Kishkinev, D. | Search bioRxiv

bioRxiv2026

The Role of Magnetic and Celestial Cues in Orientation and Navigation of Red Underwing (Catocala nupta), a European Migratory Moth

Nocturnal migration is a remarkable phenomenon observed in many insect species, including moths. Migratory moths are capable of maintaining precise directional orientation during migration, as demonstrated in both laboratory and field studies, suggesting that they use multiple environmental cues for orientation and navigation. Recent studies on Australian Bogong moths revealed that these animals can use stellar cues and likely the geomagnetic field (in conjunction with local visual cues) to select and maintain population-specific migratory direction. However, the underlying orientation mechanisms used by most other migratory moths are still largely unresolved. Further, it remains unclear whether migratory moths can adjust their orientation using Earths magnetic field parameters for determining their position relative to the goal (i.e. location or map information) - an ability clearly shown in some migratory birds which respond to virtual magnetic displacements by correcting their orientation (experiments when animals are exposed to magnetic cues corresponding to other geographic locations). Here, we present results from virtual magnetic displacement experiments conducted on red underwings (Catocala nupta). In addition, we tested their orientation under simulated overcast conditions and in a vertical magnetic field to get indications whether this species relies on geomagnetic or celestial cues to maintain its population-specific migratory direction. Our results show that (1) red underwings did not compensate for virtual magnetic displacement, indicating the absence of a magnetic map; (2) they remained significantly oriented in the absence of geomagnetic information, suggesting the use of a stellar compass; and (3) there was no evidence of magnetic compass orientation in absence of any visual cues.

animal behavior and cognition↗

bioRxiv2025

Not All Butterflies Are Monarchs: Compass Systems in the Red Admiral (Vanessa atalanta), a European Diurnal Migrant

Seasonal migration in animals is a widespread and complex phenomenon, yet the mechanisms underlying orientation and navigation remain poorly understood in many taxa. While significant progress has been made in migratory birds, where multiple compass systems are well described, similar knowledge for migratory Lepidoptera remains limited. Most insights into butterfly and moth orientation come from just two species: the monarch butterfly (Danaus plexippus) and the Australian Bogong moth (Agrotis infusa), both of which possess multimodal compass systems involving visual and geomagnetic cues. However, these species follow unusual migratory strategies that include diapause or aestivation and multigenerational round-trip migrations between breeding region and very specific non-breeding areas, that are not representative of most other Lepidoptera migrants. In contrast, European species such as the painted lady (Vanessa cardui) and red admiral (Vanessa atalanta) undertake regular seasonal migrations involving multiple generations and no diapause, yet the sensory mechanisms guiding their orientation remain largely unexplored. Here, we report findings from a two-year study investigating compass orientation in red admirals using a flight simulator under a range of controlled light and magnetic conditions. Our experiments yielded three key results: (1) red admirals orient using solar cues when selecting migratory direction; (2) the sun compass in this species appears to be time-independent, as clock-shifted individuals did not alter orientation; and (3) there is no sign of magnetic sense in red admirals. These findings sharply contrast with those from monarch butterflies, which rely on both time-compensated sun and light-dependent magnetic compasses. Our results reveal important interspecific variation in compass use among diurnal Lepidoptera and underscore the need to expand orientation research beyond traditional model systems to better understand the diversity of migratory strategies and orientation mechanisms in migratory Lepidoptera.

animal behavior and cognition↗