两者都是瓢虫的意思，ladybird是英语叫法，ladybug是美语叫法。

英语的原文解释如下：Ladybug and ladybird refers to the same insect, a Coccinellidae beetle. In North America, the insect is primarily referred to as a ladybug, though sometimes it is called a lady beetle. In British English, the insect is called a ladybird. In the late 1600s, it was also labeled the ladycow. The English Oxford Dictionary discerns that this insect was referred to as “bird” because of its ability to fly, and “lady” in homage to Our Lady, the Virgin Mary.翻译过来，在北美，这种昆虫主要被称为ladybug，有时也被称为lady beetle。在英式英语中，这种昆虫被称为ladybird。在17世纪末，它也被称为ladycow。《牛津英语词典》发现，这种昆虫之所以被称为“bird”，是因为它有飞翔的能力，而“女士”则是为了向圣母玛利亚致敬。