N RANCHING
atural Resources
professional from Pearland who, in 2002, fi rst realized they were something new. The accepted common name, tawny crazy ant, was established by a committee of the Entomological Society of America in 2012. “They call them crazy ants because they don’t trail
like other ants, but move in all kinds of directions,” Allen said. “They don’t have a single nest where the queen
stays, but rather have multiple nests and queen ar- eas; like a super colony made up of a lot of smaller colonies. In areas where these ants are, we have documented decreases in arthropod diversity and population densities,” he said. “Reduction of density and diversity of arthropods can fundamentally af- fect the proper functioning of an ecosystem and can result in a cascade of negative effects on populations of organisms that rely on them. These ants take over the environment. They are so competitive and develop such huge populations that they displace fi re ants, and that’s saying something.” Allen said that though the ants are stingless, re-
cent research has demonstrated that crazy ant formic acid can break down the alkaloid venom of fi re ants. So when tawny crazy ants are attacked by fi re ants, they coat themselves and their nest mates as a defense against the fi re ant venom. They found a home along the Texas Gulf Coast, but
now have moved into San Antonio, Austin and the Bryan-College Station area, where they have become a signifi cant nuisance to homeowners. Allen said at this point, nobody knows how far north
the ants can survive cold weather. “We have noticed it takes them a while to get started in the spring, to get their numbers up, but by August and September they have huge populations working throughout the area they infest.” Dr. Robert Puckett, AgriLife Extension entomologist
at College Station, has been involved in tawny crazy ant research for several years. Puckett noted that at many infestation sites across southeast Texas, ant den- sities appeared to be lower in 2014 than in past years. However, he and other researchers suspect this is due to the colder and more persistent cold temperatures during the winter and spring of 2013/2014. Allen said Ree, Puckett and McDonald have evalu-
ated several insecticides, but have yet to fi nd one that has provided effective long-term control. “There are some pretty good materials that work
for maybe a couple months in urban areas, but those pesticides are not labeled in agriculture,” Allen said.
64 The Cattleman February 2015
“So we’re lacking effective insecticides to help us out in agriculture.” The entomologists said the ants’ trademark is their
sudden appearance in huge populations. They are small and don’t move in straight lines, but dart erratically one way and then another, which is the fi rst tip to identify- ing them. Beyond that, they are a small, tawny-colored ant requiring expert scrutiny for identifi cation. Allen said the fi rst step, once tawny crazy ants are
suspected, is to contact the local AgriLife Extension agent who can refer them to an expert for positive confi rmation. In addition to their potential to damage crops, there
have been confi rmed reports of the ants decimating honeybee apiaries. “Honeybees are used on crops for pollination and if
these ants are in a fruit orchard, citrus grove or similar crop that requires bees for pollination, they can basi- cally cause the bees to leave the hives. They come in by the millions and swarm the hive. They drive the bees out and then feed on the immature stages of the honeybee.” Allen also said the ants can be accidentally intro-
duced to a new location by anything from a relocated potted plant to an incoming oilfi eld drilling rig. “These ants, of course, are associated with soil.
And in the oilfi eld, big machines are set up, left for a period of time and then packed up and moved, making it very easy to move these ants in soil still attached to the oilfi eld equipment,” Allen said. “In Louisiana, ants are showing up miles from previously infested areas and they appear to have been moved on oilfi eld equipment.” Allen said sugarcane aphids, a new pest to most
of the state, tore across Texas almost from border to border this year, damaging grain and forage sorghum crops. This could make prime honeydew-producing ant cows, although that has not happened so far. “No one I know of has seen a tawny crazy ant/
sugarcane aphid association yet,” he said. “However, when you have a honeydew producer like the sugar- cane aphid, a cooperative relationship between the two would be a natural. Aphids suck up the plant’s sap for the protein and then excrete sugar water, so plants get covered with sticky, shiny sugar water; the perfect food for the tawny crazy ant.” “This ant is something that is on the radar. It is not
a problem in agricultural crops yet, but we know it’s out there and that it has the potential to cause dam- age,” Allen said.
thecattlemanmagazine.com
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