Research I conducted in Puerto Rico’s Luquillo Rainforest uncovered a major collapse of insect populations between 1976 and 2012, with total biomass caught in sticky traps and sweep nets declining by 65% to 98% (Lister and Garcia, 2018). Long-term data for forest insectivores indicated they declined in parallel with their insect prey in a classic bottom-up trophic cascade. At mid-elevations, mean annual temperature increased by 2°C since the 1970s. Our analyses implicated climate warming and rainfall as major drivers of insect decline. To determine if these trends are occurring in other tropical locations, I received a grant to repeat our Puerto Rico study in a tropical dry forest within the Chamela-Cuixmala Biosphere Reserve in western Mexico.
