Like AIDS for chocolate

We try not to use pesticides here at Texan99 Farms, but we draw the line when we get an outbreak of leafcutter ants, which can strip a citrus tree overnight and kill it.   Hands off the grapefruit crop, you six-footed marauders!  For that, we deploy the dreaded broad-spectrum pesticide Orthene, because we've tried everything else and it's the only thing that seems to work.

A similar scorched-earth policy seems called for when parasites threaten the world's chocolate crop.  That's just picking a fight the ants are going to wish they hadn't picked, or at least I hope so.  This post from Ed Yong (who writes Not Exactly Rocket Science) examines the troubling state of the globe's plant pathology field, with a special focus on the imperiled African cocoa crop.  Since one of the few things that grab my interest as tightly as chocolate is the technique of crowdsourcing, I was drawn to this paragraph about the plant pathogens that continue to challenge modern farmers:
"Farming has always been a community affair but, in the modern era, we’ve lost those connections and knowledge is held by a few," [said David Hughes, an ant-loving evolutionary biologist from Pennsylvania State University].  To rebuild these links, he teamed up with his Penn State colleague Marcel Salathé, a computer scientist who studies the spread of behaviour through social networks.  Earlier this year, the duo launched, an open-access website where people can ask each other for help with agricultural problems.  Users vote the answers up and down, and accumulate points depending on how helpful they are.  It’s like Quora for gardeners.  "We’ll never invest in people like [Harry Marshall Ward, a 19th-century plant pathologist] again," Hughes said. "The second-best solution is to rely on the crowd." 
*     *     * 
It’s an approach that could have been lifted from an ant’s playbook.  Individual ants are hardly great strategists [or are they?], but through their interactions, they can achieve incredible feats of swarm intelligence.  Some successfully rear bugs, and build tents to defend them from threats.  Others grow a delectable fungus by feeding it chopped up leaves, while killing off other moulds with antibiotic-secreting bacteria.  For millions of years, ants have raised crops, herded livestock and weeded their gardens, all by working together as a large connected society.  Humans could learn a thing or two from that approach.


Anonymous said...

My daddy fought a couple of battles with cutter ants. It took years of persistent effort to get rid of them.

I absolutely don't blame you for using the orthene, especially since the best stuff is off the market. I'd suggest, though, that you add in the Terro bait (or boric acid mixed with sugar) especially if you know the location of the mounds. The beauty of Terro bait is, it's not toxic to animals and children, not to mention your own, precious self. It's also good for killing off a colony entirely, something no acute poison will do.

Terro bait is too slow to stop an acute attack. It has to get into the food supply in order to work. But, if it does get into the food supply, it will kill the entire colony.

If the ants attack a plant you don't care about, there is a Terro dust that you could put on the leaves, so that the ants take the leave pieces back to the colony. Otherwise, you might try watering it in at the mound, or experiment with bait stations near the mound. I would put bait stations on any trails the ants make, but as far away from the trees as possible.

The big key will be finding the right bait, but in order to become functional, a cutter-ant hill has to survive those first few weeks without the leaves. I suspect there is some kind of food the ants will accept besides fresh leaves. It could be plain ol' sugar, as is already in the bait.

If you kill off a large number of workers using the orthene, you might force the colony to turn to its less-desired source of supply, which could be sugar-laden bait.

Good luck.


Texan99 said...

Sometimes we find the feeder holes, and sometimes not. I assume there's a mother-ship of a nest somewhere deep underground, perhaps rather far away, deep in the woods where we can't locate it. The feeder holes come up all over the place.

We'll have to try the Terra bait. We've tried other baits, and in prior years even had some success with them. This year, nothing has worked but the Orthene.

There are plenty of leaves for them to eat in the woods. I'll even put up with their munching on some of my sprawling vines, which can handle being chewed back by 10% or so. They just have to leave my fruits and vegetables alone!

Eric Blair said...

"all by working together as a large connected society. Humans could learn a thing or two from that approach."

"Specialization is for insects" (attributed to Heinlein)

So which one is it? Although in contrast to your statement, I find myself less annoyed at Heinlein's statement than I usually am.

Those little ants are little biological machines, that give everything for the hive.

Is that what you really want?

Texan99 said...

I wonder if human beings are sufficiently different from ants that they're capable of collaborating on decisions by free interaction, without becoming as soulless and collectivized as an ant?

It's possible to strain a metaphor too hard.

james said...

I wonder if there's some signature we could use to locate the big nests. One firm in Queensland claims to be able to spot fire ant mounds, but that might be easier.

Grim said...

Our gardens here at Grim's Hall don't have those particular pests, T99, but we do have fire ants. Also black widows. I keep hoping the one will eat the other, or vice versa.

Texan99 said...

They say mud-daubers (sp.?) kill black widows. I see dead black widows on the porch now and then.

That's interesting about the Queensland firm. If I knew for sure where a mound was, it would be worth hacking into the dense yaupon-and-greenbriar brush to get to it. I wonder how deep underground they are? As far as I know, the only natural access to them is from the feeder holes, which can pop up far from the home nest. And of course we can't be sure if we're dealing with one nest or many. All our neighbors, the whole county really, have the same problem. It may be worse this year because it's been awfully dry for several years in a row.

E Hines said...

I use an Ortho powder against fire ant mounds; our neighborhood had a rash of them a few years ago. The stuff smells like death, too.

I can't imagine that it wouldn't work on those cutter ants. It doesn't kill immediately, but the powder sticks to the ants so they carry it deep within the mound. In the fire ants' case, they carry to the the several queens there, so we get the source, too.

On the other hand, C4 in the hole is more fun.

Separately, a hive intelligence might be cool for ants; I'm not one of those. I'll live with the vicissitudes of human intelligences; the gains are worth it. Of course an ant's interests might be different from mine.

Eric Hines