I believe this is the article you are referring to. It has gotten a lot of publicity and is good for raising awareness.

However, this article explains that the main patterns affecting insect biomass (not abundance diversity) and in the discussion explains why the long-term study above may not account for larger effects, such as an increase in temperature in a historically mild climate. They specifically designate a subsection of the discussion to comparisons between the two studies.

edited for clarification