Hi. Your question is incomplete and it would be necessary for a text, a table, a graph or any other element that demonstrates the diversity of species to be presented for this question to be answered. However, I will try to help you as best I can.
The word "diversity" refers to differences and varieties that the same element presents. In this case, a species with little diversity is a species that shows little or no difference between its members. So, to answer your question, you need to identify the species that has the least difference within the community it makes up. For this, you will need to analyze your question complete, with all the elements that make it up.