Methylbutynol no efficient replacement for the natural pheromone component in Ips typographus

1987 ◽  
Vol 74 (6) ◽  
pp. 292-293 ◽  
Author(s):  
A. Bakke ◽  
J. P. Vit�
Keyword(s):  
Ips Typographus ◽  
Pheromone Component ◽  
Natural Pheromone

Biosynthesis of 2-methyl-3-buten-2-ol, a pheromone component of Ips typographus (Coleoptera: Scolytidae)

1989 ◽  
Vol 19 (2) ◽  
pp. 163-167 ◽  
Author(s):  
B.S. Lanne ◽  
P. Ivarsson ◽  
P. Johnsson ◽  
G. Bergström ◽  
A.-B. Wassgren
Keyword(s):  
Ips Typographus ◽  
Pheromone Component

A compound replacing a natural pheromone component of the spruce bark beetle

1986 ◽  
Vol 73 (10) ◽  
pp. 629-630 ◽  
Author(s):  
H. H. Eidmann ◽  
J. Weslien ◽  
S. Harding ◽  
P. Baeckström ◽  
T. Norin ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Pheromone Component ◽  
Spruce Bark Beetle ◽  
Spruce Bark ◽  
Natural Pheromone

Coincident Stimulation With Pheromone Components Improves Temporal Pattern Resolution in Central Olfactory Neurons

1997 ◽  
Vol 77 (2) ◽  
pp. 775-781 ◽  
Author(s):  
Thomas A. Christensen ◽  
John G. Hildebrand
Keyword(s):  
Stimulus Duration ◽  
Strong Correlation ◽  
Temporal Pattern ◽  
Pheromone Component ◽  
Projection Neurons ◽  
Inhibitory Input ◽  
Olfactory Neurons ◽  
Essential Component ◽  
Pheromone Components ◽  
Pattern Resolution

Christensen, Thomas A. and John G. Hildebrand. Coincident stimulation with pheromone components improves temporal pattern resolution in central olfactory neurons. J. Neurophysiol. 77: 775–781, 1997. Male moths must detect and resolve temporal discontinuities in the sex pheromonal odor signal emitted by a conspecific female moth to orient to and locate the odor source. We asked how sensory information about two key components of the pheromone influences the ability of certain sexually dimorphic projection (output) neurons in the primary olfactory center of the male moth's brain to encode the frequency and duration of discrete pulses of pheromone blends. Most of the male-specific projection neurons examined gave mixed postsynaptic responses, consisting of an early suppressive phase followed by activation of firing, to stimulation of the ipsilateral antenna with a blend of the two behaviorally essential pheromone components. Of 39 neurons tested, 33 were excited by the principal (most abundant) pheromone component but inhibited by another, less abundant but nevertheless essential component of the blend. We tested the ability of each neuron to encode intermittent pheromonal stimuli by delivering trains of 50-ms pulses of the two-component blend at progressively higher rates from 1 to 10 per second. There was a strong correlation between 1) the amplitude of the early inhibitory postsynaptic potential evoked by the second pheromone component and 2) the maximal rate of odor pulses that neuron could resolve ( r = 0.92). Projection neurons receiving stronger inhibitory input encoded the temporal pattern of the stimulus with higher fidelity. With the principal, excitatory component of the pheromone alone as the stimulus, the dynamic range for encoding stimulus intermittency was reduced in nearly 60% of the neurons tested. The greatest reductions were observed in those neurons that could be shown to receive the strongest inhibitory input from the second behaviorally essential component of the blend. We also tested the ability of these neurons to encode stimulus duration. Again there was a strong correlation between the strength of the inhibitory input to a neuron mediated by the second pheromone component and that neuron's ability to encode stimulus duration. Neurons that were strongly inhibited by the second component could accurately encode pulses of the blend from 50 to 500 ms in duration ( r = 0.94), but that ability was reduced in neurons receiving little or no inhibitory input ( r = 0.23). This study confirms that certain olfactory projection neurons respond optimally to a particular odor blend rather than to the individual components of the blend. The key components activate opposing synaptic inputs that enable this subset of central neurons to copy the duration and frequency of intermittent odor pulses that are a fundamental feature of airborne olfactory stimuli.

scholarly journals Facultative and obligate diapause phenotypes in populations of the European spruce bark beetle Ips typographus

2021 ◽  
Author(s):  
Martin Schebeck ◽  
Nina Dobart ◽  
Gregory J. Ragland ◽  
Axel Schopf ◽  
Christian Stauffer
Keyword(s):  
Bark Beetle ◽  
Ovarian Development ◽  
Insect Pest ◽  
Gonad Development ◽  
Ips Typographus ◽  
Life Cycles ◽  
Species Variation ◽  
Northern European ◽  
Spruce Bark ◽  
Egg Number

AbstractThe bark beetle Ips typographus is the most destructive insect pest in Norway spruce-dominated forests. Its potential to establish multiple generations per year (multivoltinism) is one major trait that makes this beetle a severe pest. Ips typographus enters diapause to adjust its life cycle to seasonally changing environments. Diapause is characterized by developmental and reproductive arrest; it prolongs generation time and thus affects voltinism. In I. typographus a facultative, photoperiod-regulated diapause in the adult stage has been described. In addition, the presence of an obligate, photoperiod-independent, diapause has been hypothesized. The diapause phenotype has important implications for I. typographus voltinism, as populations with obligate diapausing individuals would be univoltine. To test for the presence of different I. typographus diapause phenotypes, we exposed Central and Northern European individuals to a set of photoperiodic treatments. We used two ovarian traits (egg number and vitellarium size) that are associated with gonad development, to infer reproductive arrest and thus diapause. We found a distinct effect of photoperiod on ovarian development, with variable responses in Central and Northern European beetles. We observed obligate diapausing (independent of photoperiod) individuals in Northern Europe, and both facultative (photoperiod-regulated) as well as obligate diapausing individuals in Central Europe. Our results show within-species variation for diapause induction, an adaptation to match life cycles with seasonally fluctuating environmental conditions. As the diapause phenotype affects the potential number of generations per season, our data are the basis for assessing the risk of outbreaks of this destructive bark beetle.

scholarly journals A potent dauer pheromone component in Caenorhabditis elegans that acts synergistically with other components

2008 ◽  
Vol 105 (38) ◽  
pp. 14288-14292 ◽  
Author(s):  
R. A. Butcher ◽  
J. R. Ragains ◽  
E. Kim ◽  
J. Clardy
Keyword(s):  
Caenorhabditis Elegans ◽  
Pheromone Component

scholarly journals Drivers of Spruce Bark Beetle (Ips typographus) Infestations on Downed Trees after Severe Windthrow

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Ips Typographus ◽  
Wind Damage ◽  
Stem Length ◽  
Local Conditions ◽  
Spruce Bark Beetle ◽  
Management Actions ◽  
Spruce Bark

Research Highlights: Bark beetles are important agents of disturbance regimes in temperate forests, and specifically in a connected wind-bark beetle disturbance system. Large-scale windthrows trigger population growth of the European spruce bark beetle (Ips typographus L.) from endemic to epidemic levels, thereby allowing the killing of Norway spruce trees over several consecutive years. Background and Objectives: There is a lack of evidence to differentiate how outbreaks are promoted by the effects of environmental variables versus beetle preferences of trees from endemic to outbreak. However, little is known about how individual downed-tree characteristics and local conditions such as tree orientation and solar radiation affect beetle colonization of downed trees. Materials and Methods: To answer this question, we investigated the infestation rates and determined tree death categories (uprooted, broken, and stump) in wind-damaged areas in Western Tatra Mts. in Carpathians (Slovakia) from 2014–2016, following a windthrow in May 2014. In total, we investigated 225 trees over eight transects. For every tree, we measured its morphological (tree height, crown characteristics), environmental (solar radiation, terrain conditions, trunk zenith), temporal (time since wind damage), and beetle infestation (presence, location of attack, bark desiccation) parameters. We applied Generalized Additive Mixed Models (GAMM) to unravel the main drivers of I. typographus infestations. Results: Over the first year, beetles preferred to attack broken trees and sun-exposed trunk sides over uprooted trees; the infestation on shaded sides started in the second year along with the infestation of uprooted trees with lower desiccation rates. We found that time since wind damage, stem length, and incident solar radiation increased the probability of beetle infestation, although both solar radiation and trunk zenith exhibited nonlinear variability. Our novel variable trunk zenith appeared to be an important predictor of bark beetle infestation probability. We conclude that trunk zenith as a simple measure defining the position of downed trees over the terrain can anticipate beetle infestation. Conclusions: Our findings contribute to understanding of the bark beetle’s preferences to colonize windthrown trees in the initial years after the primary wind damage. Further, our findings can help to identify trees that are most susceptible to beetle infestation and to prioritize management actions to control beetle population while maintaining biodiversity.

scholarly journals A Tetraene Aldehyde as the Major Sex Pheromone Component of the Promethea Moth (Callosamia promethea (Drury))

2013 ◽  
Vol 39 (10) ◽  
pp. 1263-1272 ◽  
Author(s):  
Rafael Gago ◽  
Jeremy D. Allison ◽  
J. Steven McElfresh ◽  
Kenneth F. Haynes ◽  
Jessica McKenney ◽  
...  
Keyword(s):  
Sex Pheromone ◽  
Pheromone Component ◽  
Callosamia Promethea
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