In Rajasthan, 50% losses are caused from a single nematode, which is:

✅Explanation:
In Rajasthan, the cereal cyst nematode (Heterodera avenae) is a major pest responsible for significant yield losses in wheat and barley crops. Under severe infestations, it can cause yield losses of up to 50% or even more. This nematode is particularly problematic in the sandy soils of Rajasthan, where it can thrive and reproduce rapidly.