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On April 19, 2011 from 12-1 pm Dr. James C. Nieh spoke about “The Decline and Fall of Bees: Pollinators in Peril” in the Events Room at the Biomedical Library. Honey bees face multiple natural and manmade dangers in their environment. Ironically, they are highly successful because of their use in modern agriculture, yet are suffering because modern agriculture imposes stresses from pesticides, diseases, parasites, and management practices such as mobile beekeeping. The research in Dr. Nieh’s laboratory explores natural threats and, more recently, the effects of pesticides on honey bee foraging. Come learn about the amazing solutions that bees have evolved in response to natural perils and how our use of pesticides may be contributing to their decline.

Effects of two series of imidacloprid pulses on caged amphipods (Gammarus roeseli) and their shredder efficiency for litter decomposition were studied for 70 days as part of a comprehensive stream mesocosm experiment. The duration of each imidacloprid pulse of 12 µg L−1 was 12 h. About 250 mL cages with an initial stock of 10 adult gammarids together with different conditioned litter substrates were used. Beside alder leaves (Alnus glutinosa), straw (× Triticosecale) was also used in different trials and tested for its suitability to serve as litter substrate. Results from tracer and microprobe measurements approved the suitability of the test system under low-flow condition of 10 cm s−1 in the surrounding stream water. Population development followed a logistic growth function with a carrying capacity of 200 Ind cage−1 for alder and 161 for straw. In the course of the study, the F1 generation reached sexual maturity and F2 offspring appeared. Increased nitrogen contents of gammarid-free trials compared to stocked ones after 70 days indicated that biofilm on both substrates was an important food source for G. roeseli. However, increased shredding activity by gammarids was only detected for alder during the second pulse series. During the remaining time and also for straw, losses of coarse particular organic matter were quite constant and slow indicating the dominance of transport limited decomposition processes on the litter surfaces. No effect of imidacloprid pulses on population levels and litter decomposition could be detected. However, the number of brood carrying females was reduced in the treatments compared to the control groups in the last 3 weeks of the study. In conclusion, repeated low-level and short-term exposition may have adverse long-term effects on G. roeseli in the field with regard to both the population size and the functional role as key shredder.

Understanding the toxicity of chemicals to organisms requires considering the molecular mechanisms involved as well as the relationships between exposure concentration and toxic effects with time. Our current knowledge about such relationships is mainly explained from a toxicodynamic and toxicokinetic perspective. This paper re-introduces an old approach that takes into account the biochemical mode of action and their resulting biological effects over time of exposure. Empirical evidence demonstrates that the Druckrey-Küpfmüller toxicity model, which was validated for chemical carcinogens in the early 1960s, is also applicable to a wide range of toxic compounds in ecotoxicology. According to this model, the character of a poison is primarily determined by the reversibility of critical receptor binding. Chemicals showing irreversible or slowly reversible binding to specific receptors will produce cumulative effects with time of exposure, and whenever the effects are also irreversible (e.g. death) they are reinforced over time; these chemical have time-cumulative toxicity. Compounds having non-specific receptor binding, or involving slowly reversible binding to some receptors that do not contribute to toxicity, may also be time-dependent; however, their effects depend primarily on the exposure concentration, with time playing a minor role. Consequently, the mechanism of toxic action has important implications for risk assessment. Traditional risk approaches cannot predict the impacts of toxicants with time-cumulative toxicity in the environment. While most toxicants with a generic mode of action can be evaluated by the traditional concentration–effect approaches, a certain number of chemicals, including carcinogens, methylmercury, rodenticides, neonicotinoids and cartap insecticides have toxic effects that are reinforced with time of exposure (time-cumulative effects). Therefore, the traditional risk approach cannot predict the impacts of the latter chemicals in the environment. New assessment procedures are needed to evaluate the risk that the latter chemicals pose on humans and the environment. An example is shown to explain how the risk of time-dependent toxicants is underestimated when using current risk assessment protocols.

Agronomist Palle Pedersen, technology manager for seed care at Syngenta, says that treated corn seed produces an extra 9 bushels an acre above a national average of about 160. “We’ve seen a dramatic yield increase,” he says. But researchers studying soybeans and other major crops have found treated seeds can come up short. A 2-year trial of treated soybeans in South Dakota, for example, found no yield benefit. Insecticide concentration in the plants was too low by the time the major pest, aphids, arrived, according to a study published last year in the Journal of Pest Science by Jonathan Lundgren of the U.S. Department of Agriculture in Brookings, South Dakota. He says that his findings mirror those of other trials. A worrying postscript: The neonicotinoids also harmed predators of the aphids, such as omnivorous pirate bugs (which feed on the soybean plant itself as well as aphids). Pedersen isn’t convinced. “It’s such a small data set, we can’t draw a conclusion out of that.”Companies say that they have copious data to prove the efficacy of treated seeds. “Admittedly, they do not increase yield all of the time, but the larger body of data says that they do provide an increase in yield a high percentage of time,” says William Hairston, director of product development for seed growth at Bayer CropScience in Research Triangle Park, North Carolina.

Sulfoxaflor is a new systemic pesticide from the sulfamine family. While it is not a neonicotinoid, it is systemic pesticide that targets the same neural receptors as the neonicotinoids. Without any prior notice to beekeepers, the EPA announced in June 2012, that it would grant a section 18 (emergency permission to use an unregistered product) for use on cotton in four southern states: Arkansas, Mississippi, Tennessee and Louisiana. The EPA has recently announced the opening of the public comment period on sulfoxaflor. The EPA plans to grant sulfoxaflor a conditional registration despite many serious unresolved questions as to its safety and consequences not only for the honeybees but for the wider environment as well. Is this a repeat process, or lack thereof, regarding the neonicotinoid, Clothianidin? In this special series called "The Neonicotinoid View", host, June Stoyer talks to beekeeper and bee advocate, Tom Theobald and commercial beekeeper, Jeff Anderson to talk about the controversy surrounding the conditional registration of this pesticide. Listen to the broadcast: http://www.youtube.com/watch?v=b2yFdozU_8s&feature=youtu.be

Honeybee colony losses continue to be unacceptably high. In the US this spring, colonies brought in to California to pollinate almonds from throughout the country, about half of the colonies were lost (New York Times, March 29, 2013). It is generally accepted that multiple pathogens ultimately bring down stressed colonies (Cornman 2012). However the role of pesticide stress on colonies remains controversial. Chronic exposure studies are often poorly constructed and frequently do not follow the exposed insects long enough for effects of the toxin to become evident. The best studies look at mortality, or behavioral effects, over a substantial fraction of the insect’s lifespan while varying the toxin concentration or dose. Time-to-effect studies lend themselves to a simple time dependent “power law” empirical model which can guide expectations for field toxicity effects (Tennekes 2011, Sánchez-Bayo 2009). Other reviews of the toxicity of imidacloprid (Cresswell 2011) attempt to establish specific “acute” or “chronic” levels, but this seems useless if the time of exposure is not explicitly included. Hence, I’ve made an effort to identify relevant time-to-effect studies in the literature most specifically for imidacloprid with insects of order hymenoptera, which includes bees and ants.

Along with the wide use of pesticides in the world, the concerns over their health impacts are rapidly growing. There is a huge body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson, Alzheimer, and amyotrophic lateral sclerosis (ALS), birth defects, and reproductive disorders. There is also circumstantial evidence on the association of exposure to pesticides with some other chronic diseases like respiratory problems, particularly asthma and chronic obstructive pulmonary disease (COPD), cardiovascular disease such as atherosclerosis and coronary artery disease, chronic nephropathies, autoimmune diseases like systemic lupus erythematous and rheumatoid arthritis, chronic fatigue syndrome, and aging.

On a warm April afternoon in Oakdale — a small farming town in the San Joaquin Valley of California — beekeepers Steve Ellis and Jeff Anderson sit at a dining-room table built for 10 in Anderson’s rural home. Ellis and his bees are visiting from his home base in Minnesota so that the bees can pollinate California almond crops during the Spring, but business is not the only reason for his visit. On the kitchen wall hangs a plaque in the shape of a bumblebee that reads “The Bee Attitudes.” The two men explain their take on beekeepers’ standard view of environmentalists. “Most are kind of philosophically opposed to quote unquote ‘wacko environmental groups,’ says Ellis, a wiry man with gentle eyes who has been keeping bees commercially for 33 years, “because they’re going to be the downfall of the world.” But now the two camps are unlikely partners in a David and Goliath battle. Ellis and a handful of other beekeepers from around the country are teaming up with some of the most powerful and sophisticated environmental groups in the U.S. They’re plaintiffs in a lawsuit, Ellis v. Bradbury, against the Environmental Protection Agency (EPA) to stop the use of two pesticides that Ellis and other beekeepers believe are killing their bee colonies. The suit not only attempts to eliminate the use of neonicotinoid pesticides containing the ingredients clothianidin and thiamethoxam, which damage the central nervous system of insects, but to challenge the way the EPA approves pesticides. If they win, it could change the way pesticides hit the market. If they lose, Ellis and the others believe it could be the end of beekeeping as we know it.

Dow AgroSciences LLC, a wholly owned subsidiary of The Dow Chemical Company (NYSE: DOW), announced today that U.S. regulatory authorities have approved the new insecticidal active ingredient, sulfoxaflor to be marketed in the U.S. as Transform® and Closer™. The U.S. registration, and the recent Canadian registration, are the result of a Global Joint Review which also includes Australia. Australian sulfoxaflor registration is expected by third quarter 2013. South Korea, Panama, Vietnam, Indonesia, and Guatemala have already registered sulfoxaflor and additional global registrations are expected in the near future. Sulfoxaflor belongs to a novel chemical class called sulfoximines invented by Dow AgroSciences and offers extremely effective control of many important sap-feeding insect pests. It can be used in a large number of major crops, including cotton, soybean, citrus, pome/stone fruit, nuts, grapes, potatoes, vegetables and strawberries.

In the early 1990s Bayer scientists launched onto the world the chemical weapon from hell; a powerful neurotoxin that, as Dutch toxicologist Dr Henk Tennekes demonstrated (and others have subsequently confirmed), causes a virtually irreversible blockage of postsynaptic nicotinergic acetylcholine receptors in the central nervous system of all invertebrates from pollinators down to soil and aquatic organisms. The pesticides industry stands accused of failure to investigate the hazards of systemic neonicotinoids fully and of failure to establish standard tests and protocols. The protection agencies stand accused of failing to protect human health and the environment.