A number of pathogens and parasites can modify the behavior of arthropods to promote the interests of the pathogen, rather than the arthropod. These pathogens create “zombies”. I have posted in the past on Zombie Ants, Spiders, Bees and Gypsy Moth Caterpillars. This is the Mayfly edition of “Zombies”.
Three Japanese Scientists, recently wrote a review in “Insects” of sex manipulation by endosymbionts of insects. They include in their review a fascinating account of Mayfly alteration. Over 10 percent of the Mayflies, Baetis bicaudatus, are parasitized by Gasteromermis nematodes. The nematodes alter the morphological sex characters of the male mayflies. Externally, the parasitized males do not look like males; they are indistinguishable from females. Internally, they don’t produce eggs and lack the internal reproductive organs of the female.Gasteromermis nematodes also modify the behavior of parasitized mayflies. Unparasitized males will form mating swarms and never return to the water. The parasitized males exhibit the oviposition behavior of the females. The Gasteromermis nematodes must return to the water to find new hosts to parasitize. When the parasitized males return to the water, the nematodes make holes in the abdomen of the adult mayfly and emerge into the water where it can parasitize new hosts. The nematodes have modified the insect behavior to benefit the spread of the nematode.
The nematodes and other parasites and pathogens that “create zombies” typically work by use of chemicals messengers to activate behavior patterns that are innate to the host. These behaviors are activated at a time that is not advantageous to the host, but fully advantageous to its “body snatcher”.