scholarly journals Initial Location Preference Together with Aggregation Pheromones Regulate the Attack Pattern of Tomicus brevipilosus (Coleoptera: Curculionidae) on Pinus kesiya

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 156 ◽  
Author(s):  
Fu Liu ◽  
Chengxu Wu ◽  
Sufang Zhang ◽  
Xiangbo Kong ◽  
Zhen Zhang ◽  
...  
Keyword(s):  
Aggregation Pheromone ◽  
Early Stage ◽  
Gas Chromatography Mass Spectrometry ◽  
Aggregation Pheromones ◽  
Initial Attack ◽  
Top Down ◽  
Field Bioassay ◽  
Attack Pattern ◽  
Initial Location ◽  
Attack Location

Research Highlights: We found that the initial attack location together with the aggregation pheromones played an important role in mediating the aggressive behavior of T. brevipilosus on P. kesiya. Background and Objectives: T. brevipilosus was identified as an aggressive species, which possesses the ability to kill live, healthy P. kesiya. In this scenario, we study the top-down attack pattern of T. brevipilosus on P. kesiya during the entirety of the reproductive period. Materials and Methods: We investigated the phenology of trunk attack on P. kesiya over a period of three years in Pu’er City, China. The hindguts extracts of the females and males T. brevipilosus were analyzed by coupled gas chromatography-mass spectrometry (GC-MS). The candidate aggregation pheromone compounds of T. brevipilosus were determined through electrophysiology experiments (electroantennographic detection, EAD and electroantennography, EAG), laboratory olfactometer bioassays, and field trapping. Results: we found that the pioneer beetles preferentially infested the crown of P. kesiya at the early stage of attack following spring flight with the later arriving beetles selectively attacking the lower area of the trunk to avoid intraspecific competition and better utilize limited resources, which exhibits a top-down attack pattern. During gallery initiation, the beetles release aggregation pheromones to attract conspecifics to conduct a mass attack. The chemical analyses indicated that the hindgut extracts of gallery-initiating beetles contained a larger amount of myrtenol, cis-verbenol, trans-verbenol, and verbenone. Myrtenol and trans-verbenol were identified as candidate aggregation pheromone compounds. In addition, a blend of these two components with S-(−)-α-pinene and S-(−)-β-pinene attracted more T. brevipilosus individuals in a field bioassay. Conclusions: We concluded that the preference for the initial attack location together with the aggregation pheromones played an important role in mediating the top-down attack pattern of T. brevipilosus on P. kesiya.

scholarly journals Computational analysis of the early stage of cuprous oxide sulphidation: a top-down process

2017 ◽  
Vol 52 (sup1) ◽  
pp. 50-53 ◽  
Author(s):  
J. H. Stenlid ◽  
A. J. Johansson ◽  
C. Leygraf ◽  
T. Brinck
Keyword(s):  
Cuprous Oxide ◽  
Computational Analysis ◽  
Early Stage ◽  
Top Down

scholarly journals Male-Produced (−)-δ-Heptalactone, Pheromone of Fruit Fly Rhagoletis batava (Diptera: Tephritidae), a Sea Buckthorn Berries Pest

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 138
Author(s):  
Vincas Būda ◽  
Laima Blažytė-Čereškienė ◽  
Sandra Radžiutė ◽  
Violeta Apšegaitė ◽  
Patrick Stamm ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Effective Means ◽  
Population Monitoring ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Sea Buckthorn ◽  
Rapid Expansion ◽  
Gas Chromatography Mass Spectrometry ◽  
Aggregation Pheromones ◽  
Detection Analysis

The plantation area of sea buckthorn (Hippophae rhamnoides L.) is expanding in many European countries due to increasing demand for berries, thus creating suitable conditions for the rapid expansion of the fruit fly Rhagoletis batava, a pest of economic importance. To decrease insecticide use, effective means for pest population monitoring are required, including the use of pheromones. Male fruit flies emit (-)-δ-heptalactone as revealed by gas chromatography-mass spectrometry analyses of samples obtained using headspace methods. The two enantiomers of δ-heptalactone were synthesized using enantioselective synthesis. A gas chromatography-electroantennographic detection analysis of both stereoisomers revealed that only (-)-δ-heptalactone elicited electrophysiological responses, whereas no signal was registered to (+)-δ-heptalactone in fruit flies of either sex. In the field assay, traps baited with (-)-δ-heptalactone caught significantly more fruit flies compared with the unbaited traps. Our results are the first to demonstrate the efficacy of (-)-δ-heptalactone as a bait for trapping R. batava. As a behaviorally attractive compound to R. batava fruit flies of both sexes, (-)-δ-heptalactone is attributed to aggregation pheromones. This is the first report of an aggregation pheromone within the genus Rhagoletis.

The Aggregation Pheromone of Metamasius spinolae (Coleoptera: Dryophthoridae) Revisited: Less is More

2020 ◽  
Vol 49 (4) ◽  
pp. 803-809
Author(s):  
Edi A Malo ◽  
Verónica Gutiérrez-Escobar ◽  
Federico Castrejón-Ayala ◽  
Julio C Rojas
Keyword(s):  
Gas Chromatography ◽  
Aggregation Pheromone ◽  
Insect Pest ◽  
Field Evaluation ◽  
Field Trials ◽  
Gas Chromatography Mass Spectrometry ◽  
Behavioral Activity ◽  
Mass Trapping ◽  
Less Is More ◽  
Main Component

Abstract The weevil Metamasius spinolae (Gyllenhal) is the most important insect pest of cultivated prickly pear in Mexico. A previous work reported that the pheromone of this weevil species was composed by three components. In this study, we reinvestigated the aggregation pheromone of M. spinolae using gas chromatography-electroantennography and gas chromatography–mass spectrometry to locate and identify new potential pheromonal compounds. The behavioral activity of identified compounds was evaluated in laboratory and field trials. Metamasius spinolae males released four compounds: 2-methyl-4-heptanone, 6-methyl-2-hepten-4-one, 2-methyl-4-octanone, and 2-hydroxy-2-methyl-4-heptanone. In the laboratory assays, depending on the concentration, the compounds were attractive, neutral, or repellent to M. spinolae. Field evaluation showed that traps baited with 2-hydroxy-2-methyl-4-heptanone singly or in most of the binary or tertiary blends where this compound was present captured a higher number of M. spinolae compared to live males and the other compounds identified. In conclusion, our results indicate that 2-hydroxy-2-methyl-4-heptanone is the main component of the aggregation pheromone of M. spinolae. We suggest that this compound should be used for developing a monitoring or a mass-trapping system for M. spinolae.

scholarly journals Beliefs in being unlucky and deficits in executive functioning: An ERP study

2014 ◽  
Author(s):  
Jaime Martin del Campo ◽  
John Maltby ◽  
Giorgio Fuggetta
Keyword(s):  
Neural Activity ◽  
Attentional Control ◽  
Time Window ◽  
Early Stage ◽  
Selection Process ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Event Related Potential ◽  
Control Group ◽  
Top Down

The present study tested the Dysexecutive Luck hypothesis by examining whether deficits in the early stage of top down attentional control led to an increase of neural activity in later stages of response related selection process among those who thought themselves to be unlucky. Individuals with these beliefs were compared to a control group using an Event-Related Potential (ERP) measure assessing underlying neural activity of semantic inhibition while completing a Stroop test. Results showed stronger main interference effects in the former group, via greater reaction times and a more negative distributed scalp late ERP component during incongruent trials in the time window of 450 – 780 ms post stimulus onset. Further, less efficient maintenance of task set among the former group was associated with greater late ERP response-related activation to compensate for the lack of top-down attentional control. These findings provide electrophysiological evidence to support the Dysexecutive Luck hypothesis.

scholarly journals Different Top-Down Goals Modulate Early Stage of Attention Bias: Irrelevant Task Suppresses the N170 of Automatic Attention Allocation to Threat Faces

2020 ◽  
Author(s):  
Haoran Dou ◽  
Limei Liang ◽  
Jie Ma ◽  
Jiachen Lu ◽  
Wenhai Zhang ◽  
...  
Keyword(s):  
Early Stage ◽  
Attention Bias ◽  
Neural Mechanism ◽  
Attention Allocation ◽  
Top Down ◽  
Neutral Face ◽  
Fearful Face ◽  
Relevant Task ◽  
The Difference ◽  
Automatic Attention

Abstract Recent research has evidenced that stimulus-driven attention bias for threat can be modulated by top-down goals. However, it remains unclear how different top-down goals affect the early stage of attention processing and its early neural mechanism. We collected electroencephalographic data from 28 healthy volunteers during four inconsistent levels in a modified spatial cueing task according to cue validity and task relevance. Our data revealed that reaction time(RT) to the target in the irrelevant task were much slower than that in the relevant task. In the irrelevant task, we did not find the difference between the RTs to the fearful and neutral face. In the relevant task, we found RTs of fearful face were faster than that of neutral face in valid cue condition(weak inconsistent level), whereas the RTs of fearful face were slower than that of neutral face in invalid cue condition(medium inconsistent level). The ERPs results showed that in relevant task(weak, medium inconsistent levels), fearful face in cue position of the target evoked larger N170 amplitudes than neutral face did, whereas this effect was suppressed in irrelevant task(strong, very strong inconsistent levels). Besides, fearful face in cue position of the target also evoked larger vertex positive potential (VPP) amplitudes than the neutral face did in valid cue condition( weak inconsistent level). These results suggest that irrelevant task may inhibit the early attention allocation to the fearful face. Furthermore, the top-down processing modulates the early attention bias for threatening faces.

scholarly journals Mass graphs and their applications in top-down proteomics

2015 ◽  
Author(s):  
Qiang Kou ◽  
Si Wu ◽  
Nikola Tolić ◽  
Ljiljana Pasa-Tolić ◽  
Xiaowen Liu
Keyword(s):  
Mass Spectrometry ◽  
Early Stage ◽  
Gene Mutations ◽  
Mass Spectrometry Data ◽  
Histone H4 ◽  
Top Down ◽  
Data Set ◽  
Alignment Algorithms ◽  
Protein Functions ◽  
Top Down Mass Spectrometry

Although proteomics has made rapid progress in the past decade, researchers are still in the early stage of exploring the world of complex proteoforms, which are protein products with various primary structure alterations resulting from gene mutations, alternative splicing, post-translational modifications, and other biological processes. Proteoform identification is essential to mapping proteoforms to their biological functions as well as discovering novel proteoforms and new protein functions. Top-down mass spectrometry is the method of choice for identifying complex proteoforms because it provides a "bird view" of intact proteoforms. The combinatorial explosion of possible proteoforms, which may result in billions of possible proteoforms for one protein, makes proteoform identification a challenging computational problem. Here we propose a new data structure, called the mass graph, for efficiently representing proteoforms. In addition, we design mass graph alignment algorithms for proteoform identification by top-down mass spectrometry. Experiments on a histone H4 mass spectrometry data set showed that the proposed methods outperformed MS-Align-E in identifying complex proteoforms.

scholarly journals Field Bioassay for Longhorn Pine Sawyer Beetle Monochamus alternatus (Coleoptera: Cerambycidae) in Korea Based on Aggregation Pheromone 2-(Undecyloxy)ethanol

2015 ◽  
Vol 25 (12) ◽  
pp. 1445-1449 ◽  
Author(s):  
Sung-Min Lee ◽  
Do Kyung Hong ◽  
Jongseong Park ◽  
Jinho Lee ◽  
Sei-Heon Jang ◽  
...  
Keyword(s):  
Aggregation Pheromone ◽  
Monochamus Alternatus ◽  
Field Bioassay

Voluntary and Stimulus-Induced Attention Detected as Motion Sensation

Perception ◽  
1993 ◽  
Vol 22 (5) ◽  
pp. 517-526 ◽  
Author(s):  
Okihide Hikosaka ◽  
Satoru Miyauchi ◽  
Shinsuke Shimojo
Keyword(s):  
Information Processing ◽  
Response Bias ◽  
Visual Information ◽  
Stimulus Change ◽  
Early Stage ◽  
Visual Information Processing ◽  
Salient Object ◽  
Voluntary Attention ◽  
Top Down ◽  
Bottom Up

Attention may be drawn passively to a visually salient object. We may also actively direct attention to an object of interest. Do the two kinds of attention, passive and active, interact and jointly influence visual information processing at some neural level? What happens if the passive and active attentions come into conflict? These questions were addressed with the aid of a novel psychophysical technique which reveals an attentional gradient as a sensation of motion in a line which is presented instantaneously. The subjects were asked to direct attention with voluntary effort: to the side opposite to a stimulus change, to an object with a predetermined colour, and to an object moving smoothly. In every case the same motion sensation was induced in the line from the attended side to the unattended side. This voluntary attention, however, can easily and quickly be distracted by a change in the periphery, though it can be regained within a period of 200 to 500 ms. The results suggest that the line motion can be induced in voluntary (top-down) as well as stimulus-driven (bottom-up) situations, thus indicating the truly attentional nature of the effect, rather than it being some kind of retinotopic sensory artifact or response bias. The results also suggest that these two kinds of attention have facilitatory effects acting together on a relatively early stage of visual information processing.

Juvenile-hormone-mediated plasticity of aggregation behaviour and olfactory processing in adult desert locusts

2001 ◽  
Vol 204 (2) ◽  
pp. 249-259 ◽  
Author(s):  
R. Ignell ◽  
F. Couillaud ◽  
S. Anton
Keyword(s):  
Juvenile Hormone ◽  
Aggregation Pheromone ◽  
Schistocerca Gregaria ◽  
Aggregation Pheromones ◽  
Surgical Removal ◽  
Aggregation Behaviour ◽  
The Central Nervous System ◽  
Receptor Neurons ◽  
Different Levels

In desert locusts Schistocerca gregaria, aggregation behaviour is elicited by aggregation pheromones. In this study, we show that the behavioural response to the major and most potent adult aggregation pheromone component, phenylacetonitrile, is age- and juvenile-hormone-dependent. Furthermore, we show that juvenile hormone influences the responsiveness of olfactory interneurons in the antennal lobe to aggregation pheromone, whereas the responsiveness of antennal receptor neurons is not changed. Old locusts and locusts injected with juvenile hormone, in contrast to young locusts and locusts deprived of juvenile hormone through allatectomy, i.e. after surgical removal of the gland producing this hormone, do not display any aggregation behaviour, as indicated by long-term behavioural observations. The lack of positive olfactory-guided behaviour coincides with an impairment of the central olfactory system, which displays a lower number of neurons responding to aggregation pheromone. Indirect and direct actions of juvenile hormone at different levels of the central nervous system may thus contribute to the regulation and modulation of behavioural responsiveness in the locust.

scholarly journals Development of Fast E-nose System for Early-Stage Diagnosis of Aphid-Stressed Tomato Plants

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3480 ◽  
Author(s):  
Shaoqing Cui ◽  
Elvia Adriana Alfaro Inocente ◽  
Nuris Acosta ◽  
Harold. M. Keener ◽  
Heping Zhu ◽  
...  
Keyword(s):  
Sensor Array ◽  
Early Stage ◽  
High Sensitivity ◽  
Gas Chromatography Mass Spectrometry ◽  
Aphid Infestation ◽  
Tomato Plants ◽  
Sensor Performance ◽  
System A ◽  
Volatile Organic ◽  
Sensitive Sensor

An electronic nose (E-nose) system equipped with a sensitive sensor array was developed for fast diagnosis of aphid infestation on greenhouse tomato plants at early stages. Volatile organic compounds (VOCs) emitted by tomato plants with and without aphid attacks were detected using both the developed E-nose system and gas chromatography mass spectrometry (GC-MS), respectively. Sensor performance, with fast sensor responses and high sensitivity, were observed using the E-nose system. A principle component analysis (PCA) indicated accurate diagnosis of aphid-stressed plants compared to healthy ones, with the first two PCs accounting for 86.7% of the classification. The changes in VOCs profiles of the healthy and infested tomato plants were quantitatively determined by GC-MS. Results indicated that a group of new VOCs biomarkers (linalool, carveol, and nonane (2,2,4,4,6,8,8-heptamethyl-)) played a role in providing information on the infestation on the tomato plants. More importantly, the variation in the concentration of sesquiterpene VOCs (e.g., caryophyllene) and new terpene alcohol compounds was closely associated with the sensor responses during E-nose testing, which verified the reliability and accuracy of the developed E-nose system. Tomato plants growing in spring had similar VOCs profiles as those of winter plants, except several terpenes released from spring plants that had a slightly higher intensity.

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