Pesticide use

PESTICIDES AND HERBICIDES AND NEONICOTINOIDS, OH MY!

Pesticides

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Overview:

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Effects:

Additional Issues:

Pesticide use reduces population numbers of native foraging pollinators. The extent of damage on native bees, wasps, beetles, moths, and butterflies is largely unknown as most of the studies have been done on the European honey bee. 
 
Pesticide poisoning can occur from direct absorption, drinking tainted nectar, gathering contaminated pollen or accidental foraging of micro-encapsulated insecticide. Toxins can also be transferred to the nest through contaminated larval food brought in for brood cell nourishment. 
 
Less than lethal doses can cause failure in bees by causing impaired navigation, difficulty with flight, and an inability to forage or tend to their youn
 
Pesticides are not just an agricultural problem. Pesticides are frequently used in urban habitats such as home gardens, municipal parks, and large public gardens. Although it is anticipated that these urban environments will not pose as large of a threat as agricultural lands, this is not true in some cases. The majority of agriculturalists are trained to spray, they are familiar with minimal dosing rates, and often prescribe integrated pest management techniques. Their lands may also be monitored for runoff. 
 

Mini Case Study:

A study in the Pugent Sound basin of Washington state, which is considered a fairly “green conscious” area of America, found that more pesticides were applied per acre in urban neighborhoods than on farmland (Xerces, Attracting Native Pollinators). 
Click HERE and see the “Be Informed” segment for more information on how to enjoy a pollinator garden that is pesticide free by employing pest management alternatives. 

Herbicides

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Overview:

In general, it is known that pesticides are worse than herbicides. Ultimately, this is because herbicides have a more indirect effect by changing the foraging environment of the pollinator rather than effecting the pollinator itself. The most recent fear by scientists is that the systemic pesticide will make its way into the plant’s by-products. For poll

Insecticides(Neonicotinoids)

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Overview:

Transfer Method:

Effects:

Additional Issues:

Neonicotinoids are a relatively new class of insecticides. Within the class houses pesticides such as imidacloprid, acetamiprid, clothianidin, dinotefuran, nithiazine, thiacloprid, and thiamethoxam. Many countries such as France and Germany have already banned the use of neonicotinoids on bee pollinated crops. Italy’s suspension of neonicotinoids during 2009’s corn growing season halted bee mortality completely in apiaries around the crops. This had not happened since 1999. 
Neonicotinoids are systemic in nature, meaning that a treated plant uptakes the insecticide into their vascular system; going from the roots to the leaves. The insecticide then remains in the plant’s system as it continues to grow. Due to these properties, there is a threat to butterflies whose caterpillars eat leaves during their larval stages. The transference of toxic compounds from neonicotinoid treated plants to pollen and nectar is the major concern, however. 
Many neonicotinoids generally affect the central nervous system of insects, resulting in paralysis and death. 
Imagine the problem when a toxic chemical is present in a plant but cannot be seen. With these insecticides, this is a very real issue as they can be applied as a seed treatment, foliar spray, or root treatment. Typically, problems arise when commercial nurseries begin to use these insecticides. Because, unless plants available for commercial sale are labelled with treatments used, plants treated with such insecticides have begun to make their way into the market. If consumers are not made aware, they may be purchasing such plants for their gardens. 

Common Neonicotinoid Pesticides

Effects on the European Honeybee: BEYONDPESTICIDES.ORG

1. Imidacloprid:

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This is the most common used neonicotinoid that is used in agriculture as a foliar or seed treatment and also in home gardening. First registered in 1994, it has been found to be highly toxic to bees and other beneficial insects. Studies show that this chemical produces sub-lethal effects in honeybees such as mobility, navigation, and feeding problems. Imidaclopid was scheduled for review of its registration back in 2016. During this review session, the Environmental Protection Agency assessed the potential issues as it relates solely to pollinators. An updated study was scheduled for January 2020 and the planned completion is set for sometime during the year. 

Mini Case Study:

In the United States, a group of beekeepers from North Dakota is taking Bayer, a well known agricultural chemical company, to court. During a period in 1995 when oilseed rape in the area was treated with imidacloprid, the beekeepers lost thousands of honeybee colonies. 

2. Clothianidin :

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Clothianidin has been found to be highly toxic to bees and other insects. It was given registration in the United States in 2003 and, according to some groups, is claimed to have been registered without sufficient test data to support its registration. 

Mini Case Study:

In 2008, bee decline in Germany was attributed to the use of this chemical and a move to ban it and other neonicotinoids pending further investigation was put forth (see HERE). Tests on bees during this period showed that 99% of them contained a buildup of this product. 
For more information, see the following three websites that detail neonicotinoids and their uses, effects, and bans across the world in the agricultural industries. Please see HERE, HERE, and HERE

Common Garden Pesticides/Herbicides

1. Glyphosate:

Overview: 
While you might not be familiar with the term “Glyphosate,” you may know one of the many herbicide products it is found in, Roundup. Since its creation in the 1970s, this ingredient has been used to control the weeds in gardens all across the country. As a broad-spectrum chemical, however, this product will effect the growth of both weeds and non-weeds alike. 
Effects:
Recently, numerous studies on how glyphosate effects our pollinator species have been published. One study in particular found that glyphosate may alter the microbial activity in the stomach of bees which could lead to weight issues and in severe cases, death (Motta et al., 2018). 
Alternatives: 
Though there are numerous alternatives to harsh herbicides two of the most popular are vinegar based products as well as corn gluten. Some vinegar based herbicides are sold commercially and in differing concentrations. Like other herbicides, vinegar will effect both weeds as well as non-weeds which means that precautions will need to be taken to minimize the harm to valuable plants(Stein and Rumsey, n.d). 
If you choose to use corn gluten as an herbicide, it is important that you apply this solution even before a weed forms. Corn gluten essentially stops the roots of the weed from growing which ultimately prevents it from growing beyond the shoot stage (Burke, 2019).  

2. Gamma-Cyhalothrin

Overview: 
Gamma-Cyhalothrin is a present ingredient in several insecticidal products being sold commercially, including the well known product Triazicide. 
Effects: 
According to Purdue University, gamma-cyhalothrin is classified as a “Highly Toxic” pesticide that can do significant harm to the bees who are exposed to the chemical in higher dosages(Krupke et al., 2016). Additional studies have also determined that this chemical is potentially toxic to birds as well(“gamma-cyhalothrin”, 2019). 
Alternatives: 
One alternative to harsh pesticides you may want to consider is neem oil. Collecting the oil is typically done by pressing the seeds of the neem tree which is typically found in india. Essentially, neem oil acts as a natural repellent for many insects and can disrupt their reproductive cycle. The oil not only reduces unwanted insect populations but is also safer towards pollinator species(Bond et al., 2012).