Locust research in the age of model organisms: introduction to the special issue in honor of M.P. Pener's 80th birthday.

This special issue of the Journal of Insect Physiology is devoted to locust research in the age of model organisms. Prospective authors with diverse research approaches were invited to contribute and we are delighted by the enthusiastic response. All submissions, including broad reviews, targeted reviews, and experimental papers, were peer-reviewed and, in most cases, revised prior to publication. The result is a superb collection of articles, representing a wide variety of research areas with one thing in common: the use of locusts, either as the major research animal or as a model. The goal of collecting these works was to provide a venue through which a panorama of cutting-edge locust research could emerge, demonstrating that even nowadays, when research tends to focus increasingly on a few selected so-called model organisms, the locust has not lost its appeal as an outstanding preparation for physiological studies in various fields, from endocrinology to neurobiology, integrative physiology and biochemistry. Following is a short review of the 21 contributions included in this special issue, divided into five themes or general subjects. Locomotion and neural control: The locust’s superb capacity for flight has always attracted much research (Fig. 1); covering behavioral studies as well as various aspects of neural and neuroendocrine control. The work by Wilson (1961), focusing on the neural mechanisms for the generation of locust flight, has served as a landmark in our understanding of rhythmic behaviors and the central pattern-generating circuits that control them. In their review, Ayali and Lange present the locust as a unique preparation in which central pattern generator networks have been suggested and studied in practically all aspects of the animal’s behavior. These include flight as well as other means of locomotion, respiration, feeding and molting, oviposition and more. Extensive laboratory studies have been carried out on flight fuels, their utilization and mobilization in locusts. Van der Horst and Rodenburg focus on hormonal regulation of lipid mobilization and transport during locust flight activity. This updated review presents the locust as a broad and profound research model for integrative physiology and biochemistry, while also acknowledging its limitations as such. Much work related to neurohormones and flight has been focused on the role of the biogenic amine octopamine. Verlinden et al. provide an excellent and timely reminder of the various roles of octopamine in multiple physiological and behavioral processes in locusts and other arthropods. Octopamine exerts its effects by binding to specific receptor proteins that belong to the superfamily