Orb Weaver Sac Question

[dord]

I've been wondering if araneids' eggs will hatch early if kept indoors during winter or if they require the overwintering period, I plan on trying to raise some slings in large mesh butterfly enclosures. One of the staff at my school caught an orange Araneus marmoreus to show my biology class, it ended up making a sac on the side of the jar. My cousin says he found a mother Argiope aurantia as well, very excited!

 

[WildSpider]

I've been wondering if araneids' eggs will hatch early if kept indoors during winter or if they require the overwintering period, I plan on trying to raise some slings in large mesh butterfly enclosures. One of the staff at my school caught an orange Araneus marmoreus to show my biology class, it ended up making a sac on the side of the jar. My cousin says he found a mother Argiope aurantia as well, very excited!

That's a cool project you've got planned ! I can't answer your question about the eggs but if I might suggest keeping the slings in another enclosure than the one planned. Spiders can get their tarsal claws stuck in mesh.

 

[Ungoliant]

I've been wondering if araneids' eggs will hatch early if kept indoors during winter or if they require the overwintering period

I'm not sure. I've never read that they require cold temperatures to emerge at the right time, but I can't rule that out, as many plant and animal species in temperate climates rely on seasonal temperature change.

In late October 2014, we were about to have freezing temperatures for the first time in the season. I found a very gravid-looking Nephila clavipes. Knowing the freeze would kill her, I brought her inside and placed her into a terrarium with the hope that she would be able to make her egg sac. (I didn't want her to die right before she would have had a chance to lay her eggs.) I planned to let the egg sac hatch outside the following spring, when their spiderlings normally emerge.

A few days later, she made the egg sac. The mother passed away a couple months later.

Once spring arrived, and the freezing temperatures were over, I placed the egg sac back outside in the hope that it would hatch. I kept checking on it for months. When it still had not hatched in July 2015 (I normally begin seeing Nephila clavipes spiderlings in late April or early May), I decided to open the egg sac.

To my disappointment, all of the contents were dry and hard.

Normally, these spiders overwinter in their egg sacs without maternal care (as the mothers are killed by freezing temperatures), so I don't think that was the issue.

I think it's unlikely this species needs freezing temperatures, because it is most common in tropical climates that never freeze. (They actually live for 2-3 years in tropical climates, but where there are winter freezes, they are just an annual species.)

Possibilities:

• The eggs were unfertilized. (This seems unlikely, but I can't rule it out.)
• The egg sac was defectively constructed, allowing the contents to dry out.
• The spiderlings could not get out on their own. (Again, this seems unlikely, because in the wild their mothers are dead when they emerge the following spring.)
• The developing spiderlings died for other reasons.

 

[dord]

That's a cool project you've got planned ! I can't answer your question about the eggs but if I might suggest keeping the slings in another enclosure than the one planned. Spiders can get their tarsal claws stuck in mesh.

Oops... forgot about that. Thanks for reminding me.

I'm not sure. I've never read that they require cold temperatures to emerge at the right time, but I can't rule that out, as many plant and animal species in temperate climates rely on seasonal temperature change.

In late October 2014, we were about to have freezing temperatures for the first time in the season. I found a very gravid-looking Nephila clavipes. Knowing the freeze would kill her, I brought her inside and placed her into a terrarium with the hope that she would be able to make her egg sac. (I didn't want her to die right before she would have had a chance to lay her eggs.) I planned to let the egg sac hatch outside the following spring, when their spiderlings normally emerge.

A few days later, she made the egg sac. The mother passed away a couple months later.

Once spring arrived, and the freezing temperatures were over, I placed the egg sac back outside in the hope that it would hatch. I kept checking on it for months. When it still had not hatched in July 2015 (I normally begin seeing Nephila clavipes spiderlings in late April or early May), I decided to open the egg sac.

To my disappointment, all of the contents were dry and hard.

Normally, these spiders overwinter in their egg sacs without maternal care (as the mothers are killed by freezing temperatures), so I don't think that was the issue.

I think it's unlikely this species needs freezing temperatures, because it is most common in tropical climates that never freeze. (They actually live for 2-3 years in tropical climates, but where there are winter freezes, they are just an annual species.)

Possibilities:

• The eggs were unfertilized. (This seems unlikely, but I can't rule it out.)
• The egg sac was defectively constructed, allowing the contents to dry out.
• The spiderlings could not get out on their own. (Again, this seems unlikely, because in the wild their mothers are dead when they emerge the following spring.)
• The developing spiderlings died for other reasons.

I'd heard of the difference between N. clavipes's lifecycle in temperate and tropical climates, though perhaps it's species or genus specific. If I manage to raise slings to adulthood, I'll have to experiment with their sacs.