scholarly journals Olfactory and behavioural responses of the blood-sucking bug Triatoma infestans to odours of vertebrate hosts

2001 ◽  
Vol 204 (3) ◽  
pp. 585-597 ◽  
Author(s):  
P. Guerenstein ◽  
P. Guerin
Keyword(s):  
Olfactory Receptors ◽  
Isobutyric Acid ◽  
Triatoma Infestans ◽  
Behavioural Responses ◽  
Air Stream ◽  
Blood Sucking ◽  
Electrophysiological Recordings ◽  
Electrophysiological Responses ◽  
Vertebrate Hosts ◽  
High Firing

Olfactory receptors in basiconic and grooved-peg sensilla on the antenna of fifth-instar Triatoma infestans nymphs respond to host odours. Gas chromatography analyses of host odour extracts coupled to electrophysiological recordings from basiconic sensillum receptors indicate that nonanal is a constituent of sheep wool and chicken feather odour that stimulates one of the receptors in this type of sensillum. Similar analyses revealed isobutyric acid in rabbit odour to be a chemostimulant for one of the receptors in grooved-peg sensilla. The response of the aldehyde receptor was higher to heptanal, octanal and nonanal than to other aliphatic aldehydes, and the response of the acid receptor was higher to isobutyric acid than to other short-chain branched and unbranched acids. The behavioural responses of fifth-instar T. infestans nymphs to nonanal and isobutyric acid in an air-stream on a servosphere indicate that, whereas nonanal causes activation of the bugs, isobutyric acid induces an increase in upwind displacement, i.e. odour-conditioned anemotaxis. Binary mixtures of these compounds did not improve the attraction obtained with isobutyric acid alone. A comparison of the behavioural and electrophysiological responses of the bugs to different amounts of isobutyric acid in air suggests that attraction is obtained at concentrations that causes low-to-moderate increases in the firing rate of the acid-excited receptor in the grooved-peg sensilla, whereas at a dose that evokes relatively high firing rates (>40 Hz) no attraction is obtained.

scholarly journals Identifying Current and Missing Knowledge in the Control of Pyrethroid-Resistant Triatoma infestans, Vector of Chagas Disease

2017 ◽  
Vol 9 (7) ◽  
pp. 47
Author(s):  
Gonzalo Roca Acevedo ◽  
María Inés Picollo
Keyword(s):  
Chagas Disease ◽  
Chemical Control ◽  
Rational Design ◽  
Pyrethroid Resistance ◽  
Triatoma Infestans ◽  
Vector Transmission ◽  
Pyrethroid Insecticides ◽  
Blood Sucking ◽  
Deltamethrin Resistance ◽  
Metabolic Detoxification

Triatomines are blood-sucking bugs that occur mainly in Latin America. They are vectors of Trypanosoma cruzi, the parasite that causes Chagas disease. Chemical control of Chagas disease´s vectors by using pyrethroid insecticides has been highly successful for the elimination of domestic infestation and consequently the reduction of the vector transmission. However, at the beginning of the 2000s a decrease in the effectiveness of the chemical control of triatomines was detected in several areas from Argentina and Bolivia, particularly in the Gran Chaco eco-region.During the last 15 years, several studies demonstrated the evolution of insecticide resistance in Triatoma infestans and established the presence of different toxicological profiles, the autosomal inherence of resistance, the biological costs of deltamethrin resistance, the expression of deltamethrin resistance thorough the embryonic development, and the main mechanisms of resistance (target-site insensitivity and metabolic detoxification of insecticides).The emergence of pyrethroid resistance coupled with the usual difficulties in sustaining adequate rates of insecticide applications emphasize the need of incorporating other tools for integrated vector and disease control, such as the proposal of the organo-phosphorus insecticide fenitrothion as an alternative chemical strategy for the management of the resistance because it was effective against pyrethroid-resistant populations in laboratory and semi-field trials.New studies on the current situation of presence and spread of resistant populations of triatomines and the acceptance of the use of alternative insecticides are critical requirements in the implementation of strategies for the management of resistance and for the rational design of campaigns oriented to reducing the vector transmission of Chagas’ disease.

Filling dynamics of the Brindley’s glands in the blood-sucking bug Triatoma infestans (Hemiptera: Reduviidae)

2014 ◽  
Vol 71 ◽  
pp. 122-127 ◽  
Author(s):  
Florencia Palottini ◽  
Andrés González ◽  
Gabriel Manrique
Keyword(s):  
Triatoma Infestans ◽  
Blood Sucking

The Octopamine Receptor Is a Possible Target for Eugenol-Induced Hyperactivity in the Blood-Sucking Bug Triatoma infestans (Hemiptera: Reduviidae)

2019 ◽  
Author(s):  
Mercedes M N Reynoso ◽  
Alejandro Lucia ◽  
Eduardo N Zerba ◽  
Raúl A Alzogaray
Keyword(s):  
Drosophila Melanogaster ◽  
Latin America ◽  
Essential Oils ◽  
Chagas Disease ◽  
American Cockroach ◽  
Triatoma Infestans ◽  
Aromatic Plants ◽  
Blood Sucking ◽  
Site Of Action ◽  
Octopamine Receptor

Abstract Eugenol is a major component of the essential oils in cloves and other aromatic plants. In insects, it produces toxic effects and repellency, and there is evidence that its site of action is the octopamine receptor. The objective of the present study was to explore whether the octopamine receptor is involved in the hyperactivity produced by eugenol in the blood-sucking bug Triatoma infestans (Klug). This insect is the main vector of Chagas disease in Latin America. Four treatments were topically applied on third instar nymphs: 1) octopamine, 2) eugenol, 3) phentolamine hydrochloride (an antagonist of the octopamine receptor) followed by octopamine, and 4) phentolamine hydrochloride followed by eugenol. Both octopamine and eugenol hyperactivated the nymphs. However, pretreatment with phentolamine hydrochloride inhibited the hyperactivating effect of both compounds. These results are in agreement with previous works on Drosophila melanogaster (Meigen) (Diptera: Drosophilidae) and the American cockroach. They suggest that the octopamine receptor is a possible site of action for eugenol.

scholarly journals Elucidating the Mechanism of Trypanosoma cruzi Acquisition by Triatomine Insects: Evidence from a Large Field Survey of Triatoma infestans

2020 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Aaron W. Tustin ◽  
Ricardo Castillo-Neyra ◽  
Laura D. Tamayo ◽  
Renzo Salazar ◽  
Katty Borini-Mayorí ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Regression Models ◽  
Control Strategies ◽  
Protozoan Parasite ◽  
Etiologic Agent ◽  
Triatoma Infestans ◽  
Large Field ◽  
Blood Sucking ◽  
Triatomine Bugs ◽  
Cruzi Infection

Blood-sucking triatomine bugs transmit the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. We measured the prevalence of T. cruzi infection in 58,519 Triatoma infestans captured in residences in and near Arequipa, Peru. Among bugs from infected colonies, T. cruzi prevalence increased with stage from 12% in second instars to 36% in adults. Regression models demonstrated that the probability of parasite acquisition was roughly the same for each developmental stage. Prevalence increased by 5.9% with each additional stage. We postulate that the probability of acquiring the parasite may be related to the number of feeding events. Transmission of the parasite does not appear to be correlated with the amount of blood ingested during feeding. Similarly, other hypothesized transmission routes such as coprophagy fail to explain the observed pattern of prevalence. Our results could have implications for the feasibility of late-acting control strategies that preferentially kill older insects.

scholarly journals Triatoma infestansApyrases Belong to the 5′-Nucleotidase Family

2004 ◽  
Vol 279 (19) ◽  
pp. 19607-19613 ◽  
Author(s):  
Eric Faudry ◽  
Silene P. Lozzi ◽  
Jaime M. Santana ◽  
Marian D'Souza-Ault ◽  
Sylvie Kieffer ◽  
...  
Keyword(s):  
Blood Platelets ◽  
Gel Filtration ◽  
Peptide Sequencing ◽  
Triatoma Infestans ◽  
Nucleoside Triphosphate ◽  
Blood Sucking ◽  
Tandem Mass Spectroscopy ◽  
Molecular Masses ◽  
Sequence Similarities ◽  
Human Blood Platelets

Apyrases are nucleoside triphosphate-diphosphohydrolases (EC 3.6.1.5) present in a variety of organisms. The apyrase activity found in the saliva of hematophagous insects is correlated with the prevention of ADP-induced platelet aggregation of the host during blood sucking. Purification of apyrase activity from the saliva of the triatomine bugTriatoma infestanswas achieved by affinity chromatography on oligo(dT)-cellulose and gel filtration chromatography. The isolated fraction includes fiveN-glycosylated polypeptides of 88, 82, 79, 68 and 67 kDa apparent molecular masses. The isolated apyrase mixture completely inhibited aggregation of human blood platelets. Labeling with the ATP substrate analogue 5′-p-fluorosulfonylbenzoyladenosine showed that the five species have ATP-binding characteristic of functional apyrases. Furthermore, tandem mass spectroscopy peptide sequencing showed that the five species share sequence similarities with the apyrase fromAedes aegyptiand with 5′-nucleotidases from other species. The complete cDNA of the 79-kDa enzyme was cloned, and its sequence confirmed that it encodes for an apyrase belonging to the 5′-nucleotidase family. The gene multiplication leading to the unusual salivary apyrase diversity inT. infestanscould represent an important mechanism amplifying the enzyme expression during the insect evolution to hematophagy, in addition to an escape from the host immune response, thus enhancing acquisition of a meal by this triatomine vector of Chagas' disease.

scholarly journals Flies Avoid Current Atmospheric CO2 Concentrations

2021 ◽  
Vol 12 ◽  
Author(s):  
Habibe K. Üçpunar ◽  
Ilona C. Grunwald Kadow
Keyword(s):  
18Th Century ◽  
Sensory System ◽  
Olfactory Receptors ◽  
Food Sources ◽  
Behavioral Experiments ◽  
Electrophysiological Recordings ◽  
Vinegar Fly ◽  
Key Odorants ◽  
Receptor Neurons ◽  
Atmospheric Co2 Concentrations

CO2 differs from most other odors by being ubiquitously present in the air animals inhale. CO2 levels of the atmosphere, however, are subject to change. Depending on the landscape, temperature, and time of the year, CO2 levels can change even on shortest time scales. In addition, since the 18th century the CO2 baseline keeps increasing due to the intensive fossil fuel usage. However, we do not know whether this change is significant for animals, and if yes whether and how animals adapt to this change. Most insects possess olfactory receptors to detect the gaseous molecule, and CO2 is one of the key odorants for insects such as the vinegar fly Drosophila melanogaster to find food sources and to warn con-specifics. So far, CO2 and its sensory system have been studied in the context of rotting fruit and other CO2-emitting sources to investigate flies’ response to significantly elevated levels of CO2. However, it has not been addressed whether flies detect and potentially react to atmospheric levels of CO2. By using behavioral experiments, here we show that flies can detect atmospheric CO2 concentrations and, if given the choice, prefer air with sub-atmospheric levels of the molecule. Blocking the synaptic release from CO2 receptor neurons abolishes this choice. Based on electrophysiological recordings, we hypothesize that CO2 receptors, similar to ambient temperature receptors, actively sample environmental CO2 concentrations close to atmospheric levels. Based on recent findings and our data, we hypothesize that Gr-dependent CO2 receptors do not primarily serve as a cue detector to find food sources or avoid danger, instead they function as sensors for preferred environmental conditions.

scholarly journals Rapid Extraction of Emotion Regularities from Complex Scenes in the Human Brain

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Antonio Schettino ◽  
Christopher Gundlach ◽  
Matthias M. Müller
Keyword(s):  
Adaptive Behavior ◽  
Perceptual Load ◽  
Relevant Information ◽  
Complex Scene ◽  
Emotional Cues ◽  
Rapid Extraction ◽  
Electrophysiological Recordings ◽  
Electrophysiological Responses ◽  
Early Visual Cortex ◽  
Scene Processing

Adaptive behavior requires the rapid extraction of behaviorally relevant information in the environment, with particular emphasis on emotional cues. However, the speed of emotional feature extraction from complex visual environments is largely undetermined. Here we use objective electrophysiological recordings in combination with frequency tagging to demonstrate that the extraction of emotional information from neutral, pleasant, or unpleasant naturalistic scenes can be completed at a presentation speed of 167 ms (i.e., 6 Hz) under high perceptual load. Emotional compared to neutral pictures evoked enhanced electrophysiological responses with distinct topographical activation patterns originating from different neural sources. Cortical facilitation in early visual cortex was also more pronounced for scenes with pleasant compared to unpleasant or neutral content, suggesting a positivity offset mechanism dominating under conditions of rapid scene processing. These results significantly advance our knowledge of complex scene processing in demonstrating rapid integrative content identification, particularly for emotional cues relevant for adaptive behavior in complex environments.

Sign in / Sign up

Export Citation Format

Share Document