Comments on: Genetics of Behavior: Fire Ants

By: Aaron Golas

Aaron Golas — Tue, 25 Mar 2008 20:32:14 +0000

This reminds me of killifish, in a roundabout way. Normally killifish are obligate internally self-fertilizing hermaphrodites. Males are occasionally born, but they don’t get to play the reproduction game.However, there are populations of killifish for which sexual reproduction has been observed between males and “females” (immature hermaphrodites). Since these sexually-reproducing populations correlate with geologically young environments, it is speculated that sexual reproduction is induced as a mechanism for generating diversity for adaptation.

By: Dietrich Gotzek

Dietrich Gotzek — Tue, 25 Mar 2008 10:29:54 +0000

Hi Greg,glad to see that someone is actually reading our papers. 😉 You raise a good question and honestly, as you mention, at this point we can only speculate.Within colonies, it seems clear that Gp-9 (or the locus/region that it marks) is a selfish element and workers (of which a sufficiently large percentage must also carry the b-like allele) only allow b-like bearing queens to reproduce.At the colony level things are a lot less clear and we only have some anecdotal evidence from the introduced North American range and unfortunately know nothing about what goes on in the native range in South America. Reed has given part of the answer above (again I’m glad to see that someone paid attention during seminars). As far as we know, there are no known ecological differences between the two forms and they occupy identical niches. It seems that polygyne colonies can simply outcompete monogyne colonies since they form much larger colonies and are not aggressive towards other polygyne colonies. Monogyne colonies on the other hand are highly territorial and aggressive towards non-nest mates. There are reports that the two can co-occur for prolonged periods of time although it is not clear whether the monogyne colonies in these situations are established colonies, capable of holding their own against the polygyne form, or whether they are newly established and can only persist transiently. At least in the study populations around Athens, GA, the polygyne form has almost completely displaced the monogyne form, with the latter only holding on in small pockets here and there. Clearly a lot more work is needed in this area… :)Cheers!

By: Reed A. Cartwright

Reed A. Cartwright — Sun, 23 Mar 2008 13:00:47 +0000

As far as the adaptive advantage of the polygyne colonies, I’ll try to remember back to the departmental seminars.I believe the working hypothesis is that polygyne colonies are bigger and can colonize new territories faster. This will be adaptive as long as fire ants’ range is expanding.I’ll send the lead author a note to drop in.

By: JuliaL

JuliaL — Sat, 22 Mar 2008 22:13:31 +0000

Now how about a post on how to kill fire ants?I am generally non-violent, and even try to carry spiders out of the house or sweep out a roach rather than kill them, but fire ants have become the enemy. They attack people who are innocently gardening or children who pick up a toy left outside for a few hours. They spread so rapidly that they can quickly make a yard all but unusable.When I was a child, I would lie in the grass and watch the clouds go by. Now that same grass is so full of fire ants that I have to make my grandchildren play on the paved driveway. The poisons readily available kill butterflies, sometimes injure birds, and wash into the nearby wetlands to kill dragonflies and small fish.I’ve tried vinegar, hot water, and dishwashing detergent. They all help a little, but are extremely labor intensive to apply and do their own damage to surrounding vegetation and insect life.The person who eventually finds an affordable way to get rid of fire ants without doing in all the nearby living things is going to be very rich I think. Maybe a way to affect their genes so that they build mounds as though protecting a queen but in fact without a queen or with a queen that can’t reproduce?

By: Reed A. Cartwright

Reed A. Cartwright — Sat, 22 Mar 2008 22:07:33 +0000

I graduated with the lead author at UGA. I’m glad to see some more stuff come out about this system.