Ecology and distribution of the recently discovered ked Lipoptena andaluciensis (Diptera: Hippoboscidae) in Spain

Hippoboscid flies (Diptera: Hippoboscidae) are obligate hematophagous ectoparasites of birds and mammals, with recognized ecological and epidemiological importance. Despite their relevance, the ecology and distribution of many species within this family remain poorly understood. We combined active screening of 372 wild ungulates (2013-2024) and passive CO₂-baited trap sampling (2023 - 2024) across Andalusia, Spain, to investigate the occurrence, host prevalence, and phenology of Lipoptena andaluciensis flies. We used these data to model its potential distribution and spatial overlap with key host species using an ensemble species distribution modeling approach. The presence of L. andaluciensis was confirmed in four Andalusian provinces, with the first record dating to 2018. Host prevalence increased significantly in recent years, reaching 69.7% in 2023 and 72.9% in 2024. Roe deer (Capreolus capreolus) and fallow deer (Dama dama) showed the highest infestation prevalence (70.0% and 50.4%, respectively), followed by red deer (Cervus elaphus, 27.2%) and mouflon (Ovis aries musimon, 3.9%). No flies were found on Iberian ibex (Capra pyrenaica) or wild boar (Sus scrofa). Winged adults were active, at least, from April to November, while wingless forms were present on hosts at least from June to March. Species distribution models identified extensive areas of high environmental suitability across central and southern Spain, driven primarily by vegetation density (NDVI), soil moisture, and land surface temperature. The models revealed a strong spatial overlap with the distribution of roe deer and fallow deer. Our findings document the widespread presence and high recent prevalence of L. andaluciensis in southern Spain and identify cervids, particularly roe deer, as its primary hosts. The extensive suitable habitat predicted beyond its current known range and the recording of its presence in Italy suggest that the potential distribution is larger than expected and the species may have been overlooked in Spain and probably in other countries of southern Europe. This study provides a critical baseline for monitoring the population dynamics and assessing the ecological and veterinary impact of this neglected ectoparasite.