Millipedes: North American Natives

[Harlequin]

My A. evides are molting, so I thought I'd post a couple photos of their molting chambers, which they are building at or near the surface of the substrate (surprisingly)


See it? It's on the leaf, and it's about the size of a grape.

I took it out of the substrate for a moment to make it more visible for the photos:

 

[billrogers]

Congratulations on your finds! I do not think that the species is difficult to breed, but I have not done so myself. Strangely, all seven of my Narceus sp. millipedes are female. While it could be chance (but all things being equal, the odds are 1 in 128 or a 0.008% probability), such gender disparity has been observed in several millipede species.
Anyway, you'll want to have a male with one or more females (there is no problem with having more than one male, but I think it is best to not have more males than females) in an enclosure at least shoebox size with at least 4 in of substrate. The substrate could consist of compost throughout (such as the millipede substrate from BugsInCyberspace) or if you use coir as a base, make sure that you mix finely ground well-decayed wood or leaves into it (I like to use fermented oak sawdust from BugsInCyberspace) so that plings will have access to food throughout the substrate. The substrate should be kept moist but not saturated anywhere.

Btw, in Spriobolids such as Narceus americanus, males can be identified by their missing two pairs of legs (a pair on the eighth and ninth segments), the first pair of which is replaced by gonopods. You can see the gap in this male Narceus americanus-annularis male:

I realized something... I have found maybe four adult N. americanus under logs and all have been females (as far as I am aware, but I am no expert lol), but I found one male in one of my pitfall traps, and another climbing a rock wall. I wonder in the males don't hide like the females do or prefer to hide somewhere else. I also found around six juvie pedes under logs but I can't tell their gender for awhile.

BTW, what is the growth rate with these guys?

 

[SDCPs]

This is an incredible thread. Thanks for the photos and thanks for starting it!! You have excellent photography skills or a great camera--probably both!

 

[Hisserdude]

My A. evides are molting, so I thought I'd post a couple photos of their molting chambers, which they are building at or near the surface of the substrate (surprisingly)

View attachment 213417
See it? It's on the leaf, and it's about the size of a grape.

I took it out of the substrate for a moment to make it more visible for the photos:
View attachment 213418 View attachment 213419

Very cool, glad they seem to be doing well for you! Interesting how they make their molting chambers on top of the substrate, would have though they would make them at the bottom of their cage if anything.

 

[Harlequin]

I realized something... I have found maybe four adult N. americanus under logs and all have been females (as far as I am aware, but I am no expert lol), but I found one male in one of my pitfall traps, and another climbing a rock wall. I wonder in the males don't hide like the females do or prefer to hide somewhere else. I also found around six juvie pedes under logs but I can't tell their gender for awhile.

BTW, what is the growth rate with these guys?

Hmm... @ErinM31 would probably be better to answer this since she has experience keeping them, but I know the gender skew is very high in favor of females with N. americanus. I was thinking it was like 10 or 12 to 1, but it's been a while since I ran across it. I've noticed that in several species of millipedes, the males seem to wander more than females, meaning that females are more often found when digging in debris, whereas males are more often found or trapped while traveling. I had a great deal of difficulty finding male Abacion while searching through leaf debris, but I found 2 large males traveling across the open ground on one of my night collections.
As far as far as the growth rate, they take years to mature, 4-5 if I recall. They're very slow-growing.

This is an incredible thread. Thanks for the photos and thanks for starting it!! You have excellent photography skills or a great camera--probably both!

Thanks! Actually, most of the photos I've posted were shot with an iPhone 5S with a macro attachment. I have an SLR with better lenses, but the iPhone is a lot handier for a quick snapshot

Very cool, glad they seem to be doing well for you! Interesting how they make their molting chambers on top of the substrate, would have though they would make them at the bottom of their cage if anything.

Thanks! Yeah, I'm not sure if they're molting on the surface because that's their natural habits or because the substrate is really damp. I have to keep that box overly damp because it's the one that has plings in it, so the subadults may be molting on the surface due to moisture. But that's just a guess.

 

[ErinM31]

Hmm... @ErinM31 would probably be better to answer this since she has experience keeping them, but I know the gender skew is very high in favor of females with N. americanus. I was thinking it was like 10 or 12 to 1, but it's been a while since I ran across it. I've noticed that in several species of millipedes, the males seem to wander more than females, meaning that females are more often found when digging in debris, whereas males are more often found or trapped while traveling. I had a great deal of difficulty finding male Abacion while searching through leaf debris, but I found 2 large males traveling across the open ground on one of my night collections.
As far as far as the growth rate, they take years to mature, 4-5 if I recall. They're very slow-growing.

I'm afraid I haven't experience enough with this species to answer. I have not read of such behavior differences between genders in any species of millipede, but there could well be studies of which I am not aware (but would be very interested in!). Many species can be found in groups (both genders) while others tend to be found singly (again both genders). Gender skew has definitely been reported in millipedes, such as Orthoporus ornatus. I have personally found a gender skew in Narceus, with all seven I have of the genus being female. It is interesting that both @billrogers and @Harlequin have found males from completely different orders traveling -- like male spiders looking for a mate. I will inquire and look for any studies on the subject and if it has not been done, someone certainly should!

As for growth rate, I have not had mine for long, but I believe that Harlequinn is correct and they take around 4 years to mature. From what I've seen of my Narceus gordanus, they take a looong time to complete a molt and there is no noticeable difference afterward (maybe in part because they were buried for over a month -- it's not like I've been measuring them). It is quite a different experience that with tarantula slings!