8 replies to this topic

[Aaron567]

Solenopsis pergandei

 

Solenopsis pergandei is a species of subterranean thief ants that is native and most abundant in Florida and other parts of the far southeastern US but has apparently been found as far west as New Mexico and as far north as Virginia. It is definitely one of the largest, if not the largest, species of subterranean Solenopsis in the US, with queens able to reach about 6 millimeters in length and workers exceeding 2 millimeters. In addition to that, they're also very bulky which makes them look even larger. Workers of S. pergandei have eyes that are nearly nonexistent, and this is due to their very strict subterranean behavior. To my knowledge they will pretty much never emerge above the surface except for during nuptial flights, whereas I've occasionally seen other species of subterranean thief ants foraging on the surface during overcast days.

 

While they aren't fire ant-sized, they're larger than any other thief ant that I know of. Looking at this comparison "chart" I made, you can see that they're very pale in color, even more so than S. carolinensis. This is true for workers as well.

 

 

 

July 14, 2020

 

On July 14 a large flight of Solenopsis pergandei happened at dawn. Alates fly to blacklights in large numbers, and I was able to collect more than 70 dealate queens by 6:00 AM. Instead of keeping all 70+ queens, I decided only to keep 12 of them and release the rest. 12 queens were split equally among two bare test tubes.

 

 

 

July 23, 2020

 

Here they are with eggs and small larvae. This would be the first time I have gotten S. pergandei queens to larvae while in a bare test tube without soil. This species is known to be incredibly sensitive and queens tend to have a high death/failure rate. By this time, one queen in each tube died, making it a total of 5 queens per tube.

 

 

 

July 31, 2020

 

Here they are yesterday with some fairly large larvae among their large egg pile. Looking good and I should be seeing pupae soon.

 

Edited by Aaron567, November 1 2020 - 11:11 AM.

[BitT]

Wow, they look like they have gasters made of gold. So pretty. Look forward to see more of your girls. Are you keeping them in a dark place or just using the paper trick? How warm are you keeping them? Just curious since you say they are sensitive.

[Aaron567]

Wow, they look like they have gasters made of gold. So pretty. Look forward to see more of your girls. Are you keeping them in a dark place or just using the paper trick? How warm are you keeping them? Just curious since you say they are sensitive.

 

They're in a dark drawer with a slip of paper over them so they're not as disturbed when I check on my other queens. Just measured the temperature of the drawer they're in and it's about 92 degrees F, definitely a bit warm but apparently it's fine for them.

[Froggy]

Totally should have kept all 70+ of them in one colony 

[Aaron567]

September 12, 2020

 

Probably should've updated this sooner, but these queens just didn't work out. Right as both groups got pupae and the pupae were getting ready to hatch, their brood piles became overtaken by a discrete white fungus and none of the pupae hatched despite many of them coming very close. The fungus was strange in that it was very small and I didn't realize what was going on with the pupae not hatching until I took macro photos and saw the fungus covering it. Soon after, the queens all died. I had the same thing happen to one of my groups of Solenopsis carolinensis, and a group of Pheidole bicarinata this year. It's possible that they could've been contaminated with the wooden skewer I used to push down the cotton in their test tubes when I was setting them up because I've never really had these problems with small ants before. I am still pretty sure it's possible to keep Solenopsis pergandei without substrate, so next time I will make sure I'm more careful with keeping everything sterile when I am creating their test tube setups, and I will also keep more of them instead of releasing most of the queens I got. I guess I was a bit too confident with the 12 queens I kept

 

I actually kept a couple of groups of dirt-setup Solenopsis pergandei just in case the bare tube ones died, and the dirt tube ones actually had very high success rates with getting nanitics and they did not experience the fungus problems. Unfortunately, I'm now only down to one more dirt colony and it's not looking great. There were probably around 20 workers at one point, but every time the dirt in the tube would dry out a bit (even with the inner brood & queen chamber still moist), worker die-offs happened. This does not happen with S. carolinensis or any of the other subterranean Solenopsis I have kept, because normally they'd retreat to where there is more moisture and be just fine.

 

Another thing is the brood and feeding situation; I fed these dirt colonies small cricket legs, and they seemed to feed on them, but the queens would never get full and new eggs were never laid. Instead I am left right now with two skinny queens, several strangely shaped larvae, and a few workers. It looks like the colony even had one or two full-sized workers at some point but they died. Another thing I should mention is that any time I gave them cricket legs, they'd completely mold over after only a day or two, which is not surprising given that I had to keep the dirt damp all the time. This could've possibly contributed to the worker deaths, if the workers happen to be particularly sensitive to mold.

 

This is how the last colony is looking right now. I'm going to keep feeding them but I don't have much hope left for them at this point.

 

[RushmoreAnts]

Is that two or three queens I see in there.........

[Aaron567]

Is that two or three queens I see in there.........

 

Should be two.

[RushmoreAnts]

Yeah, some of the workers who were blurred by the dirt stuck to the plastic must look like extra queen gasters to me.

[Aaron567]

November 1, 2020

 

All S. pergandei colonies are dead now.