Some German cockroaches have changed their mating strategies
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Some cockroaches have evolved an aversion to the glucose used in their toxic bait. As a result, male cockroaches have adapted their mating strategy. This is the case when natural selection and sexual selection have related effects.
Male cockroaches secrete a few drops of sweet liquid on their backs to lure females into mating. While her female rides him and eats her “wedding gift”, the male slips her genital hook into her and takes her to her prescribed place for her 90 minutes of copulation. Lock in position.
But since glucose-averse females reject sweet gifts, some males have started secreting new milk formulas to hook females faster, says Ayako Wada Katsumata of North Carolina State University in Raleigh. .
“It’s amazing that just one change in taste can stimulate the evolution of both foraging strategies and sexual behavior,” she says.
Pesticide manufacturers often add glucose-rich corn syrup to their bait to mask the bitterness of the venom. was discovered by researchers.
In 2013, Wada-Katsumata and Coby Schal, also at North Carolina State University, tested cockroach neurons and found that glucose-averse individuals actually perceive glucose itself as bitter.
Interested in whether that evolutionary adaptation influences how females respond to male sweet marriage gifts, Wada-Katsumata, Shar and their colleagues videotaped 251 pairs of German cockroaches. recorded (german cockroach) in the laboratory. Cockroaches included those from the Florida population that developed glucose aversion and those that did not.
The researchers found that the glucose-averse females quickly stopped eating the marriage gifts of males from the glucose-averse population and did not mate with them. I was eating male secretions from a glucose-averse population long enough to rock.
The team also found that these males locked onto the female within 2.2 seconds after she began feeding.
Analysis of the secretions revealed that the secretions of the non-glucose aversive group contained five times more glucose than the glucose aversive group. It was also high in maltose, a sugar that breaks down into glucose within seconds when exposed to saliva.
In contrast, the secretions of men in the glucose-averse group were mostly made up of maltotriose, a complex sugar that breaks down to glucose after about 5 minutes in saliva.
This means that by the time a woman can taste the glucose she doesn’t like, it’s too late, says Schall. No. She is engaged in mating and will be engaged in it for 90 minutes.There is no escape.”
The findings clearly show a link between natural selection and sexual selection, which is often difficult to establish in biology, says Katsumata Wada. “I think the glucose-averse cockroach system is a good example for understanding the evolution of animal behavior.”
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