Inducible Defenses in Cladocera:

2021 ◽  
pp. 177-202
Author(s):  
RALPH TOLLRIAN ◽  
STANLEY I. DODSON
Keyword(s):  
Inducible Defenses

scholarly journals Density-dependent adjustment of inducible defenses

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Ralph Tollrian ◽  
Sonja Duggen ◽  
Linda C. Weiss ◽  
Christian Laforsch ◽  
Michael Kopp
Keyword(s):  
Inducible Defenses ◽  
Density Dependent

scholarly journals Inducible Defenses with a "Twist": Daphnia barbata Abandons Bilateral Symmetry in Response to an Ancient Predator

PLoS ONE ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. e0148556 ◽  
Author(s):  
Quirin Herzog ◽  
Max Rabus ◽  
Bernard Wolfschoon Ribeiro ◽  
Christian Laforsch
Keyword(s):  
Bilateral Symmetry ◽  
Inducible Defenses

Rapid evolution of constitutive and inducible defenses against an invasive predator

Ecology ◽  
2014 ◽  
Vol 95 (6) ◽  
pp. 1520-1530 ◽  
Author(s):  
Ana L. Nunes ◽  
Germán Orizaola ◽  
Anssi Laurila ◽  
Rui Rebelo
Keyword(s):  
Rapid Evolution ◽  
Inducible Defenses ◽  
Invasive Predator

scholarly journals Inducible morphological defense in Daphnia pulex: food quantity effects revised

2020 ◽  
Author(s):  
Sandra Klintworth ◽  
Eric von Elert
Keyword(s):  
Chemical Cues ◽  
Daphnia Pulex ◽  
Food Concentration ◽  
Bacterial Degradation ◽  
Inducible Defenses ◽  
Chemical Cue ◽  
High Food ◽  
Food Quantity ◽  
Morphological Defense ◽  
Food Concentrations

Abstract In aquatic systems, organisms largely rely on chemical cues to perceive information about the presence of predators or prey. Daphnia recognize the presence of the predatory larvae of Chaoborus via a chemical cue, emitted by the larvae, a so-called kairomone. Upon recognition, neckteeth, an alteration of the carapace, are induced in Daphnia that reduce predation rates of Chaoborus. Neckteeth induction was often reported to entail costs. In a previous study, food quantity affected the level of neckteeth induction, with stronger neckteeth induction at low food concentrations and weak induction at high food concentrations. However, reducing neckteeth induction at high food quantities seems to be maladaptive and not in accordance with the concept that inducible defenses are associated with costs. Here, we hypothesized that weaker neckteeth induction at high food concentrations is caused by increased bacterial degradation of the kairomone. More specifically, we assume that higher algal food concentration is associated with higher bacterial abundances, which degrade the kairomone during the experiment. We tested our hypothesis by treating food algae with antibiotics before providing them as food to Daphnia. Antibiotics reduced bacterial abundances at high and low food concentrations. Reduced bacterial abundances at high food concentrations led to the same level of neckteeth induction as at low food concentrations. A linear regression revealed a significant correlation of neckteeth induction to bacterial abundances. We therefore conclude that differences in neckteeth induction at different food concentrations are not caused by the food quantity effects but by differences in bacterial degradation of the kairomone.

Efficacy of tree defense physiology varies with bark beetle population density: a basis for positive feedback in eruptive species

2011 ◽  
Vol 41 (6) ◽  
pp. 1174-1188 ◽  
Author(s):  
Celia K. Boone ◽  
Brian H. Aukema ◽  
Jörg Bohlmann ◽  
Allan L. Carroll ◽  
Kenneth F. Raffa
Keyword(s):  
Bark Beetle ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Behavioral Plasticity ◽  
Critical Threshold ◽  
Inducible Defenses ◽  
Positive Feedbacks ◽  
Level Densities ◽  
Chemical Attributes ◽  
Lodgepole Pines

We evaluated the ability of constitutive and inducible defenses to protect trees and restrict herbivore reproduction across the endemic, incipient (i.e., transitory), and eruptive phases of a native bark beetle species. Host defenses were major constraints when mountain pine beetle (Dendroctonus ponderosae Hopkins) populations were low, but inconsequential after stand-level densities surpassed a critical threshold. We annually examined all lodgepole pines (Pinus contorta Douglas var. latifolia) in six 12–18 ha stands for 3–6 years for beetle attack and establishment as beetle densities progressed through various population phases. We also assayed a suite of tree physiological and chemical attributes and related them to subsequent attacks during that year. Rapidly inducible defenses appeared more important than constitutive defenses, and total monoterpenes were more important than particular constituents. Trees that exude more resin and accumulate higher monoterpene concentrations in response to simulated attack largely escaped natural attacks when populations were low. In stands where beetles had reached incipient densities, these defenses were ineffective. Larger diameter trees had more pronounced defenses than smaller diameter trees. As populations increased, beetles selected increasingly larger, more resource-rich trees, despite their better defenses. When populations were too low for cooperative attack, beetles exploited trees weakened by lower-stem insects. Behavioral plasticity allows beetles to persist at endemic levels until conditions shift, after which positive feedbacks predominate.

Qualitative effects of inducible defenses in trophic chains

2007 ◽  
Vol 4 (1-2) ◽  
pp. 58-70 ◽  
Author(s):  
Rodrigo Ramos-Jiliberto ◽  
Leslie Garay-Narváez
Keyword(s):  
Inducible Defenses ◽  
Trophic Chains

Micronutrient Fertilization of Greenhouse Cucumbers Mitigates Pirimicarb Resistance in Aphis gossypii (Hemiptera: Aphididae)

2020 ◽  
Vol 113 (6) ◽  
pp. 2864-2872
Author(s):  
Mohammad Homayoonzadeh ◽  
Mojtaba Esmaeily ◽  
Khalil Talebi ◽  
Hossein Allahyari ◽  
Jamasb Nozari ◽  
...  
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Aphis Gossypii ◽  
Cucumber Plant ◽  
Guaiacol Peroxidase ◽  
Inducible Defenses ◽  
Plant Interactions ◽  
Glutathione S Transferase ◽  
Fold Reduction ◽  
Biological Performance ◽  
Carbohydrate Contents

Abstract The nutritional status of host plants can have direct impacts on herbivore physiology and insect–plant interactions. We investigated the effect of micronutrients, including manganese, iron, zinc, and copper, on cucumber plant physiology, and on the biology and physiology of a strain of Aphis gossypii Glover selected over 12 generations to be resistant to pirimicarb. The micronutrient treatment increased the activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase in cucumber plants, and also increased levels of total phenolics, hydrogen peroxide, salicylic acid, and total chlorophyl, whereas malondialdehyde levels were unaffected. Pirimicarb-resistant cotton aphids that fed on micronutritient-amended cucumber plants expressed significantly decreased levels of acetylcholinesterase and detoxifying enzymes, specifically glutathione S-transferase, and carboxylesterase. Analysis of energy reserves in resistant A. gossypii fed on micronutritient-amended plants revealed decreases in the lipid and protein contents of aphids, whereas glycogen and carbohydrate contents showed no response. Resistant cotton aphids fed on micronutritient-amended plants showed significantly reduced fecundity, longevity, and reproductive periods, and a 1.7-fold reduction in pirimicarb LC50 compared with those fed on control plants. We conclude that micronutrient amendment negatively impacts the biological performance of insecticide-resistant cotton aphids, and diminishes their resistance to pirimicarb. Both direct effects on plant health, such as enhanced inducible defenses, and indirect effects on aphid fitness, such as reduced biological performance and detoxification abilities, were implicated. Therefore, optimization of micronutrient amendments could be a useful complement to other tactics for managing insecticide-resistant A. gossypii on cucumbers, and warrants exploration in other contexts.

Inducible Defenses and the Allocation of Resources: A Minimal Model

1992 ◽  
Vol 139 (3) ◽  
pp. 521-539 ◽  
Author(s):  
Colin W. Clark ◽  
C. Drew Harvell
Keyword(s):  
Minimal Model ◽  
Inducible Defenses ◽  
Allocation Of Resources
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