Females are more likely than males to take advantage of sugar water or other resources.
In an experiment to test the hypothesis that access to nutritional resources would affect the frequency of second matings, females with access to sugar were less likely to mate more than once.
Available food makes the female less receptive to advances from males, which present a nuptial gift as part of courtship.
The gift is a spermatophore, nutritional content mixed into his ejaculate, a package which can be up to 20% of his body weight.
Females with other nutritional resources can afford to refuse a mating.

A female without an additional nutrient source is less choosy in the mating process.
She does not even refuse matings with close relatives, such as brothers.
The species does suffer from inbreeding depression, but it does not seem to take behavioral action to avoid it.

In addition, bean beetles are known to exhibit homosexual behavior.
Males will mount both females and other males.
This could potentially have fitness benefits for the male, as the male does not waste time determining whether his partner is male or female.
Sometimes it is faster to test physically than to attempt to determine via other methods.

The female usually oviposits on the smooth side of a bean rather than the rough top, and it avoids legumes without smooth surfaces.
It also has a way of distributing the eggs among small and large legumes so that each larva has access to roughly the same amount of nutrients; its assessment of legumes is based on mass rather than surface area, and on the number of eggs already present.

When preparing to pupate, the larva digs a cell in the bean and lines it with feces.
If it encounters another larva in the bean, both retreat and create walls of feces.
If the wall is removed, the two larvae fight to the death.
This behavior is not well understood.
Females are more likely than males to take advantage of sugar water or other resources. In an experiment to test the hypothesis that access to nutritional resources would affect the frequency of second matings, females with access to sugar were less likely to mate more than once. Available food makes the female less receptive to advances from males, which present a nuptial gift as part of courtship. The gift is a spermatophore, nutritional content mixed into his ejaculate, a package which can be up to 20% of his body weight. Females with other nutritional resources can afford to refuse a mating.
A female without an additional nutrient source is less choosy in the mating process. She does not even refuse matings with close relatives, such as brothers. The species does suffer from inbreeding depression, but it does not seem to take behavioral action to avoid it.
In addition, bean beetles are known to exhibit homosexual behavior. Males will mount both females and other males. This could potentially have fitness benefits for the male, as the male does not waste time determining whether his partner is male or female. Sometimes it is faster to test physically than to attempt to determine via other methods.
The female usually oviposits on the smooth side of a bean rather than the rough top, and it avoids legumes without smooth surfaces. It also has a way of distributing the eggs among small and large legumes so that each larva has access to roughly the same amount of nutrients; its assessment of legumes is based on mass rather than surface area, and on the number of eggs already present.
When preparing to pupate, the larva digs a cell in the bean and lines it with feces. If it encounters another larva in the bean, both retreat and create walls of feces. If the wall is removed, the two larvae fight to the death. This behavior is not well understood.
Callosobruchus maculatus