Behavioral Manipulation for Pest Control

Pest control is moving towards a dramatic reduction in pesticide-based approaches in favor of more eco-friendly strategies characterized by the promotion of ecological intensification of agriculture and reduction of human inputs (especially pesticides) [...]

Insect Behavioral Change and the Potential Contributions of Neuroinflammation—A Call for Future Research

Many organisms are able to elicit behavioral change in other organisms. Examples include different microbes (e.g., viruses and fungi), parasites (e.g., hairworms and trematodes), and parasitoid wasps. In most cases, the mechanisms underlying host behavioral change remain relatively unclear. There is a growing body of literature linking alterations in immune signaling with neuron health, communication, and function; however, there is a paucity of data detailing the effects of altered neuroimmune signaling on insect neuron function and how glial cells may contribute toward neuron dysregulation. It is important to consider the potential impacts of altered neuroimmune communication on host behavior and reflect on its potential role as an important tool in the “neuro-engineer” toolkit. In this review, we examine what is known about the relationships between the insect immune and nervous systems. We highlight organisms that are able to influence insect behavior and discuss possible mechanisms of behavioral manipulation, including potentially dysregulated neuroimmune communication. We close by identifying opportunities for integrating research in insect innate immunity, glial cell physiology, and neurobiology in the investigation of behavioral manipulation.

Vibrational communication and mating behavior of the greenhouse whitefly Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae)

The greenhouse whitefly (GW), Trialeurodes vaporariorum is considered one of the most harmful insect pests in greenhouses worldwide. The GW mating behavior has been partially investigated and its vibrational communication is only in part known. A deeper knowledge of its intraspecific communication is required to evaluate the applicability of control methods based on techniques of behavioral manipulation. In this study, for the first time, we provided a detailed ethogram of the GW mating behavior and we characterized the vibrational signals emitted during the process of pair formation. We characterized two types of male vibrational emissions (“chirp” and “pulses”), differently arranged according to the behavioral stage to form stage-specific signals, and a previously undescribed Male Rivalry Signal. We recorded and characterized two new female signals: The Female Responding Signal and the Female Rejective Signal. The mating behavior of GW can be divided into six different stages that we named “call”, “alternated duet”, “courtship”, “overlapped duet”, “mating”, “failed mating attempt”. The analysis performed with the Markovian behavioral transition matrix showed that the “courtship” is the key stage in which male exhibits its quality and can lead to the “overlapped duet” stage. The latter is strictly associated to the female acceptance and therefore it plays a crucial role to achieve mating success. Based on our findings, we consider the use of vibrational playbacks interfering with GW mating communication a promising option for pest control in greenhouses. We discuss the possibility to start a research program of behavioral manipulation to control the populations of GW.

Traffic networks are vulnerable to disinformation attacks

Disinformation continues to raise concerns due to its increasing threat to society. Nevertheless, a threat of a disinformation-based attack on critical infrastructure is often overlooked. Here, we consider urban traffic networks and focus on fake information that manipulates drivers’ decisions to create congestion at a city scale. Specifically, we consider two complementary scenarios, one where drivers are persuaded to move towards a given location, and another where they are persuaded to move away from it. We study the optimization problem faced by the adversary when choosing which streets to target to maximize disruption. We prove that finding an optimal solution is computationally intractable, implying that the adversary has no choice but to settle for suboptimal heuristics. We analyze one such heuristic, and compare the cases when targets are spread across the city of Chicago vs. concentrated in its business district. Surprisingly, the latter results in more far-reaching disruption, with its impact felt as far as 2 km from the closest target. Our findings demonstrate that vulnerabilities in critical infrastructure may arise not only from hardware and software, but also from behavioral manipulation.

Behavioral manipulation of the spider Macrophyes pacoti (Araneae: Anyphaenidae) by the araneopathogenic fungus Gibellula sp. (Hypocreales: Cordycipitaceae)

Host manipulation has already been documented in several distinct host-parasite associations, covering all major phyla of living organisms. While in animals we know that several species have the ability to manipulate their hosts for the benefit of the parasite, in arthropopathogenic fungi there is very little knowledge about possible behavioral manipulation. We report for the first time the interaction between the araneopathogenic fungus Gibellula sp. Cavara and the spider Macrophyes pacoti Brescovit, Oliveira, Sobczak & Sobczak, 2019 (Anyphaenidae) in addition to investigating the potential change in behavior of spiders infected by the parasitic fungus. We also investigated whether the rainfall regime influences the abundance of infected spiders and the parasitism rate by the araneopathogenic fungus. Our results corroborated our hypothesis that the fungus induces vertical segregation in the spider population, inducing infected spiders to be at higher heights than uninfected ones. Dead infected spiders were found in a stretched position that probably helps in fixing the carcass on the leaves by increasing the contact surface between the host and the substrate. Our results also confirm the positive relationship between the rainy season and the greater number of parasitic spiders and the parasitism rate.

Toxoplasma gondii infections are associated with boldness towards lions in wild hyena hosts

Toxoplasma gondii is widely reported to manipulate the behavior of its non-definitive hosts in ways that promote lethal interactions with the parasite’s definitive feline hosts. Nonetheless, there is a lack of data on the association between T. gondii infection and costly behavioral interactions with felids in nature. Here, we report that three decades of field observations reveal T. gondii infected hyena cubs approach lions more closely than uninfected peers and have higher rates of lion mortality. Our findings support the hypothesis that T. gondii’s manipulation of host boldness is an extended phenotype that promotes parasite transmission from intermediate hosts to feline predators. While upregulating hyena boldness toward lions might achieve this, it may also reflect a collateral influence of manipulative traits that evolved in other hosts (e.g., rodents). In either case, our findings corroborate the potential impacts of a globally distributed and generalist parasite (T. gondii) on fitness-related interaction with felids in a wild host.One Sentence SummaryWild hyenas infected with the parasite T. gondii show evidence of costly behavioral manipulation when interacting with lions.