Exploring Hydrocarbon Depletion
Beekeepers across the United States lost 44 percent of their honey bee colonies during the year spanning April 2015 to April 2016, according to the latest preliminary results of an annual nationwide survey. Rates of both winter loss and summer loss—and consequently, total annual losses—worsened compared with last year. This marks the second consecutive survey year that summer loss rates rivaled winter loss rates.
"We're now in the second year of high rates of summer loss, which is cause for serious concern," ... "Some winter losses are normal and expected. But the fact that beekeepers are losing bees in the summer, when bees should be at their healthiest, is quite alarming." - "The high rate of loss over the entire year means that beekeepers are working overtime to constantly replace their losses," said Jeffery Pettis, a senior entomologist at the USDA and a co-coordinator of the survey. "These losses cost the beekeeper time and money. More importantly, the industry needs these bees to meet the growing demand for pollination services. We urgently need solutions to slow the rate of both winter and summer colony losses."
The mysterious "zombie bee" parasite that kills honeybees has reached the southern United States after scientists confirmed a case in Virginia about an hour outside Roanoke, researchers announced this week.
The discovery suggests the phenomenon is more widespread than previously thought, although researchers still know little about how many bees it actually kills.
Flies attach themselves to the bees and inject their eggs, causing erratic "zombie-like" behavior in the bees such as flying at night and toward light. The bees often die within hours. Fly larvae burst out of their carcasses days later.
The phenomenon was first discovered in California in 2008 and has spread to states including Oregon, South Dakota and New York. But even as "zombie bees" reach the South, scientists still don't know what role they might play in the pollinator's alarming decline.
"We're trying to answer some of these questions about how important this is," said John Hafernik, a biology professor at San Francisco State University who studies "zombie bees." ''We don't know whether it's a major player in honeybee decline or a minor actor in a B-movie."
researchers...collected bees from 51 hives across 17 locations in the province of Otago in Southern New Zealand and measured their chlorpyrifos levels. They detected low levels of pesticide in bees at three of the 17 sites and in six of the 51 hives they examined.
Detecting chlorpyrifos was not a surprise. In 2013, Associate Professor Kim Hageman and her team from Otago’s Department of Chemistry showed that chlorpyrifos was detectable in air, water, and plant samples even in non-sprayed areas of the country, because this pesticide has a high ability to volatilise and travel great distances.
In the laboratory they then fed other bees with similar amounts of the pesticide, which is used around the world to protect food crops against insects and mites, and put them through learning performance tests.
Study lead author Dr Elodie Urlacher says they found that chlorpyrifos-fed bees had worse odour-learning abilities and also recalled odours more poorly later, even though the dose they ingested is considered to be "safe".
“For example, the dosed bees were less likely to respond specifically to an odour that was previously rewarded. As honeybees rely on such memory mechanisms to target flowers, chlorpyrifos exposure may be stunting their effectiveness as nectar foragers and pollinators,” Dr Urlacher says.
The study identified the threshold dose for sub-lethal effects of chlorpyrifos on odour-learning and recall as 50 picograms of chlorpyrifos ingested per bee, she says.
“This amount is thousands of times lower than the lethal dose of pure chlorpyrifos, which is around 100 billionths of a gram. Also, it is in the low range of the levels we measured in bees in the field.”
The current study is the first to establish the threshold at which a pesticide has an effect on memory specificity in bees while also measuring doses in bee populations in the field, she says.
“Our findings raise some challenging questions about regulating this pesticide’s use. It’s now clear that it is not just the lethal effects on bees that need to be taken into account, but also the serious sub-lethal ones at minute doses,” Dr Urlacher says.
One possible cause of the alarming bee mortality we are witnessing is the use of the very active systemic insecticides called neonicotinoids. A previously unknown and harmful effect of neonicotinoids has been identified by researchers at the Mainz University Medical Center and Goethe University Frankfurt. They discovered that neonicotinoids in low and field-relevant concentrations reduce the concentration of acetylcholine in the royal jelly/larval food secreted by nurse bees. This signaling molecule is relevant for the development of the honeybee larvae. At higher doses, neonicotinoids also damage the so-called microchannels of the royal jelly gland in which acetylcholine is produced. The results of this research have been recently published in the eminent scientific journal PloS ONE.
Wessler and Grünewald were able to directly demonstrate that neonicotinoids reduce the acetylcholine content of the larval food produced by nurse bees. Acetylcholine is a signaling molecule produced in the microchannels of the royal jelly gland of nurse bees. Comparable to neonicotinoids, it stimulates the nicotinic acetylcholine receptors that are also present in this gland.
"In lab tests we artificially removed acetylcholine from the larval food and the result was that bee larvae fed with this died earlier than bee larvae that received food containing acetylcholine," explained Wessler. In order to examine the effect of neonicotinoids on the acetylcholine content in the jelly in more detail, bee colonies were exposed to various concentrations of neonicotinoids in flight tunnels (clothianidin: 1, 10 and 100 μg/kg glucose solution; thiacloprid 200 and 8800 μg/kg). "This exposure led to a reduction in the acetylcholine content of the jelly. Thus we were able to demonstrate that the field-relevant dose of the neonicotinoid agent thiacloprid (200 μg/kg) significantly reduces acetylcholine content by 50 percent. On exposure to higher doses, we were even able to verify that acetylcholine content can be reduced by 75 percent. Exposure of the bees with the higher doses results in serious damage to the microchannels and secretory cells of the jelly gland," emphasized Professor Ignatz Wessler. "Our research results thus confirm that the neonicotinoids can jeopardize the normal development of honeybee larvae."
The EU came to a similar conclusion back in December 2013 and imposed temporary restrictions on the use of three neonicotinoids, i.e., clothianidin, imidacloprid, and thiamethoxam. It had already been reported in several scientific publications that high but not lethal doses of various neonicotinoids could be associated with the falls in the populations of wild bees, bumblebees, and queen bees. Also reported were abnormalities in breeding activity and impaired flight orientation in the case of honeybees.
Ignaz Wessler et al, Honeybees Produce Millimolar Concentrations of Non-Neuronal Acetylcholine for Breeding: Possible Adverse Effects of Neonicotinoids, PLOS ONE (2016). http://journals.plos.org/plosone/articl ... ne.0156886
On Sunday morning, the South Carolina honey bees began to die in massive numbers.
Death came suddenly to Dorchester County, S.C. Stressed insects tried to flee their nests, only to surrender in little clumps at hive entrances. The dead worker bees littering the farms suggested that colony collapse disorder was not the culprit — in that odd phenomenon, workers vanish as though raptured, leaving a living queen and young bees behind.
Instead, the dead heaps signaled the killer was less mysterious, but no less devastating. The pattern matched acute pesticide poisoning. By one estimate, at a single apiary — Flowertown Bee Farm and Supply, in Summerville — 46 hives died on the spot, totaling about 2.5 million bees.
Sunday was different. Summerville resident Andrew Macke, who keeps bees as a hobby, wrote on Facebook that the hot weather left bees particularly exposed. Once temperatures exceed 90 degrees, bees may exit the nest to cool down in what is called a beard, clustering on the outside of the hive in a ball. Neither Macke nor Stanley had covered their hives.
And then came the plane.
“They passed right over the trees three times,” Stanley said to ABC 4 News. After the plane left, the familiar buzzing stopped. The silence in its wake was like a morgue, she said.
Examples of brood patterns from colonies chronically exposed to imidacloprid (0, 10, 20, 50 and 100 ppb) during brood rearing illustrating a dose-dependent effect where the amount of empty cells in a given brood area increases with treatment concentration
The world's best-selling insecticide may impair the ability of a queen honey bee and her subjects to maintain a healthy colony, says new research led by a University of Nebraska-Lincoln entomologist.
The research examined the effects of imidacloprid, which belongs to a popular class of nicotine-based insecticides known as neonicotinoids. Honey bees often become exposed to neonicotinoids in the process of pollinating crops and ornamental plants while foraging for the nectar and pollen that feed their colonies.
Queen bees in colonies that were fed imidacloprid-laced syrup laid substantially fewer eggs - between one-third and two-thirds as many, depending on the dose of imidacloprid - than queens in unexposed colonies, the study reported.
"The queens are of particular importance because they're the only reproductive individual laying eggs in the colony," said lead author Judy Wu-Smart, assistant professor of entomology. "One queen can lay up to 1,000 eggs a day. If her ability to lay eggs is reduced, that is a subtle effect that isn't (immediately) noticeable but translates to really dramatic consequences for the colony."
Wu-Smart and her colleague, the University of Minnesota's Marla Spivak, assessed colonies populated by 1,500, 3,000 and 7,000 honey bees. Some colonies received normal syrup, with others given syrup that contained imidacloprid in doses of 10, 20, 50 and 100 parts per billion, or PPB.
Colonies that consumed the imidacloprid also featured larger proportions of empty cells, the signature hexagonal hollows that serve as cribs for honey bee broods. About 10 percent of cells in the unexposed colonies were vacant, compared with 24, 31, and 48 percent of the 20, 50 and 100 PPB colonies, respectively. The finding suggests poor brood health in the exposed colonies, Wu-Smart said.
The researchers further found that exposed colonies collected and stored far less pollen, which they convert into a "bee bread" that provides crucial protein for recently hatched larvae. While more than four percent of the cells in unexposed hives contained pollen, less than one percent of cells in even the 10 PPB colonies did.
And the honey bee equivalent of biohazard containment - the removal of mite-infested or diseased pupae before they can infect the hive - also suffered. An unexposed colony of 7,000 bees removed more than 95 percent of the ailing brood, but a 100 PPB colony eliminated only 74 percent and a 50 PPB colony just 63 percent. Wu-Smart said this reduction in hygienic behavior indicates that the exposed colonies could be more susceptible to pests and pathogens.
Average (SE) number of eggs laid by queens per 15 minute observation period pooled over three week chronic exposure of imidacloprid (IMD) (0, 10, 20 50, and 100 ppb) in 1500-, 3000-, and 7000-bee colonies ((dose*size*week) interaction: F16,1053 = 0.93; p = 0.54; (dose*size) interaction: F8,1053 = 6.17; p < 0.0001).
Unfortunately, Wu-Smart said, growers typically apply insecticides or sow insecticide-treated seeds at that same time. Even imidacloprid-treated crops that bees typically do not pollinate, such as corn, can contribute to exposure when winds sweep up the dust stirred by planting machines and carry it across miles of landscape. That dust can settle in willow trees, dandelions, clovers and other flowering plants that represent food sources for honey bees.
Full Copy: Judy Wu-Smart et al, Sub-lethal effects of dietary neonicotinoid insecticide exposure on honey bee queen fecundity and colony development, Scientific Reports (2016). DOI: 10.1038/srep32108
16 August 2016 (CEH) – Exposure to neonicotinoid seed treated oilseed rape crops has been linked to long-term population decline of wild bee species across the English countryside, according to research published today in Nature Communications.
The research, led by the Centre for Ecology & Hydrology using data provided by Fera Science Ltd and the Bees, Wasps and Ants Recording Society, examined changes in the occurrence of 62 wild bee species with oilseed rape cropping patterns across England between 1994 and 2011 - the time period spanning the introduction of wide-scale commercial use of neonicotinoids.
The scientists found evidence suggesting that neonicotinoid use is linked to large-scale and long-term decline in wild bee species distributions and communities.
The decline was, on average, three times stronger among species that regularly feed on the crop such as Buff-tailed bumblebee (Bombus terrestris) compared to species that forage on a range of floral resources, indicating that oilseed rape is a principle mechanism of neonicotinoid exposure among wild bee communities.
For five of the species investigated, including the spined mason bee (Osmia spinulosa) and the furrow bee (Lasioglossum fulvicorne), neonicotinoid use was equivalent to at least 20% of local population extinctions of wild bees
According to the researchers, the data suggest that neonicotinoid use is correlated with wild bee biodiversity losses at a national scales and has implications for the conservation of bee communities in intensively farmed landscapes. The results add to an extensive body of evidence that will inform the review of the risks neonicotinoid pesticides pose to bees being undertaken by the European Food Standards Authority and anticipated to be complete by January 2017.
A bumblebee is now on the endangered species list for the first time in a "race against extinction," the U.S. Fish and Wildlife Service announced Tuesday.
The agency placed the rusty patched bumblebee on the list because of a dramatic population decline over the past 20 years. Since the late 1990s, the population of the species has plummeted 87%.
Named because of the rust-colored marks on its back, the bee was once common and abundant across 28 states from Connecticut to South Dakota. Today, the bee is only found in small, scattered populations in 13 states.
t's not just the rusty patched bumblebee that is struggling in the U.S. Other species have experienced dramatic declines in recent decades. The reduction is believed to be caused by a combination of habitat loss, disease, pesticide use, climate change and an extremely small population size.
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