Statement A is incorrect as species diversity decreases and not increases as we move away from the equator towards the poles temperature decreases and conditions becomes harsh, vegetation decreases and less resources available to support species.
Statement B is correct as Stellar's sea cow and passenger pigeon had extinct which is because of over exploitation by man.
Statement C is correct as Lantana and Eicchornia are invasive weed species in India. These weeds invades disturbed natural ecosystems and adversely affects biodiversity. The weed is distributed throughout India.
Statement D is correct as the historic 'Convention on Biological Diversity' was held in 1992,Biodiversity Convention which is a multilateral treaty.
Statement E is correct as among animals insects are the most species rich taxonomic group, they are most abundant species among animals.
Therefore, the correct answer is option A.