SCG6538 - Paraguay 1962 – World Health Day “Anopheles Darlingi” MosquitoIssued by the Republic of Paraguay on April 7, 1962, this 1. 50 guaran stamp commemorates World Health Day under the auspices of the World Health Organization (W. H. O.). The design by Mosdssy highlights the Anopheles darlingi mosquito, a principal vector of malaria in South America, shown with its eggs under magnification beside a laboratory microscope. Printed by De La Rue de Colombia, the issue symbolizes scientific research and global efforts