It's here, the temperatures are rising, the sun is shining... the fine weather is coming! We're already imagining our evenings by the lake, with a little meal and cocktails...𝗲𝘁 𝗱𝗲𝘀 𝗺𝗼𝘂𝘀𝘁𝗶𝗾𝘂𝗲𝘀?
And yes, while we love to enjoy the lake in spring and summer, many species of insects enjoy it too! But are they really mosquitoes, 𝗰𝗲𝘀 𝗽𝗲𝘁𝗶𝘁𝗲𝘀 𝗯𝗲̂𝘁𝗲𝘀 𝗾𝘂𝗶 𝘃𝗼𝗹𝗲𝗻𝘁 𝗲𝗻 𝗴𝗿𝗼𝘂𝗽𝗲𝘀 𝗮𝘂 𝗯𝗼𝗿𝗱 𝗱𝗲 𝗹'𝗲𝗮𝘂?
𝗘𝗵 𝗻𝗼𝗻, 𝗰𝗲 𝘀𝗼𝗻𝘁 𝗱𝗲𝘀 𝗖𝗵𝗶𝗿𝗼𝗻𝗼𝗺𝗲𝘀! This family does indeed look a lot like mosquitoes, and belongs to the same order as them (Diptera, one of the most important insect orders). However, they are distinguished by 𝗹'𝗮𝗯𝘀𝗲𝗻𝗰𝗲 𝗱'𝗼𝗿𝗴𝗮𝗻𝗲 𝗽𝗶𝗾𝘂𝗲𝘂𝗿 (so they're harmless!) and 𝗹𝗮 𝗽𝗿𝗲́𝘀𝗲𝗻𝗰𝗲, 𝗰𝗵𝗲𝘇 𝗹𝗲 𝗺𝗮̂𝗹𝗲, 𝗱'𝗮𝗻𝘁𝗲𝗻𝗻𝗲𝘀 𝗲𝗻 𝗳𝗼𝗿𝗺𝗲 𝗱𝗲 𝗽𝗲𝘁𝗶𝘁𝘀 𝗽𝗹𝘂𝗺𝗲𝗮𝘂𝘅 which give them a fluffy appearance.
During 𝗽𝗲́𝗿𝗶𝗼𝗱𝗲 𝗱𝗲 𝗿𝗲𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻, the males fly in groups along the water's edge or above the trees. They are joined by females, whom they recognise thanks to the acoustic perception organs present on their famous feathers! The female then lays her eggs on the water. The newborn will first go through a larval stage before emerging as an adult.
These include 𝗹𝗲𝘀 𝗹𝗮𝗿𝘃𝗲𝘀 𝗱𝗲 𝗖𝗵𝗶𝗿𝗼𝗻𝗼𝗺𝗶𝗱𝗲́𝘀 𝗱𝗮𝗻𝘀 𝗽𝗿𝗲𝘀𝗾𝘂𝗲 𝘁𝗼𝘂𝘀 𝗺𝗶𝗹𝗶𝗲𝘂𝘅 𝗮𝗾𝘂𝗮𝘁𝗶𝗾𝘂𝗲𝘀 𝗼𝘂 𝘀𝗲𝗺𝗶-𝗮𝗾𝘂𝗮𝘁𝗶𝗾𝘂𝗲𝘀. This includes rivers and lakes as well as tree cavities and sewers! Yuck!
No! These species survive pollution very well and are therefore very important for ecosystems! 𝗖𝗲 𝘀𝗼𝗻𝘁 𝗴𝗲́𝗻𝗲́𝗿𝗮𝗹𝗲𝗺𝗲𝗻𝘁 𝗹𝗲𝘀 𝗽𝗿𝗲𝗺𝗶𝗲̀𝗿𝗲𝘀 𝗲𝘀𝗽𝗲̀𝗰𝗲𝘀 𝗮̀ 𝗿𝗲𝘃𝗲𝗻𝗶𝗿 𝗮𝗽𝗿𝗲̀𝘀 𝘂𝗻𝗲 𝗽𝗼𝗹𝗹𝘂𝘁𝗶𝗼𝗻 𝗼𝗿𝗴𝗮𝗻𝗶𝗾𝘂𝗲 𝗱𝘂𝗿𝗮𝗯𝗹𝗲, 𝗲𝗹𝗹𝗲𝘀 𝗰𝗼𝗻𝘁𝗿𝗶𝗯𝘂𝗲𝗻𝘁 𝗮𝗹𝗼𝗿𝘀 𝗮̀ 𝗹𝗮 𝗿𝗲́𝘀𝗶𝗹𝗶𝗲𝗻𝗰𝗲 𝗱𝗲 𝗹'𝗲́𝗰𝗼𝘀𝘆𝘀𝘁𝗲̀𝗺𝗲. This is because their larvae dig small holes in the surface layers of sediment (the silt deposits at the bottom of the water), bringing oxygen and minerals to the surface. These minerals are necessary for the survival of many species!
These species are also very useful because of their abundance: as they are found everywhere and in large numbers, they form the basis of an entire food chain: 𝗲𝗹𝗹𝗲𝘀 𝗽𝗲𝗿𝗺𝗲𝘁𝘁𝗲𝗻𝘁 𝗱𝗲 𝗻𝗼𝘂𝗿𝗿𝗶𝗿 𝗹𝗲𝘀 𝗱𝗲𝗻𝘁𝘀 𝗱𝗲𝘀 𝗰𝘆𝗰𝗹𝗶𝘀𝘁𝗲𝘀... but also various fish (The Trout and the Féra, for example) Tritons, predatory insects and birds!
So these chironomids are rather nice, aren't they?
Information from Doris, Chironomidae
Photo credit: Entomart and Michel Lonfat
