This is a juvenile form of the Cereal leaf beetle (Oulema melanopus) after being parasitized by Tetrastichus julis, a parasitoid wasp which lays its eggs inside the larva of the beetle. The eggs hatch within the larvae and begin to feed while it is still alive, before they burst out and kill it.
The veterinarians felt that the loss of her litter had caused the tigress to fall into a depression. The doctors decided that if the tigress could surrogate another mother's cubs, perhaps she would improve. After checking with many other zoos across the country, the depressing news was that there were no tiger cubs of the right age to introduce to the mourning mother..