My bags were packed and I was all set to head back home after a couple of days in the wild. I came out of my room having completed the customary last-minute check for anything that might have been inadvertently left behind. As I walked out, I espied a gorgeous little hard-to-miss metallic blue-green insect flying about. Out of curiosity, I stopped to see what it was up to. Even as I watched, it disappeared under a wooden table in the corridor of the building. The usual series of events occurred – my camera bag came out and so did the camera; with my gear in place, I was all set to watch and photograph what was likely to transpire.
I bent down and peered under the table, and was pleasantly surprised to see the nest of a beautiful Potter Wasp (Delta conoideum), in the angle between one of the legs and a side of the table. The Potter Wasp was sitting on its nest, while the metallic wasp that had caught my eye earlier was hovering about the nest.
I quickly crawled under the table and positioned myself to witness some action. Soon, the metallic wasp went closer to the Potter Wasp and chased it away. It was at this juncture that I guessed the metallic insect to be a Cuckoo Wasp! This interaction happened several times during my wait under the table. At times, the two wasps even collided mid-air; though the Cuckoo Wasp was much smaller than the Potter Wasp, it seemed very capable of taking on its larger cousin.
The metallic Cuckoo Wasp finally landed on the mud nest, wandered about it for a few minutes, and then settled in one place. It seemed to be using its head to do something to the mud nest. I realised what it was up to only when my attention was drawn to the mud that was falling down to the ground – it was digging into the nest! After a few minutes, it moved a bit, and the end of its abdomen was now in the almost-imperceptibly-little cavity that had been excavated.
It remained in this position for a while. Though the wasp moved in circles, the tip of its abdomen was plugged into the cavity. I could guess what the Cuckoo Wasp was doing – laying its eggs inside the Potter Wasp’s nest!
The Potter Wasp approached its nest, only to be promptly chased away by the Cuckoo Wasp. The Cuckoo Wasp returned to the nest after chasing away the Potter Wasp, to get on with its business of laying eggs. This happened several times.
At this juncture, I decided to leave the wasps and get on with the journey that had been put on hold. On my return to Bangalore, I shared the images with L.Shyamal, and he confirmed that it indeed was a Cuckoo Wasp; he also gave me the identity of the nest owner.
Many species of Cuckoo Wasps are a metallic blue-green and those with this colouring are often referred to as Emerald Wasps. They belong to the family Chrysididae, represented by some 3000 species around the world. As can be guessed by the name, Cuckoo Wasps lay their eggs inside the nests of other insects – often, other wasps like Potter and Mud-dauber Wasps. The larvae of the Cuckoo Wasps are known to feed on the larvae of the host and also on the food provisioned by the female host for its larvae.
The dramas that unfold in nature are as always surprising, and at the same time, intriguing. I am not sure if I will be at the right place at the right time to see a new generation of Cuckoo Wasps emerge from the nest of the Potter Wasp. However, I shall always cherish the memories of the interaction between the two, the spectacle that I witnessed, and the subsequent learnings about these beautiful wasps!