Alien invasives can disturb the ecosystem with serious environmental, ecological and economic consequences. Insect invasives have become an environmental concern in India. The invasives also have impact on natural resources like native plants and animals. The yellow crazy ants, Anoplolepis longipes Emery from Hawaii have invaded native ecosystems of Christmas Island in the Indian Ocean. These ants disturbed and displaced Red land crab (Gecarcoidea natalis Pockock), a variety of arthropod, and some reptiles, birds and mammals. Coconut hispid beetle, Brontispa longissima Gestro var. Selebensis is hispid palm leaf beetle that attacks coconut tree and is native of Indonesia. It is an introduced pest in 20 countries and many islands in the Pacific Ocean and has been recently found in India. Their impacts on tropical and subtropical cropping systems have been severe. Woolly aphid, Adelges has severe adverse ecological impacts which will become more severe as its distribution expands on Hemlock trees which provide important habitats for many wildlife species in Canada and North America. Erythrina gall wasp, Quadrastichus erythrinae Kim (Eulophidae: Hymenoptera) invasive insect pest on Erythrina spp in Kerala and Karnataka was first reported in Taiwan. Whiteflies Aleurodicus disperses Russel native of Caribbean and Central America have spread to Hawaii, Sri Lanka and India causing damage to many horticultural crops and teak plantations. On continents, the threat of invasives to biodiversity is variable. It is better known in developed countries than developing ones. Insect invasive species have proved to be one of the main drivers behind biodiversity loss, affecting landscapes, inducing transformation of ecosystems, undermining the buffering role played by indigenous species and many more impacts that can not be predicted now.