Breeding Behavior in All Male Colony

[clay coda]

Dear friends of roaches,

I have an all male colony of about twenty g. portentosa who appear to be displaying mating behaviors. At night, they hiss loudly and fight constantly, appearing to defend prime territory in their enclosure. The largest males especially then attempt end-to-end mating with other males, pushing out from their rear what I assume to be their sex organ. They try for about ten seconds while hissing before moving on, generally to fight another male. They appear healthy and the behavior is only potentially problematic for me as it is amazingly loud and goes all night. In the day they are relatively docile and quiet.

In terms of environment, they live in a twenty gallon tank with many cork rounds and egg cartons to hide in which I've heard should be sufficient, but do they possibly need more space? They have constant access to dog food, fresh vegetables and water. Their enclosure doesn't mold over and I live in a warm area. The obvious explanation is a female is among them but I have twice sorted through every one by hand; they all have large protuberances and the additional sections on the underside of their abdomens.

Is it possible they're just exhibiting homosexuality? Has anyone else seen this behavior in an all male colony? I can attempt to create footage of this behavior if people are interested. 

Thanks a million,

[Xenoblatta]

8 hours ago, clay coda said:

Has anyone else seen this behavior in an all male colony?

I have never had a colony with only males, but I have seen this kind of homosexual behaviour in colonies with both sexes... ?‍❤️‍? ?‍❤️‍?

 

[varnon]

That is an interesting observation. My guess would be that they are just doing what male hissers do: feeding, fighting and, mating (the three Fs of animal behavior). They may not have a suitable target for their reproductive behavior, but they still have the drive. I would only talk about sexual orientation in the case that courting both males and females was an option. Here, we cannot say they are homosexual because a lack of females means we can't observe a preference for mating with males vs females.

In Xenoblatta's colonies however, it would be interesting to record the mating preferences of roaches. Maybe there are some that have no preference (bisexual) or prefer other male roaches (homosexual). On the other hand, maybe they would exclusively prefer female roaches if there was no competition. Also, I'm sure you have all observed that the females are often not in the mood.

Very interesting topic. Maybe there is a research project here on sexual preferences in cockroaches.

[clay coda]

8 hours ago, varnon said:

I would only talk about sexual orientation in the case that courting both males and females was an option.

I agree with you here and I think this point is insightful. Sexuality aside I'm mostly curious about the origin of the behavior. I had read that g. portentosa males will only fight and use the mating hiss if a female is present. Has anyone actually observed this happening? Upon thinking on it more, it seems slightly implausible that the drive to mate would disappear completely in the absence of females, though I'm also curious if my males will continue this behavior indefinitely without ever seeing results. 

It might be worth noting that as nymphs they were raised along females and were separated right before adulthood so that I could have a stable colony as pets. Perhaps it would be different if they'd been raised exclusively with other males. I'm curious to hear other experiences with male-to-male sexual behavior and single sex colony mating practices. 

[Test Account]

A few comments

male-male mating is a normal behavior for many insects; see research on Google Scholar

I had a pair of Cotinis mutabilis last summer and they would repeatedly take turns trying to inseminate each other

male Cotinis are also obsessed with inseminating my fingers, and I have seen Dynastes doing this on a finger too