Reproduction is a driving force that motivates animals from all walks of life to engage in behaviors that will boost their likelihood of passing on their genetic information. While foreplay might not be something that springs to mind when thinking of insect sex (as we’re sure you often do), it might surprise you to learn that even beetles are capable of giving a little love before they get their procreation on.
Yes, that’s right. Beetles could well be out there giving each other oral sex as you read this. Namely, the desert darkling beetle Platyope mongolica which was first described in 1835. A new paper published in the journal Ecology and Evolution gives multiple steamy accounts of how males of the species improve their chances of mating by stimulating the females’ genitals with their mouth parts. Something that’s not common among the invertebrates.
The researchers began their deep dive into beetle sex by going out into the field to observe. Far from a simple exercise in voyeurism, the research hoped to glean new insights into the evolutionary significance of oral sexual behavior in insects, which could have wider ramifications on the study of sexual selection and evolution in general. See, it’s not all just watching beetles get it on.
Sexy season for darkling beetles kicks off in early May, and sees the beetles scrabble out of the undergrowth in broad daylight to go in search of a mate. Prospective partners are easy enough to spot as males will begin pursuing females. At first, she’ll resist but if in the mood the female will pause allowing the male to catch up.
Here, the researchers observed that the males would make their first contact with the females’ genitals mouth-first. Multiple observations revealed that the complete mating cycle consisted of four steps: pursuit, oral sexual contact, mounting, and then – the grand finale – copulation.
Interestingly, the male is under some pressure when giving as experimental conditions employing the use of petroleum jelly revealed that if a female is unimpressed by the male’s performance she’ll move along. This was observed several times as males would rub their mouth parts on the female, only to have her leave and they have to pursue them once again. This would carry on until the male successfully reached the fourth and final step.
“This is the first time that precopulatory oral sexual behavior in the desert darkling beetle, P. mongolica, is reported,” wrote the study authors. “We investigated the role of this oral sexual behavior in copulation. The results suggest that precopulatory oral sexual contact, an important phase of mating latency in P. mongolica, plays an important role in copulation.”
The results demonstrate that even in critters as small as beetles, a bit of foreplay can have a big impact on the tolerance and success of copulation.