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Scanning electron microscopy of the antennal sensilla in female Culicoides paraensis (Diptera: Ceratopogonidae)
Felippe-Bauer, M. L.;Bauer, P. G.;Silva Filho, F. C.;
Memórias do Instituto Oswaldo Cruz , 1989, DOI: 10.1590/S0074-02761989000400002
Abstract: we studied by sanning electron microscopy the number, types, structure and distribution of the antennal sensilla of the medical important ceratopogonid culicoides paraensis (goeldi). there are about 174 sense organs on the antenmal flagellum which are classified as sensilla chaetica; sharp-tipped and blunt-tipped (type i and ii) sensilla trichodea; sensilla basiconica; sensilla coeloconica; sensilla ampullacea and styloconic-type sensilla. the role of antennal sensory organs are discussed regarding the host preference of the biting midges.
Transcriptomic Immune Response of Tenebrio molitor Pupae to Parasitization by Scleroderma guani  [PDF]
Jia-Ying Zhu, Pu Yang, Zhong Zhang, Guo-Xing Wu, Bin Yang
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054411
Abstract: Background Host and parasitoid interaction is one of the most fascinating relationships of insects, which is currently receiving an increasing interest. Understanding the mechanisms evolved by the parasitoids to evade or suppress the host immune system is important for dissecting this interaction, while it was still poorly known. In order to gain insight into the immune response of Tenebrio molitor to parasitization by Scleroderma guani, the transcriptome of T. molitor pupae was sequenced with focus on immune-related gene, and the non-parasitized and parasitized T. molitor pupae were analyzed by digital gene expression (DGE) analysis with special emphasis on parasitoid-induced immune-related genes using Illumina sequencing. Methodology/Principal Findings In a single run, 264,698 raw reads were obtained. De novo assembly generated 71,514 unigenes with mean length of 424 bp. Of those unigenes, 37,373 (52.26%) showed similarity to the known proteins in the NCBI nr database. Via analysis of the transcriptome data in depth, 430 unigenes related to immunity were identified. DGE analysis revealed that parasitization by S. guani had considerable impacts on the transcriptome profile of T. molitor pupae, as indicated by the significant up- or down-regulation of 3,431 parasitism-responsive transcripts. The expression of a total of 74 unigenes involved in immune response of T. molitor was significantly altered after parasitization. Conclusions/Significance obtained T. molitor transcriptome, in addition to establishing a fundamental resource for further research on functional genomics, has allowed the discovery of a large group of immune genes that might provide a meaningful framework to better understand the immune response in this species and other beetles. The DGE profiling data provides comprehensive T. molitor immune gene expression information at the transcriptional level following parasitization, and sheds valuable light on the molecular understanding of the host-parasitoid interaction.
Morphometry and distribution of sensilla on the antennae of Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae)
Bisotto-de-Oliveira, R;Redaelli, LR;Sant'ana, J;
Neotropical Entomology , 2011, DOI: 10.1590/S1519-566X2011000200009
Abstract: antennal sensilla of anastrepha fraterculus (wied.) were examined using scanning electron microscopy. in the flagellum, there are trichoid, basiconic, clavate type i and ii, and styloconic sensilla and microtrichia. only microtrichiae and chaetica sensilla were observed in the scape and pedicel. the number of sensilla in the flagellum was similar between sexes. at the apex there was a higher density of trichoid and an absence of clavate sensilla, while basiconic sensilla were more abundant in the proximal region.
Patterns of antenal sensilla of Panstrongylus megistus from three Brazilian states
Villela, MM;Catalá, S;Juberg, J;Silva, IG;Dias, JCP;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000700002
Abstract: the objective of the present study was to analyze and describe the phenotype of the antennal sensilla of panstrongylus megistus, one of the epidemiologically most important species of triatomines in brazil. specimens from the brazilian states of goiás (go), minas gerais (mg), and rio grande do sul (rs) were compared, based on studies of four types of sensilla on three antennal segments: thick-walled trichoid (tk), thin-walled trichoid (th), bristles (br), and basiconica (ba). discriminant analysis allowed the separation of the rs specimens from those of go and mg. multivariate discriminant analysis demonstrated that the sensilla of males differed from those of females, the variables with greatest weight being the ba of all three segments and the tk of flagellum 1. the basiconica sensilla were significantly more abundant in females, on all three segments. antennal sensilla patterns also demonstrated significant differences among p. megistus specimens.
Relationship between antennal sensilla pattern and habitat in six species of Triatominae
Carbajal de la Fuente, AL;Catalá, S;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000800010
Abstract: in order to determine if habitat similarity is correlated with a similarity of sensilla pattern, we analyzed six species of triatominae present in two biogeographic regions of brazil: the "caatinga" and the "cerrado". in broad terms triatoma infestans (cerrado) and t. brasiliensis (caatinga) are found in human domiciles, t. sordida (cerrado) and t. pseudomaculata (caatinga) colonize peridomestic habitats, and rhodnius neglectus (cerrado) and r. nasutus (caatinga) inhabit palm tree crowns. the number and distribution of four sensilla types (bristles, thin and thick walled trichoidea, and basiconica) were compared in these species. sexual dimorphism of sensilla patterns was noted in t. sordida, t. brasiliensis and t. pseudomaculata. a principal component analysis showed three main groups: (i) species that live in the palms, (ii) domiciliated species and (iii) those living in the peridomestic habitat. t. infestans almost exclusively domestic, was placed at the centre of the canonical map and some individuals of other species overlapped there. these results support the idea that the patterns of antennal sensilla are sensitive indicators of adaptive process in triatominae. we propose that those species that inhabit less stable habitats possess more types of sensilla on the pedicel, and higher number of antennal sensilla.
Relationship between antennal sensilla pattern and habitat in six species of Triatominae  [cached]
Carbajal de la Fuente AL,Catalá S
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: In order to determine if habitat similarity is correlated with a similarity of sensilla pattern, we analyzed six species of Triatominae present in two biogeographic regions of Brazil: the "caatinga" and the "cerrado". In broad terms Triatoma infestans (cerrado) and T. brasiliensis (caatinga) are found in human domiciles, T. sordida (cerrado) and T. pseudomaculata (caatinga) colonize peridomestic habitats, and Rhodnius neglectus (cerrado) and R. nasutus (caatinga) inhabit palm tree crowns. The number and distribution of four sensilla types (bristles, thin and thick walled trichoidea, and basiconica) were compared in these species. Sexual dimorphism of sensilla patterns was noted in T. sordida, T. brasiliensis and T. pseudomaculata. A principal component analysis showed three main groups: (i) species that live in the palms, (ii) domiciliated species and (iii) those living in the peridomestic habitat. T. infestans almost exclusively domestic, was placed at the centre of the canonical map and some individuals of other species overlapped there. These results support the idea that the patterns of antennal sensilla are sensitive indicators of adaptive process in Triatominae. We propose that those species that inhabit less stable habitats possess more types of sensilla on the pedicel, and higher number of antennal sensilla.
Antennal sensilla of two female anopheline sibling species with differing host ranges
R Jason Pitts, Laurence J Zwiebel
Malaria Journal , 2006, DOI: 10.1186/1475-2875-5-26
Abstract: Scanning electron and light microscopy were used to examine the antennae ultrastructures of adult female An. gambiae s.s. and An. quadriannulatus. Sensory structures, called sensilla, were categorized and counted; their distributions are reported here as well as densities calculated for each species.Both An. gambiae s.s. and An. quadriannulatus bear five classes of sensilla on their antennae: chaetica (bristles), trichodea (hairs), basiconica (pegs), coeloconica (pitted pegs), and ampullacea (pegs in tubes). Female An. quadriannulatus antennae have approximately one-third more sensilla, and a proportionally larger surface area, than female An. gambiae s.s. antennae.The same types of sensilla are found on the antennae of both species. While An. quadriannulatus has greater numbers of each sensilla type, sensilla densities are very similar for each species, suggesting that other factors may be more important to such olfactory-driven behaviours as host preference.Odors are the principle sensory signals that direct female mosquitoes to their preferred blood meal hosts [1,2]. Antennae of adult mosquitoes bear numerous sensory structures called sensilla, which are the physical sites of chemical detection. Within sensilla, olfactory signal transduction relies on odorant receptor proteins localized on the dendritic membranes of olfactory receptor neurons to initiate the events that ultimately lead to the perception of both the quality and the quantity of odors. Behavioural responses to volatile cues, including host finding by female mosquitoes, are critical components of vectorial capacity, the ability of an insect to transmit disease [2]. Two closely related mosquito sibling species, An. gambiae s.s. and An. quadriannulatus, display very different patterns of blood meal host preference. An. gambiae s.s. exhibits a high degree of anthropophily, while An. quadriannulatus exhibits strong zoophily [2]. Indeed, the strong preference for human blood meals by An. gambiae s.s. fema
Distribution of mechanoreceptive sensilla and their functions in the defensive behavior of tenebrionid beetle pupae
Kurauchi T, Nakamura T, Toh Y, Ichikawa T
Open Access Insect Physiology , 2011, DOI: http://dx.doi.org/10.2147/OAIP.S18079
Abstract: tribution of mechanoreceptive sensilla and their functions in the defensive behavior of tenebrionid beetle pupae Original Research (1907) Total Article Views Authors: Kurauchi T, Nakamura T, Toh Y, Ichikawa T Published Date May 2011 Volume 2011:3 Pages 13 - 25 DOI: http://dx.doi.org/10.2147/OAIP.S18079 Toshiaki Kurauchi1, Tatsuya Nakamura1, Yoshihiro Toh2, Toshio Ichikawa2 1Basic Biology, Graduate School of System Life Sciences, 2Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan Background: Pupae of the tenebrionid beetles exhibit different defensive behaviors in response to tactile stimulation of different parts of their bodies. Little is known about the mechanosensory mechanisms that initiate these defensive behaviors. To understand the mechanisms, we examined the distribution and function of the mechanoreceptive sensilla on the pupal body of Zophobas atratus. Methods: The sensilla on the surface of the pupal cuticle were observed using light and scanning electron microscopy. The tactile sensitivity of various parts of the pupal body was tested using three probes with different bending forces. The function of particular sensilla was examined by stimulating them electrically. Results: Hair (trichoid) sensilla were classified according to their length, ie, long hair sensilla (80–200 μm) were mostly located on the lateral regions of each body segment and short hairs (5–50 μm) were distributed across almost the entire surface of the pupal body, except for the elytra and intersegmental membrane of the abdomen. In addition to the trichoid sensilla, almost all parts of the pupal body, including the elytra and the intersegmental membrane, had campaniform sensilla (CS) with a dome-like structure in the cuticular layer; these sensilla detected strains in the cuticle. The CS were concentrated on the articulation of segmented appendages and the lateral region of the intersegmental membrane. The defensive response (abdominal rotation) to electrical stimulation was greatly reduced when afferent nerves from CS clustered on the apical region of the tarsus were transected. Conclusion: CS may be responsible for the high sensitivity of pupal appendages to tactile stimuli. The CS located on the appendages and abdominal intersegmental membrane may trigger specific and effective defensive behaviors. Both types of mechanoreceptive sensilla may enable pupal perception of the external environment, including the location of potentially harmful stimuli, and are involved in the control of defensive posture and movement.
Maternal Care in the Parasitoid Sclerodermus harmandi (Hymenoptera: Bethylidae)  [PDF]
Zhenjie Hu, Xingli Zhao, Yisong Li, Xiaoxia Liu, Qingwen Zhang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0051246
Abstract: Guarding behavior is an important activity in sub-social insects, and this behavior is believed to improve the survival of offspring. Sclerodermus harmandi (Hymenoptera: Bethylidae) is one of most powerful epizoic parasitoid wasps, and it parasitizes Monochamus alternatus, a borer of wood and also the primary vector of the pinewood nematode Bursaphelenchus xylophilus. After laying eggs, S. harmandi exhibits sub-social behavior involving the female tending the clutch of eggs until emergence (guarding behavior). In this study, the benefits of this maternal care with regard to improvements in the survival of offspring were examined. During the developmental stages, only offspring in the egg and larval stages were sensitive to guarding behavior. A positive relationship between the survival of the offspring and the duration of guarding was detected with logistic regression analysis. A female replacement experiment demonstrated that multiparous S. harmandi stepmothers showed guarding behavior and that this behavior improved the survival of the immature offspring, whereas nulliparous stepmothers failed to exhibit the guarding behavior. These results indicate that S. harmandi females display maternal care and that this behavior improves the survival of offspring.
Analysis of antenal sensilla patterns of Rhodnius prolixus from Colombia and Venezuela
Esteban, Lyda;Angulo, Víctor Manuel;Feliciangeli, M Dora;Catalá, Silvia;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000800014
Abstract: antennal sensilla patterns were used to analyze population variation of domestic rhodnius prolixus from six departments and states representing three biogeographical regions of colombia and venezuela. discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between r. prolixus populations east and west of the andean cordillera. the distribution of thick and thin-walled trichoids on the second flagellar segment also showed correlation with latitude, but this was not seen in the patterns of other sensilla. the results of the sensilla patterns appear to be reflecting biogeographic features or population isolation rather than characters associated with different habitats and lend support to the idea that domestic r. prolixus originated in the eastern region of the andes.
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