Collecting harvester queen ants (Part II)
The fire ants seems to be able to detect 'free' food and starting to send out army of ants to hunt down the harvester queen ants
when the weather turn cooler before sun set. By 6-7 PM, most of the harvester queen ants have done with digging. The queens that
haven't done with the hole have most likely been killed by the fire ants which seems to know the particular harvester queen ant
mound, and follow the queen ants down into the hole. Therefore, to avoid the fire ant from doing so, the harvester queen will plug
the entrance with a ball of dirt (See pic below) to prevent fire ant from invading.
Any harvester queen mount that has a open hole was likely doomed, especially when fire ants can be seen crawling out (and in)
the holes. However, there were still plenty of plugged holes on the field, indicating that many queens were still able to dig deep and
survived from fire ant attacks.
By then I have decided to call it a day. Giving all the queen ants to Lara, and also leaving Lara to continue collecting till the light went
I was curious to know if the swarm would continue the following day, so I went there in the morning at about 10 AM. The weather
was hot (90F) and cloudy, but i did not see any winged ants wondering around the harvester nest, nor did I see any fresh queen
holes. There was a brief rain around noon so I left the park, the rain did not last for more than 10 minutes. By the time I went back at
2 PM, there were few more wingless queen wondering on the ground, and some fresh holes formed by the queen too, which
meant this species prefer to perform nuptial flight in the afternoon, especially after the rain and the weather is hot, but the amount of
queens declined sharply compared to the previous day, probably due to the less amount of rain on the following day. HOwever, I
was still able to collect some more queen ants by digging up the holes, although I have also killed some queen ants while digging
After that, I saw a field with some large trees at the other end of the park. I was curious if there is any mantis I could find so I went to
I was able to meet up with Lara on Saturday (6/25/11) to see how she keeps her P. barbatus queens in her bug lab in University of
Houston. Lara collected about 86 harvester queen ants from the same park and about 78 of them were able to form colony,
showing strong trait from the queen when suitable condition were provided. According to Lara, keeping the queens at 30C seemed
to work. 26C will also work but the colony took a longer time to form. Lara did an experiment on providing half the harvester queens
with food (wheat) while leaving the rest without food. Both groups of queens were able to reproduce. The only difference was that
queens with food were able to produce larger larvae and therefore bigger first batch worker ants after just a month. I wonder what
did the queen without the food supply feed the larvae, Lara thought the queen might have regurgitated and fed the larvae instead.
She also showed me another species of harvester ant (Pogonomyrmex occidentalis) which is under her care right now.
I have collected grass mantis mostly at the tree bark, so that was the first place I went for. I was surprise to see a grass mantis
nymph near the bottom of the tree trunk. A good sign that mantis are doing well even after one of the longest drought in Texas.
But I was attracted to a cool species of ant, a wasp-like ant, with scientific name Pseudomyrmex sp. The species were given a flat
and thin rectangular nursery with thin piece of wood surrounding it. This ant will 'excavate' their own entrance into the nursery, and
each entrance is guarded by an ant, with its head sticking on entrance (Top right pic below), which is pretty cool.
Here are some of the queen ants I am setting it up for P. barbatus. Hopefully some will form a colony in the future.