Habitat Fragmentation and Insect Biodiversity Change in Mexican Landscapes

The long-term and large-scale cause of habitat fragmentation and loss is determined by human intervention, primarily due to the expansion of agriculture and increase in deforestation and urbanization. In this chapter, we present case studies to discuss the effects of habitat fragmentation on insect diversity and change in Mexican tropical areas. In this context, insect assemblages have responded in varied and contrasting ways. First, butterfly diversity and abundance from tropical dry forest fragments ranging from 10 to 90% forest cover area responded negatively to habitat loss. Ants and dung beetles from tropical rainforest fragments and surrounding matrix features showed idiosyncratic (significant) responses to patch attributes (the case for hypogeic ants) and/or to landscape composition (the case for dung beetles). At a larger (national) scale, loss of primary vegetation had a significant effect on species composition of dragonflies and damselflies, yet this effect does not necessarily mirror the effects detected for species richness, which likely are driven by species turnover effects. Unveiling complex dynamics for many insect populations and spatial patterns of insect diversity in fragmented landscapes requires accounting for species-level trait effects and responses, along with monitoring of trends in habitat extent and fragmentation over a range of spatial scales.