Under Mediterranean climatic condition and by a large survey of parasitism on adult Culicidae, two models of host and parasite relationships are compared. Culex pipiens (wintering female) and Arrenurus sp. are characteristic of permanent inland water and Ochlerotatus caspius (wintering eggs) and Thyas barbigera, from salt or brackish water and temporary ponds. The seasonal variation of load (nb mites/indiv.) can be explained by the shorter development of the host, and by traits of life in more or less unpredictable environment. Parasitism cannot control the pullulating mosquitoes except during some weeks, at the end the most favourable periods for culicids.