Further reports of Anopheles algeriensis Theobald, 1903 (Diptera: Culicidae) in Germany, with evidence of local mass development.

Anopheles algeriensis, a thermophilic mosquito species widely distributed in the Mediterranean, is supposed to be extremely rare and to occur in very low abundances in central and northern Europe. Being one of seven native Anopheles species, it has been reported from Germany a few times only, with all but one report several decades ago. Only in 2013, the endemic persistence of the species was confirmed when two larval specimens were found north of Hamburg. We here report the trapping of An. algeriensis adults at three additional sites in northeastern Germany, with one of them representing two thirds of all mosquitoes collected over two monitored seasons, 2015 and 2017, and a second one with still 12.3% of all specimens caught during the mosquito season 2016. At a third site, one single female was trapped in 2015. Despite considerable efforts, breeding sites could not be identified at the two locations characterised by the high abundances. Anopheles algeriensis has been shown to be vector-competent for Plasmodium parasites and might locally play a role in malaria epidemiology when abundance is high.