Mobile Ad hoc Network (MANET) possesses unique characteristics which makes it vulnerable to security threats. In MANET, it is highly challenging to protect the nodes from cyberattacks. Power conservation improves both life time of nodes as well as the network. Computational capabilities and memory constraints are critical issues in the implementation of cryptographic techniques. Energy and security are two important factors that need to be considered for improving the performance of MANET. So, the incorporation of an energy efficient secure routing protocol becomes inevitable to ensure appropriate action upon the network. The nodes present in a network are limited due to energy constraints and secure communication protocols. Hence, the current study proposed an energy-efficient defense scheme using swarm intelligence approach. The functioning of the proposed method was validated under NS2 simulation. The experimental results confirmed that the proposed work outperformed existing methods in terms of packet delivery ratio, average end-to-end delay and throughput.