Connect the four pics.
Answer in comments.
Answer: These are all species named after Frank Zappa. The four pics are respectively Zappa Confluentus, Pachygnatha Zappa, Amaurotoma Zappa and Phialella Zappai.
Correctly answered by Praneetha and Sharath. Nice crack!! 
Zappa Confluentus, Pachygnatha Zappa, Amaurotoma Zappa and Phialella Zappai
Frank Zappa
Frank Zappa