(Courtesy: “Drosophila are hosts to the first described parasitoid wasp of adult flies” in nature, with authors’ permission)
A new species of wasp has been discovered that lays its eggs inside adult fruit flies. The wasp larva grows inside the fly and then rips the fly open when it emerges, a recent study described.
Known as Syntretus perlmani the adult wasp lives throughout the eastern U.S., with the ones analyzed in the study collected from Mississippi, Alabama and North Carolina.
S. perlmani.
(Matthew Ballinger / FOX Weather)
An adult female wasp, which is smaller than the lead tip of a pencil, infects a larger adult fruit fly by stabbing it in the abdomen with an organ that she then uses to inject an egg into the insect.
During the study, scientists observed a host fly that appeared to be aware of the wasp’s attempt to deposit her egg and was seen trying to defend itself.
Wasp tries to implant egg into fruit fly.
(“Drosophila are hosts to the first described parasitoid wasp of adult flies” in nature, with authors’ permission / FOX Weather)
The egg grows for about 18 days, and the fly remains reasonably active during this time.
“I can speculate that it’s in the wasp larva’s best interest that their fly host still be able to acquire food resources during the nearly three-week infection,” researcher Logan D. Moore told FOX Weather.
TEXAS WARNS OF CICADA-KILLING WASPS THAT ARE PARALYZING PREY ACROSS THE STATE
Although the fly continues to live with the wasp egg growing larger inside, it is losing nutrients and some of its bodily functions to the egg.
Wasp larva growing inside fruit fly.
(Matthew Ballinger / FOX Weather)
“Parasitic infection by this wasp larva alters the behavior of the fly by diminishing its ability to successfully reproduce,” said Scott Richard Shaw, one of the study’s authors.
As its reproductive capabilities diminish, the wasp larva growing inside it thrives and eventually emerges by ripping through the fruit fly.
Wasp larva emerging from fruit fly.
(Matthew Ballinger / FOX Weather)
The insect world is filled with examples of parasitic species, with most parasitic wasps targeting juvenile insects. Thus, the discovery with S. perlmani is notable.
“What is so unusual about this case is that the newly discovered wasp attacks the adult stage of a fly – the first time this has been discovered,” Shaw said.
Shaw noted that the wasps only attack the adult stage of the fly, so they are most likely active when the flies are active, too.
This suggests that the wasps are more likely to lay their eggs in fruit flies during the spring and summer months in the northern U.S., but potentially year-round in the South.
Wasp larva emerging from fruit fly.
(Matthew Ballinger / FOX Weather)
As unsettling as the wasp’s method may seem, scientists say it may benefit the ecosystem, especially in reducing the fruit fly population.
Shaw pointed out that this underscores the wasps’ potential as natural control agents and their overall economic importance as biological control agents in curbing various insect pests without chemicals.