Pub Date : 2025-09-20DOI: 10.1016/j.jinsphys.2025.104889
Matan Shelomi , Fabian Bäumler , Thies H. Büscher
Phasmatodea excretory organs differ from other insects’. They consist of two types of Malpighian tubules, excretory and calciferous, and the enigmatic midgut appendages, which are an autapomorphy of this lineage. To gain a better understanding of these three tubules, we used micro-computed tomography to visualize their structural organization in a female Epidares nolimetangere. The midgut appendices were conspicuous, with ducts arising from their ampules penetrating the midgut wall and connecting to the exoperitrophic space. Radio-dense material was observed in the calciferous Malpighian tubules, differentiating them from the excretory Malpighian tubules. While their key role in the development of the biomineralized eggs of Phasmatodea is assumed, the process of how this material is transferred to the eggshells remains unclear. These observations validate previous anatomic and microscopy findings of the Phasmatodea excretory tubules with the description of the structural organization of the excretory organs in a species so far not examined in this regard.
{"title":"Structural organization of excretory organs in Phasmatodea based on micro-computed tomography","authors":"Matan Shelomi , Fabian Bäumler , Thies H. Büscher","doi":"10.1016/j.jinsphys.2025.104889","DOIUrl":"10.1016/j.jinsphys.2025.104889","url":null,"abstract":"<div><div>Phasmatodea excretory organs differ from other insects’. They consist of two types of Malpighian tubules, excretory and calciferous, and the enigmatic midgut appendages, which are an autapomorphy of this lineage. To gain a better understanding of these three tubules, we used micro-computed tomography to visualize their structural organization in a female <em>Epidares nolimetangere</em>. The midgut appendices were conspicuous, with ducts arising from their ampules penetrating the midgut wall and connecting to the exoperitrophic space. Radio-dense material was observed in the calciferous Malpighian tubules, differentiating them from the excretory Malpighian tubules. While their key role in the development of the biomineralized eggs of Phasmatodea is assumed, the process of how this material is transferred to the eggshells remains unclear. These observations validate previous anatomic and microscopy findings of the Phasmatodea excretory tubules with the description of the structural organization of the excretory organs in a species so far not examined in this regard.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"166 ","pages":"Article 104889"},"PeriodicalIF":2.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-18DOI: 10.1016/j.jinsphys.2025.104887
Lelei Wen , Lieping Wang , Xiaoguo Jiao , Haixin Zhang , Lang Hu , Zhilin Zhang , Baoyu Peng , Yu Peng , Changchun Li
The biochemical composition of prey is a critical factor shaping the life-history strategies of obligate predators, yet the molecular mechanisms through which specific nutrients regulate complex developmental processes remain largely unknown. Using the wolf spider Pardosa pseudoannulata as a model, where arachidonic acid (ARA) is indispensable for preventing molting death, we integrated life-history analysis and RNA sequencing to elucidate its regulatory role. We discovered a significant life-history trade-off: while essential for survival, dietary ARA significantly prolonged early instar duration. Transcriptomic analysis revealed that ARA orchestrates a two-phase developmental strategy to resolve this conflict. The “preparation” phase, marked by the upregulation of juvenile hormone synthesis (JHAMT), corresponds to the developmental delay and facilitates resource accumulation. This is followed by an “execution” phase, where ARA triggers the entire ecdysone cascade, from biosynthesis (e.g., Spook, Shade) and signaling (USP) to catabolism (CYP18A1). This hormonal activation was coupled with the substantial upregulation of downstream effector genes, including dozens of cuticular proteins. Our findings indicate that ARA acts as a key signaling molecule that coordinates the hormonal crosstalk between developmental timing and molting. This study provides a comprehensive molecular model for the nutritional regulation of arthropod development, linking nutrition, physiology, and survival.
{"title":"Arachidonic acid regulates hormonal crosstalk to promote molting success and mediate a life-history trade-off in a wolf spider","authors":"Lelei Wen , Lieping Wang , Xiaoguo Jiao , Haixin Zhang , Lang Hu , Zhilin Zhang , Baoyu Peng , Yu Peng , Changchun Li","doi":"10.1016/j.jinsphys.2025.104887","DOIUrl":"10.1016/j.jinsphys.2025.104887","url":null,"abstract":"<div><div>The biochemical composition of prey is a critical factor shaping the life-history strategies of obligate predators, yet the molecular mechanisms through which specific nutrients regulate complex developmental processes remain largely unknown. Using the wolf spider <em>Pardosa pseudoannulata</em> as a model, where arachidonic acid (ARA) is indispensable for preventing molting death, we integrated life-history analysis and RNA sequencing to elucidate its regulatory role. We discovered a significant life-history trade-off: while essential for survival, dietary ARA significantly prolonged early instar duration. Transcriptomic analysis revealed that ARA orchestrates a two-phase developmental strategy to resolve this conflict. The “preparation” phase, marked by the upregulation of juvenile hormone synthesis (<em>JHAMT</em>), corresponds to the developmental delay and facilitates resource accumulation. This is followed by an “execution” phase, where ARA triggers the entire ecdysone cascade, from biosynthesis (e.g., <em>Spook</em>, <em>Shade</em>) and signaling (<em>USP</em>) to catabolism (<em>CYP18A1</em>). This hormonal activation was coupled with the substantial upregulation of downstream effector genes, including dozens of cuticular proteins. Our findings indicate that ARA acts as a key signaling molecule that coordinates the hormonal crosstalk between developmental timing and molting. This study provides a comprehensive molecular model for the nutritional regulation of arthropod development, linking nutrition, physiology, and survival.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"166 ","pages":"Article 104887"},"PeriodicalIF":2.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145103002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-17DOI: 10.1016/j.jinsphys.2025.104886
Yi Zhang , Ya-Nan Liu , Yu-Dan Li , Tong-Xian Liu , Xing-Xing Wang
The ladybird Harmonia axyridis is an important predatory natural enemy with a broad dietary spectrum and few avoided food sources. Nevertheless, it shows avoidance behavior toward aphid corpses, likely to minimize the risk of pathogen infection in the wild. The molecular basis of this behavior remains unclear, and gustatory receptors (GRs) are hypothesized to be involved. Here, we examined the avoidance of H. axyridis toward pea aphid (Acyrthosiphon pisum) corpses and investigated the role of candidate GR genes in contact chemoreception via the maxillary palps. Using SEM and immunofluorescence, we characterized the microstructure of the maxillary palps and mapped neuronal distributions. Behavioral assays combined with RNAi were performed to evaluate three candidate GR genes associated with corpse recognition. Our results show that feeding behavior on A. pisum is largely determined by gustatory input through maxillary palp contact. The palp surface is densely covered with sensilla, and internally the tissue displays a complementary distribution of dopaminergic and serotonergic neurons. RNAi assays demonstrated that three GR genes (GR2-like, GR28b-like, and GR64e-like) mediate corpse avoidance. Silencing GR2-like alone significantly reduced avoidance, while simultaneous knockdown of GR28b-like and GR64e-like further weakened the response, suggesting functional interactions among gustatory receptors in H. axyridis. These findings reveal a gustatory mechanism underlying corpse avoidance in predatory insects and provide insights relevant to biological control and artificial diet development.
{"title":"Maxillary palp gustatory receptors mediate aphid corpses avoidance in Harmonia axyridis","authors":"Yi Zhang , Ya-Nan Liu , Yu-Dan Li , Tong-Xian Liu , Xing-Xing Wang","doi":"10.1016/j.jinsphys.2025.104886","DOIUrl":"10.1016/j.jinsphys.2025.104886","url":null,"abstract":"<div><div>The ladybird <em>Harmonia axyridis</em> is an important predatory natural enemy with a broad dietary spectrum and few avoided food sources. Nevertheless, it shows avoidance behavior toward aphid corpses, likely to minimize the risk of pathogen infection in the wild. The molecular basis of this behavior remains unclear, and gustatory receptors (GRs) are hypothesized to be involved. Here, we examined the avoidance of <em>H. axyridis</em> toward pea aphid (<em>Acyrthosiphon pisum</em>) corpses and investigated the role of candidate <em>GR</em> genes in contact chemoreception via the maxillary palps. Using SEM and immunofluorescence, we characterized the microstructure of the maxillary palps and mapped neuronal distributions. Behavioral assays combined with RNAi were performed to evaluate three candidate <em>GR</em> genes associated with corpse recognition. Our results show that feeding behavior on <em>A. pisum</em> is largely determined by gustatory input through maxillary palp contact. The palp surface is densely covered with sensilla, and internally the tissue displays a complementary distribution of dopaminergic and serotonergic neurons. RNAi assays demonstrated that three <em>GR</em> genes (<em>GR2-like</em>, <em>GR28b-like</em>, and <em>GR64e-like</em>) mediate corpse avoidance. Silencing <em>GR2-like</em> alone significantly reduced avoidance, while simultaneous knockdown of <em>GR28b-like</em> and <em>GR64e-like</em> further weakened the response, suggesting functional interactions among gustatory receptors in <em>H. axyridis</em>. These findings reveal a gustatory mechanism underlying corpse avoidance in predatory insects and provide insights relevant to biological control and artificial diet development.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"166 ","pages":"Article 104886"},"PeriodicalIF":2.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145086104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-15DOI: 10.1016/j.jinsphys.2025.104885
Devin T. Mazolewski , J.Joe Hull , Colin S. Brent , Andrew B. Nuss
Insulin signaling controls many physiological processes in insects, and it has a demonstrated role in cellular uptake of circulating sugars. Although model insects have pioneered much of our understanding of insulin signaling, high throughput genetic sequencing has enabled opportunities for the physiological study of less explored insect species. Lygus hesperus, the western tarnished plant bug, is a significant agricultural pest of numerous crops and recent efforts have focused on molecular approaches for identifying new pest management strategies. In this work, three insulin-like peptides (LhILP1, LhILP2, and LhILP3) were characterized from the transcriptome of L. hesperus. LhILP1 and LhILP2 structurally resemble classic insulin-like peptides while LhILP3 resembles arthropod Insulin-like Growth Factors (aIGFs). All three LhILPs were primarily expressed in the head, and were observed throughout development. We examined their function by observing clearance rates of injected trehalose from the hemolymph in adult L. hesperus males following RNAi knockdown of the respective LhILPs. Untreated males cleared the trehalose within 6 h and showed a corresponding increase in glycogen content. While knockdown of LhILP1 did not impact clearance rate, knockdown of LhILP2 prevented clearance of circulating trehalose and glycogen accumulation. Knockdown of LhILP3 also prevented trehalose clearance, but this appears to be influenced by co-knockdown of LhILP2, rather than a direct effect. Head ligation stopped the release of head-produced LhILPs, preventing the clearance of injected trehalose, a condition that could be rescued with co-injection of heterologous insulin. Stage-specific expression in LhILP RNAi insects suggest that LhILPs have multiple additional roles besides hemolymph carbohydrate homeostasis in L. hesperus that remain to be explored.
{"title":"An insulin-like peptide mediates trehalose storage in the western tarnished plant bug, Lygus hesperus","authors":"Devin T. Mazolewski , J.Joe Hull , Colin S. Brent , Andrew B. Nuss","doi":"10.1016/j.jinsphys.2025.104885","DOIUrl":"10.1016/j.jinsphys.2025.104885","url":null,"abstract":"<div><div>Insulin signaling controls many physiological processes in insects, and it has a demonstrated role in cellular uptake of circulating sugars. Although model insects have pioneered much of our understanding of insulin signaling, high throughput genetic sequencing has enabled opportunities for the physiological study of less explored insect species. <em>Lygus hesperus</em>, the western tarnished plant bug, is a significant agricultural pest of numerous crops and recent efforts have focused on molecular approaches for identifying new pest management strategies. In this work, three insulin-like peptides (LhILP1, LhILP2, and LhILP3) were characterized from the transcriptome of <em>L. hesperus</em>. LhILP1 and LhILP2 structurally resemble classic insulin-like peptides while LhILP3 resembles arthropod Insulin-like Growth Factors (aIGFs). All three LhILPs were primarily expressed in the head, and were observed throughout development. We examined their function by observing clearance rates of injected trehalose from the hemolymph in adult <em>L</em>. <em>hesperus</em> males following RNAi knockdown of the respective LhILPs. Untreated males cleared the trehalose within 6 h and showed a corresponding increase in glycogen content. While knockdown of LhILP1 did not impact clearance rate, knockdown of LhILP2 prevented clearance of circulating trehalose and glycogen accumulation. Knockdown of LhILP3 also prevented trehalose clearance, but this appears to be influenced by co-knockdown of LhILP2, rather than a direct effect. Head ligation stopped the release of head-produced LhILPs, preventing the clearance of injected trehalose, a condition that could be rescued with co-injection of heterologous insulin. Stage-specific expression in LhILP RNAi insects suggest that LhILPs have multiple additional roles besides hemolymph carbohydrate homeostasis in <em>L. hesperus</em> that remain to be explored.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"167 ","pages":"Article 104885"},"PeriodicalIF":2.3,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-11DOI: 10.1016/j.jinsphys.2025.104881
Xu Wu , Wen-Mei Li , Qiang Xu , Xiao-Ping Yi , Da-He Zhang , Ming-Zhe He , Yu-Hong Ren
RNA interference (RNAi) has shown excellent potential for pest management worldwide. However, the application of RNAi against insects can be inefficient and unreliable. Finding a better delivery system is a crucial factor for enhancing RNAi efficacy. Here, we present a novel and effective approach of conjugating double-stranded RNA (dsRNA) with a cell-penetrating disulfide polymer (CPD) to improve dsRNA stability and RNAi efficiency. The fall armyworm (FAW), Spodoptera frugiperda, is a globally agricultural insect. Chitin synthase B (CHSB) and methoprene-tolerant (Met) genes, which are essential for the development and growth of FAW, were selected as target genes. The CPD was synthesized using a two-step method for dsRNA delivery. The synthesized CPD/dsRNA complex protected dsRNA from nuclease degradation. The biological application of CPD in Sf9 cells demonstrated low cytotoxicity and high cell viability. Moreover, the CPD-loaded dsRNA entered the cells within 6 h. Bioassays of FAW showed that the relative expression levels of the CHSB and Met genes were reduced. Specifically, at 72 h, the relative expression levels of the CHSB and Met genes were 48.14 % and 37.60 % of those in the control group, respectively. The weight and body length of the larvae decreased significantly, and the mortality rate of CPD/dsCHSB reached 30 %. This CPD was demonstrated for the first time to have excellent delivery performance in insects and is expected to become a new and effective tool for pest control, representing a significant advancement in pest management.
{"title":"Improvement of RNAi efficiency by delivering of dsRNA formulated with cell-penetrating disulfide polymer in the fall Armyworm, Spodoptera frugiperda","authors":"Xu Wu , Wen-Mei Li , Qiang Xu , Xiao-Ping Yi , Da-He Zhang , Ming-Zhe He , Yu-Hong Ren","doi":"10.1016/j.jinsphys.2025.104881","DOIUrl":"10.1016/j.jinsphys.2025.104881","url":null,"abstract":"<div><div>RNA interference (RNAi) has shown excellent potential for pest management worldwide. However, the application of RNAi against insects can be inefficient and unreliable. Finding a better delivery system is a crucial factor for enhancing RNAi efficacy. Here, we present a novel and effective approach of conjugating double-stranded RNA (dsRNA) with a cell-penetrating disulfide polymer (CPD) to improve dsRNA stability and RNAi efficiency. The fall armyworm (FAW), <em>Spodoptera frugiperda</em>, is a globally agricultural insect. Chitin synthase B (<em>CHSB</em>) and methoprene-tolerant (<em>Met</em>) genes, which are essential for the development and growth of FAW, were selected as target genes. The CPD was synthesized using a two-step method for dsRNA delivery. The synthesized CPD/dsRNA complex protected dsRNA from nuclease degradation. The biological application of CPD in Sf9 cells demonstrated low cytotoxicity and high cell viability. Moreover, the CPD-loaded dsRNA entered the cells within 6 h. Bioassays of FAW showed that the relative expression levels of the <em>CHSB</em> and <em>Met</em> genes were reduced. Specifically, at 72 h, the relative expression levels of the <em>CHSB</em> and <em>Met</em> genes were 48.14 % and 37.60 % of those in the control group, respectively. The weight and body length of the larvae decreased significantly, and the mortality rate of CPD/ds<em>CHSB</em> reached 30 %. This CPD was demonstrated for the first time to have excellent delivery performance in insects and is expected to become a new and effective tool for pest control, representing a significant advancement in pest management.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"166 ","pages":"Article 104881"},"PeriodicalIF":2.3,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-10DOI: 10.1016/j.jinsphys.2025.104884
Jisheng Liu , Qiuying He , Xianfeng Lin , Guy Smagghe
RNA interference (RNAi), a key post-transcriptional gene silencing mechanism, has emerged as a powerful tool in insect physiology research and the development of next-generation pest control methods. In insects, the small interfering RNA (siRNA) pathway, which is activated by long double-stranded RNA (dsRNA), represents the primary mechanism through which RNAi operates. This comprehensive review explores the recent innovations that have increasingly centered on nanoparticle-based delivery systems to overcome physiological barriers in insects, such as nuclease activity in the gut and inefficient cellular uptake. Nanomaterials based on different (bio)chemistries such as natural organic (chitosan), liposomal-based (liposomes), inorganic (star polycations, carbon quantum dots, layered double hydroxides), synthetic polymers (guanylated polymers), and peptide-based (branched amphiphilic peptide capsules, cell-penetrating peptides), have been employed to encapsulate dsRNA, enhancing its stability and facilitating its targeted delivery to insect tissues. These nanoparticles improve systemic RNAi responses by enabling the efficient traversal of cellular membranes and endosomal escape, crucial steps within the unique physiological context of insect cells. Their nanoscale dimensions, biocompatibility, low toxicity, and cost-effectiveness position them at the forefront of RNAi innovation. As our understanding of insect molecular and cellular biology deepens, these nanocarriers offer transformative potential in the development of species-specific, eco-friendly insecticides, marking a significant advance in both insect physiology studies and sustainable pest management technologies.
{"title":"Recent progress in nanoparticle-mediated RNA interference in insects: Unveiling new frontiers in pest control","authors":"Jisheng Liu , Qiuying He , Xianfeng Lin , Guy Smagghe","doi":"10.1016/j.jinsphys.2025.104884","DOIUrl":"10.1016/j.jinsphys.2025.104884","url":null,"abstract":"<div><div>RNA interference (RNAi), a key post-transcriptional gene silencing mechanism, has emerged as a powerful tool in insect physiology research and the development of next-generation pest control methods. In insects, the small interfering RNA (siRNA) pathway, which is activated by long double-stranded RNA (dsRNA), represents the primary mechanism through which RNAi operates. This comprehensive review explores the recent innovations that have increasingly centered on nanoparticle-based delivery systems to overcome physiological barriers in insects, such as nuclease activity in the gut and inefficient cellular uptake. Nanomaterials based on different (bio)chemistries such as natural organic (chitosan), liposomal-based (liposomes), inorganic (star polycations, carbon quantum dots, layered double hydroxides), synthetic polymers (guanylated polymers), and peptide-based (branched amphiphilic peptide capsules, cell-penetrating peptides), have been employed to encapsulate dsRNA, enhancing its stability and facilitating its targeted delivery to insect tissues. These nanoparticles improve systemic RNAi responses by enabling the efficient traversal of cellular membranes and endosomal escape, crucial steps within the unique physiological context of insect cells. Their nanoscale dimensions, biocompatibility, low toxicity, and cost-effectiveness position them at the forefront of RNAi innovation. As our understanding of insect molecular and cellular biology deepens, these nanocarriers offer transformative potential in the development of species-specific, eco-friendly insecticides, marking a significant advance in both insect physiology studies and sustainable pest management technologies.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"167 ","pages":"Article 104884"},"PeriodicalIF":2.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145054140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-05DOI: 10.1016/j.jinsphys.2025.104872
Letícia Sophia Silva , Marcelo Gustavo Lorenzo , Gabriel da Rocha Fernandes , Alessandra Aparecida Guarneri
Triatomines are vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Their locomotor activity is influenced by endogenous and exogenous factors, but whether individual behavioral profiles persist across developmental stages remains unclear. This study evaluated non-oriented locomotor activity in Rhodnius prolixus under varying nutritional states (short-fasting, long-fasting, fed), developmental stages (5th instar nymphs and adults), sex (males and females), and light phase (photophase vs. scotophase). In a longitudinal design using actometers, we recorded the movements of 81 insects (42 males, 39 females) over 24-hour periods at specific time points through their 5th instar and adult stage. Results revealed significant variability in activity, but statistical modeling indicated that individual differences contributed minimally to activity variation, with sex, daytime, nutritional state, and developmental stage being the primary determinants. Females were consistently more active than males and both sexes presented higher movement levels during the scotophase compared to the photophase. Adults exhibited greater activity than nymphs. While fed adults displayed higher activity levels than starved individuals, possibly linked to mating or shelter-seeking behaviors, nymphs maintained consistently low activity regardless of nutritional state, indicating a potential energy-conserving starvation-survival strategy. These findings suggest that R. prolixus locomotor activity is not an individually intrinsic trait but rather one dynamically modulated by physiological and environmental conditions, with sex- and light-phase-dependent differences shaping dispersal and survival strategies across life stages.
{"title":"Factors affecting locomotor plasticity in Rhodnius prolixus","authors":"Letícia Sophia Silva , Marcelo Gustavo Lorenzo , Gabriel da Rocha Fernandes , Alessandra Aparecida Guarneri","doi":"10.1016/j.jinsphys.2025.104872","DOIUrl":"10.1016/j.jinsphys.2025.104872","url":null,"abstract":"<div><div>Triatomines are vectors of <em>Trypanosoma cruzi</em>, the causative agent of Chagas disease. Their locomotor activity is influenced by endogenous and exogenous factors, but whether individual behavioral profiles persist across developmental stages remains unclear. This study evaluated non-oriented locomotor activity in <em>Rhodnius prolixus</em> under varying nutritional states (short-fasting, long-fasting, fed), developmental stages (5<sup>th</sup> instar nymphs and adults), sex (males and females), and light phase (photophase vs. scotophase). In a longitudinal design using actometers, we recorded the movements of 81 insects (42 males, 39 females) over 24-hour periods at specific time points through their 5<sup>th</sup> instar and adult stage. Results revealed significant variability in activity, but statistical modeling indicated that individual differences contributed minimally to activity variation, with sex, daytime, nutritional state, and developmental stage being the primary determinants. Females were consistently more active than males and both sexes presented higher movement levels during the scotophase compared to the photophase. Adults exhibited greater activity than nymphs. While fed adults displayed higher activity levels than starved individuals, possibly linked to mating or shelter-seeking behaviors, nymphs maintained consistently low activity regardless of nutritional state, indicating a potential energy-conserving starvation-survival strategy. These findings suggest that <em>R. prolixus</em> locomotor activity is not an individually intrinsic trait but rather one dynamically modulated by physiological and environmental conditions, with sex- and light-phase-dependent differences shaping dispersal and survival strategies across life stages.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"166 ","pages":"Article 104872"},"PeriodicalIF":2.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145015521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-04DOI: 10.1016/j.jinsphys.2025.104880
Yechzkel Trablsi , Eran Levin , Sofia Bouchebti
Cellulose and chitin are the two most abundant polysaccharides on Earth. To digest these structural carbohydrates, herbivorous and omnivorous insects typically rely on cellulases, while insectivorous species often express chitinases. The American cockroach (Periplaneta americana), an extreme generalist omnivore, is known to thrive on a variety of diets. However, little is known about its ability to metabolize structural polysaccharides such as cellulose and chitin. In this study, we fed cockroaches 13C-labeled cellulose and chitin to assess their metabolic capacity and the tissue-level allocation of these polysaccharides across sexes and life stages. Our results show that P. americana metabolized chitin at a significantly higher rate than cellulose and incorporated only chitin-derived carbon into body tissues, with clear sex- and life stage-specific patterns: nymphs allocated more chitin-derived carbon to their muscles, while females incorporated more into the fat body and reproductive tissues.
These results provide in vivo evidence of P. americana’s capacity to metabolize both cellulose and chitin but also reveal a strong preference for chitin utilization under carbohydrate-rich conditions. This study contributes to our understanding of nutrient allocation strategies in generalist insects and offers evolutionary insight into the digestive capabilities of Blattodea, shedding light on their adaptive strategies for utilizing a wide range of dietary materials.
{"title":"Metabolization of the two most abundant polysaccharides, cellulose and chitin, by an extreme generalist insect, the American cockroach","authors":"Yechzkel Trablsi , Eran Levin , Sofia Bouchebti","doi":"10.1016/j.jinsphys.2025.104880","DOIUrl":"10.1016/j.jinsphys.2025.104880","url":null,"abstract":"<div><div>Cellulose and chitin are the two most abundant polysaccharides on Earth. To digest these structural carbohydrates, herbivorous and omnivorous insects typically rely on cellulases, while insectivorous species often express chitinases. The American cockroach (<em>Periplaneta americana</em>), an extreme generalist omnivore, is known to thrive on a variety of diets. However, little is known about its ability to metabolize structural polysaccharides such as cellulose and chitin. In this study, we fed cockroaches <sup>13</sup>C-labeled cellulose and chitin to assess their metabolic capacity and the tissue-level allocation of these polysaccharides across sexes and life stages. Our results show that <em>P. americana</em> metabolized chitin at a significantly higher rate than cellulose and incorporated only chitin-derived carbon into body tissues, with clear sex- and life stage-specific patterns: nymphs allocated more chitin-derived carbon to their muscles, while females incorporated more into the fat body and reproductive tissues.</div><div>These results provide in vivo evidence of <em>P. americana</em>’s capacity to metabolize both cellulose and chitin but also reveal a strong preference for chitin utilization under carbohydrate-rich conditions. This study contributes to our understanding of nutrient allocation strategies in generalist insects and offers evolutionary insight into the digestive capabilities of Blattodea, shedding light on their adaptive strategies for utilizing a wide range of dietary materials.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"166 ","pages":"Article 104880"},"PeriodicalIF":2.3,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-09-01DOI: 10.1016/j.jinsphys.2025.104854
Nathalia R. Moreira, Christiane Cardoso, Renata O. Dias, Clelia Ferreira, Walter R. Terra
{"title":"Corrigendum to “A physiologically-oriented transcriptomic analysis of the midgut of Tenebrio molitor”. [J. Insect Physiol. 99 (2017) 58–66]","authors":"Nathalia R. Moreira, Christiane Cardoso, Renata O. Dias, Clelia Ferreira, Walter R. Terra","doi":"10.1016/j.jinsphys.2025.104854","DOIUrl":"10.1016/j.jinsphys.2025.104854","url":null,"abstract":"","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"165 ","pages":"Article 104854"},"PeriodicalIF":2.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144649688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-08-24DOI: 10.1016/j.jinsphys.2025.104868
Anam Noreen Abbas , Mubashir Tariq , Faisal Munir , Uroosa Zaheer , Ibrahim Adam , Muhammad Asad , Guang Yang
The forkhead box (Fox) family of transcription factors is essential for controlling physiological functions, metabolism and development in insects. However, the role of the Fox gene in the diamondback moth, Plutella xylostella, a major agricultural pest of cruciferous crops, is still unknown. The purpose of this work was to characterize the PxFox1 gene and investigate its role in the reproduction and development of P. xylostella. The Fox gene in P. xylostella (PxFox1) is identified from the P. xylostella genome. The Fox gene was conserved in lepidoptera with the presence of Forkhead domain. PxFox1 was expressed in different developmental stages and tissues of P. xylostella, highly in the female adult and integument. The PxFox1 knockout mutants were generated by using the CRISPR/Cas9 technique. The significant reduction in the number of eggs and hatching rate was observed in mutants as compared with the wild-type. Meanwhile, an extended larval duration, shortened pupal phase, and reduced adult lifespan were observed in the mutants. Furthermore, PxFox1 mutants displayed significant phenotypic abnormalities such as malformed wings, irregular body segmentation, and reduced body size, highlighting the gene’s essential role in the morphological development. These results showed that PxFox1 is necessary for P. xylostella development, survival, and reproduction. Targeting PxFox1 could provide a potential genetic pest control strategy for managing P. xylostella populations, offering new insights into insect gene regulation for sustainable pest management.
{"title":"Roles of Fox gene in the development and reproduction of diamondback moth","authors":"Anam Noreen Abbas , Mubashir Tariq , Faisal Munir , Uroosa Zaheer , Ibrahim Adam , Muhammad Asad , Guang Yang","doi":"10.1016/j.jinsphys.2025.104868","DOIUrl":"10.1016/j.jinsphys.2025.104868","url":null,"abstract":"<div><div>The forkhead box (Fox) family of transcription factors is essential for controlling physiological functions, metabolism and development in insects. However, the role of the Fox gene in the diamondback moth, <em>Plutella xylostella</em>, a major agricultural pest of cruciferous crops, is still unknown. The purpose of this work was to characterize the <em>PxFox1</em> gene and investigate its role in the reproduction and development of <em>P. xylostella</em>. The <em>Fox</em> gene in <em>P. xylostella (PxFox1</em>) is identified from the <em>P. xylostella</em> genome. The <em>Fox</em> gene was conserved in lepidoptera with the presence of Forkhead domain. <em>PxFox1</em> was expressed in different developmental stages and tissues of <em>P. xylostella</em>, highly in the female adult and integument. The <em>PxFox1</em> knockout mutants were generated by using the CRISPR/Cas9 technique. The significant reduction in the number of eggs and hatching rate was observed in mutants as compared with the wild-type. Meanwhile, an extended larval duration, shortened pupal phase, and reduced adult lifespan were observed in the mutants. Furthermore, <em>PxFox1</em> mutants displayed significant phenotypic abnormalities such as malformed wings, irregular body segmentation, and reduced body size, highlighting the gene’s essential role in the morphological development. These results showed that <em>PxFox1</em> is necessary for <em>P. xylostella</em> development, survival, and reproduction. Targeting <em>PxFox1</em> could provide a potential genetic pest control strategy for managing <em>P. xylostella</em> populations, offering new insights into insect gene regulation for sustainable pest management.</div></div>","PeriodicalId":16189,"journal":{"name":"Journal of insect physiology","volume":"165 ","pages":"Article 104868"},"PeriodicalIF":2.3,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144912428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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