Testing migratory Bogong moth (Agrotis infusa) in orientation experiments using an artificial representation of the Milky Way

anglais. The Bogong Moth, Agrotis Infusa, is a migratory moth native to South-Eastern Australia. These nocturnal insects migrate over more than 1000 km from their breeding grounds to caves in the Australian alps. To find their way during this migration, individuals of the species use several compass cues, both magnetic and celestial. This study aimed to investigate the ability of the moth to navigate after an artificial Milky Way made up of an LED strip. The LED was programmed to give light in different conditions, with two sides and three different widths of lights and was placed on a dome on top of a Mouritsen-Frost flight simulator. The end results did not show a significant directedness, but indicated a preference for the moths to fly away from the light. However, further experiments are needed to confirm this. This study and its methods provide a base for further research.

anglais. Navigating using the milky way, the Bogong moth The Bogong moth is a small animal that spends its life in south eastern Australia. During its lifetime the moth flies incredible distances from their breeding grounds spread out over vast areas to the Australian alps where it spends summer time in caves before flying back, thereby completing a journey of around 1000 km per individual. To find its way during this long migration the animal uses several methods of navigation, one of which is using the starry night sky. I investigated the Bogong moth's ability to navigate using an artificial representation of the Milky way made up of a LED strip. I used moths that had been shipped from Australia to Lund University and put them in an arena made up of a cylinder. They were hanging freely in the middle of this arena and could fly in any direction they desired. The rotation and direction of the moths when different configurations of LEDs were turned on was measured and this gave me the data needed. Each separate experiment was divided into three equally long parts. The basis was that the first part of the experiment had LEDs turned on on one side (called A), in the second part the LEDs of the opposite side (called B) were turned on and in the third part the same LEDs were turned on as in the first part (A again). This gave a so-called ABA experiment. To see if the direction of the experiments were not just random, control tests were done using the same condition in all three parts (AAA/BBB). Results and future outlook The most telling results from the experiments I got by first finding the angles between the mean direction of the moths between A and B and then between B and A (A⟶B⟶A). A mean was then taken of these two angles and when compared to the controls a clear difference could be seen that the animals showed another behaviour when the condition was changed. The trend was that more animals of the ABA experiments had an angle of around 90 degrees whereas the controls were more normally distributed between all angles. Other analysis done in the direction of the moths showed preference for flying away from the lights, but these findings were not with enough significance (not high enough probability of being true) to say for certain if the animals were actually directed or not. To say for sure if the Bogong moth actually uses the milky way more experiments would therefore have to be done. The animals used for these experiments were not completely fresh from delivery but were kept in captivity for quite some time which could affect the animals' will to navigate and new experiments should therefore be done on moths that were completely fresh from delivery. Supervisor: David Dreyer and Eric Warrant Bachelor thesis 15hp in molecular biology 2021 Institution of Biology. Lund University