Sensory structures on the antenna of soldier and worker castes of the termite species Odontotermes parvidens (Termitidae: Isoptera: Blattaria)

2021 ◽  
Author(s):  
Khirod Sankar Das ◽  
Cynthia Bansara Marwein ◽  
K. Chanreila L. Nonglait ◽  
Sudipta Choudhury
Keyword(s):  
Termite Species ◽  
Sensory Structures ◽  
Worker Castes

scholarly journals A technical soda lignin as sole carbon-diet for a higher termite species, Nasutitermes ephratae: insight into the changes in the gut bacterial community and in the lignin phenolic fraction

2020 ◽  
Author(s):  
Edouard Miambi ◽  
My Dung Jusselme ◽  
Laurent Cézard ◽  
Florian Pion ◽  
Stéphanie Baumberger ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Bacterial Community ◽  
Survival Rates ◽  
Gas Chromatography Mass Spectrometry ◽  
Termite Species ◽  
Pyrolysis Gas ◽  
Phenolic Fraction ◽  
Technical Lignin ◽  
Worker Castes ◽  
Soda Lignin

Abstract BackgroundTermites account for natural biomass utilization systems (NBUS) that evolved the ability to overcome the overall recalcitrance of lignins towards lignocellulose transformation processes. With the objective of applying this capacity to the conversion of technical lignins produced by biorefineries, a higher wood-feeding termite species, Nasutitermes ephratae was fed with a commercial grass soda lignin (Protobind 1000, PB1000). The survival rates of Protobind 1000-fed termites were determined as well as changes in the structure of gut bacterial community and in the chemical composition of this technical lignin. ResultsThe ingestion of PB1000 by worker castes of N. ephratae was revealed by Pyrolysis-Gas Chromatography Mass Spectrometry (Py-GC/MS) analyses directly performed on termites. Survival rates were reduced by two –fold in the termites fed with PB1000 compared to controls. The relative abundance of Firmicutes and Bacteroidetes increased in the gut bacterial community of termites fed with PB1000. The digestion of PB1000 by termites triggered an increase in the syringyl-to-guaiacyl (S/G) ratios. These changes in the chemical composition of PB1000 in the gut of termites was marked by a decrease in relative content of free phenolic monomers.ConclusionThis work showed the abilities of digestive tract of a wood-feeding higher termite species, N. ephratae to metabolize the fraction of the volatile phenolic monomers of PB1000. Overall, our results provide insights into the bacterial lineage candidates for development of bacterial inoculum for pretreatment processes in valorization of technical lignin in biorefinery.

Comparative Study of the Fine Morphology of Sensory Receptors in Aspidogaster conchicola and Cotylaspis insignis

1972 ◽  
Vol 30 ◽  
pp. 150-151
Author(s):  
Venita F. Allison ◽  
J. E. Ubelaker ◽  
J. H. Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nervous System ◽  
Osmic Acid ◽  
Sensory Receptors ◽  
Transmission Electron ◽  
Sensory Structures ◽  
Fine Morphology ◽  
Scanning Electron

It has been suggested that parasitism results in a reduction of sensory structures which concomitantly reflects a reduction in the complexity of the nervous system. The present study tests this hypothesis by examining the fine morphology and the distribution of sensory receptors for two species of aspidogastrid trematodes by transmission and scanning electron microscopy. The species chosen are an ectoparasite, Cotylaspis insignis and an endoparasite, Aspidogaster conchicola.Aspidogaster conchicola and Cotylaspis insignis were obtained from natural infections of clams, Anodonta corpulenta and Proptera purpurata. The specimens were fixed for transmission electron microscopy in phosphate buffered paraformaldehyde followed by osmic acid in the same buffer, dehydrated in an ascending series of ethanol solutions and embedded in Epon 812.

MANAGEMENT OF ELECTROPHYSICAL CHARACTERISTICS OF THE POLYSILICON SENSORY STRUCTURES OF MICROELECTRONIC SENSORS

2019 ◽  
Author(s):  
P. G. Mikhailov ◽  
◽  
T. A. Glebova ◽  
A. V. Sokolov ◽  
A. U. Analieva ◽  
...  
Keyword(s):  
Sensory Structures

scholarly journals When SEM becomes a deceptive tool of analysis: the unexpected discovery of epidermal glands with stalked ducts on the ultimate legs of geophilomorph centipedes

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Andy Sombke ◽  
Carsten H. G. Müller
Keyword(s):  
Sensory Function ◽  
Sexually Dimorphic ◽  
Non Invasive ◽  
Defensive Role ◽  
Transmission Electron ◽  
Sensory Structures ◽  
Taxonomic Studies ◽  
Invasive Techniques ◽  
Epidermal Glands ◽  
Intrinsic Musculature

Abstract Background The jointed appendage is a key novelty in arthropod evolution and arthropod legs are known to vary enormously in relation to function. Among centipedes, the ultimate legs always are distinctly different from locomotory legs, and different centipede taxa evolved different structural and functional modifications. In Geophilomorpha (soil centipedes), ultimate legs do not participate in locomotion and were interpret to serve a sensory function. They can be sexually dimorphic and in some species, male ultimate legs notably appear “hairy”. It can be assumed that the high abundance of sensilla indicates a pronounced sensory function. This study seeks for assessing the sensory diversity, however, documents the surprising and unique case of an extensive glandular epithelium in the ultimate legs of three phylogenetically distant species. Results The tightly aggregated epidermal glands with stalked ducts – mistakenly thought to be sensilla – were scrutinized using a multimodal microscopic approach comprising histology as well as scanning and transmission electron microscopy in Haplophilus subterraneus. Hence, this is the first detailed account on centipede ultimate legs demonstrating an evolutionary transformation into a “secretory leg”. Additionally, we investigated sensory structures as well as anatomical features using microCT analysis. Contrary to its nomination as a tarsus, tarsus 1 possesses intrinsic musculature, which is an indication that this podomere might be a derivate of the tibia. Discussion The presence and identity of ultimate leg associated epidermal glands with stalked ducts is a new discovery for myriapods. A pronounced secretory as well as moderate sensory function in Haplophilus subterraneus can be concluded. The set of characters will improve future taxonomic studies, to test the hypotheses whether the presence of these specialized glands is a common feature in Geophilomorpha, and that tarsus 1 may be a derivate of the tibia. As the number of epidermal glands with stalked ducts is sexually dimorphic, their function might be connected to reproduction or a sex-specific defensive role. Our results, in particular the unexpected discovery of ‘glandular hairs’, may account for a striking example for how deceptive morphological descriptions of epidermal organs may be, if based on non-invasive techniques alone.

scholarly journals Transcriptomic analyses of the termite, Cryptotermes secundus, reveal a gene network underlying a long lifespan and high fecundity

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Silu Lin ◽  
Jana Werle ◽  
Judith Korb
Keyword(s):  
Life History ◽  
Social Insects ◽  
Social Communication ◽  
Gene Network ◽  
Social Insect ◽  
Nutrient Sensing ◽  
Model Organisms ◽  
Termite Species ◽  
High Fecundity ◽  
Trade Off

AbstractOrganisms are typically characterized by a trade-off between fecundity and longevity. Notable exceptions are social insects. In insect colonies, the reproducing caste (queens) outlive their non-reproducing nestmate workers by orders of magnitude and realize fecundities and lifespans unparalleled among insects. How this is achieved is not understood. Here, we identified a single module of co-expressed genes that characterized queens in the termite species Cryptotermes secundus. It encompassed genes from all essential pathways known to be involved in life-history regulation in solitary model organisms. By manipulating its endocrine component, we tested the recent hypothesis that re-wiring along the nutrient-sensing/endocrine/fecundity axis can account for the reversal of the fecundity/longevity trade-off in social insect queens. Our data from termites do not support this hypothesis. However, they revealed striking links to social communication that offer new avenues to understand the re-modelling of the fecundity/longevity trade-off in social insects.

scholarly journals Fine Morphology of Antennal and Ovipositor Sensory Structures of the Gall Chestnut Wasp, Dryocosmus kuriphilus

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 231
Author(s):  
Milos Sevarika ◽  
Marco Valerio Rossi Stacconi ◽  
Roberto Romani
Keyword(s):  
Ultrastructural Organization ◽  
Antennal Sensilla ◽  
Dryocosmus Kuriphilus ◽  
Transmission Electron ◽  
Significant Damage ◽  
Sensory Structures ◽  
Host Plant Location ◽  
Oviposition Sites ◽  
Fine Morphology

Dryocosmus kuriphilus is a gall-inducing insect, which can cause significant damage on plants of the genus Castanea Mill., 1754. Antennae and ovipositor are the main sensory organs involved in the location of suitable oviposition sites. Antennal sensilla are involved in the host plant location, while ovipositor sensilla assess the suitability of the ovipositional bud. On both organs, diverse sensillar organs are present. Here, the distribution and ultrastructural organization of the sensilla were investigated by scanning and transmission electron microscopy. The antennae of D. kuriphilus are filiform and composed of 14 antennomeres, with the distal flagellomere bearing the highest number of sensilla. On the antennae, 6 sensilla types were found; sensilla chaetica, campaniformia, coeloconica-I, coeloconica-II, trichoidea and placoidea. The sensilla placoidea and trichoidea were the most abundant types. On the external walls of the ovipositor, gustatory and mechanoreceptive sensilla were observed. Internally, the egg channel hosted two additional sensory structures. The putative functional role of each sensilla in the context of insect’s ecology is discussed as well as the ovipositional mechanism used by this insect.

scholarly journals Concentration-Dependent Feeding Deterrence to 20-Hydroxyecdysone for Three Subterranean Termite Species (Blattodea: Rhinotermitidae)

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 218
Author(s):  
Lucas Carnohan ◽  
Sang-Bin Lee ◽  
Nan-Yao Su
Keyword(s):  
Reticulitermes Flavipes ◽  
Coptotermes Formosanus ◽  
Subterranean Termite ◽  
Choice Test ◽  
Molting Hormone ◽  
Feeding Deterrence ◽  
Insect Feeding ◽  
Substrate Consumption ◽  
Termite Species ◽  
Potential Methods

Effective active ingredients in toxicant bait formulations must be non-deterrent to insect feeding behavior at lethal concentrations. This study evaluated feeding deterrence for Coptotermes formosanus Shiraki, C. gestroi (Wasmann), and Reticulitermes flavipes (Kollar) when provided access to cellulose impregnated with various concentrations of the insect molting hormone, 20-hydroxyecdysone (20E). Termites were exposed to 20E concentrations of 200, 500, 1000 and 2000 ppm and to noviflumuron at 5000 ppm in a 24 h choice-test, and the mass of substrate consumption from treated and untreated media pads was compared for each treatment. 20E feeding deterrence was detected at 500, 1000 and 2000 ppm for C. gestroi, and at 2000 ppm for C. formosanus. No significant differences in consumption of treated and untreated substrate was detected at any concentration for R. flavipes. Potential methods for reducing deterrence are discussed.

scholarly journals Sensory processing and corollary discharge effects in posterior caudal lobe Purkinje cells in a weakly electric mormyrid fish

2014 ◽  
Vol 112 (2) ◽  
pp. 328-339 ◽  
Author(s):  
Karina Alviña ◽  
Nathaniel B. Sawtell
Keyword(s):  
Purkinje Cells ◽  
Mossy Fiber ◽  
Corollary Discharge ◽  
Electrophysiological Response ◽  
Caudal Lobe ◽  
Mormyrid Fish ◽  
Sensory Structures ◽  
Proprioceptive Inputs ◽  
Weakly Electric ◽  
Complete Account

Although it has been suggested that the cerebellum functions to predict the sensory consequences of motor commands, how such predictions are implemented in cerebellar circuitry remains largely unknown. A detailed and relatively complete account of predictive mechanisms has emerged from studies of cerebellum-like sensory structures in fish, suggesting that comparisons of the cerebellum and cerebellum-like structures may be useful. Here we characterize electrophysiological response properties of Purkinje cells in a region of the cerebellum proper of weakly electric mormyrid fish, the posterior caudal lobe (LCp), which receives the same mossy fiber inputs and projects to the same target structures as the electrosensory lobe (ELL), a well-studied cerebellum-like structure. We describe patterns of simple spike and climbing fiber activation in LCp Purkinje cells in response to motor corollary discharge, electrosensory, and proprioceptive inputs and provide evidence for two functionally distinct Purkinje cell subtypes within LCp. Protocols that induce rapid associative plasticity in ELL fail to induce plasticity in LCp, suggesting differences in the adaptive functions of the two structures. Similarities and differences between LCp and ELL are discussed in light of these results.

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