This wheel bug nymph is attacking a green cloverworm caterpillar. Wheel bugs are a type of assassin bug. They use their beak-like mouthparts to inject toxin into their prey's body, immobilizing the prey before feeding on its body fluids. Green cloverworms will defoliate soybeans and alfalfa, although they rarely cause significant damage. Wheel bug (Arilus cristatus, Hemiptera:Reduviidae) Caterpillar (Hypena scabra, Lepidoptera: Erebidae | Yasser-Agronomist