Aggressive African bees were accidentally released in Brazil in 1957. As “killer bees” spread northward, David Roubik, staff scientist at the Smithsonian Tropical Research Institute, began a 17-year study that revealed that Africanized bees caused less damage to native bees than changes in the weather and may have increased the availability of their food plants.


Let me add a little context before you go back to the press release.

Apis mellifera, is most well known ‘honey bee,’ and is one of the only stinging honey bees (famous for being suicidal stingers … worker bees will swarm an invader and thousands of bees may give their lives to protect the hive). Most other honey bees neither sting nor make huge hives (most of the stingy things are wasps or some other kind of bee that is not exploited for honey because they make none or only a dab), but they do tend to make some kind of storage of some kind of honey, live colonially, and serve as pollen vectors.

In other words, honey bees as a group share the characteristic of being relatively numerous and storing food that they can protect aggressively, and of being generalized pollen vectors. So, one question that might arise is: How interchangeable might they be in a given local ecological setting? This is important when considering the effects of species invasion.

(By the way, next time you are at the heath food store or the healthy-seeming fast food emporium, and they ask you if you want “bee pollen” in your smoothie, don’t forget to ask them exactly what “bee pollen” is ….)

Anyway, Apis mellifera is a wild insect of Africa and Asia, tropical and semi tropical, living in a wide range of ecologies, as long as there is nectar. This is the species that was domesticated to create the honey bee of the bee farm, the one that produces the honey in the white boxes set off to the side of the orchard, and so on.

The so called “African Killer Bees” are nothing other than the wild version of the honey bee. This is a little hard for many people to get their heads around because there are not a lot of well known cases of a wild and domestic animal. There are not wild cattle that could accidentally interbreed with our domestic cattle. Pigs have been interbreeding between wild and domestic for so long that the rare European wild boar are probably closely related to the domestic form, though they are known to be more aggressive.

The wolf, of course, is the wild form of the dog. Same species, with multiple populations, some wild, some domesticated.

So when wild Apis mellifera and domestic Apis mellifera interbred in Brazil way back in time, some of the wild traits were re-introduced to the domestic bees, and that included some increase in aggressiveness (to a more normal level) and an increase in honey production.

Aggressive African bees were accidentally released in Brazil in 1957. As “killer bees” spread northward, David Roubik, staff scientist at the Smithsonian Tropical Research Institute, began a 17-year study that revealed that Africanized bees caused less damage to native bees than changes in the weather and may have increased the availability of their food plants.

Scientists feared that dangerous swarms of Africanized bees would compete with native bees. Roubik took on the daunting task of sorting out the role of invading pollinators in tropical forests. In 1988, he set up bee traps in Sian Ka’an Biosphere Reserve–a vast area of mature tropical rainforest in Quintana Roo state on the Mexican Yucatan–with Rogel Villanueva-Gutiérrez, professor at the Colegio de la Frontera del Sur in Mexico. Africanized bees arrived in 1989.

“Our long view of the invasion shows that bees maintain higher-order evolutionary relationships with plants despite ups and downs in bee species within families,” said Roubik. “Evolutionary relationships between bees and flowers, along with their flowering schedules, may be the fundamental currency that maintains this community.”

Pollen from each plant species has a unique shape. Researchers compared pollen on bees in traps to pollen from flowers in the forest to determine which plants the bees were visiting.

Over the next 17 years, a severe drought and three hurricanes devastated native bees, but their populations rebounded each time. Africanized bees took over pollination of two plant families that had been important food sources for native bees: the cashew family and the spurge family. However, Pouteria, one of the plants native bees prefer, became more common. A few rare species of bees disappeared from traps later in the study.

Roubik cautions that native populations in less diverse areas might be less resilient to invasions. “Basically we’re seeing ‘scramble competition’ as bees replace a lost source of pollen with pollen from a related plant species that has a similar flowering peak–in less-biodiverse, unprotected areas, bees would not have the same range of options to turn to.”

These results are published in the Biol. J. Linnean Soc.

Comments

  1. #1 Sean
    October 5, 2009

    “Apis mellifera, the ‘honey bee,’ is the only stinging bee”
    is only true if you state that it is the only stinging social bee in the Americas. Asia of course has other stinging Apis, including the formidable Apis dorsata.
    Sorry, I cannot seem to make my binomials italics.

  2. #2 MadScientist
    October 6, 2009

    “Other bees neither stink nor make huge hives”

    I’ve never encountered a bee that stunk although I’ve only been familiar with fewer than 10 types of bees.

    So, this beesness about the “killer bees” is really just a load of beegotry and breeding in an African variety was a good thing?

  3. #3 CSVOY
    October 6, 2009

    Africanized bees are not very good news.
    They are a substantial threat to the chicks of birds nesting in cavities, including some that are extremely endangered such as the Blue-throated Macaws (Ara glaucogularis).

  4. #4 Greg Laden
    October 6, 2009

    Ok, I was thinking only of African and South American bees when I said that only the honey bee stung. I extrapolated to Asia. I had not realized that the giant cliff stinging honey be of asia was a different species, but indeed it is (and there are actually two or three closely related species of giant asian stinging honeybee).

    The bumble/humble bee is, BTW (since this may occur to some people) in a different genus. (and they are not suicidal stingers)

  5. #5 Jason
    October 6, 2009

    I still don’t understand the ‘only stinging bee’ statement. I’ve been stung by Halictidae which are certainly bees… wait you meant ‘not the only’ didn’t you?

  6. #6 Jim Thomerson
    October 6, 2009

    If we are talking about a study done in the Yucatan, we are not talking South America. Are there similar studies done in South America?

    As a child in Texas, we kept honey bees, and I occasionally got stung with an unpleasant swelling and itch reaction which would last several days. Many years later, I got stung twice in one day by killer bees in Venezuela. One, working rotting mangos in the yard, got up my pants leg. Later that day we seined in a creek where a swarm had settled under the bridge. We made it back to the car with my friend getting a few stings. One bee made it in to the car and stung me whilst I was kiling it with my thumb. Neither sting amounted to much, compared with my youthful experience. We did encounter a killer bee swarm on another occasion, but understood what it was and did not approach. They have killed several people in Venezuela.

  7. #7 Sean
    October 7, 2009

    @Jason
    He means the only stinging social bee. And of course he is quite right, bumblebees are social and they do sting. There are even some bumblebees in South America.

  8. #8 rx1
    October 7, 2009

    I still don’t understand the ‘only stinging bee’ statement.

  9. #9 Greg Laden
    October 7, 2009

    Let me be more specific and clear: The genus Apis = the honey bees icluding dozens of species. Of these many many species of honey bees only a couple of species sting. When I said “only stinging” I was thinking only of Africa and South America and thought the cliff-honey bees of Asia were the same species as the honey be, but I was wrong. So it turns out that there are a few stinging honey bee species.

    Halictidae are not honey bees. And they don’t sting much either, but yes, they have a little bit of a sting.

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