{"id":954794,"date":"2026-11-06T14:16:10","date_gmt":"2026-11-06T14:16:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/954794\/"},"modified":"2026-11-06T14:16:10","modified_gmt":"2026-11-06T14:16:10","slug":"these-bizarre-insects-make-sounds-with-their-genitals-to-escape-hungry-predators","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/954794\/","title":{"rendered":"These bizarre insects make sounds with their genitals to escape hungry predators"},"content":{"rendered":"

For tens of millions of years, moths<\/a> have been fending off one of their biggest predators \u2013 bats<\/a>. And to protect themselves from the snapping jaws of death, they\u2019ve had to get quite creative.\u00a0<\/p>\n

One of the most unique defence mechanisms these insects have had to develop shows up in hawkmoths (Sphingidae), a family of moths containing around 1,600 species<\/a>, also commonly known as sphinx moths. To protect themselves from echolocating<\/a> bats, they produce deterring sounds with their genitalia.\u00a0<\/p>\n

Research\u00a0published<\/a>\u00a0in the journal\u00a0Proceedings of the Royal Society B shows that they\u2019ve actually evolved it multiple times across their evolution<\/a> \u2013\u00a0arriving at the same, bizarre adaptation each time.\u00a0<\/p>\n

This discovery builds on more than a decade of research into anti-bat ultrasound production in moths, carried out by Jesse Barber, a sensory ecologist at the American Museum of Natural History in New York City and Akito Kawahara, entomologist from the Florida Museum of Natural History in Gainesville. Their\u00a0earlier work<\/a>\u00a0established this behaviour as one of the most diverse mimicry<\/a> rings on the planet.\u00a0<\/p>\n

\u201cMale hawkmoths have used their genitalia to produce these sounds across evolution, but other moths, such as tiger moths, use different organs to produce noise,\u201d Paul Masonick, a postdoctoral researcher at the Florida Museum of Natural History and co-author of the study, told BBC Wildlife.<\/p>\n

To investigate the evolution and anatomical details of this remarkable defence mechanism, the scientists combined field experiments, in which they recorded the ultrasound produced by male hawkmoths, with specimens from museum collections to reconstruct their phylogenetic history.\u00a0<\/p>\n

The mechanics\u00a0<\/p>\n

But why genitals? Why was that the natural starting point for an evolution of a sound-making defence? As Masonick says, this has been a known fact across scientific literature for more than a century. The \u2018why\u2019 isn\u2019t very clear, but one thing is certain \u2013 hawkmoths are just quite weird, in general.<\/p>\n

\u201cHawkmoths\u2019 ears are on their mouth organ. They hear with their mouths and they stridulate [produce sound] with their genitals,\u201d he remarked.<\/p>\n

Among the 143 hawkmoth species tested thus far, 77 emit ultrasound. What the scientists uncovered in this study is that different lineages use this mechanism slightly differently.\u00a0<\/p>\n

It always involves the male\u2019s valves \u2013\u00a0little appendages in their genitalia, which they rub against a fixed structure on their abdomen. This is known as a \u2018scraper and file\u2019 system, which Masonick likens to scraping your finger against a hair comb. \u201cThe comb is the file, and your finger is acting as the scraper. That\u2019s stridulation,\u201d he says.\u00a0<\/p>\n

There are three unique ways this stridulation happens in hawkmoths: scale-on-scale, in which the valve appendages are rubbing against another structure on the undersurface of the abdomen; scale-on-spine, where the scales are dragged across stiff, elongated spines sticking out of the posterior of the body; and scale-on-nodule, in which the valvular scales are rubbed against small bumps and ridges covering the male genitalia.\u00a0<\/p>\n

\"\"The three distinct stridulatory systems in hawkmoths. Credit: Masonick et al.<\/p>\n

The escape<\/p>\n

Some hawkmoths are \u2018better\u2019 at deterring bats, because the kind of sound they\u2019re able to produce influences how they ultimately escape the predator.\u00a0<\/p>\n

\u201cThere\u2019s one lineage in particular,\u00a0Sphinginae. These moths have ears, and produce sound with a really high duty cycle,\u201d says Masonick. \u201cThis is the proportion of time that the sound is being emitted during a stridulatory bout. We think that this can jam the bat sonar and confuse an echolocating bat<\/a>.\u201d<\/p>\n

Not all moths are lucky enough to be able to produce sound of this quality, but they still find a way to fight off their predators. Some make sounds with lower duty cycles that the bat might associate with something negative, effectively tricking it into not even trying to target the moth.\u00a0<\/p>\n

\u201cHawkmoths are palatable to bats, but there are many toxic moths out there, like tiger moths,\u201d says Masonick. \u201cSome tiger moths also produce ultrasound. So, if a bat has had a negative experience eating a tiger moth, and encounters a hawkmoth producing similar noise, it might avoid it. This is a potential form of mimicry.\u201d<\/p>\n

Then there are hawkmoths who are deaf and can\u2019t hear a bat approaching \u2013 but even those use stridulation, albeit as a last-ditch effort to escape once they\u2019ve been captured.<\/p>\n

\u201cUsually, bats don\u2019t just bite large moths out of the air, but wrap their wings and tail membranes around them, manipulating it for a second before going in for the kill,\u201d explains Masonick. \u201cDuring that split second, we think the moth might have enough time to emit noise and startle the bat enough to be released from its grasp.\u201d<\/p>\n

Although most hawkmoths are nocturnal, just like most bats, some of them actually prefer either the day or evening. Those species, such as the hummingbird hawkmoth<\/a>, have lost the ability to stridulate. They don\u2019t have the organs or ears, despite being closely related to the nocturnal species, which further highlights how predator-prey interactions influence diverse adaptations across the animal kingdom.\u00a0<\/p>\n

Hummingbird hawkmoth feeding nectar from flower. Credit:\u00a0Ilya2k\/Getty Images
\nNext frontier\u00a0<\/p>\n

According to Masonick, the next question to be answered when it comes to ultrasound production in hawkmoths is: what are the females<\/a> doing?\u00a0<\/p>\n

\u201cWe have very limited acoustic data for females but based on some of my co-authors\u2019 earlier work, we know there are some females that do produce ultrasound with their genitals,\u201d he says.\u00a0<\/p>\n

\u201cBut they don\u2019t have the same structures that the males do, so we have no idea how they\u2019re doing it. It\u2019s the Wild West, the next frontier when it comes to hawkmoth bioacoustics research.\u201d<\/p>\n

Read the full findings\u00a0here<\/a>.<\/p>\n

Top image: Australian hawkmoth perched on a leaf. Credit: Ken Griffiths\/Getty Images<\/p>\n","protected":false},"excerpt":{"rendered":"For tens of millions of years, moths have been fending off one of their biggest predators \u2013 bats.…\n","protected":false},"author":2,"featured_media":954795,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[64,63,128],"class_list":["post-954794","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-au","tag-australia","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/954794","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=954794"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/954794\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/954795"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=954794"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=954794"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=954794"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}