Contribution to the knowledge of the distribution of Chaoborus species (Diptera: Chaoboridae) in the NE Iberian Peninsula, with notes on the spatial and temporal segregation among them

Contribution to the knowledge of the distribution of Chaoborus species (Diptera: Chaoboridae) in the NE Iberian Peninsula, with notes on the spatial and temporal segregation among them Phantom midges are characteristic inhabitants of standing waters and are well known for their diel migrations. Despite the extensive body of literature covering their ecology, there are still knowledge gaps with regards to the factors that determine their distribution. Furthermore, although spatial and temporal segregation patterns among chaoborids have long been reported, the prevalence of such patterns in shallow waters remains unclear. We investigated the distribution of Chaoborus species, as well as their spatial and temporal segregation and diel mesohabitat migration, in the NE Iberian Peninsula. We detected three Chaoborus species (C. crystallinus, C. pallidus and C. flavicans), with the latter being the most dominant, and co-occurrences among these species being very low. C. flavicans did not perform diel horizontal migrations, although in one of the ponds it showed high affinities to vegetated areas during both dayand night-time, similar to its potential predators. Therefore, although we did not observe the role of diel horizontal migrations as an antipredator mechanism in shallow water bodies, aquatic vegetation could confer refuge to the chaoborid larvae.