Harvard Says Honeybees Abandoning Hives And Dying Due To Insecticide Use

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Harvard study shows neonicotionoids are devastating colonies by triggerring colony collapse disorder. Scientists found bees from six of the 12 neonicotinoid-treated colonies had left their hives and died.

The mysterious vanishing of honeybees from hives can be directly linked to insectcide use, according to new research from Harvard University. The scientists showed that exposure to two neonicotinoids, the world’s most widely used class of insecticide, lead to half the colonies studied dying, while none of the untreated colonies saw their bees disappear.

“We demonstrated that neonicotinoids are highly likely to be responsible for triggering ‘colony collapse disorder’ in honeybee hives that were healthy prior to the arrival of winter,” said Chensheng Lu, an expert on environmental exposure biology at Harvard School of Public Health and who led the work.

The loss of honeybees in many countries in the last decade has caused widespread concern because about three-quarters of the world’s food crops require pollination. The decline has been linked to loss of habitat, disease and pesticide use. In December 2013, the European Union banned the use of three neonicotinoids for two years.

In the new Harvard study, published in the Bulletin of Insectology, the scientists studied the health of 18 bee colonies in three locations in central Massachusetts from October 2012 till April 2013. At each location, two colonies were treated with realistic doses of imidacloprid, two with clothianidin, and two were untreated control hives.

“Bees from six of the 12 neonicotinoid-treated colonies had abandoned their hives and were eventually dead with symptoms resembling CCD,” the team wrote. “However, we observed a complete opposite phenomenon in the control colonies.” Only one control colony was lost, the result of infection by the parasitic fungus Nosema and in this case the dead bees remained in the hive.

Previously, scientists had suggested that neonicotinoids can lead to CCD by damaging the immune systems of bees, making them more vulnerable to parasites and disease. However, the new research undermines this theory by finding that all the colonies had near-identical levels of pathogen infestation.

“It is striking and perplexing to observe the empty neonicotinoid-treated colonies because honey bees normally do not abandon their hives during the winter,” the scientists wrote. “This observation may suggest the impairment of honey bee neurological functions, specifically memory, cognition, or behaviour, as the results from the chronic sub-lethal neonicotinoid exposure.” Earlier research showed neonicotinoid exposure can damage the renowned ability of bees to navigate home.

The new research follows similar previous work by the same group and comparison of the two studies shows that cold winters appear to exacerbate the effects of neonicotinoids on the bees. In the cold winter of 2010-11, 94% of the insecticide-exposed colonies suffered CCD compared to 50% in the new study.

“Sudden deaths of entire honey bee colonies is a persistent concern in North America,” said Paul de Zylva, Friends of the Earth’s senior nature campaigner. “Comprehensive research into the role pesticides play in bee decline is urgently required – including how they may compound other pressures, such as a lack of food and loss of habitat.” Lu agreed: “Future research could help elucidate the biological mechanism that is responsible for linking sub-lethal neonicotinoid exposures to CCD. Hopefully we can reverse the continuing trend of honeybee loss.”

In April, a landmark European study revealed the UK is suffering one of the worst rates of honeybee colony deaths in Europe. “The UK government [which opposed the EU’s neonicotinoid ban] has accepted the need for a national action plan to reverse bee and pollinator decline,” said de Zylva. “But its draft plan is dangerously complacent on pesticides, placing far too much trust in chemical firms and flawed procedures.”

LINK: http://www.theguardian.com/environment/2014/may/09/honeybees-dying-insecticide-harvard-study

The Green Manure Crop With Added Bite

The Green Manure Crop With Added Bite

Caliente Mustard Seed is not just a green manure it also acts as a “biofumigant” for the soil. Biofumigants suppress various soil borne pests and diseases by releasing naturally occurring compounds when you incorporate them back into the soil.

The foliage must be crushed or finely chopped for it to release a natural gas (isothiocyanate) which effectively reduces and suppresses a range of harmful nematodes and diseases in the soil.

The combination of biofumigation plus the digging in of the green material (organic matter), increases beneficial soil microbes, which out-compete pathogen microbes helping to keep soil diseases down.

Caliente Mustard is a Brassica so if problems are present with Club-root, Caliente Mustard will succumb to the disease so use appropriately within a rotation

The benefits of use for the home gardener for most crop and soil types are:
-Improved root systems and a measurable increase in yield of following crops
-Suppression of a range of soil-borne diseases including Verticillium wilt, Rhizoctonia, Pythium, Fusarium, and Sclerotinia
-Suppresses a range of harmful nematode species
Improved soil structure and fertility
-Suppresses weeds; mainly soft-seeded annuals, soon after incorporation

Caliente Mustard can be sown in spring or late summer for a quick crop, or mid-autumn for over-wintering in milder areas.

The finer the chop the better the result, running over the area with a rotary mower or strimmer to chop well before digging the chopped up foliage and roots into the top 15-20cm (6inches) of the soil within 20 mins of chopping up, otherwise 80% of the beneficial gases will escape into the air.
Rake the soil to a fine tilth and firm or roller to keep gases locked in. Water the area thoroughly.
Rest the soil for 14 days before sowing/planting new seeds/crops, then sow/grow crops as soon as possible to get the best benefits from Caliente Mustard.

Although I’m in the colder area I’m going to experiment and mix this in with my “field bean” crop for over wintering and cover with fabric, hopefully some will survive in amongst the field beans and I’ll dig the lot in come Spring 2015. I’m hoping they’ll survive in little “micro climate” pockets with the added assistance of the horticultural fabric.