Question
I have large dark (2cm) beetle type insects on my lemon tree Are the good  or  bad insects

Answer
Rudy, there are literally dozens of beetle species. Although some are beneficial insects, most of the dark ones are problematical. My advice is to spray the trees with pyrythum or rotenone. Both are organic pesticides that are not toxic to humans or the environment. You can purchase these products at most garden centers or through on-line sites such as Planet Natural or Gardens Alive.

Good luck, and please write again if I can ever be of assistance.

Regards,

Mike