Intraspecific communication for mate finding in insects: Neural modifications underlying its evolution in eneopterine crickets and its susceptibility to neonicotinoid insecticides

• Applicant: Dr. Stefan Schöneich
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 458552427

The soaring use of neonicotinoid pesticides in global agriculture over the last decades is considered a key factor that could significantly contribute to the decline of insect populations and biodiversity. However, apart from recent studies with pollinating bees, the risks for the wide range of non-target insect populations arising from neonicotinoid pollution of the ecosystems are poorly understood. Contrary to sterile worker bees, the paramount task for most adult insects is to find mating partners, which is an obligatory prerequisite for reproductive success. Therefore, many insects use species-specific communication systems for conspecific mate attraction over longer distances and the evolution of new intraspecific communication signals has been shown to be a strong driving force for speciation in crickets and other acoustically communicating insects. My proposed project has two main goals: 1.) To identify and describe the neural adaptations in the sensory pathways for intraspecific communication underlying the evolution of a new acoustic-vibratory mate-finding strategy, that we recently discovered in a derived tribe of eneopterine crickets. 2.) To exploit cricket acoustic communication as a well-studied model system to evaluate for the first time potential effects of sublethal intoxication by neonicotinoid insecticides (e.g. imidacloprid, which is most used in global agriculture) on a mate finding strategy that is used by many different insect groups. To achieve these goals we will use a combination of different physiological and anatomical research methods to compare the neuronal processing of auditory and vibrational signals between the field cricket Gryllus bimaculatus and strategically selected species (based on phylogenetic data, accessibility and experimental suitability) from the different tribes of eneopterine crickets. In the experiments we will also systematically test for changes in the sensitivity and response characteristics of auditory and vibration-sensitive neurons by different sublethal dosages of imidacloprid and related neonicotinoid insecticides. Moreover, we will conduct recordings of spontaneous calling song production in males and walking behaviour of females in Gryllus bimaculatus to investigate the susceptibility of crucial mate finding behaviours to sublethal neonicotinoid dosages. This project thus has the potential not only to give neurobiological insight to the evolution of insect communication signals, it also offers the opportunity to test the susceptibility of insect mate finding communication to neonicotinoid insecticides, which are suspected to be a major contributor to the recent decline of insect populations and biodiversity.

• DFG Programme: Research Grants