Question

I need an example where insects introduced for biocontrol have switched hosts over long time frames, perhaps ironically due to success in controlling the original host. Are there long-term risks of short-term success? Are there risks in eradication—would it be beneficial to the overall system to allow EAB to persist at low levels?

Answer 1

Insects as biocontrol agents can be introduced into the ecosystem to control the host organisms. This strategy widely helped in controlling the invasive weeds in the agricultural ecosystem by introducing the natural herbivorous insects.

Rhinocyllus conicus (inflorescence-feeding weevil) has introduced into agriculture in North America to control Carduus spp(thistle weed) which is a widespread weed. It helps to limit the adverse effects of pests without implementing chemical and mechanical methods which are expensive and less eco-friendly. Introducing Rhinocyllus is an initial success while dealing with invasive thistle species.

In longterm observations, the introduced bio-controlling agent can cause unintended effects. Current research suggesting that R. conicus populations are increasing day by day in nature preserves and National Parks in the central USA. These increased R.conicus showing adverse effects on native thistles and their inflorescence insects. So unintentionally the number of native plants affected and results in loss of biodiversity and ecosystem balance.