Cicadas are emerging in various parts of the United States after spending 17 years underground—and they may soon have to contend with killer wasps that are out to hunt them.
"Periodical cicadas" are large flying insects that appear at either 13 or 17 year intervals, with the timing staggered in different states, according to the U.S. Department of Agriculture. These differ to "annual cicadas," which emerge every year.
Periodical cicadas spend the majority of their lives underground as "nymphs"—an immature form of the insect. But when the 13 or 17-year period is over—depending on the species—the insects crawl out of the soil and molt, transforming into their adult phase.
These insects are grouped into broods, which each appear during different years. As a result, adults emerge somewhere in the United States, almost very year, with southwest Virginia, North Carolina and West Virginia being the hotspots in 2020.
In their adult phase, cicadas live for two-to-four weeks, and in this time the males try and attract a female mate by producing a loud buzzing sound.
While this buzzing sound is key to the proliferation of the cicadas, the "singing" of the males also coincides with the emergence from the ground of adult cicada killer wasps in some parts of the United States, The North Plate Telegraph reported.
These insects, some species of which grow up to two inches in length, hunt both male and female cicadas, catching them in trees, on the ground or mid-flight. Once the wasps have captured a cicada, they sting the insect in order to paralyze it. They then drag the cicada back to their burrow, providing food for their growing eggs.
Killer wasps are not the only threat to cicadas. New research has revealed gruesome insights into the parasitic fungus Massospora, which manipulates infected male cicadas into flicking their wings like females—a display that the males see as an invitation to mate.
This tempts the unsuspecting male to approach, thus, providing the fungus—which contains hallucinogenic compounds that are found in magic mushrooms—with an effective way to jump from one insect to another, according to a study published in the journal PLOS Pathogens.
"Essentially, the cicadas are luring others into becoming infected because their healthy counterparts are interested in mating," Brian Lovett, a co-author from West Virginia University, said in a statement. "The bioactive compounds may manipulate the insect to stay awake and continue to transmit the pathogen for longer."
The fungus has horrific consequences for the cicada, eating away at the insect's genitals and abdomen, while producing fungal spores that can infect other individuals. The authors of the PLOS study compared Massospora to rabies, which also takes over the body of its living host as a means to spread to other individuals.
"When you're infected with rabies, you become aggressive, you become afraid of water and you don't swallow," Lovett said. "The virus is passed through saliva and all of those symptoms essentially turn you into a rabies-spreading machine where you're more likely to bite people.
"In that sense, we're all very familiar with active host transmission. Since we are also animals like insects, we like to think we have complete control over our decisions and we take our freewill for granted.
"But when these pathogens infect cicadas, it's very clear that the pathogen is pulling the behavioral levers of the cicada to cause it to do things which are not in the interest of the cicada but is very much in the interest of the pathogen," he said.
Matthew Kasson, another co-author of the study from West Virginia University, said in a statement: "The fungus could more or less lay in wait inside its host for the next 17 years until something awakens it, perhaps a hormone cue, where it possibly lays dormant and asymptomatic in its cicada host."
