THE SPEEDY BEE, September 1993 “Moscas on the Move: The African Bee in Northern Mexico”
Richard Bean, beekeeper extraordinaire, a lanky, laconic Kansan, who could put much meaning into few words observed a wide ribbon of honey bees marching into the runner box. “Moscas on the move,” he said. A perfect metaphor for what I had been seeing all week. Indeed, “moscas” were on the move in more ways than one. The word “mosca” in Spanish means fly, but in this area of northern Mexico, it also means honey bee.
In March 1993, we had come to Linares, 150 miles south of the Texas-Mexican border, to visit the research station of Dr. Orley “Chip” Taylor, a man who has had much experience with changing honey bee populations. First in the Guianas, then Venezuela and Central America, he has seen the invasion of the notoriously successful African honey bee (AHB) and is full admiration for this insect.
A University of Kansas entomologist, Chip has been involved is continuing controversy because his notions about African bees do not always agree with interpretations by others. He continues to believe, for example, that African and European populations are not mixing or hybridizing as predicted by many scientists. His studies of drone flying times and allozyme analysis indicate that “Africanization” of the extant European population is the norm, Although hybridization takes place, the European characteristics disappear with time, leaving a population with predominantly African traits.
Results of these studies and confirmation from other investigators, therefore, indicate the vast majority of honey bees in the American tropics are best characterized as African, not Africanized. Chip’s three-year grant to study the frontal wave of migrating bees in northern Mexico now provides a good opportunity to analyze in detail the full extent of the shift from strictly European to a mixture of African and European honey bee populations.
I jumped at Chip’s invitation to come to Mexico and see the African bee and its impact on the region for myself. I traveled with Alonso Suazo, who also has experience with the African bee in his native Honduras. Alonso is schooled in the delicate procedure known as instrumental insemination. Only controlled matings using this technique can provide definite answers to many of the questions about the dynamics between the European and African bee populations. The flight to McAllen, Texas was uneventful. We landed in cool, cloudy and rainy weather, marginal for working bees, not a good omen for the subsequent week. Things went from ominous to bad when we discovered that through miscommunication our transportation was not ready. The delay meant an extra night in McAllen.
Fortunately, The next morning was sunny and warm, the kind of weather we would enjoy for the rest of our stay. The day before, the airport manager in McAllen told us not to miss the statue commemorating the first sighting of African bees in Texas. We took this as a joke at first, but down a side street in the little town of Hidalgo, we saw a scene that could only be described as surreal.
Mounted on a float in all its glory, “The World’s Largest Killer Bee,” was being readied for a parade. In true Texas style, the bee statue stood taller than a human being. Lifelike in most of its detail, including a huge stinger, there was much to admire about this apparition. My eyes strayed to the feet where I expected to see claws, but this bee surprised. It had cloven hooves. I supposed this must be an obligatory conclusion emanating from the area’s long experience with cattle culture.
Another close call occurred at the border where our Central American colleague was given the runaround by the authorities. This caused further delay. Chip complained that this was one of the worst problems about doing research in Mexico. The rules for crossing the border seemed to change daily. Previously, when Alonso visited Mexico, he didn’t require a visa, now one was needed and it was a Saturday morning and the Mexican consulate was closed. Finally, after some quick thinking and talking, we obtained a notarized document concerning Alonso’s citizenship and reason for entering Mexico.
After more delays in the border town of Reynosa, we headed south on two-lane Mexico 85. This part of the country was high chaparral. Later, we turned east entering the coastal plain, lying in the shadow of the Sierra Madre Oriental that flanks northern Mexico’s great central plateau. The white citrus blooms perfumed the air as we approached Linares. An excited Chip pushed our van down several back roads. He and Richard craned their necks to see if honey bees inhabited the blue bait hives hung high in the air. In the citrus area, almost 85 percent of the plastic-covered boxes contained bees. In contrast, just a few miles away on the University land where there was no citrus, not a single one had been inhabited.
However, we did see what Chip characterized as “heavy scouting.” Many individual bees were examining the bait hives closely, even going inside and audibly tapping on the walls. He indicated this behavior meant that in the matter of a few days (perhaps hours in some cases) these bait hives would hold bees. And they would all be full very soon when the mesquite bloomed.
The seat of Chip’s research station was a two-bedroom house with screened porch, kitchen and bath, situated in the middle of a now almost empty citrus grove. Most of the trees in the area were heavily damaged by the 1989 freeze. Many like those around the house, had been plowed up and other trees or crops were now being planted. The house was flanked by experimental apiaries and shaded in summer by a large pecan tree that was just leafing out and usually inhabited by a gaggle of noisy Mexican brown jays.
Every evening after supper, we sat outside at a table, contemplating the sky turning pink, then purple behind the Sierra Madre Oriental. With darkness, the tropical night exploded into insect noise and stars.
Field work at the research station revolved around the hanging and running bait hives, and associated bee work. It was exciting activity. The back roads in the area delineated the bait hive lines. Every 50 yards or so, a long extendible fiberglass pole would be used to deploy a bait hive in a tree. The cardboard boxes were precut and easily assembled. They were readily available as part of the Mexican program to control the African bee under the auspices of the Secretaria de Agricultura y Recursos Hidraulicos (SARH). The resultant bait hives, about the size of five standard frames, were covered with blue plastic to prevent damage by rain and suspended by a special wire hook. After a bait hive is constructed, a special pheromone lure is pushed through the top of the box. This is the most important part of the technology; without this lure, the boxes are not efficient at bringing in swarms. Chip also applied some of the pheromone to nearby trees and was able to attract several small swarms in this manner. Printed on the outside of each box was the SARH logo and on the other side it said: “Trampas pars abejas enjambres: CUIDADO NO TOCAR.”
In spite of the “do not touch” warning, bait hives were routinely mutilated and/or stolen. Chip complained they were wonderful targets for local childrens’ sling shots and many routinely had rocks inside. An interesting ethic apparently prevailed in some local people who decided to take the free bees these bait hives offered. In many cases, the boxes were lowered, the bees removed and then the bait hive was carefully replaced.
After the bait hives had been in place in trees for a period of time, they were monitored from vehicles. Chip would drive and Richard rode shotgun. With practiced eyes they scanned the boxes looking for activity. If there were bees, evidenced by activity around the two slits at the bottom, the shout “Sí, hay!” (yes, they are there!) would elicit a stop. We then retrieved the poles from the van and lowered the bait hive. A few puffs of smoke would calm the bees. Richard then cut open the box to expose the comb. Chip noted in his log the age of the brood and three measurements of worker comb that Richard called out. Usually, the measurements were below 5 cm per ten cells (small bees), a good sign they were African. The adults in the swarm bait hive were drummed or dumped onto a plastic sheet connected to a paper pot hive, called a runner box. As the insects ran toward the darkness, Richard and Chip looked for the queen. She was placed in a tube, and along with a sample of adults, in a plastic bag. Later they would be frozen and then shipped back to Chip’s lab in Kansas for analysis. In addition, I collected a sample of open brood for my work. Finally, Richard shook the pot full of adults into a big catcher box in the back of the van. These insects would later be used to make nuclei or strengthen colonies back at the house.
At first, I was apprehensive. After all, we were dealing with African bees that have a fearsome reputation for defensiveness. But seldom were we attacked and in most cases a veil was not necessary. Granted the colonies were small, less than 5 pounds (16,000 bees), but they were essentially African, characterized by a small cell size, a tiger striped queen (black tipped abdomen with orange or red stripes) and a generally super excited behavior. Chip said that this size colony, however, was rarely a problem. Only when colonies became large and well-organized was defensive behavior characteristic. We routinely called these boxes of bees swarms. Clearly, however, they were also established colonies, complete with brood and stores. A conundrum. When does a routinely gentle African swarm turn into a highly organized defensive colony?
Many of the stinging incidents in Mexico have related to just this question. African bee colonies, once very gentle, after their population builds, can literally explode with little warning. In spite of the apparent lax defensive behavior, however, I learned never to lower my guard. Later, I was to see some more defensive colonies which seemed to bear no resemblance to the bees in the bait hives. Thus, a first lesson about African bees is they are not always predictable.
The very term “swarm” seems to be at the heart of many misconceptions about African bees. Most U.S. beekeepers know only one kind of swarm, the reproductive one that marks the European honey bee. This occurs in spring, and summer and sometimes in the fall, when overpopulated colonies divide, sending half their population with the old queen (the swarm) out to find a new home.
The African bee in northern Mexico, however, is showing something quite different from the usual. Typical of most life in the subtropics, Chip said, in order to survive, organisms must be able to take advantage of sporadic shifts in environmental conditions. The vegetation does it, exploding in a surge of growth after a rain, so why not the bees? African honey bees, it turns out are supremely adaptable to this lifestyle. Therefore, the “swarms” we were catching in our bait hives at this time (early March) were not often reproductive swarms, but colonies which had abandoned (“absconded”) from their previous nests to search for better locations. They were literally “moscas on the move.”
The first swarms, therefore, begin to appear from January through mid-March. These are classic African honey bee absconding swarms migrating from one site to another. The nests are characterized by a great deal of brood and little honey. African bees produce brood first, then honey. In spite of this, the populations often don’t grow as rapidly as one might expect, Chip says, because the life span of African workers is less than that of Europeans. The brood simply replaces the adult bees that quickly die off. Finally, the bees may also move again on short notice.
Reproductive swarms for both African and European honey bees can be seen in the Linares area April through June. These have drones associated with them; the colonies usually have more honey than found in absconding bees. Migrating absconding swarms of African bees are then observed again July through August, followed by a small peak in reproductive swarming September through October.
Although there is a typical absconding and swarming pattern most years, it can easily be broken by external events. In July 1991, for example, Chip observed a uncharacteristically large spurt of activity in the Linares area following several inches of rain falling in this normally dry period. When it is extremely dry, he’s also seen African bees can go into what he calls “torpor,” a lowered metabolism state, apparently waiting for more favorable environmental conditions. He observed one combless swarm that remained in a tree for about a month during a dry period. Chip says similar behavior is seen in Apis laboriosa, a large, tropical Asian bee related to Apis dorsata, that migrates away from its comb during cold periods, also forming combless clusters.
An extraordinary number of swarms usually signals local residents that the African bee has invaded new territory. Beekeepers who have seen relatively few swarms issue over the years can be overwhelmed by the sheer increase. We discussed this with a local large-scale beekeeper who had collected well over 200 swarms last season, many more than he’d seen in any one season in his beekeeping career, Besides swarming, other phenomena that had reduced honey production, according to this bee keeper, were the disastrous freeze of 1989 and dramatic reduction in rainfall after Hurricane Gilbert.
Chip believes that the real factor affecting honey production is Africanization of the area, characterized by the influx of large numbers of unproductive feral bees, not the weather. The rainfall data for the region, he said does not support the beekeeper’s view that a serious scarcity has occurred. Hurricane Gilbert did have a great impact in the area, but has long past and the freeze occurred some four years ago. In spite of the citrus flow, this beekeeper did not expect any honey from that crop in any case. Rather, he was using the citrus to build up populations for the mesquite flow to follow.
It was obvious this beekeeper had no idea of the consequences of the African bee phenomenon. Unfortunately, because of this, it was easy to place the blame on other forces, even the “gringo” who coincidentally had arrived and began to hang blue boxes in nearby trees. We tried to tell this beekeeper the full story one afternoon in the shade of his honey house. Whether we succeeded in convincing him of how beekeeping would change because of the African honey bee or not remains to be seen.
Beyond the African honey bee, the beekeepers in the region are also facing another problem. We found this out during a visit to the nearby Universidad Autonoma de Nuevo Leon (UANL). This lovely little campus has 18 faculty and 46 students working in a wide variety of agricultural areas. There we met the exuberant Dr. Celina Garza, trained in Germany, and working with honey bee diseases, pests and management. She believes it is only a matter of time before the parasitic honey bee mite, Varroa destructor, makes its way to Linares. The mite has already been confirmed in nearby state of Tamaulipas. Mexican officials and researchers are now discussing the kinds of controls that might be used. Not only are they looking at Apistan®, but also formic acid and several compounds used in Germany.
The scenario will be reversed from that expected in the U.S. where Varroa awaits arrival of the feral African population. In northern Mexico, the African population precedes the mite.
Chip also outlined another disease problem that no longer plagues the area. In 1985-87, a bad outbreak of tracheal mites (Acarapis woodi) occurred in the Linares region with large scale colony loss. This was much studied by U.S. researchers and others. Now this mite is not a problem, but the reason for the decline remains unclear. It seems likely that “natural selection” weeded out the European populations that were susceptible to this mite. What the tracheal mite’s effect might be on a newly arrived African population is not known. And contrary to popular belief, Chip says, the African bees moving through this area are not immune to diseases. He has seen chalkbrood, especially in drones, and also what he calls an “atypical” foulbrood, associated with African bee mother lines that does not appear to respond to Terramycin® treatment for American foulbrood.
So just how many swarms has Chip sampled in his three-year experience in northern Mexico? Would you believe 1400? They are all cataloged jn his black book he brought out for us one evening. In 1991, using 320 bait hives, he collected 500 swarms, and in 1992, in half that number (160), he sampled 800. This year we had just gathered number 100. Chip is also quick to point out that he is catching only a percentage of all the swarms in the area that are making their way toward Texas.
As reported above, besides trapping swarms, Chip is also working on controlled crosses using instrumental insemination. Thus, another of the daily beekeeping tasks was to catch drones. We did this with some facility at the entrance to European colonies; it is almost impossible to do this in African colonies, Chip said, because of defensive behavior. Fortunately, we were not called on for that task. European drones were in big demand at this particular time. It was imperative to catch those leaving the colony. Returning drones would invariably evert their genitalia when grabbed; they were figuratively and literally “hot.” The body temperature of these males, Chip said, goes up dramatically on their flights; one reason for their returning may be simply to cool down.
The captured drones were returned to the house where Alonso Suazo was busily inseminating a number of queens through harvesting semen from drones. He showed me how to judge whether drones were mature enough and then how to evert the genitalia and collect the semen in a fine glass needle. We also made up five-frame nuclei (nucs) to house the young queens that were being inseminated. The big shaker box in the back of the van was disassembled and the bees, recently happily inhabiting the bait hives, were shaken into a number of nucs. Richard made up syrup and we gave to each nuc a division board feeder and some brood, if possible, to hold the bees.
Because they abscond so readily, keeping African bees in a particular box is one of the biggest management challenges posed by these insects. This is the reason a standard practice by many in Latin America is to immediately requeen any swarms caught. Establishing nuclei had to be done as close to dark as possible. If not, the air becomes filled with bees and the drifting among colonies was enormous.
Midway through our stay, Dr. Roger Hoopingarner and his wife, Barbara, arrived at Chip’s invitation. Roger, a research and extension apiculturist at Michigan State University, came to see the, bees up close and conduct some foraging and drifting experiments of his own. On the day of their arrival, we planned a trip into the nearby foothills to visit some European colonies at about 1500 meters elevation. It seems that European bees retain their characteristics longer at higher altitudes, and Chip had some hives in the mountains, which serve as stock for his experiments. Alonso told me that this does not necessarily occur in Honduras where the honey producing colonies at high altitudes are very definitely African. Such geographic variation in behavior by this adaptive insect also has added to the confusion surrounding the “true story” of the impact of the African bee in the American tropics.
After a steep climb, we entered university grounds maintained by the UANL at Linares. Typical of tropical locations in the highlands, the beekeepers make a good deal of honey off many different plants. The flows occur in the fall. The major nectar plants were unknown to us, but the honey we tasted from combs in that area is characteristically green and strong tasting. Unlike other mountainous areas, there appear to be no plants producing quantities of nectar that might damage bee colonies or impair human health, our Mexican consultant told us. He also informed us of a new development; the first recorded damage of bee colonies by black bear in the area in a good many years.
Back at the house, Roger Hoopingarner was getting his experiment together. He was fitting hives with an apparatus to mark bees with pigment. He used a passive marking technique. Above the colony’s entrance, he placed a wooden box filled with the pigment. As the bees squeezed themselves through the entrance a tiny bit of the powder would fall through a cloth the bees touched with their back. The results of this marking were variable; I still remember one bee which looked for all the world like a red fly as it flitted around a recently inhabited queen cage. Once marked, the number of bees that drifted from specific colonies and in which hive they wound up could be determined.
I was asked by Dr. Glenn Hall, who had to stay behind in Florida, to collect larvae and then pickle them in cold alcohol. These samples were required to do DNA analysis which would also be correlated to Chip’s results. The collection of larvae only, preferably the largest ones in the comb just prior to capping, is not an easy task. It is accomplished by literally squirting them out of the comb with water. After straining out the water, the larvae are put in alcohol. This liquid is then agitated periodically and changed four times over the next three days to gradually dehydrate and preserve the specimens. It is a time-consuming process and one that must be done at the close of each collecting day. For this scientist, thus, the end of each work day also signaled the beginning of my particular task.
We were out of touch with most of the world at the house. No television and only a little short wave radio intruded into our daily life. This was by design, however, as we focused on the jobs at hand and spent time communing with nature. If one wanted to remain electronically tuned into the world, it was possible in Linares. The suburbs of the town were forested with television antennas. Satellite dishes also adorned the tops of bars. Chip said one could literally request any of several hundred channels in these drinking establishments. One night on a lark, he was able to see a University of Kansas basketball game.
On the night of March 12, snappy winds and a few static-filled reports on radio about a major storm system in the United States did not signal any reason for concern. But when we reached the border the next day and saw several satellite dishes destroyed and signs blown down, we realized that something out of the ordinary had occurred, Still, it was only when we arrived in Houston and our plane connection was two hours late, did it finally sink in that the blizzard of ’93 (The Storm of the Century) was a reality.
The white blanket from Louisiana across Mississippi and Alabama was easily seen from the aircraft, and our landing in perhaps the last airport open on the east coast, Jacksonville, Florida, was chaotic. The gates had lost power, an earlier tornado had damaged an aircraft, and at dusk it was easy to see the snow blowing sideways. I arrived home in the dark. A tree had fallen behind our house taking the power lines with it and crushing a car. That night it went down to 26 degrees F, and I very much missed the warm Mexican winds of the week before.
How the saga of the African bee will play as it becomes established in the U.S. is still unclear. Chip was featured as The Man Who Loves Mysteries,” in the February 1993 issue of Bee Culture magazine. Whether he will be able to solve this perhaps greatest mystery of his career or not remains to be seen. Clearly though, he loves being around these “moscas.” My lasting memories of that sojourn to Mexico will be of him holding up a paper pot trying to lure a swarm into it or gleefully squatting over a swarm that landed on a single sunflower in a bare field, a true “grounder,” before it took off again only to be lured into a nearby bait hive.
Post Script: Subsequent to this report, Dr. Taylor https://eeb.ku.edu/orley-r-taylor has transitioned out of honey bee research and founded Monarch Watch, an outreach program focused on education, research and conservation relative to monarch butterflies. This program has produced many new insights into the dynamics of monarch migration, inspired public schools and others to create habitats for monarch butterflies, and assisted Monarch Watch in educating the public about the decline in resources for monarchs, pollinators and all wildlife that share the same habitats.