Who is the female artist from 70s who sang about Alexander beetle?

The female artist you are referring to is Melanie Safka, who is better known as Melanie. She is an American singer-songwriter who rose to prominence in the 1970s with her hit songs "Brand New Key" and "Lay Down (Candles in the Rain)." However, she did not sing about an "Alexander beetle." Her song from 1971 "Alexander Beetle" is about a horse.