Coccinellids in a changing world

Current rates of biodiversity change and loss exceed those historically recorded and show no indication of slowing. Comparisons of recorded extinctions of known species over the last 100 years with rates of extinction of characteristic species in the fossil record indicate that humans have increased the species extinction rate by 100 times. The major drivers of biodiversity change are considered to be habitat change, climate change, invasive species, overexploitation and pollution but changes in biodiversity and ecosystems are most often caused by the interactions between multiple drivers, across both spatial and temporal dimensions. Dietary and habitat generalist and specialist coccinellids should exhibit differing responses to these drivers of change. On continental scales, coccinellids move rather than adapt and when possible, maintain environmental constancy rather than geographic constancy. Only when dispersal is not possible due to barriers of unfavourable habitats must they evolve or die. This means that permanent, relatively continuous latitudinal wildlife corridors are essential to allow species (particularly stenotopic species) to mobilize for survival as environments change. This chapter will review evidence relating specifically to the impacts of drivers of change on coccinellids.