Dear Editor,The attacker is always going to intrude covertly networked control systems(NCSs)by dynamically changing false data injection attacks(FDIAs)strategy,while the defender try their best to resist attacks by de...Dear Editor,The attacker is always going to intrude covertly networked control systems(NCSs)by dynamically changing false data injection attacks(FDIAs)strategy,while the defender try their best to resist attacks by designing defense strategy on the basis of identifying attack strategy,maintaining stable operation of NCSs.To solve this attack-defense game problem,this letter investigates optimal secure control of NCSs under FDIAs.First,for the alterations of energy caused by false data,a novel attack-defense game model is constructed,which considers the changes of energy caused by the actions of the defender and attacker in the forward and feedback channels.展开更多
To solve security problems in cross-technology communication(CTC),we take the Internet of Things(IoT)control system as an example,and propose a comprehensive solution against the attack on the physical layer CTC from ...To solve security problems in cross-technology communication(CTC),we take the Internet of Things(IoT)control system as an example,and propose a comprehensive solution against the attack on the physical layer CTC from ZigBee to Wi-Fi.Specifically,we propose a noise interference strategy by adding an appropriate amount of dedicated noise signals,which can interfere with the eavesdropping and simulation of ZigBee signals without affecting the reception of the receiver.Moreover,we also propose a regression modeling strategy which collects data,extracts features,and trains a binary logistic regression model so that the receiver can actively distinguish simulated attack signals.We build the experimental platform by using GNU Radio and USRP devices.Experimental results demonstrate that the security defense strategies can identify and distinguish the signals from the attacker with a high accuracy,effectively solving the signal emulation attack on the physical layer CTC from ZigBee to Wi-Fi.展开更多
Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning colora- tion or mimicry. However, such color patterns have also been hypothesized to aid snakes in escaping ...Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning colora- tion or mimicry. However, such color patterns have also been hypothesized to aid snakes in escaping predators through a ＂flicker-fusion＂ effect. According to this hypothesis, banded color patterns confuse potential predators when a snake transitions from resting to moving because its bands blur together to form a different color. To produce this motion blur, a moving snake＇s bands must transition faster than the critical flicker-fusion rate at which a predator＇s photoreceptors can refresh. It is unknown if coral snakes or their mimics meet this requirement. We tested this hypothesis by measuring the movement speed and color pat- terns of two coral snake mimics, Lampropeltis triangulum campbelli and L. elapsoides, and comparing the frequency of color transitions to the photoreceptor activity of the avian eye. We found that snakes often produced a motion blur, but moving snakes created a blurring effect more often in darker conditions, such as sunrise, sunset, and nighttime when these snakes are often active. Thus, at least two species of coral snake mimics are capable of achieving flicker-fusion, indicating that their color patterns may confer an additional defense aside from mimicry展开更多
This study systematically reviews the Internet of Things(IoT)security research based on literature from prominent international cybersecurity conferences over the past five years,including ACM Conference on Computer a...This study systematically reviews the Internet of Things(IoT)security research based on literature from prominent international cybersecurity conferences over the past five years,including ACM Conference on Computer and Communications Security(ACM CCS),USENIX Security,Network and Distributed System Security Symposium(NDSS),and IEEE Symposiumon Security and Privacy(IEEE S&P),along with other high-impact studies.It organizes and analyzes IoT security advancements through the lenses of threats,detection methods,and defense strategies.The foundational architecture of IoT systems is first outlined,followed by categorizing major threats into eight distinct types and analyzing their root causes and potential impacts.Next,six prominent threat detection techniques and five defense strategies are detailed,highlighting their technical principles,advantages,and limitations.The paper concludes by addressing the key challenges still confronting IoT security and proposing directions for future research to enhance system resilience and protection.展开更多
The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphi...The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphic life cycle,exhibiting phase alternation between free-living cells of approximately 3-6μm in diameter and gelatinous colonies(palmelloid stage)reaching several millimeters.The knowledge on the factors that induced the morphological transition of P.globosa in the last two decades was reviewed.Emphasis is given to infochemicals,an additional biological factor induced by predator,with the attempt to reveal a relevant mechanism of induced morphological defense.展开更多
This paper studies a special defense game using unmanned aerial vehicle(UAV)swarm against a fast intruder.The fast intruder applies an offensive strategy based on the artificial potential field method and Apollonius c...This paper studies a special defense game using unmanned aerial vehicle(UAV)swarm against a fast intruder.The fast intruder applies an offensive strategy based on the artificial potential field method and Apollonius circle to scout a certain destination.As defenders,the UAVs are arranged into three layers:the forward layer,the midfield layer and the back layer.The co-defense mechanism,including the role derivation method of UAV swarm and a guidance law based on the co-defense front point,is introduced for UAV swarm to co-detect the intruder.Besides,five formations are designed for comparative analysis when ten UAVs are applied.Through Monte Carlo experiments and ablation experiment,the effectiveness of the proposed co-defense method has been verified.展开更多
The rapid integration of artificial intelligence (AI) into critical sectors has revealed a complex landscape of cybersecurity challenges that are unique to these advanced technologies. AI systems, with their extensive...The rapid integration of artificial intelligence (AI) into critical sectors has revealed a complex landscape of cybersecurity challenges that are unique to these advanced technologies. AI systems, with their extensive data dependencies and algorithmic complexities, are susceptible to a broad spectrum of cyber threats that can undermine their functionality and compromise their integrity. This paper provides a detailed analysis of these threats, which include data poisoning, adversarial attacks, and systemic vulnerabilities that arise from the AI’s operational and infrastructural frameworks. This paper critically examines the effectiveness of existing defensive mechanisms, such as adversarial training and threat modeling, that aim to fortify AI systems against such vulnerabilities. In response to the limitations of current approaches, this paper explores a comprehensive framework for the design and implementation of robust AI systems. This framework emphasizes the development of dynamic, adaptive security measures that can evolve in response to new and emerging cyber threats, thereby enhancing the resilience of AI systems. Furthermore, the paper addresses the ethical dimensions of AI cybersecurity, highlighting the need for strategies that not only protect systems but also preserve user privacy and ensure fairness across all operations. In addition to current strategies and ethical concerns, this paper explores future directions in AI cybersecurity.展开更多
To investigate the attack and defense strategies in complex net works,the authors propose a two-player zero-sum static game model with complete information which considers attack and defense strategies simultaneously....To investigate the attack and defense strategies in complex net works,the authors propose a two-player zero-sum static game model with complete information which considers attack and defense strategies simultaneously.The authors assume that both the attacker and defender have two typical strategies:Targeted strategy and random strategy.The authors explore the Nash equilibriums of the attacker-defender game and demonstrate that when the attacker's attack resources are not so significantly abundant as the defender's resources,there exists a pure-strategy Nash equilibrium in both model net works and real-world net works,in which the defender protects the hub t arge ts with large degrees preferentially,while the attacker prefers selecting the targets randomly.When the attack resources are much higher than defense resources,both the attacker and the defender adopt the targeted strategy in equilibriums.This paper provides a new theoretical framework for the study of attack and defense st rat egies in complex net works.展开更多
Resource partitioning among sympatric species is crucial for assembling ecological communities,such as caterpillar—ant assemblages in tropical forests.Myrmecophilous caterpillars use behavioral and chemical strategie...Resource partitioning among sympatric species is crucial for assembling ecological communities,such as caterpillar—ant assemblages in tropical forests.Myrmecophilous caterpillars use behavioral and chemical strategies to coexist with ants,avoiding attacks.While these strategies are well-understood in single pair of interacting species,such as those involving myrmecophiles and ants,their role in complex multitrophic interactions that include several species of plants,herbivores and ants remains unclear.We aimed to identify the role of cuticular hydrocarbons and specialized morphological structures that caterpillars use to interact with ants(called ant organs)in the recognition process between two riodinid caterpillar species and their respective ant—plant systems.We hypothesized that caterpillars'cuticular profiles would be conspicuous,possessing cues of rewards to ants,allowing specific ants to recognize and not attack them on plants.We performed experiments exposing caterpillars to ants to assess the role of larval ant organs and the specificity of caterpillar—ant interactions on plants.We analyzed cuticular hydrocarbons of caterpillars,ant workers and plants using gas chromatography/mass spectrometry.Our experiments showed that larval ant organs were activated according to each treatment and caterpillars were consistently accepted by their associated ants when transferred to host plants occupied by the same ant species.However,caterpillars transferred to plants with a non-associated ant species that do not tend them were often killed.This highlights the specificity of these interactions.Caterpillar cuticular hydrocarbon profiles,while present in far lower amounts than those of ant workers and plants,were distinctive,suggesting a strategy of chemical conspicuousness that helps caterpillars to be recognized by ants and prevents attacks in specific antplant systems.Our results indicate that ants recognize conspicuous cuticular hydrocarbons,while caterpillars convey multimodal signals from ant organs during interactions,which are essential for caterpillar survival in these specific interactions.展开更多
Cascading failure is a potential threat in power systems with the scale development of wind power,especially for the large-scale grid-connected and long distance transmission wind power base in China.This introduces a...Cascading failure is a potential threat in power systems with the scale development of wind power,especially for the large-scale grid-connected and long distance transmission wind power base in China.This introduces a complex network theory(CNT)for cascading failure analysis considering wind farm integration.A cascading failure power flow analysis model for complex power networks is established with improved network topology principles and methods.The network load and boundary conditions are determined to reflect the operational states of power systems.Three typical network evaluation indicators are used to evaluate the topology characteristics of power network before and after malfunction including connectivity level,global effective performance and percentage of load loss(PLL).The impacts of node removal,grid current tolerance capability,wind power instantaneous penetrations,and wind farm coupling points on the power grid are analyzed based on the IEEE 30 bus system.Through the simulation analysis,the occurrence mechanism and main influence factors of cascading failure are determined.Finally,corresponding defense strategies are proposed to reduce the hazards of cascading failure in power systems.展开更多
It is universally acknowledged by network security experts that proactive peer-to-peer (P2P) worms may soon en-gender serious threats to the Internet infrastructures. These latent threats stimulate activities of model...It is universally acknowledged by network security experts that proactive peer-to-peer (P2P) worms may soon en-gender serious threats to the Internet infrastructures. These latent threats stimulate activities of modeling and analysis of the proactive P2P worm propagation. Based on the classical two-factor model,in this paper,we propose a novel proactive worm propagation model in unstructured P2P networks (called the four-factor model) by considering four factors:(1) network topology,(2) countermeasures taken by Internet service providers (ISPs) and users,(3) configuration diversity of nodes in the P2P network,and (4) attack and defense strategies. Simulations and experiments show that proactive P2P worms can be slowed down by two ways:improvement of the configuration diversity of the P2P network and using powerful rules to reinforce the most connected nodes from being compromised. The four-factor model provides a better description and prediction of the proactive P2P worm propagation.展开更多
Aims The biochemical defense of lichens against herbivores and its rela-tionship to lichen frequency are poorly understood.Therefore,we tested whether chemical compounds in lichens act as feeding defense or rather as ...Aims The biochemical defense of lichens against herbivores and its rela-tionship to lichen frequency are poorly understood.Therefore,we tested whether chemical compounds in lichens act as feeding defense or rather as stimulus for snail herbivory among lichens and whether experimental feeding by snails is related to lichen fre-quency in the field.Methods In a no-choice feeding experiment,we fed 24 lichen species to snails of two taxa from the Clausilidae and Enidae families and compared untreated lichens and lichens with compounds removed by acetone rinsing.Then,we related experimental lichen consump-tion with the frequency of lichen species among 158 forest plots in the field(schwäbische alb,germany),where we had also sampled snail and lichen species.Important findings In five lichen species,snails preferred treated samples over untreated controls,indicating chemical feeding defense,and vice versa in two species,indicating chemical feeding stimulus.Interestingly,com-pared with less frequent lichen species,snails consumed more of untreated and less of treated samples of more frequent lichen spe-cies.removing one outlier species resulted in the loss of a significant positive relationship when untreated samples were analyzed separately.However,the interaction between treatment and lichen frequency remained significant when excluding single species or including snail genus instead of taxa,indicating that our results were robust and that lumping the species to two taxa was justified.our results imply lichen-feeding snails to prefer frequent lichens and avoid less frequent ones because of secondary compound rec-ognition.This supports the idea that consumers adapt to the most abundant food source.展开更多
基金supported in part by the National Science Foundation of China(62373240,62273224,U24A20259).
文摘Dear Editor,The attacker is always going to intrude covertly networked control systems(NCSs)by dynamically changing false data injection attacks(FDIAs)strategy,while the defender try their best to resist attacks by designing defense strategy on the basis of identifying attack strategy,maintaining stable operation of NCSs.To solve this attack-defense game problem,this letter investigates optimal secure control of NCSs under FDIAs.First,for the alterations of energy caused by false data,a novel attack-defense game model is constructed,which considers the changes of energy caused by the actions of the defender and attacker in the forward and feedback channels.
文摘To solve security problems in cross-technology communication(CTC),we take the Internet of Things(IoT)control system as an example,and propose a comprehensive solution against the attack on the physical layer CTC from ZigBee to Wi-Fi.Specifically,we propose a noise interference strategy by adding an appropriate amount of dedicated noise signals,which can interfere with the eavesdropping and simulation of ZigBee signals without affecting the reception of the receiver.Moreover,we also propose a regression modeling strategy which collects data,extracts features,and trains a binary logistic regression model so that the receiver can actively distinguish simulated attack signals.We build the experimental platform by using GNU Radio and USRP devices.Experimental results demonstrate that the security defense strategies can identify and distinguish the signals from the attacker with a high accuracy,effectively solving the signal emulation attack on the physical layer CTC from ZigBee to Wi-Fi.
文摘Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning colora- tion or mimicry. However, such color patterns have also been hypothesized to aid snakes in escaping predators through a ＂flicker-fusion＂ effect. According to this hypothesis, banded color patterns confuse potential predators when a snake transitions from resting to moving because its bands blur together to form a different color. To produce this motion blur, a moving snake＇s bands must transition faster than the critical flicker-fusion rate at which a predator＇s photoreceptors can refresh. It is unknown if coral snakes or their mimics meet this requirement. We tested this hypothesis by measuring the movement speed and color pat- terns of two coral snake mimics, Lampropeltis triangulum campbelli and L. elapsoides, and comparing the frequency of color transitions to the photoreceptor activity of the avian eye. We found that snakes often produced a motion blur, but moving snakes created a blurring effect more often in darker conditions, such as sunrise, sunset, and nighttime when these snakes are often active. Thus, at least two species of coral snake mimics are capable of achieving flicker-fusion, indicating that their color patterns may confer an additional defense aside from mimicry
文摘This study systematically reviews the Internet of Things(IoT)security research based on literature from prominent international cybersecurity conferences over the past five years,including ACM Conference on Computer and Communications Security(ACM CCS),USENIX Security,Network and Distributed System Security Symposium(NDSS),and IEEE Symposiumon Security and Privacy(IEEE S&P),along with other high-impact studies.It organizes and analyzes IoT security advancements through the lenses of threats,detection methods,and defense strategies.The foundational architecture of IoT systems is first outlined,followed by categorizing major threats into eight distinct types and analyzing their root causes and potential impacts.Next,six prominent threat detection techniques and five defense strategies are detailed,highlighting their technical principles,advantages,and limitations.The paper concludes by addressing the key challenges still confronting IoT security and proposing directions for future research to enhance system resilience and protection.
基金Supported by the Key Deployment Project of Center for Ocean Mega-Science,Chinese Academy of Sciences(No.COMS2019R04)the National Overseas High-level Talent Project,Taishan Scholar Program from Shandong Province of China(No.tsqn20190403)the Shuangbai Plan from Yantai City(No.2018020)。
文摘The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphic life cycle,exhibiting phase alternation between free-living cells of approximately 3-6μm in diameter and gelatinous colonies(palmelloid stage)reaching several millimeters.The knowledge on the factors that induced the morphological transition of P.globosa in the last two decades was reviewed.Emphasis is given to infochemicals,an additional biological factor induced by predator,with the attempt to reveal a relevant mechanism of induced morphological defense.
基金the Aeronautical Science Foundation of China(2020Z023053001).
文摘This paper studies a special defense game using unmanned aerial vehicle(UAV)swarm against a fast intruder.The fast intruder applies an offensive strategy based on the artificial potential field method and Apollonius circle to scout a certain destination.As defenders,the UAVs are arranged into three layers:the forward layer,the midfield layer and the back layer.The co-defense mechanism,including the role derivation method of UAV swarm and a guidance law based on the co-defense front point,is introduced for UAV swarm to co-detect the intruder.Besides,five formations are designed for comparative analysis when ten UAVs are applied.Through Monte Carlo experiments and ablation experiment,the effectiveness of the proposed co-defense method has been verified.
文摘The rapid integration of artificial intelligence (AI) into critical sectors has revealed a complex landscape of cybersecurity challenges that are unique to these advanced technologies. AI systems, with their extensive data dependencies and algorithmic complexities, are susceptible to a broad spectrum of cyber threats that can undermine their functionality and compromise their integrity. This paper provides a detailed analysis of these threats, which include data poisoning, adversarial attacks, and systemic vulnerabilities that arise from the AI’s operational and infrastructural frameworks. This paper critically examines the effectiveness of existing defensive mechanisms, such as adversarial training and threat modeling, that aim to fortify AI systems against such vulnerabilities. In response to the limitations of current approaches, this paper explores a comprehensive framework for the design and implementation of robust AI systems. This framework emphasizes the development of dynamic, adaptive security measures that can evolve in response to new and emerging cyber threats, thereby enhancing the resilience of AI systems. Furthermore, the paper addresses the ethical dimensions of AI cybersecurity, highlighting the need for strategies that not only protect systems but also preserve user privacy and ensure fairness across all operations. In addition to current strategies and ethical concerns, this paper explores future directions in AI cybersecurity.
基金supported by the National Natural Science Foundation of China under Grant Nos.71871217 and 71371185the Natural Science Foundation of Hunan Province under Grant No.2019JJ20019
文摘To investigate the attack and defense strategies in complex net works,the authors propose a two-player zero-sum static game model with complete information which considers attack and defense strategies simultaneously.The authors assume that both the attacker and defender have two typical strategies:Targeted strategy and random strategy.The authors explore the Nash equilibriums of the attacker-defender game and demonstrate that when the attacker's attack resources are not so significantly abundant as the defender's resources,there exists a pure-strategy Nash equilibrium in both model net works and real-world net works,in which the defender protects the hub t arge ts with large degrees preferentially,while the attacker prefers selecting the targets randomly.When the attack resources are much higher than defense resources,both the attacker and the defender adopt the targeted strategy in equilibriums.This paper provides a new theoretical framework for the study of attack and defense st rat egies in complex net works.
基金support from the São Paulo Research Foundation(FAPESP)through grants to LDL(2021/00984-7),DSA(2015/17358-0)FSN(2021/05598-8 and 2018/10996-0)+1 种基金provided by Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES)to LDL and LAK-Finance Code O01 and by the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico(CNPq)to FSN(05082/2018-5 and 307702/2018-9)and LAK(175508/2023-2)funded by the NationalGeographic Society to LAK(#WW-224R-17).
文摘Resource partitioning among sympatric species is crucial for assembling ecological communities,such as caterpillar—ant assemblages in tropical forests.Myrmecophilous caterpillars use behavioral and chemical strategies to coexist with ants,avoiding attacks.While these strategies are well-understood in single pair of interacting species,such as those involving myrmecophiles and ants,their role in complex multitrophic interactions that include several species of plants,herbivores and ants remains unclear.We aimed to identify the role of cuticular hydrocarbons and specialized morphological structures that caterpillars use to interact with ants(called ant organs)in the recognition process between two riodinid caterpillar species and their respective ant—plant systems.We hypothesized that caterpillars'cuticular profiles would be conspicuous,possessing cues of rewards to ants,allowing specific ants to recognize and not attack them on plants.We performed experiments exposing caterpillars to ants to assess the role of larval ant organs and the specificity of caterpillar—ant interactions on plants.We analyzed cuticular hydrocarbons of caterpillars,ant workers and plants using gas chromatography/mass spectrometry.Our experiments showed that larval ant organs were activated according to each treatment and caterpillars were consistently accepted by their associated ants when transferred to host plants occupied by the same ant species.However,caterpillars transferred to plants with a non-associated ant species that do not tend them were often killed.This highlights the specificity of these interactions.Caterpillar cuticular hydrocarbon profiles,while present in far lower amounts than those of ant workers and plants,were distinctive,suggesting a strategy of chemical conspicuousness that helps caterpillars to be recognized by ants and prevents attacks in specific antplant systems.Our results indicate that ants recognize conspicuous cuticular hydrocarbons,while caterpillars convey multimodal signals from ant organs during interactions,which are essential for caterpillar survival in these specific interactions.
基金This work was financially supported by a grant from the National Basic Research Program of China(973 Program)(No.2012CB215204)the Key Project of the CAS Knowledge Innovation Program“Research and demonstration of the coordinated control system based on multi-complementary energy storage”(No.KGCX2-EW-330).
文摘Cascading failure is a potential threat in power systems with the scale development of wind power,especially for the large-scale grid-connected and long distance transmission wind power base in China.This introduces a complex network theory(CNT)for cascading failure analysis considering wind farm integration.A cascading failure power flow analysis model for complex power networks is established with improved network topology principles and methods.The network load and boundary conditions are determined to reflect the operational states of power systems.Three typical network evaluation indicators are used to evaluate the topology characteristics of power network before and after malfunction including connectivity level,global effective performance and percentage of load loss(PLL).The impacts of node removal,grid current tolerance capability,wind power instantaneous penetrations,and wind farm coupling points on the power grid are analyzed based on the IEEE 30 bus system.Through the simulation analysis,the occurrence mechanism and main influence factors of cascading failure are determined.Finally,corresponding defense strategies are proposed to reduce the hazards of cascading failure in power systems.
基金Project (No. 09511501600) partially supported by the Science and Technology Commission of Shanghai Municipality, China
文摘It is universally acknowledged by network security experts that proactive peer-to-peer (P2P) worms may soon en-gender serious threats to the Internet infrastructures. These latent threats stimulate activities of modeling and analysis of the proactive P2P worm propagation. Based on the classical two-factor model,in this paper,we propose a novel proactive worm propagation model in unstructured P2P networks (called the four-factor model) by considering four factors:(1) network topology,(2) countermeasures taken by Internet service providers (ISPs) and users,(3) configuration diversity of nodes in the P2P network,and (4) attack and defense strategies. Simulations and experiments show that proactive P2P worms can be slowed down by two ways:improvement of the configuration diversity of the P2P network and using powerful rules to reinforce the most connected nodes from being compromised. The four-factor model provides a better description and prediction of the proactive P2P worm propagation.
基金DFG(German Research Foundation)Priority Program 1374‘Infrastructure-Biodiversity-Exploratories’(FI 1246/6-1,FI 1246/9-1).
文摘Aims The biochemical defense of lichens against herbivores and its rela-tionship to lichen frequency are poorly understood.Therefore,we tested whether chemical compounds in lichens act as feeding defense or rather as stimulus for snail herbivory among lichens and whether experimental feeding by snails is related to lichen fre-quency in the field.Methods In a no-choice feeding experiment,we fed 24 lichen species to snails of two taxa from the Clausilidae and Enidae families and compared untreated lichens and lichens with compounds removed by acetone rinsing.Then,we related experimental lichen consump-tion with the frequency of lichen species among 158 forest plots in the field(schwäbische alb,germany),where we had also sampled snail and lichen species.Important findings In five lichen species,snails preferred treated samples over untreated controls,indicating chemical feeding defense,and vice versa in two species,indicating chemical feeding stimulus.Interestingly,com-pared with less frequent lichen species,snails consumed more of untreated and less of treated samples of more frequent lichen spe-cies.removing one outlier species resulted in the loss of a significant positive relationship when untreated samples were analyzed separately.However,the interaction between treatment and lichen frequency remained significant when excluding single species or including snail genus instead of taxa,indicating that our results were robust and that lumping the species to two taxa was justified.our results imply lichen-feeding snails to prefer frequent lichens and avoid less frequent ones because of secondary compound rec-ognition.This supports the idea that consumers adapt to the most abundant food source.
