Dr Warwick Kerr, the “Man Who Created Killer Bees”, has died

It is with regret that we report that the humanitarian, geneticist, and scientist, Professor Warwick Kerr, passed away this morning, September 15, 2018. He was six days past his 96th birthday.  Dr Kerr, a Brazilian bee scientist, had one of the most maligned lives of any research scientist. He will be remembered by some as the man who gave us ‘Killer Bees’ – the African-European bee known for its (sometimes) aggressive behaviour. The Africanized Honey Bee, a hybrid which Dr Kerr was largely responsible for creating, helped turn his impoverished homeland of Brazil from a backwater of agriculture and honey production into one of the most prolific honey and agriculture countries in the world.

Dr Kerr was born in Brazil. He developed an early sympathy for his country’s poverty-stricken aboriginal hunters and farmers who supplemented their families’ diets with honey from native stingless bees. He also saw how other farmers struggled to pollinate their crops and produce honey with the imported European honey bees. Those bees originated in Portugal and were not well-adapted to Brazil’s tropical climate. His goal was to improve the lot of farmers. In the 1950s, he brought African bee stock to Brazil. He was an accomplished geneticist and planned to breed a tropics-adapted bee that would be successful in Brazil.  A technician mistakenly removed queen excluders from the breeding hives and 26 imported queens swarmed.

They spread slowly at first, but there was no way to put them back in the box once they escaped into the rainforest. It seemed like an unmitigated disaster. As it happened, at the same time, Brazil was ruled by a vicious military dictatorship which Kerr vocally opposed. He was in deep trouble and imprisoned in 1964 when he publicly fought government corruption. In 1969 he was re-arrested, this time for protesting that Brazilian soldiers who had raped and tortured a nun went unpunished. Sister Maurina Borges, who ran the Ribeirão Preto Orphanage, was an activist; the soldiers were part of Brazil’s military dictatorship, committing crimes encouraged by the government. [See page 16 of this 2005 interview with Kerr.] He helped her and he protested, drawing attention to himself. The military couldn’t kill Dr Kerr as he had a powerful international reputation as a brilliant geneticist. So, the Brazilian government set about destroying the reputation of the great scientist, claiming that he had created assassin bees. He hadn’t, but it sold newspapers. The press ran with the story. Shamefully, that includes the North American press.

Before we return to the Africanized bees, it’s appropriate to highlight Kerr’s work as a geneticist. He had studied at the University of California then Columbia University, working under the fabled geneticist Theodosius Dobzhansky in 1952. Dr Kerr discovered the incredibly complicated caste system of the Brazilian stingless bee, Melipona.

Sex among stingless bees

Warwick Kerr first worked with Melipona bees, not honey bees. Some of Brazil’s poor and indigenous were wild honey gatherers, or meleiros. Meleiro, isolated and rural, is named for the meleiros people, who are named for the Melipona honey trees. There are only 7,000 meleiro people, but their precarious existence in the 1940s – which included raiding Melipona bee trees – concerned Dr Kerr during his bee research. He hoped that his work would draw attention to the importance of preserving Melipona, their habitat, and the people who lived off those bees. Understand and help the Melipona, and you help the meleiros, figured Kerr.

Melipona quadrifasciata,
photo by
Elinor Lichtenberg

Kerr studied Melipona quadrifasciata, a eusocial stingless bee, native to southeastern coastal Brazil. The indigenous meleiros call it Mandaçaia, which means “beautiful guard,” as there are always guard bees defending the narrow entrance of their colony. Brazil’s Melipona builds mud hives inside hollow trees. These have narrow passages allowing just one bee to pass at a time. Stingless bees, they can give a nasty bite, but their intricate passage system also defends against predators.

Dr Kerr’s first influential paper “Genetic Determination of Castes in Melipona” (1949) researched the development of males, females, and workers among Brazil’s common stingless bee. Kerr found that their caste development was different from honey bees. Drones in both species are haploid, but in Melipona, things get weird for the girls.

In Apis mellifera, “a larva develops into a queen or into a worker depending upon the food it receives. In Melipona, on the other hand, caste determination is genotypic. Fertile females (queens) are heterozygous in some species for two, and in other species for three, pairs of genes, homozygosis for any one of which makes the individual develop into a worker.” – Kerr, 1949.

For the exotic Melipona quadrifasciata, alleles (one-half of a gene that controls an inheritance, for example the ‘b’ in a ‘Bb’ gene) determine caste. Drones (as in honey bees) are haploids with a single set of chromosomes; queens and workers are diploid (two sets of chromosomes, one from each parent), but queens have some specific alleles that are different, or heterozygous (for example, AaBb), while workers have identical, or homozygous, caste-determining genes (AABB, AAbb, aaBB, or aabb combinations). If you find this confusing, imagine sorting it out with 1940s technology, as Kerr did.

From Kerr’s 1950 Melipona paper

African Honey Bees

Warwick Kerr was responsible for bringing African genetic stock to Brazil in 1956. As a geneticist, he wanted to improve the health and hardiness of the European honey bee which came from Portugal in 1834. That European strain was poorly adapted to the tropics, so the Italian honey bee (Apis mellifera ligustica) was imported in the 1880s, but it wasn’t much better. A few farmers and monks kept the languid bees, mostly to collect beeswax for church candles.

In 1956, Brazil’s annual honey production from the European honey bees was just 15 million pounds. Brazilian agriculture was expanding and needed a tropical honey bee for pollination and honey production. After the African bees arrived, Brazil’s beekeepers produced 110 million pounds. Brazil went from 43rd in the world to 7th largest honey producer. By 1994, L.A. Times headlined: “Brazil’s honey production has soared since the ornery invaders took over beekeepers’ hives”. Today, most of the world’s organic honey is produced by Africanized honey bees in Brazil’s remote forests. The honey is doubly organic – produced in areas untouched by pesticides and produced in Africanized hives which are naturally resistant to varroa – so mite meds aren’t used in those colonies.

Honey bees with African genes are more aggressive than European bees. Beekeepers in Brazil had to learn appropriate management techniques. Although the venom is the same, more bees attack if their colony is disturbed. People have died from massive stings. Those deaths are sorrowful and this story about Dr Kerr’s bees should not dishonour personal tragedies. Some of the traits which make Africanized bees exceptional pollinators (refined olfactory sense, quicker movements, flights in inclement weather, superior navigation skills) also make them more likely to sting en masse. However, they can be managed by farmers and beekeepers. Indiscriminate killers they are not.

It may surprise some readers to learn that Kerr’s Africanized stock is now preferred by many beekeepers, even in the United States where its resistance to the deadly varroa mite and its superior honey production has made it a favourite. I correspond regularly with a southern California beekeepers who tells me that she would not want to keep any other type of honey bee.

The real Warwick Kerr

Kerr was born in São Paulo, Brazil, in 1922, into a middle-class family with Scottish roots. He received an agricultural engineering degree, then specialized in genetics. His work as an entomologist spanned decades, with research that included genetics of honey bees and native Brazilian bees, as we’ve just seen.

Warwick Kerr’s post-doc research was at the University of California, Davis (1951), and at Columbia University in New York, under the renowned evolutionary biologist Theodosius Dobzhansky. One of Kerr’s influential papers, “Experimental Studies of the Distribution of Gene Frequencies in Very Small Populations of Drosophila melanogaster“, cites Dobzhansky as an adviser and is co-authored by a University of Chicago genetics statistician. This fruit fly research was done way back in 1954 and the paper was one of the first to deal with the nascent field of genetics statistics. Eventually, Kerr published 620 research papers during his 60-year career.

Warwick Kerr was largely responsible for establishing the study of genetics in Brazil. He was a director of the National Institute for Research in the Amazon and worked at the University of São Paulo. Later, at the Universidade Estadual do Maranhão, he created the Department of Biology and served as Dean of the University.

Warwick Kerr said that his most important work was developing staff, technicians, teachers, and researchers in his country. At the University of São Paulo, he established a department of genetics which focuses on entomological and human genetics, using mathematical biology and biostatistics. Kerr had memberships in the Brazilian Academy of Sciences, the Third World Academy of Science, and the US National Academy of Sciences.

I’ll end with a pleasant little video made five years ago. In it, you will see that Dr Warwick Kerr’s interests had shifted to botany. The film is in Portuguese, but even if you don’t understand the language, you’ll get a good idea of the enthusiasm and curiosity which had filled Warwick Kerr’s life.

About Ron Miksha

Ron Miksha is a bee ecologist working at the University of Calgary. He is also a geophysicist and does a bit of science writing and blogging. Ron has worked as a radio broadcaster, a beekeeper, and Earth scientist. (Ask him about seismic waves.) He's based in Calgary, Alberta, Canada.
This entry was posted in Bee Biology, Culture, or lack thereof, Genetics, People, Queens, Science and tagged , , , , . Bookmark the permalink.

32 Responses to Dr Warwick Kerr, the “Man Who Created Killer Bees”, has died

  1. Susan Rudnicki says:

    Awww!! thanks so much for this! You filled out his profile wonderfully–such a interesting, vibrant life he had. I love my AHB ferals, they are so resilient and never need coddling. Caught two swarms this week (one just moved into a empty nuc) and am taking a big colony out of a old lady’s ceiling on Monday. And I think your small remark about the So Cal beek must be me. May I re-post this on the TF Facebook group, with credit to you?

    Liked by 1 person

    • Ron Miksha says:

      Hi Susan!
      Yes, you are guilty as charged! My niece in Arizona may also be keeping AHB (I don’t know for sure.), but I was thinking of you. Certainly, please let others know about Dr Kerr’s death and re-post this.

      Liked by 1 person

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  3. An interesting man and scientist.

    Liked by 1 person

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  5. This is Superb. I want to tell you how much I appreciated your clearly written and thought-provoking article.

    Liked by 1 person

  6. Brian Tamboline says:

    Thank you for this , greatly appreciated. I posted a link to your blog in BeeSource. Hope that’s OK. I should have checked first, I guess. My bad.

    Liked by 1 person

  7. Brian Tamboline says:

    Would it be ok if I post the link to Bee_L? this time I’m asking in advance. They have a serious audience.


  8. Brian Tamboline says:

    Thank you Ron, a gentleman as always.


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  10. Great article, A little known fact that I learned from Mike Allsopp from Stellenbosch University at our recent BEECON. Dr. Kerr and his team along with Scutellata also introduced Capensis queens (Cape honeybee) from South Africa to South America, Ironically more destructive than “killer bees” Dr. Kerr had to terminate all these Capensis queens and Capesis colonies as they started to invade all other hives with Laying workers (false queens). The “Capensis invasion” have been a huge disaster here in South Africa and destroyed much of our commercial beekeeping in the summer rainfall areas….If Capensis had ever got into the USA it would destroy the commercial beekeeping industry there IMO.. http://www.arc.agric.za/arc-ppri/Pages/Insect%20Ecology/Honeybee-Biology.aspx

    Liked by 1 person

    • Ron Miksha says:

      Hello Justin,
      Thanks for your comments and compliments. It would be good to know if this story of a failed importation were true. Since Kerr was trying to use a high-yield honey producing strain, it seems doubtful, but, of course, possible.
      Do you think that the cape bee, if imported to Kerr’s south Brazil lab, would have travelled genetically as far as AHB has? Would it have survived the jungles and tropics? One way to guess an answer would be to note how far Capensis has migrated from South Africa’s cape. Is the Capensis bee endemic in Kenya or Gambia? (I don’t know its range.) Those would be similar to the climates of northern Brazil, Venezuela, Colombia, Central America, and southern Mexico which the cape bee would have to transverse before reaching the States. What are your thoughts?


      • Anonymous says:

        Hi Ron apologies for my slow reply! Capensis clones are spread mainly by beekeeping activity, in apiaries and moving hives. More so than on their own accord, like the African bee does with it’s propensity to spread via swarming. Id imagine that it would take some time for the problem to spread from one apiary to another as it has in South Africa. I gott his info from Mike Allsopp (Entomologist) at Stellenbosch University Capetown. “Sorry that we did not get a chance to chat at Bee-con.
        Capensis has been an ever-present problem in the midlands since the early 1990’s (even if there were KZN beekeepers that did not believe it) – and behaves very much like it does in other parts of the country (such as Douglas). Namely, it is hardly noticeably for a period and then suddenly there is a huge surge, and many (or most) colonies are afflicted and die (or are killed). Thereafter it is quiet for a while, and the pattern repeats itself.

        We do not understand why this is. Certainly it has a lot to do with beekeeping activity (the problem almost incubates in apiaries, and takes some time to develop); and problem season as well (worse in some years); but it also almost certainly is something about the capensis clones that we don’t quite understand as yet – and that is that they lose virulence quite quickly and become less and less affective, and so the problem gets less and less – and then suddenly, the virulence is back – and it is like the first days of the infection again. We have some ideas of what is going on, but still have quite a bit to figure out.

        As to what to do – pretty much what you suggest:

        • definitely do NOT introduce any fresh swarms to infected apiaries
        • For the infected apiaries – isolate them – – and you can keep the colonies going for as long as they are productive – but, in my experience, they will all go in the end – so it is often best to just eliminate them and start again
        • I wouldn’t worry about the surrounding area – the invasion distance is very limited – just clear out the infected apiary and everything in the immediate proximity
        • I also wouldn’t worry about hive entrances & colony landmarks & spacing – all minor factors – key to remember is that it takes years to develop in the apiary – which means that by the time you see it, unless you are very vigilant, it is already in every hive”

        Liked by 1 person

      • Anonymous says:

        I meant to add the Cape bee (pseudo clones) is spread mainly via Commercial beekeeping (especially migratory beekeeping within large apiaries, holding yards for pollination etc) which is how it has spread around South Africa, it has spread all over everywhere commercial beekeeping is practiced here causing the death of thousands and thousands of colonies. It has not spread yet to many other African states because they don’t move their bees around much and they are so isolated. Perhaps it would have been contained locally and remained a problem in South America like it has in Africa? But I’d hate to imagine the devastation Capensis would cause if it ever got to California Almond area!

        Liked by 1 person

      • Ron Miksha says:

        Thank you for adding to this. I have learned a lot from your notes, which are from your personal knowledge and experience.
        I’m surprised that someone hasn’t already brought Capensis to California, even though it would not have any known benefit. That’s a different story from the main African honey bee races that you successfully keep. It was among those subspecies that Kerr chose to bring tropical genes to Brazilian honey bees.
        Regards, Ron


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  12. Damien says:

    Thank you for this well written and informative post!

    Few people in the world have helped so many as Dr Kerr did. His work not only helped rich people, but poor people too, which makes him all the more impressive.

    Liked by 2 people

  13. Mark James says:

    Great article. But you are minimizing this doctor’s contribution to the killer bees. HE was the one who imported them and HE was the one who did not manage his inept staff (who let them loose — how about at least a warning sign there) This release made him suicidal for a while. While they do pollinate better and make more honey, they do kill people (over a thousand deaths to date) and HE is responsible for this. I consider the release mistake to be one of gross negligence. Killer bees is his greatest legacy.


    • Ron Miksha says:

      Thanks for reading and commenting.

      Going straight to the source, I communicated with people who knew Dr Kerr. He was not suicidal. The military government spread rumours about him. One of those rumours, disbursed by his political enemies, claimed that he tried to kill himself. Not true, according to people who knew him. Please share your source for your contrary information – I’ll follow up on it.

      Lots of people have mentioned the deaths caused by AHB. Every one of them is a tragedy. Are those stings Dr Kerr’s fault? Is the ‘greatest legacy’ of the Wright brothers the 3,000 deaths caused when their invention was turned into a murder weapon in 2001? What about cars? Electricity? One hundred Americans are killed each year by cows and horses, which are also imported livestock. What shall we get rid of to keep ourselves safe?

      What about honey bees in general – the honey bees that are kept in New Jersey, for example, are not native to North America. They have killed people, yet they help agriculture. Since honey bee introduction in 1636, European honey bees have caused over a thousand deaths to date in North America. Should honey bees be removed from the United States? Should we disparage the European settlers who brought them? Honey bees in the USA are integral to agriculture. Certainly, American agriculture has prevented starvation in some parts of the world. In Brazil, AHB improved agriculture enough to curb malnutrition and lengthen human lives. Brazil now exports food to countries where starvation occurs – maybe the Africanized stock saved lives. It makes no sense to have a double-standard: The USA can have non-Africanized bees (which nevertheless kill people every year) but developing nations like Brazil can not. Sorry, I don’t agree with that way of thinking.


      Liked by 2 people

      • Anonymous says:

        You couldn’t be more wrong. If the Wright brothers decided to test their plane above a schoolyard, and crashed their plane into some kids, killing them, yes it would be their responsibility. You’re comparing apples to oranges. It’s not what somebody else did with Kerr’s research, it’s that he himself mishandled his research, did a sloppy job and lead to thousand of deaths.

        Of course Brazil can try to introduce bee’s, and try to improve the stock in whatever way they please, just like they can build nuclear power plants. Nobody is saying that’s a problem. The problem comes when the people in charge fail miserably at it causing damage, that’s the issue.


      • Ron Miksha says:

        You wrote, “You couldn’t be more wrong.” I’m pretty sure that I could be more wrong, if I tried. For example, I could agree with you.

        Do you blog? You should, I’d certainly follow you. In two short paragraphs, you gave your permission to the Brazilian people to improve their bee stock (very kind of you), you equated the terror of Africanized bees with nuclear power plants, and you revealed the long-held secret that the Wright brothers had crashed their first plane into a schoolyard crowded with kids and killed them (that’s why they were chased out of Ohio to the beaches of North Caroline). You forgot to bring Hitler into the conversation, but you did manage to add an apostrophe to the word ‘bees’ while making it plural (“Brazil can try to introduce bee’s…”) – showing a fun disregard for proper English. Thanks for making my day!

        Meanwhile, upon his death, Dr. Kerr was honoured with flags at half-staff for his charity and his contributions to the welfare of his country. Not bad for someone whom you say failed miserably.


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  17. Lawrence wheeler says:

    Dr. Kerr was a very smart entomologist he took measures to screen off and by lock the experimental bees from escape. The Dr. was blamed for the escape, but often the truth is forgotten. A recently hired worker wondered why the hives were blocked and forcibly took off the screens without asking, first, why Dr. Are the screens there and the rest of the story is in any of these stories in Google. Yes, Dr. Kerr was running the experiment but sometimes a uneducated assistant is due to the pandora getting out of the box. All researchers should remember this as warning to guard your research and who has access to it. With the kind of man kerr was trying to solve the Brazilian honey problem and if the bees weren’t accidentally released. He said in his interview he after discovering their extreme attack nature would of destroyed the bees and looked for a different solution. There are always chances with experiments for something that can go wrong, but isn’t this how we learn? Even with bees

    Liked by 1 person

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