- Author: Kathy Keatley Garvey
What are witchetty grubs?
Briefly, they're large, white, wood-eating larvae of the cossid moth Endoxyla leucomochla, which feeds on the roots of the witchetty bush (after which the grubs are named). "The term may also apply to larvae of other cossid moths, ghost moths (Hepialidae), and longhorn beetles (Cerambycidae)," Wikipedia tells us. "The raw witchetty grub tastes similar to almonds, and when cooked, the skin becomes crisp like roast chicken, while the inside becomes light yellow, like a fried egg."
Like a Pacifier
Turpin's abstract: "Edible insect larvae constitute a large part of the traditional Australian Aboriginal diet. Perhaps the most widely known example is the ‘Witchetty grub' (Endoxyla spp.). These played a role similar to that of a pacifier for infants being weaned. The term ‘witchetty' is the common name of the tree whose roots this popular grub dwells in (Acacia kempeana). The naming of specific larvae based on their host tree is a common naming strategy in the Aboriginal language Kaytetye, for which there are some 25 ethnospecies. This paper draws on Kaytetye people's knowledge, uses and naming of ethnospecies within the 'edible insect larvae' food class, which is one of five Kaytetye food classes."
Cooperative Extension specialist Ian Grettenberg, an agricultural entomologist and assistant professor in the UC Davis Department of Entomology and Nematology, coordinates the department's weekly (virtual) seminars, held every Wednesday, except during holidays.
Turpin's hosts are evolutionary ecologists and biologists Scott Carroll and Jenella Loye of the Institute for Contemporary Evolution who engage in Carroll-Loye Biological Research. The scientists are affiliated with the Sharon Lawler lab, UC Davis Department of Entomology and Nematology.
"I've visited her pioneering entomophagy studies among the remnant, so-called 'remote' central Australian peoples," said Carroll. "Academic entomologists know almost nothing about the biology of these insects. I learned that Giant Moth witchetty grubs are the most delicious, energy-packed animals I have ever eaten. Myfany will tell us about these and many more that have been central to the diets of Australians. I am looking forward to this exciting interdisciplinary seminar."
Carroll describes Turpin as being "at the nexus of entomology, linguistics, and the indigenous human diet."
Important Source of Food
In an article on "Edible Insect Larvae in Kaytetye: Their Nomenclature and Significance," published in March 2017 in the Journal of Ethnobiology, she wrote: "Insects have traditionally constituted an important source of food in many cultures, but changes in dietary practices and other lifestyle traits are threatening the transmission of insect-related knowledge and vocabulary to younger generations of Indigenous Australians. This paper describes the rich cultural and culinary traditions surrounding an important insect group, namely a class of edible insect larvae consumed by a desert community in central Australia. Twenty-nine different edible insect larvae are named in the Kaytetye language, with the names encoding the identity of the host plant on which the larvae are found. We describe the complexities involved in the naming system, paying special attention to cultural and linguistic factors. The difficulties in the scientific identification of these ethnotaxa are discussed, as are the significance of our data to (1) questions of universal patterns in ethnoclassification and nomenclature and (2) the purported lack of binomially-labeled folk species in the languages of hunter-gatherer societies."
Turpin, with the Sydney Conservatorium of Music, has been working on Australian Aboriginal songs and languages since 1996, according to her website. "Her research interests include the relationship between language and music, especially of lesser-known cultures; and identifying ways to support the continuation of endangered languages and performance arts. More specifically, her work examines Aboriginal song-poetry and its relationship to spoken languages. She is also involved in linguistic documentation of the Aboriginal language Kaytetye as well as Indigenous ecological knowledge and the lexicon in Arandic languages."
Link to form for Zoom link and instructions: https://forms.
For technical issues, contact Grettenberger at imgrettenberger@ucdavis.edu. For more information on the seminar speaker contact Scott Carroll or Jenella Loye at scott@carroll-loye.com.
- Author: Kathy Keatley Garvey
Grub? Food? Yes, think specifically of insect larvae.
Myfany Turpin of the University of Sydney will speak on "Grub's Up! The Category of Edible Insect Larvae in Central Australian Aboriginal Languages" at the UC Davis Entomology and Nematology's virtual seminar at 4:10 p.m., Wednesday, Oct. 7.
This is the first of a series of fall seminars hosted by the department and coordinated by Ian Grettenberger, Cooperative Extension specialist and assistant professor.
"Dr. Turpin is a linguist and musicologist that has worked on the use of insects as aboriginal food sources," Grettenberger said.
In an article on "Edible Insect Larvae in Kaytetye: Their Nomenclature and Significance," published in March 2017 in the Journal of Ethnobiology, she wrote: "Insects have traditionally constituted an important source of food in many cultures, but changes in dietary practices and other lifestyle traits are threatening the transmission of insect-related knowledge and vocabulary to younger generations of Indigenous Australians. This paper describes the rich cultural and culinary traditions surrounding an important insect group, namely a class of edible insect larvae consumed by a desert community in central Australia. Twenty-nine different edible insect larvae are named in the Kaytetye language, with the names encoding the identity of the host plant on which the larvae are found. We describe the complexities involved in the naming system, paying special attention to cultural and linguistic factors. The difficulties in the scientific identification of these ethnotaxa are discussed, as are the significance of our data to (1) questions of universal patterns in ethnoclassification and nomenclature and (2) the purported lack of binomially-labeled folk species in the languages of hunter-gatherer societies."
Turpin, with the Sydney Conservatorium of Music, has been working on Australian Aboriginal songs and languages since 1996, according to her website. "Her research interests include the relationship between language and music, especially of lesser-known cultures; and identifying ways to support the continuation of endangered languages and performance arts. More specifically, her work examines Aboriginal song-poetry and its relationship to spoken languages. She is also involved in linguistic documentation of the Aboriginal language Kaytetye as well as Indigenous ecological knowledge and the lexicon in Arandic languages."
Turpin's hosts are evolutionary ecologists and biologists Scott Carroll and Jenella Loye of the Institute for Contemporary Evolution who engage in Carroll-Loye Biological Research. The scientists are affiliated with the Sharon Lawler lab, UC Davis Department of Entomology and Nematology.
Link to form for Zoom link and instructions: https://forms.
For technical issues, contact Grettenberger at imgrettenberger@ucdavis.edu. For more information on the seminar speaker, contact Scott Carroll or Jenella Loye at scott@carroll-loye.com.
- Author: Kathy Keatley Garvey
The Western corn rootworm is called that because its larvae ravage America's corn crops to the economic tune of $1 billion a year.
Enter a team of nine researchers, including UC Davis biologist Scott Carroll. They analyzed data over a six-year period and concluded that crop rotation works well in battling the notorious pest that annually causes $800 million in yield loss and $200 million in treatment costs.
“Answering this question was important not only to grower success but the agricultural economy, said Carroll, an associate of the UC Davis Department of Entomology and Nematology and owner of the Davis-based Institute for Contemporary Evolution. “Bt crops are far-and-away the single most important factor reducing soil and crop insecticide applications in the United States at present.”
When Bacillus thuringiensis (Bt) corn was introduced in 2003, the pest seemed under control. The genetically engineered corn is a transgenic, insecticidal crop that kills rootworm larvae but is harmless to humans.
However, when the pest began developing resistance to the Bt corn toxins, the U.S. Department of Agriculture recommended crop rotation as a method of control. Crop rotation, an age-old agricultural tactic, is a consistent and economical means of controlling rootworms the season following an outbreak. It reduces rootworm densities, and is considered more effective than insecticides.
With crop rotation, “the frequency of problem fields declined by 92 percent in 2014 to 2016 relative to 2011 to 2013,” the nine-member team wrote in the research article, “Crop Rotation Mitigates Impacts of Corn Rootworm Resistance to Transgenic BT Corn,” in the current edition of the Proceedings of the National Academy of Sciences.
“Corn rootworm is one of the nation's most devastating pests, giving a sense of urgency to protecting the efficacy of industrial pest control approaches with reduced non-target effects,” said Carroll, who studies basic and applied aspects of evolutionary biology. “Transgenic insecticidal Bt crops in the United States are cultivated under a very interesting socio-evolutionary model of resistance management that is mandated by the U.S. Environmental Protection Agency. Individual growers must implement resistance management--usually by devoting a small acreage to planting a 'refuge' of non-Bt crops in order to nurture a local reservoir population of Bt-susceptible pest insects.”
Carroll pointed out that the “outstanding productivity of Bt corn has led a portion of growers to reduce or eliminate their required refuge planting. Moreover, many time-tested practices for integrated pest management have fallen by the wayside as growers have found they could rely solely on the genetics of the seemingly invulnerable Bt varieties.”
“As predicted, Bt resistance evolution in corn rootworm has accelerated. In response to this dire risk, in 2016 EPA began mandating crop rotation as a complementary means of reducing the damage to Bt corn fields caused by resistant corn rootworms. Our working group analyzed the success of this traditional agricultural tactic to help sustain the efficacy of the high-tech Bt tactic.”
Carroll said that under the leadership of his colleague Yves Carrière at the University of Arizona, “our team analyzed six years of field data from 25 crop reporting districts in Illinois, Iowa and Minnesota—three states facing some of the most severe rootworm damage to Bt cornfields.
“The answer we found is that traditional crop rotation is working to protect the Bt corn fields from rootworm damage, including in areas that have seen the evolution of behavioral resistance to crop-rotation by rootworms.”
The bottom line, said Carrière, is this: "Farmers have to diversify their Bt crops and rotate. Diversify the landscape and the use of pest control methods. No one technology is the silver bullet.”
The project also included scientists from North Carolina State and McGill University, along with Carroll's colleague, Peter Jørgensen of the Stockholm Resistance Center.
While Jorgensen was pursuing his master's degree program at the University of Copenhagen and studying at UC Davis, he worked with Carroll and Sharon Strauss of the Department of Evolution and Ecology.
“This PNAS paper,” Carroll said, “is one of several that have developed from a pursuit Peter and I organized on 'Living with Resistance' at the National Socio-Environmental Synthesis Center in Annapolis, with the aim to explore more sustainable approaches to managing evolutionary challenges to health and food security.”
The abstract:
"Transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) can suppress pests and reduce insecticide sprays, but their efficacy is reduced when pests evolve resistance. Although farmers plant refuges of non-Bt host plants to delay pest resistance, this tactic has not been sufficient against the western corn rootworm, Diabrotica virgifera virgifera. In the United States, some populations of this devastating pest have rapidly evolved practical resistance to Cry3 toxins and Cry34/35Ab, the only Bt toxins in commercially available corn that kill rootworms. Here, we analyzed data from 2011 to 2016 on Bt corn fields producing Cry3Bb alone that were severely damaged by this pest in 25 crop reporting districts of Illinois, Iowa, and Minnesota. The annual mean frequency of these problem fields was 29 fields (range 7 to 70) per million acres of Cry3Bb corn in 2011 to 2013, with a cost of $163 to $227 per damaged acre. The frequency of problem fields declined by 92% in 2014 to 2016 relative to 2011 to 2013 and was negatively associated with rotation of corn with soybean. The effectiveness of corn rotation for mitigating Bt resistance problems did not differ significantly between crop-reporting districts with versus without prevalent rotation-resistant rootworm populations. In some analyses, the frequency of problem fields was positively associated with planting of Cry3 corn and negatively associated with planting of Bt corn producing both a Cry3 toxin and Cry34/35Ab. The results highlight the central role of crop rotation for mitigating impacts of D. v. virgifera resistance to Bt corn."
- Author: Kathy Keatley Garvey
If you've been reading The New York Times, Washington Post, Los Angeles Times, and National Geographic, you know about this.
And about the newly published research paper, “Introduced Herbivores Restore Late Pleistocene Ecological Functions” in the Proceedings of the National Academy of Sciences (PNAS).
It's the work of an 11-member international team led by Australian ecologist Erick Lundgren of the University of Technology, Sydney. The co-authors include evolutionary biologist Scott Carroll of the UC Davis Department of Entomology and Nematology.
Out-of-place and troublesome species, such as hippos, feral hogs, wild horses and burros, may actually be restoring the ecological services of extinct animals, the ecologists said.
The authors pored over scientific literature; created a list of living and extinct herbivores over the last 126,000 years; and categorized them by their body size, anatomy, habitat, diet, and how their bodies digested the vegetation. Then they compared their lifestyles in overlapping regions.
One of the studies dealt with the abandoned hippos of Colombian drug lord Pablo Escobar (1949-1993), who purchased a male and three females in the 1980s from a California zoo and kept them in fields along the Magdalena River, northwestern Colombia. Without humans and other predators decimating them, the population today is 80 to 100 and is expected to reach 800 to 5000 by 2050.
The out-of-place hippos may be filling the exotic roles of extinct massive animals, such as giant llamas and rhinoceros-sized relatives, the ecologists related.
Said Carroll: “That paleontological analysis found that, amazingly, introduced herbivores– including Pablo Escobar's escaped Colombian hippos– often match the functional traits of extinct natives better than do those missing species' closest living native relatives. In this way, the ‘out-of-place' make the world more similar to the pre-extinction past. The ‘shoot-first- and-ask-questions later' approach as a maxim is as reckless as it sounds, and it's not going to sustain our life-saving drugs, nor the species we revere or ecosystems we rely on, into the future.”
“Many introduced herbivores restore trait combinations that have the capacity to influence ecosystem processes, such as wildfire and shrub expansion in drylands,” the team wrote.
As for feral hogs in North America, Carroll said their rooting increases tree growth and attracts bird flocks, like the ecological work of their extinct ancestors. Likewise, the feral horses and burros, known for their well-digging behavior, are replacing the original American horses, which went extinct 12,000 years ago.
In their abstract, the authors pointed out that humans “have caused extinctions of large-bodied mammalian herbivores over the past 100,000 years, leading to cascading changes in ecosystems. Conversely, introductions of herbivores have, in part, numerically compensated for extinction losses. However, the net outcome of the twin anthropogenic forces of extinction and introduction on herbivore assemblages has remained unknown. We found that a primary outcome of introductions has been the reintroduction of key ecological functions, making herbivore assemblages with nonnative species more similar to preextinction ones than native-only assemblages are. Our findings support calls for renewed research on introduced herbivore ecologies in light of paleoecological change and suggest that shifting focus from eradication to landscape and predator protection may have broader biodiversity benefits.”
Carroll, who also co-led an author group of the newly published “Coevolutionary Governance of Antibiotic and Pesticide Resistance” in the journal Trends in Ecology, said that the publications together “address both sides of the human-environment co-existence issue.”
“Reading the titles, you might not expect these two studies are two sides of the same coin,” Carroll said, “but for me they address both sides of the human-environment issue that most compels me: How can we create more workable, productive and respectful long-term relationships with other species? To help think about this as an evolutionary biologist, I divide the key challenges of human interactions with Nature into those that arise from competitor and parasite species that adapt too quickly for us to control, and those that arise in in our efforts to protect more valued species– like endangered large mammals– that adapt too slowly to survive human impacts.”
“Pesticide and drug resistance are nature's predictable resilience to our reliance on an escalating war of toxic eradication,” Carroll commented. “A broader understanding shows how we can develop our own behavior to instead cultivate susceptibility to control in species we fight, using both new and known practices for improved sanitation, locally diversified agriculture, and eating lower on the food chain to inflect their evolution in a positive direction. Similarly, after millennia of driving much of the Earth's giant mammal community to extinction, we need to step back from our reflex to extinguish the errant survivors to preserve a modern sense of what's natural, without stopping to consider how these new neighbors (commonly fading from their native lands) may restore ancient ecological functions our own ancestors extinguished not so long ago.”
Carroll emphasized that “neither of these studies dismisses the serious problems irruptive populations can cause for meeting our food, health and environmental needs, nor seeks to oversimplify complex challenges. But it's actually important to work against being limited by prejudicial generalizations that lead us to sort other species into ‘good' versus ‘bad' bins. This is a sensibility that ecologists in particular should strive to cultivate. To continue to feed and shelter ourselves and remain healthy while sharing the Earth with other species, we need to develop methods that respect the tremendous information and know-how inherent in each species. I want us to do a much better job of working with that intrinsic functional diversity and adaptive potential as our best resource for advancing resilient and biodiverse ecological systems into the future.”
Carroll and his wife, UC Davis ecologist Jenella Loye, own Carroll-Loye Biological Research, Davis. They engage in public health and environmental entomology and natural product development.
(Editor's Note: The lead author of Coevolutionary Governance of Antibiotic and Pesticide Resistance is Peter Søgaard Jørgensen, who during his University of Copenhagen graduate work, spent a year at Davis studying soapberry bug host adaptation in California with Scott Carroll. The duo led the multi-year international "Living with Resistance" pursuit at the National Science Foundation's National Socio-Environmental Synthesis Center. Carroll served as the senior author.)
/span>/span>- Author: Kathy Keatley Garvey
When the United Nations meets Sept. 21 in New York, they want the UN to reframe its action on the global antimicrobial drug resistance (AMR) crisis.
It's crucial. How crucial is it?
Antimicrobial drug resistance threatens both personal and planetary health and the issue is as crucial as the global threat of climate change, Carroll says.
In a paper titled “Use Antimicrobials Wisely,” published in the current edition of Nature, a nine-member international research team, including Carroll, explained their advocacy.
“We're concerned about what will happen if the proposed UN solutions focus mainly on incentives for new drug development, at a time when the drug industry itself is abandoning those efforts against infectious disease due to AMR,” said Carroll, who co-leads the international group on resistance to pesticides and antimicrobial drugs. He founded and directs the Institute for Contemporary Evolution, Davis, and is affiliated with the Sharon Lawler lab, UC Davis Department of Entomology and Nematology.
The paper, published in the Comment section, is the first product from a two-year working group sponsored by the National Socio-Environmental Synthesis Center in Annapolis, Md. “We are taking a similar socio-environmental approach in our concurrent work on pesticide stewardship,” Carroll said.
“While new drugs have a role, we think it's more important for society to learn how to steward pathogen susceptibility, so we develop that theme in the paper,” Carroll said. “And because we also depend on microbes for digestion, immunity, and general health, and microbes support ecosystem functioning through nutrient cycles and the maintenance of soil and water quality, we further argue that our AM drug habits and waste streams threaten both personal and planetary health. “
Lead authors of the paper are Peter Jorgensen of Stockholm, Sweden, and Didier Wernli of Geneva Switzerland. Jørgensen, who spent part of his Danish graduate program working with Carroll in Davis, is now a postdoctoral researcher at the Royal Swedish Academy of Science, Stockholm.
Carroll described AMR as more than a medical dilemma—it's a socio-ecological problem. “The vulnerability of pathogens to antimicrobial drugs is a communal resource, readily threatened by overuse, to be lost as a classic 'tragedy of the commons.' There is a lot of contemporary theory for social resilience in the face of socio-ecological challenges, and– linking to entomology– the early success of the pioneering management of Bt crop pest resistance evolution is an encouraging precedent.”
In its planetary health approach, the group seeks to be “more cognizant not only of preserving drug susceptibility in pathogenic microbes, but also protecting from wholesale destruction the community of microbes on which we depend for life,” Carroll said.
In the paper, the scientists pointed out that “Resistance affects animal and environmental health as well as human health, and so requires coordinated action across economic sectors. No single concern exemplifies this better than the high rate of antibiotic use in agriculture (largely as growth promoters or disease prevention).” They wrote that in the United States, 70 to 80 percent of all anti-microbials consumed are given to livestock.
An example of antimicrobial resistance involves the malaria mosquito, Anopheles gambiae. The World Health Organization (WHO) in a document, "Global Action Plan on Anti-Microbial Resistance," wrote:
"Antimicrobial resistance can affect all patients and families. Some of the commonest childhood diseases in developing countries – malaria, pneumonia, other respiratory infections, and dysentery – can no longer be cured with many older antibiotics or medicines. In lower- income countries, effective and accessible antibiotics are crucial for saving the lives of children who have those diseases, as well as other conditions such as bacterial blood infections. In all countries, some routine surgical operations and cancer chemotherapy will become less safe without effective antibiotics to protect against infections."
Expect to hear more about this alarming crisis--the global antimicrobial drug resistance crisis. Meanwhile, read the WHO Global Action Plan.