Looking For Love In All The Wrong Places

The tops of the space shuttle launch pads at Cape Canaveral’s Kennedy Space Center are unlikely spots for courtship and frenzied lovemaking. But every fall and winter, thousands of paper wasps leave their nests and swarm up 300 feet to the tops of the launch towers to mate.

Paper wasps mistake the tall launch towers for their usual mating sites - trees and hilltops - said Agricultural Research Service entomologist Peter J. Landolt. Because Florida is relatively devoid of hills, a paper wasp doesn’t have too many choices in mating spots, he said.

"The launch towers and other man-made structures are frequently the tallest thing in the area," he said, noting that the wasps will see the towers and swarm there from up to a mile away.

Every September for the last five years, the mating swarms have departed from nests in bushes or on houses. About two years ago, National Aeronautics and Space Administration (NASA) officials sought help in the form of a reliable control method for Agricultural Research Services (ARS) entomologist Landolt and Hal C. Reed, both of the Insect Attractants, Behavior and Basic Biology Research Laboratory in Gainesville, Fla.

Thus far, the scientists have worked out a scenario that they believe describes the annual mating ritual.

"We still need to do tests to confirm much of what we believe, but we’re pretty sure we understand most of the behavior," Reed said.

GIRL MEETS BOY, WASP STYLE. To begin the mating ritual, literally thousands of males begin leaving their nests in September to swarm at Kennedy, he said. The males aggregate around the launch pad’s crane, which has along arm, and near the crane motor’s housing room. They fly around, staying in the area of about 20-30 feet in diameter.

There, they search for anything that protrudes - a bolt, for example - to sit on. After sitting down, they rub their heads and their tails on the perch to release sex attractants, or pheromones, into the air. In an increasing frenzy, the males begin to fight each other for a perch to sit on.

They bite. They wrestle. And they try to knock a perched buddy off of his bolt.

"We believe each male wants an ideal spot to sit and wait for virgin females to arrive so he can mate, said Landolt, who notes that the gland-rubbing behavior serves to release male pheromones into he air. "Every male wants his pheromone odor to be strongest so that females will be attracted to him."

Next, hundreds of females, responding to both the permeating aroma of pheromone chemicals and the desirable sight of the tall launch pad tower, leave their nests and swarm to the top.

"We believe they’re going to the launch pad to hibernate under the protection of the crane housing room during the winter and possibly to mate as well," Reed said.

At the top, males greet females, and females selectively decide which male they want. In mid-air, couples mate. This takes only about a minute. Once inseminated, females fly into the crane housing room. There they huddle together, clustered on one of the room’s walls, to keep warm and protect themselves from predators. Or they squeeze into the room’s cracks and crevices. They’ll stay there all winter, living off stored body fat until spring, when they will return to the ground to build nests out of paper and lay their eggs.

Nearly all of the females the scientists collected from inside the crane housing rooms had been mated "That’s how we know the males are mating with them before they go inside," Landolt said.

The males that mated eventually died, having dutifully served their sole purpose in life. Those that miss the opportunity continue to hang in there on the perches, biting, fighting and filing the air with pheromones to beckon more swarms of females. That swarming goes on until mid-December.

WAITING FOR MATING. Landolt and Reed have not yet watched this mating ritual from start to finish, and much of what they know about the wasps is still in the hypothetical. During the next few years, they’ll set out to find out if their ideas are correct.

They hope to go into the Everglades and search for nesting wasps in tall trees to corroborate the theory that wasps are visually mistaking launch towers for trees. These tests can’t be done in suburban areas in Florida; the few trees there are invariably near man-made structures that are taller, Landolt said. He said that even in forests it’s common to find wasps in and near, for example, the taller fire towers, as is the case in a number of Florida forests, including the Ocala National Forest.

One aspect of the ritual is certain: both male and female wasps do produce chemicals that make the insects attractive to one another. Landolt and Reed also know for sure that the male’s pheromones are released from glands in his tail and head. They removed two glands from that area and extracted them in solvent In tests in a wind tunnel, females flew to the extract as if the extract were a male.

With the help of a chemist, they will identify, isolate and then reproduce the chemicals, creating lures for use in wasp traps. "We envision that the trap would actually be a simulated hibernation site," Reed said. A large container with a small entry hole for females, baited with the lure to draw them to it, could be put somewhere near the launch pad. The container would keep females warm and allow them to cluster together, so they wouldn’t seek another overwintering spot in the launch tower.

Reed said the trap would face the south or west sides, which are warmer, because that’s where the wasps tend to be. Then, one cold evening when the wasps are quiet and clustered closely together, NASA personnel could climb up to the trap and vacuum up the unsuspecting females or completely remove the trap from the site.

Another alternative, he said, might be to build wood trap towers around the vegetation that surrounds the launch pad.

"The launch pad is a huge stimulus, so there’s no way we could build something taller," he said, but if trap towers were at least taller than the vegetation, perhaps they would attract the wasps leaving the vegetation, intercepting them before they can get to the launch pad. The wasps would be welcome to stay there, instead of causing problems at the pad.

Reed points out that development of both trap and lure will take several years to research.

NASA’S UNSTUNG HEROES. This work is being funded by NASA, amid concern for employee and equipment safety, Landolt said.

In the five years that the wasps have been making their annual swarm to the launch pad, only one NASA employee has been stung - despite the large numbers of wasps there. Landolt points out that males don’t sting at all, and females usually only sting when they are in their nests on the ground - and that’s to defend their home and their young.

"But just seeing a thousand or more wasps buzzing around at 300 feet can in and of itself be hazardous," he said. And painters and electricians must regularly go up onto the pad to repair it after each shuttle lift-off. In Reed’s words, "Every time we go up on the pad collecting wasps, there’s a horde of people up there working."

Landolt interjects, "When we were collecting wasps this last time, there were so many in the room that they were on us and in our clothes; I had two in my pockets. If you pinch them while they’re under your clothes, you’ll get stung."

And, he says, the sting of a paper wasp "hurts no less than the sting of, say, a yellowjacket wasp. I can testify to that from experience."

Aside from the potential employee hazard, NASA waned to ensure that the wasps would not enter the shuttle’s electronic and mechanical equipment.

"Obviously a shuttle lift-off is an effective and quick means of controlling the wasp problem," Reed said. But NASA needed a less drastic way to kill the wasps in between lift-offs.

They had been spraying chemical insecticides, but once again concern for the sensitive equipment - plus a desire to keep the chemicals out of the center because it’s located on a wildlife refuge - spurred the officials to seek nonchemical means.

And so it came to pass that ARS got a call for help from Larry Gast, who is in charge of the space center’s grounds care, "which includes handling everything from alligators and armadillos to weeds at the center," Landolt said.

As a former employee of the Insects Affecting Man and Animals Research Laboratory in Gainesville, Fla., Gast knew that ARS scientists have plenty of pest-control expertise; he’d already consulted with ARS for help in controlling fire ants, mosquitoes and other unwanted insect visitors.

That lab sent him to the attractants lab next door, where he was introduced to Landolt and Reed, experts in natural insect attractants.

When they develop a sex lure and trap system, NASA won’t be the only beneficiaries. Wasp-plagued officials at Disney World in Orlando, Fla., will also breathe a sigh of relief.

It seems that the wasps have been swarming at the top of Disney World’s gondola ride, which carries passengers from one end of the park to the other.

"The wasps are aggregating at the top of the ride’s support piers," Reed said, "and as people glide by the gondola, they see the wasps and get upset." Two years ago, operators were forced to shut the ride down for this reason.

Reed has visited the amusement park to assess the extent of their less-than-amusing problem. Wasp numbers vary; they’ve had as few as 100 to as many as 1,000. He points out that although the problem is seasonal - occurring mainly in fall and early winter - Disney World has already met with him to discuss using the technology when it’s ready.

SWARMING TOURISTS. Officials from two tourist towers, Bok Tower in Lake Wales and Citrus Tower in Clermont, have also reported the presence of wasp swarms and have also expressed interest. "We’ve collected there," Reed said, "and the swarms on the tops of those towers are at least as big, maybe bigger, than those at the shuttle site."

At Citrus Tower, which an orange grower built in the middle of his groves, wasps swarm right to where the tourists stand to overlook the groves. The very top of Bok tower houses employee offices - which wasps readily enter to disturb employees. That tourist attraction is located in the midst of public gardens.

Landolt and Reed often collect and study the wasps at these towers and at the fire towers mentioned earlier, in part because there are lots of occasions NASA won’t permit them on the launch tower.

"Anytime there is any threat of a storm or high winds, NASA doesn’t allow us to go up on the pads, for safety reasons," Reed said. Florida storms frequently bring lightening, and the tower "is like a big lightning rod," he said. During high winds, the danger of someone falling off may close down the pad. "They’re very safety conscious there," he said.

Yet another obstacle to launch pad entomology: When the shuttle blasts off, "the wasps are completely burned up, which leaves us nothing to study," Landolt said.

Despite still one more stinging obstacle - NASA’s budget restrictions - the scientists are gradually building a base of knowledge about these common but poorly misunderstood wasps. From that, they hope to develop an effective lure and trap system. That should be within the next five years, Landolt said.

The wasps may yet relinquish their launch pad lover’s lane.

Jessica Morrison Silva is with the Agricultural Research Service.