Roach question - what IS this?

Lopez · Oct 22, 2003

Emerging from a recently acquired B. discoidales

Is this a roach giving birth (I've never seen it happen before) or some form of parasite?

Excuse the terribly n00bish question, Tarantulas are more my area!

Steven · Oct 22, 2003

it's laying her eggs

trust me

Wade · Oct 22, 2003

It's the cockroach's ootheca, or "egg case". The female sticks it out periodically before it hatches, but does not drop it unless it goes bad. Expect babies soon

Wade

Lopez · Oct 22, 2003

Originally posted by gongyles
it's laying her eggs

trust me

I felt like someone asking "My T is on its back, is it DYING!!!>>>>???" when I posted that picture

Buspirone · Oct 22, 2003

It is kinda creepy looking the first time you see it, even if you are expecting it.

dennis · Oct 22, 2003

At first sight that looked like a male roach to me ...

Michael Jacobi · Oct 22, 2003

Actually, they don't lay eggs. Blaberus discoidalis is among the roaches that have "live birth". The ootheca [eggcase] is produced externally with the eggs in vertical rows. It is then rotated 90 degrees (sideways) and drawn back into the body within 15 minutes or so. Ootheca cannot survive outside the body - as can be witnessed when a roach is fed to a spider or centipede and the ootheca comes out during the attack. Those eggs are useless.

phoenixxavierre · Oct 22, 2003

Ootheca

What you're seeing here is a common thing for some roaches to do (in particular the Madagascar hissing cockroach). I'm not certain what other species do this activity on a regular basis, if any, though I've seen other species do it on singular occasions. Despite this activity, the ootheca is almost always brought to full term. No one really knows why they do this. Sometimes if stressed, malnourished or sick, they will drop the ootheca from their body.

I'd be interested to hear if that one gives birth or if it drops the eggcase.

Peace,

Paul

Michael Jacobi · Oct 22, 2003

Re: Ootheca

Originally posted by phoenixxavierre
What you're seeing here is a common thing for some roaches to do (in particular the Madagascar hissing cockroach). I'm not certain what other species do this activity on a regular basis, if any, though I've seen other species do it on singular occasions. Despite this activity, the ootheca is almost always brought to full term. No one really knows why they do this. Sometimes if stressed, malnourished or sick, they will drop the ootheca from their body.

Yes, it is known why they do this.

As I wrote, eggs are produced EXTERNALLY by "live bearing roaches". This reproduction is ovoviviparity. As successive eggs are produced the ootheca becomes longer - when the female is finished then the ootheca is rotated sideways and drawn back into the body until they "give birth", which is more like a simultaneous hatch and birth.

Roaches that are ovoviviparous include the Mad. Hisser, Blaberus species (discoid, true death's head, giant cave, etc.), Orange-heads (Eublaberus prosticus), Lobsters (Nauphoeta cinerea), Blaptica dubia and banana roaches (Panchlora species). In other words, the most common roaches kept as pets or raised as feeders are all "live bearers" and will produce an ootheca as seen in the Blaberus discoidalis photo. They are all members of the family Blaberidae. This family also includes the only viviparous roach - Diploptera punctata - it never produces an eggcase at all and truly has live birth.

Examples of egg-layers are the German cockroach and the American cockroach (aka Palmetto Bug) - the biggest pests of all!

phoenixxavierre · Oct 22, 2003

Re: Re: Ootheca

Originally posted by SpiderShoppe
Yes, it is known why they do this.

As I wrote, eggs are produced EXTERNALLY by "live bearing roaches". This reproduction is ovoviviparity. As successive eggs are produced the ootheca becomes longer - when the female is finished then the ootheca is rotated sideways and drawn back into the body until they "give birth", which is more like a simultaneous hatch and birth.

Roaches that are ovoviviparous include the Mad. Hisser, Blaberus species (discoid, true death's head, giant cave, etc.), Orange-heads (Eublaberus prosticus), Blaptica dua and banana roaches (Panchlora species). They are all members of the family Blaberidae. This family also includes the only viviparous roach - Diploptera punctata - it never produces an eggcase at all and truly has live birth.

The most common roaches kept as pets or raised as feeders are all "live bearers" and will produce an ootheca as seen in the Blaberus discoidalis photo.

Examples of egg-layers are the German cockroach and the American cockroach (aka Palmetto Bu) - the biggest pests of all!

Very interesting!

By the way, you misunderstood what I said.

Here is a quote from Darrin Vernier's web site on this process in Madagascan Hissing Cockroaches:

"This is a sight often seen with female Hissers that have recently bred. These roaches have relatively recently on the evolutionary scale begun to retain their ootheca (egg case) until birth rather than deposit it immediately for external incubation. The function of this behavior is unknown, but it appears as if the female is almost 'air drying' the ootheca before retracting it into her body. Such behavior is quite common and the ootheca nearly always subsequently carried to term except in cases of environmental stress, illness, or malnutrition."

I wasn't arguing with you, Michael. I was simply making a statement.

Later,

Paul

Michael Jacobi · Oct 22, 2003

Re: Re: Re: Ootheca

Originally posted by phoenixxavierre
... The function of this behavior is unknown, but it appears as if the female is almost 'air drying' the ootheca before retracting it into her body. Such behavior is quite common and the ootheca nearly always subsequently carried to term except in cases of environmental stress, illness, or malnutrition....

That is interesting I've never heard anyone suggest "air drying". The most intriguing thing to me is the 90 degree rotation before pulling the ootheca back inside. I'll have to see what scientific papers I can dig up on the subject. I think most of us hobbyists and dealers are limited to Richie's Allpet Roaches book for our knowledge of their biology. It's time I dig deeper! I'll have my scientist wife search for some papers and I'll come on back and give a report.

Lopez · Oct 23, 2003

Thanks for the comments gents, I shall keep you informed as best I can. This is my first "Roach Experience" and I'm still learning

Longbord1 · Oct 23, 2003

when i first saw it i got this strange taste in my mouth like i was eating General Tso's Chicken\. lol!!!!!!

now i want chinese food
mike:}

Cockroach · Oct 24, 2003

Very cool picture of her egg case. A couple of weeks ago I recieved a colony of 600+ Lobster Cockroaches, and the night that I first had them, I saw one of the females drying her ootheca on a cardboard egg carton. I'd never seen anything like it, and felt the same way I did when I saw my first molting cockroach. Again, very nice picture.

Roach question - what IS this?

Lopez

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Steven

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Wade

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Lopez

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Buspirone

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