A recent compilation from Culture.pl contains a long article on entomological etymology. Here are some excerpts on flies and mosquitoes.
Remaining in the circle of bugs from the family of flies, let’s discuss one of their most popular representatives, the housefly (Latin name, Musca domestica). The word mucha has been present in Polish since the 15th century and is a general Slavic word. It comes from the Proto-Slavic *mucha, *mous-ā, ‘fly’.
Andrzej Bańkowski describes the meaning of the word mucha as ‘unclear’. For this word, he seeks the etymology in the Sanskrit root of the verb muṣ-, ‘to steal, to rob’. Wiesław Boryś, on the other hand, believes that it is a word with an onomatopoeic root, from the sound made by flying insects, based on *mū- / *mus-. This root was expanded by the suffix -sā, which then became the regular suffix -cha. Similarly, the same transformation occurred in the suffix of the word pchła (flea).
The word mucha is also used to name other bugs, e.g. a szkląca mucha (glazed [lantern] fly) is another expression for a firefly. The diminutive of the word fly (muszka) is very popular and is the source of, among other things, the common name for the diminutive fruit fly: muszka wocówka. Mucha also creates many word compounds: for example, muchomór, a toadstool is a fungus that poisons and kills flies, and a muchołówka, flytrap, is a carnivorous plant that eats flies.
For humans, a fly is not a useful animal but rather a nuisance. You can say about someone that they are as pesky as a fly: natrętny jak mucha. Flies are associated with dirt and stench, so when something is described as mucha nie siada, ‘a fly won’t land on it’, it means that it is ‘successful, perfect, impeccable’, so clean that a fly does not want to be there. When someone is lured by something, strives to achieve something, it is said that they fly to something / someone like a fly to glue / to honey: jak mucha na lep / do miodu. On the other hand, ruszać się jak mucha w mazi / smole / miodzie, to move like a fly in goo, tar, honey, means ‘to do something slowly, sluggishly, to be lazy’. Ginąć / padać jak muchy, to die / to fall like flies, means ‘en masse’. One can also have muchy w nosie, flies up your nose, ‘to be in a bad mood’.
Another useless insect that makes people’s lives miserable is komar (the mosquito). The earlier form of the name for this insect is komor; Franciszek Sławski provides the variant forms kumar, kumor. This term functioned in many local and personal names (e.g. the towns of Komorowice, Komorowo, Komorów). It was not until the 19th century that the name with the suffix -ar became popular: the mosquito, popularized by, among others, writers from the Borderlands – Adam Mickiewicz devoted a poem to this bug. In the poem ‘Komar, niewielkie licho’ (The mosquito, little devil), he described a situation that is also probably familiar to everyone today: …
All the forms mentioned above come from the Proto-Slavic word *komarъ(or *komarьwith a soft yer), which in turn comes from the Proto-Indo-European onomatopoeic root *kem- / *kom-, ‘to buzz’. Wiesław Boryś explains the original meaning of komar as ‘(persistently) buzzing bug’.
A mosquito is primarily associated with annoyance, intrusiveness – hence you can przekomarzać się z kimś (trade barbs with someone), which Brückner translates as ‘to irritate someone like a mosquito’. You can also say about someone that they ucięli komara (lit., cut a mosquito), meaning to take a short nap, usually without getting enough sleep.
Far Outliers 