Sugar aversion hampers cockroach coupling

A new study from North Carolina State University shows the behavioral mechanism behind a sweet cockroach mating ritual that leads to rejected males.

In order to attract and hold female attention long enough to start a relationship, male german roaches offer females a pre-mating gift of body secretions that combines sugars and fats.

It is common in insects and other animals for males to present females with a tasty or valuable gift every day.

The study shows that when females mix their saliva with the male's, it degrades the sweet treat of sugar to a bitter pill that ends the courting ritual.

Female German roaches are turning down this nuptial gift and the chance to mate and wanted to understand more about the mechanism behind it.

The roaches love sugar. Wada-Katsumata published a paper in 2013 that showed the neural mechanism behind the German roaches' aversion to sugar, a behavior that may have become more pronounced due to the presence of sugar in roach baits placed inside homes. In a paper published in 2021, Wada-Katsumata and Schal showed that saliva from roaches can convert sugars into sugars.

In this case maltose and maltotriose, which are usually preferred by females, are some of the sugars in male roaches' secretions. She said that maltose is easy to convert to glucose, while maltotriose is more complex and takes a bit longer to break down.

Schal said thatCockroach saliva has a class of chemicals that break down sugars.

Bipeds are likely to be unfamiliar to the cockroach mating process. Males approach females, raise their wings, and release chemicals on their backs. Females will climb onto the male's back to feed on the secretion. While she feeds, the male will grab her with a hooked penis and move into a position to have sex. The rapid chemical conversion of complex sugars to simple sugars in saliva could kill the mood for females who are not interested in sugar. The male uses a second penis to transfer a sperm package to the female if he succeeds.

The researchers conducted various experiments to find out how glucose aversion affects cockroach courting. When feeding from a wild-type male that was not averse toglucose, they found that females interrupted feeding more frequently. Men with higher levels of maltotriose in their saliva were given more time to start having sex.

The quality of the male secretion was changed by the researchers. The more successful the sessions, the more females enjoyed fructose and fed on it longer.

There is a tradeoff between sexual selection and natural selection. Think of deer as an example. Male deer have horns, not for natural selection, but for sexual selection to appeal to females and serve as useful weapons in competition with other males. The cockroach's tergal glands evolved to attract females in the context of sexual selection.

Wild-type females accept the sugar. The wild-type secretions are not accepted by Glucose-averse females. Males can make more maltotriose which takes longer to convert to sugar, or try to mate faster. Wada-Katsumata said that under sexual selection, the male's sexual behavior is being altered by the trait of glucose aversion.

The study told manufacturers not to use the substance in baits. All sugars that containglucose are recommended by the 2021, studies. The roaches will ignore baits made with sugars. The trait will be passed down in larger numbers as more roaches survive.

Schal said that we are constantly in an evolutionary battle with roaches.

Nature Communications Biology has a study in it. The paper was co-authored by Eduardo Hatano, a PhD student and a professor.

More information: "Rapid evolution of an adaptive taste polymorphism disrupts courtship behavior", Communications Biology (2022). DOI: 10.1038/s42003-022-03415-8 Journal information: Communications Biology Citation: Sugar aversion hampers cockroach coupling (2022, May 12) retrieved 12 May 2022 from https://phys.org/news/2022-05-sugar-aversion-hampers-cockroach-coupling.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.