May 9 - Thelazia callipaeda

Oriental eyeworm, Thelazia callipaeda, is kind of a gruesome parasite. These nematodes are transmitted by flies - but not biting flies - just those that come to lap up tears from the eyes of vertebrate animals. The larvae are swallowed by these flies where they will go through a couple of developmental stages and then move to the mouthparts of the fly, where they can be released the next time the insect feeds from the tears or secretions. This species has an almost world-wide distribution and can infect many canids, cats and rabbits - and, in some cases, humans. On top of the gross factor (sorry about the photo), they can cause health issues such as conjunctivitis, visual impairment and corneal scarring.