Superweeds and Superpests

The use of genetically modified crops was intended to reduce the need for herbicides to control weeds and insecticides to control pest insects. However, The New York Times reports that instead herbicide use increased over 16 years, while insecticide use decreased somewhat. The widespread use of a single herbicide glyphosate, sold under Monsanto’s brand name Roundup, has resulted in the evolution of a number of glyphosate-resistant weeds. The Times piece, http://green.blogs.nytimes.com/2012/10/05/the-legacy-of-pesticides-superweeds-and-superpests/?src=rechp, describes different approaches to the use of these genetically modified organisms. “Roundup Ready” corn, soybeans, and cotton seeds were planted on 1.37 billion acres from 1996 to 2011. The GMO plants, tolerant of the herbicide glyphosate, were supposed to reduce or eliminate the need to till fields and reduce the need for harsher chemicals. The use of these GMOs was supposed to also save money and be less stressful on the environment. As glyphosate-resistant weeds increased, increases in the use of glyphosate slowed; and in 2010 the National Research Council warned that, “Eventually, repeated use will render glyphosate ineffective.”

Those deploying the genetically modified seed containing the Bt gene producing toxins from the soil bacterium Bacillus thuringiensis recognized the potential for evolving resistant insects, and they took precautions. They required that a percentage of non-Bt seed be planted with Bt crops to ensure that some insects susceptible to the Bt toxin survive to mate with survivors of the Bt crops. Otherwise, surviving pest insect populations could become increasingly resistant to the Bt toxin with each generation. The mechanism for ecological harm from chemical pesticides was described by Rachel Carson in Silent Spring 50 years ago: “First, many of these chemicals are indiscriminate, killing not only pest but also the predators and parasites that help to keep them at bay. Second, surviving pest populations become increasingly resistant to the applied toxins with each generation, as those most susceptible to the toxins die off. It’s natural selection in overdrive.” Today’s photo: applying herbicide to control grasses in GMO soybeans.

--Richard

Transitions

Three types of bee hives are used in Ethiopia. Ninety-seven percent of the hives are traditional hives, long baskets built at no expense of cane and banana leaves. These hives are usually hung high in trees, but they are also attached to the outside walls of houses. Some traditional hives are placed inside houses under beds. Modern bee hives similar in design to the Langstroth bee hive comprise two percent of Ethiopia’s bees. The remaining one percent of Ethiopian bee hives is top bar hives, described as “transitional hives.” These simple boxes are also built from locally available materials at no expense. Transitional hives provide an economical method of managing honey bees that allows for the benefits of modern beekeeping: ease of hive inspection, ability to combine and divide colonies, move brood between hives, requeen, and improve genetics. Most importantly, transitional hives allow for the non-destructive harvesting of high quality honey. Beeswax is harvested by crushing honeycombs. Hive products are collected without killing or losing the honey bee colony. Today’s photo from Ethiopia shows one of Teshome’s transitional bee hives mounted in a tree. This top bar hive is covered in plastic and foliage as is the custom in Ethiopia. I recommended that Teshome consider removing the foliage to improve air circulation. Chalkbrood, a honey bee fungal infection, is a major hive problem in Ethiopia’s rainy season.

Many transitions are occurring on Ethiopian farms. Beekeepers earn additional income with transitional and modern bee hives. Using standardized sized hives, beekeepers can move combs from one hive to another. Teshome recognizes the benefits of improving queen bee genetics; he uses similar techniques in cattle breeding. He foresees the ability to produce gentler bees by selecting queen stock from his best hives. His farm is steadily transitioning to a broader based economy. Teshome eagerly traces the design of my hive tool so that he can have the local blacksmith produce tools for area beekeepers to take a more hands-on approach to beekeeping.

--Richard

Biological Controls

Before embarking on my latest beekeeping trip to Africa, I checked the hive that I was using to transfer a colony of feral honey bees from a hollow tree. All was progressing well, the capture hive was full of bees; the bees even filled two honey supers with summer honey. When I returned a few weeks later, the hive was completely “slimed” by small hive beetle larvae; the bees had abandoned the hive; and the honey was fermented. The hive was overtaken by small hive beetles. Bees and beekeepers find invasive small hive beetles difficult to control. Currently, chemical and cultural controls are used to reduce small hive beetle populations.

Researchers at the University of Arkansas asked a question: Could the small hive beetles have brought their own parasites with them when they entered the US? The presence of such a parasite of the small hive beetle could possibly lead to a biological control for these bee hive scavengers. To investigate the possibility that there may be a not-yet-discovered parasite, Natasha Wright collected small hive beetle adults and larvae and samples of soil from bee yards in Arkansas and adjacent states. She dissected 749 adult beetles and 230 larvae from 13 counties in Arkansas and one county each in Oklahoma and Missouri. Natasha found no microbial pathogens in the SHB larvae, but she did find a protozoan pathogen in adult SHBs from three Arkansas counties. Most of the infected beetles were from a single apiary in nearby St. Francis County, Arkansas. One infected beetle was found in a Peace Bee Farm apiary in Crittenden County, Arkansas. In total, 5.3 percent of the adult beetles sampled were infected with the protozoan pathogen, which forms cysts in the beetles’ Malpighian tubules. The heavily infected beetles detected in St. Francis County were described as having an “impaired function in life.” Hopefully, research will find safe and effective controls for small hive beetles. For published results: www.springerlink.com/content/b103041x41163216/. Today’s photo: SHB larvae slime a hive.

--Richard

Honey Bee Super-Sisters

A reader asked a question about the mechanism in which honey bees pass their genes along to the next generation. Honey bees employ a reproductive scheme called “haplodiplodity.” For an informed answer, I called upon my friend, Jon Zawislak, apiary instructor with the University of Arkansas Cooperative Extension Service. I quote him below. It appears to me that an evolutionary advantage of haplodiploidity may be in altruistic behavior in which individual bees act for the protection of the colony over self. From Jon Zawislak:

“Begin with the strict Darwinian principle that an organism is considered to be most "successful" by passing on as many copies of its genes as it can.

Worker honey bees get half of their DNA from their mother. Of that 50%, about 25% is identical (basic Mendelian genetics). The same is true for humans, you get 50% of your DNA from your mother, of which you share about 25% identical maternal DNA with each of your siblings (although not the same 25% with each). The lopsided relationship among honey bees comes from the paternal side, from the drones. Drones have only one set of chromosomes, so their sperm does not undergo reduction division to halve the number of genes, which effectively mixes them up first. Each of the millions of sperm that a drone produces is identical, and contains his entire set of DNA. So when worker bees are "super sisters" they share 75% identical DNA: 25% from the queen and 50% from the drone (all he has, so all incidental). Workers who have different fathers share only maternal DNA, and are said to be 25% related. If this particular queen mated with 20 drones, on average each will be the father of only 5% of the workers in the hive, and each worker will share this super-sister relationship with only 5% of her family.

If a worker helps one of her super-sisters to become the next queen, she ensures that she is 37.5% related to every new bee in the colony (50% of 75%). Even if one of her half-sisters becomes the next queen, she will still be 12.5% related to all of them. But this is still better odds than if she has her own sons. If a worker becomes a laying worker, then she can produce only drones, which are 50% related to her. If one of her drone sons successfully mates, she will be 50% related to her granddaughters as well (because the drone passes on all of its DNA). But, each drone has a fairly slim chance of mating at all (a conservative estimate might say one in 1000 chance of finding a virgin queen). And if he does, he will only be one of perhaps 20 drones to do so. Therefore if a worker becomes a layer, she has less than one in 1000 chance of her son passing on 50% of her genes to just 5% of another colony.

A worker is more closely related to her super-sisters than she is to either of her parents or her own potential offspring. And even though she's only this close to as few as 5% of a colony, consider how many bees that is. In a colony of 40,000 bees, that's still 2000 super-sisters. Close kinship also promotes altruistic behaviors, where an individual promotes the well-being of close relatives, even at a potential risk to themselves. Bees demonstrate several examples... spring bees work themselves to death so that wintering bees will have food to eat during the cold months; individual bees sting and die to defend and protect the rest of the colony; and workers "give up" their own reproduction to help raise their sisters and nieces. But as we have seen, the family unit is more successful at passing on some of its genes if they all work to help their queen. Solitary bees that go it alone produce only a handful of offspring each year, rather than the thousands that a honey bee queen can produce.

Of course this idea of kinship and altruism assumes that bees know that they are closely related. Studies have shown that workers reared in isolation can distinguish between full- and half-sisters (Getz & Smith. 1986. Animal Behav. 34:1617-1626). Workers preferentially rear queens from more closely related larvae (Visscher. 1985. Behav. Ecol. Sociobiol. 18:453-460). Workers are most willing to groom and feed closely related sisters (Frumhoff & Schneider (1987) Animal Behav. 35:255-262). And workers may cannibalize eggs less closely related to themselves (Ratnieks & Visscher (1989) Nature 342:796-797).”

Today's photo: transitional top bar bee hives in Ethiopia.
--Richard

Traditional Thanksgiving

Winrock International, www.winrock.org, sends volunteers to developing countries around the world on USAID-funded food security projects. Africa is a fond memory now. I reflect on my assignment teaching beekeeping trainers in Ethiopia’s Oromia region. I travelled with Guta Abdi, the founder and managing director of Education For Development Association. Guta’s name means “full of hope” in Oromifa language. With Guta, I observed the beautiful, volcano-strewn land, resourceful farmers, and Oromia’s rich customs. My training sessions in the mountain-top village of Shambu began and ended with prayers by traditional belief elders. These people, numbering five million believers, deeply respect the land and attribute all existence to a single deity without praying to any prophet. They gather annually around six volcanic lakes for thanksgiving. Guta Abdi is shown at the thanksgiving in the center of today’s photo wearing a gray sweater and open collar. When he took me to the site, I knew I was in one of the earth’s special places.

Travelling through Oromia, I saw children proudly wearing banana leaf hats. The children of each village fold their banana leaf hats in a distinct regional design. Along mountain ridges, I saw “fachas,” tall poles with tin roofs covering a cape buffalo’s tail. The facha is a sign proclaiming that a man accomplished a feat such as killing a lion or leopard with a spear. In earlier times, a facha was placed to proclaim the killing of one’s tribesman has been revenged by killing nine of the opposing tribesmen. Fortunately, this is a past practice. I especially enjoyed sharing Ethiopian food with my host. A typical day started with eggs and red peppers, enjira, Ethiopia’s flat bread made from fermented teff grass seed, bread, and tea. Coffee and bread was served at morning and afternoon breaks. Lunch included enjira, potatoes, and a “wot,” or stew, of sheep. Supper included enjira, cabbage wot, roasted sheep with carrots, “tej” honey mead, Ethiopian beer, and “areke,” locally-made vodka. Thank you, Winrock and EFDA.

--Richard

This Will Not Be Kicked

Explaining that the natural home of the honey bee is a hollow tree, I relate that all beekeeping efforts should provide a bee hive similar to a hollow tree cavity. Each of the Ethiopian beekeeping trainers in my Shambu class sits quietly with pen and tablet listening to Tucho translate my beekeeping lessons from English to Oromifa. They take notes and write questions for me. As soon as Tucho reads their questions, I realize that my students are knowledgeable; they are paying close attention to me; and they are interested in exploring new techniques in beekeeping. They ask specific questions about ways to manipulate modern bee hives. The students see the usefulness of moving frames of brood to produce new queens, strengthen weak colonies, make colony divisions, and select for better genetics. They ask about working bees in the daytime. Their traditional practice of nighttime honey harvesting gives the beekeepers few opportunities to observe the bees’ brood nest. Having only used smoke to drive bees from the hive, they want to know how smoke works to calm bees. The students question the causes of migratory swarming and hive absconding, both frequent problems for Ethiopian beekeepers. Several follow-up questions come from my suggestion that increasing bee hive ventilation and requeening can lessen the incidence of chalkbrood, a common fungal infection of honey bees in this semi-tropical land.

Some question commonly held practices and beliefs. When they see pictures of Peace Bee Farm hives painted white with stripes of color, they ask why mine are not painted yellow like modern Ethiopian bee hives. They all laugh in understanding when I ask if they ever saw a hollow tree in the forest painted bright yellow. One asks if my hair is gray from touching it with honey on my hands; I explain that it is merely due to my age. EFDA-trained leather worker, Tolesa, crafted the soccer ball signed by my Ethiopian beekeepers in Amharic and Oromifa. This football will never be kicked.

--Richard

Shambu Area Projects

I see evidence of the influence the Education For Development Association, www.efhda.org.et, makes on the lives of Oromo farmers. Travelling Ethiopia’s western highlands, I see multiple projects in effect. Providing sanitation and clean water for drinking are great challenges, so the EFDA provides well water and fixtures to deliver spring water for drinking and cooking. A solar water disinfection project effectively purifies water in clear plastic soda bottles at almost no cost. Bottles are placed on the roofs of houses, and UV rays from the sun purify the water in six hours. Concrete drinking troughs for cattle and livestock reduce the animals’ pollution of streams as well as helping to keep animals healthy in times of drought. On individual farms and at the EFDA’s resource centers in Shambu and Walisso, farmers gather to learn sustainable agricultural practices, animal husbandry, water conservation, and methods of improving food production. EFDA pioneered in introducing apples to Ethiopia’s highland area to generate additional income for farmers.

This is Ethiopia’s rainy season, and the western highlands appear lush and green. Everywhere I look farmers are plowing the rocky volcanic soil with teams of oxen. A closer look reveals lean oxen with bones showing; the animals simply don’t have enough muscle to safely pull their plows. Tucho shows me horse and donkey harnesses used for plowing when the mighty oxen are not capable of pulling the plows. The green grass is grazed close to the ground. Tucho explains to me that this year’s rains are not sufficient to sustain the grasslands and fill the reservoirs. Fincha Lake remains unseasonably low. Tucho fears the land may not sufficiently support the population’s food requirements Tucho and Gedefa explain EFDA’ efforts to protect the environment, prevent the loss of topsoil, provide drainage systems, and encourage crop rotation. Oromo farmers are working to prevent deforestation, and degradation of the environment. They protect flood areas and forests. My beekeeping project is designed to take advantage of the resources of the forest.

--Richard