Scientists in Panama, led by Yves Basset, SIGEO-CTFS Arthropod Program Coordinator, have spent nearly 10 years studying the diversity of arthropods in a tropical forest (San Lorenzo forest). The study, called Project IBISCA-Panama, brought together 102 researchers from 21 different countries. They combed the forest from the floor to the top of the canopy for all insects and plant species. They picked beetles out of dead wood, scaled trees to get leaves and insects off high branches, and flogged trees with insecticides to collect flying insects. In all, 130,000 arthropods were sampled, comprising more than 6,000 identified species.
The findings of this study, which were recently published in Science, show arthropod species outnumbering mammal species by approximately 300 to 1. They similarly outnumber plants by 20 to 1. Scientists involved in the project say the reason for the extreme diversity of arthropods is their tiny size and limited resource requirements. Researchers also found that even for carnivorous arthropods, plant diversity was an indicator of arthropod species richness because plants provide the habitat structure and food resources on which these arthropods and their prey depend.