which actively fly in search of flightless females. The research aimed to assess the phenology of the reproductive season and the diurnal rhythms of male courtship flights, as well as the synchronisation of these flights with the photoperiod. The research was carried out (years 2003, 2004, 2009 and 2014) in a study area located in the Italian Apennines (Northern Italy - 314 m above sea level). Following the start of the reproductive season, the number of flying males was measured weekly. Males were counted while walking at a normal pace along a transect. The number of flying males was recorded every 30 min from 10 pm to midnight, as well as the time of their first appearance. Illuminance at dusk was measured using a lux meter. Courtship activity was observed in June and July. The maximum number of flying males engaged in courtship was recorded around mid-June. Males started flying on average 32.75 min after sunset, when illuminance dropped below 0.2 lux. Male flight peaked in the early part of the night (10.00 pm/11.00 pm), then a decline was observed and male flight ceased after midnight. The duration of the interflash interval was found to be inversely proportional to air temperature.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101491"},"PeriodicalIF":1.3,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-24DOI: 10.1016/j.asd.2025.101478
Sebastian Büsse
Odonata comprises Anisoptera (dragonflies), Zygoptera (damselflies), and Epiophlebia, with Anisoptera and Epiophlebia forming the clade Epiprocta. Anisoptera exhibits robust bodies, dissimilar wing pairs, and eyes that may touch, while Zygoptera has slender bodies, uniform wings, and separated eyes; Epiophlebia, however, combines features of both, reflecting likely an ancestral condition. Detailed studies of odonatan thoracic musculature reveal differences between life stages and taxa, highlighting adaptations to larval aquatic and adult aerial lifestyles.
This study revisited the thorax anatomy of Epiophlebia superstes to fill gaps in knowledge. High-resolution X-ray tomography was used to analyse, revealing 58 thoracic muscles: 17 in the prothorax, 20 in the mesothorax, and 21 in the metathorax. Comparison with previous studies confirmed the most known muscles, identified five new ones, and corrected earlier misinterpretations. Differences in muscle configurations among Odonata larvae and adults reflect their distinct ecological niches. Larvae generally possess more muscles, likely supporting their swimming and substrate-clinging activities. The generalised thorax model compiled findings from prior and current studies, simplifying the anatomy for comparative analysis with other insect groups. By enhancing understanding of Odonata thoracic anatomy, this research provides insights into the evolution of the insect flight apparatus, bridging knowledge gaps and aiding broader comparative studies.
{"title":"Review on the thorax musculature in Odonata (Insecta), including the 3D-anatomy of adult Epiophlebia superstes","authors":"Sebastian Büsse","doi":"10.1016/j.asd.2025.101478","DOIUrl":"10.1016/j.asd.2025.101478","url":null,"abstract":"<div><div>Odonata comprises Anisoptera (dragonflies), Zygoptera (damselflies), and <em>Epiophlebia</em>, with Anisoptera and <em>Epiophlebia</em> forming the clade Epiprocta. Anisoptera exhibits robust bodies, dissimilar wing pairs, and eyes that may touch, while Zygoptera has slender bodies, uniform wings, and separated eyes; <em>Epiophlebia,</em> however, combines features of both, reflecting likely an ancestral condition. Detailed studies of odonatan thoracic musculature reveal differences between life stages and taxa, highlighting adaptations to larval aquatic and adult aerial lifestyles.</div><div>This study revisited the thorax anatomy of <em>Epiophlebia superstes</em> to fill gaps in knowledge. High-resolution X-ray tomography was used to analyse, revealing 58 thoracic muscles: 17 in the prothorax, 20 in the mesothorax, and 21 in the metathorax. Comparison with previous studies confirmed the most known muscles, identified five new ones, and corrected earlier misinterpretations. Differences in muscle configurations among Odonata larvae and adults reflect their distinct ecological niches. Larvae generally possess more muscles, likely supporting their swimming and substrate-clinging activities. The generalised thorax model compiled findings from prior and current studies, simplifying the anatomy for comparative analysis with other insect groups. By enhancing understanding of Odonata thoracic anatomy, this research provides insights into the evolution of the insect flight apparatus, bridging knowledge gaps and aiding broader comparative studies.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101478"},"PeriodicalIF":1.3,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-24DOI: 10.1016/j.asd.2025.101489
Wan-Jen Li , Yi-Ning Chiu , Hauchuan Liao , Hou-Feng Li
Sex identification in termites is crucial for understanding caste development, colony organization, and reproductive strategies. Traditional methods, such as dissection and staining, are invasive and may damage specimens. In this study, a non-invasive method was developed to identify the sex of Prorhinotermes flavus (Bugnion and Popoff). The sternite morphology of all six castes, alate, neotenic, nymph, pseudergate, soldier, and larva, could be categorized into two groups. Micro-CT analyses revealed sex-specific gonadal structures in alates, neotenics, and nymphs, and their corresponding sex-specific sternite morphology was confirmed. Rearing trials were conducted to observe pseudergates molting into neotenics and soldiers, and larvae molting into pseudergates. Since the sex-specific sternite morphology of neotenics is known, we are able to confirm the sex of pseudergates, and consequently, that of soldiers and larvae. Our findings show that male alates and neotenics possess a visible ninth abdominal sternite with distinct styli. In female alates and neotenics, the seventh sternite completely covers the eighth and ninth sternites, and the styli are absent. In male pseudergates, soldiers, and nymphs, the ninth sternite with styli is also clearly visible, while in females, the seventh sternite partially covers the eighth and ninth sternites. Male larvae can be identified by the presence of bristles on the posterior margin of the eighth abdominal sternite, whereas in female larvae, these bristles are absent. This study presents the first comprehensive, non-invasive method for sexing all castes of P. flavus, enabling more precise research on caste development and social interactions in termite colonies.
白蚁的性别鉴定是理解种姓发展、群体组织和繁殖策略的关键。传统的方法，如解剖和染色，是侵入性的，可能会损坏标本。本研究建立了一种非侵入性鉴定黄喙白蚁（Bugnion and Popoff）性别的方法。所有6个等级的胸骨形态，即腭形、幼形、若虫、假门、战士和幼虫，可分为两类。显微ct分析显示，alates， neotenics和若虫的性腺结构具有性别特异性，其相应的胸骨形态也具有性别特异性。通过饲养试验，观察假幼虫蜕皮成幼体和战士，以及幼虫蜕皮成假幼虫。由于已知新生儿的性别特异性胸骨形态，我们能够确认假门的性别，从而确定士兵和幼虫的性别。我们的研究结果表明，雄性幼崽和幼崽具有明显的第九腹骨，具有明显的柱头。在雌鸟和幼鸟中，第7胸骨完全覆盖第8和第9胸骨，花柱缺失。在男性假门、士兵和仙女中，带有柱头的第九胸骨也清晰可见，而在女性中，第七胸骨部分覆盖第八和第九胸骨。雄性幼虫可以通过在第八腹部胸骨后缘上的刚毛来识别，而雌性幼虫则没有这些刚毛。本研究提出了第一个全面的、非侵入性的黄斑白蚁所有种姓的性别测定方法，使白蚁群体中种姓发展和社会互动的研究更加精确。
{"title":"A non-invasive method for sexing all castes of Prorhinotermes flavus (Blattodea: Psammotermitidae) using external morphology","authors":"Wan-Jen Li , Yi-Ning Chiu , Hauchuan Liao , Hou-Feng Li","doi":"10.1016/j.asd.2025.101489","DOIUrl":"10.1016/j.asd.2025.101489","url":null,"abstract":"<div><div>Sex identification in termites is crucial for understanding caste development, colony organization, and reproductive strategies. Traditional methods, such as dissection and staining, are invasive and may damage specimens. In this study, a non-invasive method was developed to identify the sex of <em>Prorhinotermes flavus</em> (Bugnion and Popoff). The sternite morphology of all six castes, alate, neotenic, nymph, pseudergate, soldier, and larva, could be categorized into two groups. Micro-CT analyses revealed sex-specific gonadal structures in alates, neotenics, and nymphs, and their corresponding sex-specific sternite morphology was confirmed. Rearing trials were conducted to observe pseudergates molting into neotenics and soldiers, and larvae molting into pseudergates. Since the sex-specific sternite morphology of neotenics is known, we are able to confirm the sex of pseudergates, and consequently, that of soldiers and larvae. Our findings show that male alates and neotenics possess a visible ninth abdominal sternite with distinct styli. In female alates and neotenics, the seventh sternite completely covers the eighth and ninth sternites, and the styli are absent. In male pseudergates, soldiers, and nymphs, the ninth sternite with styli is also clearly visible, while in females, the seventh sternite partially covers the eighth and ninth sternites. Male larvae can be identified by the presence of bristles on the posterior margin of the eighth abdominal sternite, whereas in female larvae, these bristles are absent. This study presents the first comprehensive, non-invasive method for sexing all castes of <em>P. flavus</em>, enabling more precise research on caste development and social interactions in termite colonies.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101489"},"PeriodicalIF":1.3,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-23DOI: 10.1016/j.asd.2025.101479
Alessandro Borsotti , Federico Ronchetti , Marcello Romano , Paolo Gabrieli , Giovanni Naro , Carlo Polidori
The insect sensory system was extensively explored in the aculeate Hymenoptera. However, there are entire lineages with only a few studies on the topic, limiting our understanding on its evolution. Here, we studied the sensory system in females and males of the bee-attacking velvet ant Myrmilla capitata, which belongs to a previously neglected family of ectoparasitoid wasps (Mutillidae). Through a Scanning Electron Microscopy analysis, we first described the M. capitata sensory systems. We then tested the hypothesis that males and females may diverge in some traits even if both are apterous and confined in the same restricted area (host bee nesting site), likely as an adaptation to the divergent stimuli they respond to (hosts for females, sexual partners for males). Despite males being larger than females, many of the analyzed traits were sexually dimorphic after having taken into account size difference. Females had slightly lower ommatidial density (worsen resolution) but larger ommatidia (better light capture) than males, which also displayed three small ocelli. The antennal flagellum harbour overall 12 types of sensilla: placoid sensilla (SP), coeloconic sensilla (SCo), sensilla campaniformia (SA), trichoid sensilla (ST) (a total of six types) and basiconic sensilla (SBa) (a total of three types). Some of the ST types and SBa types were found exclusively in either females or males, while both total ST density and SP density and size (better olfaction) were higher in females. Our results preliminarily indicate that males may take advantage of a better visual trait related with acuity to detect females, while females may more heavily rely on odours to detect the host.
{"title":"Sexual dimorphism in the sensory system of Myrmilla capitata (Hymenoptera: Mutillidae), a bee-attacking velvet ant with both sexes apterous","authors":"Alessandro Borsotti , Federico Ronchetti , Marcello Romano , Paolo Gabrieli , Giovanni Naro , Carlo Polidori","doi":"10.1016/j.asd.2025.101479","DOIUrl":"10.1016/j.asd.2025.101479","url":null,"abstract":"<div><div>The insect sensory system was extensively explored in the aculeate Hymenoptera. However, there are entire lineages with only a few studies on the topic, limiting our understanding on its evolution. Here, we studied the sensory system in females and males of the bee-attacking velvet ant <em>Myrmilla capitata</em>, which belongs to a previously neglected family of ectoparasitoid wasps (Mutillidae). Through a Scanning Electron Microscopy analysis, we first described the <em>M. capitata</em> sensory systems. We then tested the hypothesis that males and females may diverge in some traits even if both are apterous and confined in the same restricted area (host bee nesting site), likely as an adaptation to the divergent stimuli they respond to (hosts for females, sexual partners for males). Despite males being larger than females, many of the analyzed traits were sexually dimorphic after having taken into account size difference. Females had slightly lower ommatidial density (worsen resolution) but larger ommatidia (better light capture) than males, which also displayed three small ocelli. The antennal flagellum harbour overall 12 types of sensilla: placoid sensilla (SP), coeloconic sensilla (SCo), sensilla campaniformia (SA), trichoid sensilla (ST) (a total of six types) and basiconic sensilla (SBa) (a total of three types). Some of the ST types and SBa types were found exclusively in either females or males, while both total ST density and SP density and size (better olfaction) were higher in females. Our results preliminarily indicate that males may take advantage of a better visual trait related with acuity to detect females, while females may more heavily rely on odours to detect the host.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101479"},"PeriodicalIF":1.3,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号