Contracting a disease is nobody’s idea of fun, especially when the disease is of the sexually transmitted variety. As far as humans go, most sexually transmitted diseases can be cured with modern medicine, with the exception of HIV/AIDS, herpes and a few others. As it turns out, humans are far from being the only animals that can fall victim to sexually transmitted diseases, as a sizable amount of cicadas die from a brutal form of fungal disease known as Massospora cicadina.
The existence of Massospora cicadina has been known to scientists for quite some time. In fact, the first documented case of the fungal disease in cicadas was published all the way back in 1879. Now, 140 years later, experts have discovered why this fungal disease, which affects cicadas only, spread so rapidly among their populations.
Massospora cicadina is spread in two ways. The first involves infection during the larval stage. Before cicadas reach adulthood, they spend seventeen years maturing beneath the ground. Some of these larval specimens come into contact with a type of fungus that begins growing on their exoskeletons. Shortly before a compromised larva emerges from the ground’s surface, its changing body chemistry releases compounds that prompt the fungus into infecting its host. In this scenario, a cicada becomes infected shortly before emerging from the ground, which makes their seventeen year long larval stage a waste of time. However, researchers now know that the disease can spread further through sexual activity.
Infected male cicadas that emerge from the larval stage begin acting strangely due to the infection spreading to the brain. This strange behavior among males includes flicking their wings like a female. This wing flicking attracts other males that then try to mate with the infected cicada; instead they become infected too. These infected males then go on to mate with females. These females then mate with more males that are disease-free. Given the rate of sexual activity that occurs during a cicada’s short adult life, the disease spreads rapidly. Between two to five percent of the total cicada population is infected with this disease, and this estimate does not include cicadas that became infected through sexual activity.
Have you ever heard of any other types of sexually transmitted diseases that are spread among insects?