(Beyond Pesticides, July 1, 2011) The U.S. Environmental Protection Agency (EPA) has granted emergency approval for the use of the neonicotinoid pesticide dinotefuran to control brown marmorated stink bugs in seven eastern states. Dinotefuran is a member of the neonicotinoid family of systemic pesticides that is known to be highly toxic to bees and associated with Colony Collapse Disorder. The states of Delaware, Maryland, New Jersey, North Carolina, Pennsylvania, Virginia, and West Virginia had previously asked EPA for emergency approval of the pesticide due to a ballooning stink bug population. The short term emergency measure became effective June 24 and will expire on October 15 of this year.
Dinotefuran is already approved by EPA for use on other crops, such as grapes, cotton, and some vegetables. The emergency approval relates to the pesticide’s use on orchard crops such as apples, pears, peaches, and nectarines, for which it has not previously been allowed. Growers of those crops will now be able to apply dinotefuran from the ground twice per season. The agency will allow a total of 29,000 orchard acres to be treated, which does not include applications to the previously approved crops.
Under a controversial stipulation known as a Section 18 exemption in the Federal Insecticide, Fungicide, and Rodenticide Act, the federal law governing pesticides, EPA can grant temporary approval for the unregistered use of a pesticide if it determines that “emergency conditions exist which require such exemption.” In this case, the agency apparently felt that the pest was a sufficient enough risk to agriculture in the seven states that it merited the emergency approval. The Section 18 emergency exemption loophole has been used in the past to skirt pesticide regulations meant to ensure health and safety and has resulted in the widespread application of unreviewed, and often unnecessary, hazardous substances.
Neonicotinoids, including dinotefuran, are taken up by a plant’s vascular system and expressed through pollen, nectar and gutation droplets from which pollinators such as bees then forage and drink. Neonicotinoids kill sucking and chewing insects by disrupting their nervous systems. Beginning in the late 1990s, these systemic insecticides began to take over the seed treatment market. Clothianidin and imidacloprid are two of the most commonly used neonicotinoid pesticides. Both are known to be toxic to insect pollinators, and are lead suspects as causal factors in honey bee colony collapse disorder.
The brown marmorated stink bug, not to be confused with other kinds of common stink bugs, is a non-native species thought to have been accidentally introduced to North America from Asia in the 1990s. The pests were first identified in Allentown, PA and have since spread rapidly throughout the mid-Atlantic region. Because they are not native to this continent, they have no natural predators or ecological checks on population here, allowing their numbers to skyrocket.
Although they can be found in the home, marmorated stink bugs are primarily a cause for concern among farmers, who have seen the pests decimate crops in recent years. The bugs land on fruit and inject a straw-like device to suck out the juice or simply feed on the skin or flesh of the fruit. As a result of the bugs’ feeding, the fruits end up with holes, scars, or necrotic, rotted spots, leading to farmers being unable to sell the damaged produce. It is estimated that the pest caused $37 million of damage for apple growers in the state of Virginia last year. Previous attempts at controlling the pests through chemical means have proven almost entirely ineffective. It is unclear whether dinotefuran will have a markedly different result or not.
Despite urging from states and farmers in the mid-Atlantic region to approve the pesticide, recent research has increasingly shown that there are alternatives to temporary solutions like chemical controls. The U.S. Department of Agriculture (USDA) has been conducting research on controlling brown marmorated stink bugs by introducing a natural predator from its native Asia. Tiny trissolcus wasps lay their eggs only in eggs of the brown marmorated stink bug. When the wasp eggs hatch, they feed on the stink bug eggs as they grow and will eventually emerge from the shell in place of the stink bug.
Additionally research has shown that, for row crops, floating row covers can be an effective prevention measure against the bugs. There is also ongoing research on the effectiveness of pheromones and bait traps to combat them. Michigan State University has been conducting research on organic management options for brown marmorated stink bugs. Their findings suggest that products such as kaolin clay can effectively prevent the insects from feeding on fruit.
In announcing the Section 18 exemption for dinotefuran, EPA also stated that it had reviewed and approved a new product for stink bug control containing ingredients which have been approved for organic farmers. Specifically, the control measures contain azadirachtin, or neem oil, and pyrethrins, both natural products and thus, allowable for use under USDA National Organic Standards.
No pesticide should ever be necessary for home control of stink bugs. They do not carry disease and do not bite or sting. You will find them indoors most often in cooler times of the year as they seek shelter from cold temperatures. The Secretary of Agriculture for the state of Maryland, Buddy Hance, has strongly cautioned against the use of any chemicals in indoor stink bug control: “Spraying stink bugs with chemicals won’t eliminate them, and the potential damage to human health is far greater than anything stink bugs can do to you.” The Maryland Department of Agriculture (MDA) has also stated, “We do not recommend insecticides for controlling brown marmorated stink bugs because:
”¢Most are ineffective
”¢Some are broad-spectrum and will kill beneficial insects like honeybees and predators that eat pest insects.
”¢Use of broad-spectrum insecticides can lead to secondary pest outbreaks such as spider mites.
”¢They pose human and environmental health risks.”
If you do come across a stink bug in your home, MDA recommends the following measures:
”¢Seal up all external holes and cracks where stink bugs may enter;
”¢Close your window shades at night since stink bugs (and other insects) are attracted to light.
”¢Physically trap and kill the stinks bugs with insecticidal soap [or simply a cup of soapy water].
”¢Once the insect is indoors, residents can vacuum them up and place in an outdoor trash receptacle. It should be noted that if many of them are squashed or pulled into a vacuum cleaner, their odor can be quite strong.