tentou-mushi テントウムシ

Translation

tentou-mushi means "Ladybug" in English.

tentou-mushi is normally written with katakana, as テントウムシ.
tentou-mushi written with hiragana is てんとうむし.

tentou-mushi written with kanji is 天道虫.
These are jouyou kanji 常用漢字, taught in the second year of shougakkou 小学校.

tentou-mushi may also be written as 紅娘 or 瓢虫.

Despite the name, Ladybugs, also called Ladybirds, are neither Bugs nor Birds nor ladies: they're Beetles, as they belong to the order Coleoptera, and male ladybugs exist too.
tentou 天道, or tendou 天道, literally "Heaven Path," refers to the path travelled by the heavenly bodies, i.e. the stars, a.k.a. the gods, deities, etc. In Japanese, the "Sun," taiyou 太陽, may also be called otentousama お天道さま. The word tentou also refers to heavenly God and "Supreme Deity" Shàngdì 上帝.^[1][2]
tentou-mushi 紅娘 is a way to write Ladybug in Japanese with the kanji for "red" 紅 and "girl" 娘, meaning more-or-less "red girl." Similarly, Coccinellidae, the scientific name for the Ladybug, comes from the Latin word coccineus, which means "scarlet," a tone of red.^[3]

Scientific name: Coccinellidae.

Beware: some kanji that are difficult to handwrite are easy to type on the computer, which may skew the usage statistics.