Using radiotelemetry to study behavioural thermoregulation in insects under field conditions

This is the author accepted manuscript.The final version is available from Wiley via the DOI in this recordThermoregulation is a central aspect of animal physiology. Mobile ectotherms have the potential to influence their temperature through their location and orientation. Behavioural thermoregulation has been extensively studied in insects, particularly in the migratory locust Locusta migratoria. However, most field studies are confined to daytime observations typically using invasive thermocouples with obvious potential to disrupt natural behaviour. We demonstrate that miniature radiotransmitters represent an alternative and less invasive method to study insect thermoregulation. We discuss how this method can be used to study the thermal behaviour of free-ranging animals for extended periods. Specifically, we show that there is a close correlation between temperature recordings from implanted thermocouples in locusts L. migratoria and externally mounted radiotransmitters on the same animals. Our experiments match earlier observations of locust thermoregulatory behaviour confirming that the locusts with transmitters exhibit ‘normal’ thermoregulatory responses to feeding and to infections (behavioural fever). Finally, we demonstrate the practicality of a radiotransmitter-based system by recording natural thermoregulatory behaviour of locusts in a semi-field setting. Our field study showed locusts actively chose warm microclimates during the day and cold microclimates at night. We conclude that the use of radiotelemetry in studies of behavioural thermoregulation in wild insects could provide unique continuous recordings of body temperature over several days. Such data will provide researchers with a more complete understanding of how insects use behavioural thermoregulation in nature.Danish research council (Det Frie Forskningsråd ǀ Natur og Univers

Hunting for cultivable Micromonospora strains in soils of the Atacama Desert

Innovative procedures were used to selectively isolate small numbers of Micromonospora strains from extreme hyper-arid and high altitude Atacama Desert soils. Micromonosporae were recognised on isolation plates by their ability to produce filamentous microcolonies that were strongly attached to the agar. Most of the isolates formed characteristic orange colonies that lacked aerial hyphae and turned black on spore formation, whereas those from the high altitude soil were dry, blue-green and covered by white aerial hyphae. The isolates were assigned to seven multi- and eleven single-membered groups based on BOX-PCR profiles. Representatives of the groups were assigned to either multi-membered clades that also contained marker strains or formed distinct phyletic lines in the Micromonospora 16S rRNA gene tree; many of the isolates were considered to be putatively novel species of Micromonospora. Most of the isolates from the high altitude soils showed activity against wild type strains of Bacillus subtilis and Pseudomonas fluorescens while those from the rhizosphere of Parastrephia quadrangulares and from the Lomas Bayas hyper-arid soil showed resistance to UV radiation