Boll's sand roach nymphs breeding?

B

blatta70

Third Instar
Hello, this is Mark. This past Fall I acquired a colony of Boll's Sand Roaches (Arenivaga bolliana)which included several adult males/females and about twenty or so nymphs of various instars. For those who are not familiar, these roaches are sexually dimorphic with only adult males possesing wings and the adult females appearing as very dark overgrown nymphs. All seem to be doing fine and the adult females have produced several oothecas. However, within the last month, the older nymphs which are an orange-brown color have begun producing small oothecas. I asked the person who I received the roaches from if he had this happen before and he said no. I have been keeping the temperatures in the low 60's during the winter and last month began warming them up to mimic their normal season patterns. They have been feeding on various fruits/vegetation matter as well as plenty of cat food so I doubt this is diet related. I first thought that perhaps this was a different species, possibly a parthenogenic sand roach that matured and had been living with these Boll's sand roaches unnoticed. Several species of the Polyphagidae are parthenogenic so this could certainly happen. But, the breeder claims that these are positively all the same species. Now I'm beginning to wonder if there is something I have done incorrectly to cause this. I keep several species of native, pest, and tropical roaches and have never had this happen before. Any feedback and or suggestions would be greatly appreciated.

Thanks, Mark

 
Hello Mark,

They would have to be adults to produce oothecae, maybe they are simply stunted (out of the group, some of which reached normal size) or your conditions are such that they couldn't reach their wild size. It is very common for insects to not reach full size potential in captivity.

 
Orin, thanks for responding. Any suggestions as to how I could remedy this situation. I would really like to have full sized adults. I currently house them in a ten gallon aquarium which has substrate and the inside back and sides are also lined with coconut fiber which they climb. So, they should have plenty of room. Is there anything else that you can think of that I should be changing.

Thanks, Mark

 
Hi Mark,

Curious about the numbers we're talking here. You said the adult females only produced a couple so far. I forget sometimes because only the males come to the surface, but I have Arenivaga in culture, so I know what the oothecae look like. But how many of these smaller oothecae have you seen? I've noticed a size difference in polyphagid oothecae where some are twice as long as others. Is it possible that you have some recently matured roaches that have just built their first trial oothecae? The first few eggs of females in many phasmid species are "testers". They are considerably different in size, shape and color than the eggs they begin to lay routinely.

I would be interested to see side by side comparisons of your females and also the oothecae if you have the time.

Thanks for sharing...

 
Hello Pete. There are approximately 40 roaches in the aquarium. Right now, only the orangish-brown females which on average are 3/4" in length are producing oothecas. These oothecas are maybe 1/4" long at the most and are a translucent tan. The eggs can be seen through the outer covering of the ootheca. So far I have counted 14 of this sized ootheca. They also have a slightly different shape than the oothecas produced by the full sized dark females that I have. These females are about an inch in length and the oothecas are 1/2". Interestingly, yesterday one of the full sized females began laying individual eggs. Could this be a sign of malnutrition? I feed them fruits, baby food and cat food. All of the food offered to them is consumed readily. Any suggestions?

Thanks, Mark

 
....Have you tried not using cat food at all, and do you use oak leaves? My polyphagids are fed few fruits and vegetables, no prepared pellet/stick/animal food, and nibble on oak leaves. All of mine are very robust as matured females or males.

 
I'm not sure what to make of this. My Texas Arenivaga (haven't looked into species, but possibly the same) are doing just fine. I actually don't have any dried leaves in with them. Matt did just remind me to add some soon, but they seem pretty content for very long periods of time with next to nothing. I drop various bits of table greens in occasionally, but suspect they subsist mostly on the cheap goldfish discs (fish food) that I occasionally sprinkle in. Pinches of fruit and oatmeal-cricket feed are also added from time to time. I have a milk jug cap that they occasionally sit in and eat the discs out of too. Really, mine don't eat much or often and I probably have a similar number in the 2 gallon container. Very low maintenance roaches, adapted probably to sparse livin'.

My females lay normal polyphagid-shaped cases. They are maroonish and translucent enough to count about 14-16 eggs in each one, when held up to the light (in two rows of 7 or 8 eggs). Adult females look very much like P. aegyptiaca (very scarab-like), though 1.5 to 2X as large. They have a dull, faint cream-colored line on the front edge of their pronotum, but are otherwise very dark brown and dusty-looking (always buried). Males are often on the surface at night and also cream in color. Immatures are brownish-red.

My only guess is that a single female would be laying them, but it's not a good guess based on the number 14. A different species is the only thing that makes sense to me, but they just sound way too small for normal ooths.

I do make sure their substrate (potting soil in this case) remains moist enough to discolor in parts of the lower level.

 
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If it's a nutrition issue I'd imagine a mix of crushed hardwood leaves included in the diet could remedy the problem.

 
Several of the smaller females have been producing the "mini" oothecas. I have been observing them carrying the oothecas around for a day or so before releasing. They seem very healthy and active otherwise. It will be interesting to see if these ootheca hatch. I'm not holding my breath though especially if these are starter eggs. I have been checking online and there are several species of Arenivaga found in Texas which is where these were apparently collected. It still makes me wonder if maybe these smaller females are one of these. The only A. bolliana that I am certain I have are the adults that I received with the colony. Several of the adult males have died since, probably do to age. These are the only males that I knowingly have.......no smaller winged male forms.

There are oak leaves in the Arenivaga's housing but there is no evidence of any feeding. The roaches use them for cover more than anything. I do use oak leaves for feeding my Parcoblatta colonies that I have had for years. They also feed on the same diet that I have been giving the Arenivaga and have had no problems. But obviously, there isn't a single diet formula that is suitable for all roach species. Our hobby would be a whole lot easier if there was.

I appreciate everyone's advise. Please let me know if you have anymore suggestions.

Thanks, Mark

 
I reread your original post. You might be right about the oothecae having been produced parthenogenetically. Another possibility is that they are just small, infertile ooths that won't hatch because the species isn't (or is rarely) capable of parthenogenesis. Maybe it's a different species and you don't have males to produce nice big viable ooths. Maybe it's a case of stunted individuals AND they are laying infertile ooths because your males died. I'm still voting for different species because I've never seen a case of several stunted individuals simultaneously and continuously producing stunted eggs/oothecae. Any stunted insects I've raised have always had normal productions once they got their motors running. Parthenogenetic productions are often smaller and can take longer to hatch. Your translucent cases also fit in line with the theory they are unfertilized. It's just a question of whether they hatch or not. If they hatch, it will be interesting to see if any males are among them. Either way, you have something unique, so keep us posted please!

 
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Hello, this is Mark. Well, not much has changed with my sand roaches (species in question) until this morning. I was pleasantly surprised to have had a newly molted adult winged male Boll's Sand Roach. He is normal size and appears in perfect health. Interestingly, he molted from a nymph of the same size and color as the small females producing the oothecas. Right now, my guess is as good as yours. I will keep you posted if anything else occurs.

Mark

 
blatta70 said:
Hello, this is Mark. This past Fall I acquired a colony of Boll's Sand Roaches (Arenivaga bolliana)which included several adult males/females and about twenty or so nymphs of various instars. For those who are not familiar, these roaches are sexually dimorphic with only adult males possesing wings and the adult females appearing as very dark overgrown nymphs. All seem to be doing fine and the adult females have produced several oothecas. However, within the last month, the older nymphs which are an orange-brown color have begun producing small oothecas. I asked the person who I received the roaches from if he had this happen before and he said no. I have been keeping the temperatures in the low 60's during the winter and last month began warming them up to mimic their normal season patterns. They have been feeding on various fruits/vegetation matter as well as plenty of cat food so I doubt this is diet related. I first thought that perhaps this was a different species, possibly a parthenogenic sand roach that matured and had been living with these Boll's sand roaches unnoticed. Several species of the Polyphagidae are parthenogenic so this could certainly happen. But, the breeder claims that these are positively all the same species. Now I'm beginning to wonder if there is something I have done incorrectly to cause this. I keep several species of native, pest, and tropical roaches and have never had this happen before. Any feedback and or suggestions would be greatly appreciated.Thanks, Mark
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Hello, this is Mark. I just wanted to let those who are interested know that I found several newly hatched Arenivaga nymphs today. Apparently the ootheca are fertile after all.

 
I have an update also. In my own culture I found what appear to be two different species of male Arenivaga! One is considerably larger than the other. I know a photo would be helpful, but it's time to feed the bugs at the moment! My culture was wild caught as a colony in Texas.

I do have hatchlings now also.

 
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Peter Clausen said:
I have an update also. In my own culture I found what appear to be two different species of male Arenivaga! One is considerably larger than the other. I know a photo would be helpful, but it's time to feed the bugs at the moment! My culture was wild caught as a colony in Texas.I do have hatchlings now also.
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Are you positive its two species ?? Some roaches the males or females can be radically different in size. Lucihhormetica, Therea, Arenivaga, Byrsotria, and more.....

 
The theory is supported by two different sizes of oothecae as well. I scanned the surface for a male of any kind last night, but no go for a photo. Didn't dig down, but will soon. Plenty of oothecae present in two sizes though. I have to doublecheck, but I believe hatchlings came from one of the larger, darker oothecae (I had separated it).

 
Peter Clausen said:
The theory is supported by two different sizes of oothecae as well. I scanned the surface for a male of any kind last night, but no go for a photo. Didn't dig down, but will soon. Plenty of oothecae present in two sizes though. I have to doublecheck, but I believe hatchlings came from one of the larger, darker oothecae (I had separated it).
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So what you have two species breeding simultaneously in what was thought to be a single species culture? Neat, I wish that happened to me!

 
BugmanPrice said:
So what you have two species breeding simultaneously in what was thought to be a single species culture? Neat, I wish that happened to me!
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Yep, it appears to be true, but seems so unlikely that they would be living together in a single wild colony. I did snap photos of oothecae and males side by side yesterday but haven't downloaded them off the camera yet.

 
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