Unlucky in Devon - 25

Red Spider Mite - By Trancelius (Own work) [CC-BY-3.0 (www.creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

It is unlucky -

"To kill a small red spider, because this insect is supposed to bring money in its track, hence it is often called the "money-spider."

Hewett 1900