Category Archives: Insecticides

Insecticides Prove Necessary for Managing New Invasive Stink Bug

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The brown marmorated stink bug is native to Asia and was introduced into the US in the 1990s. The stink bug feeds on many orchard crops, small fruit, grapes, vegetables and row crops—particularly in mid-Atlantic states. Developing long-term control strategies takes time, which makes the immediate use of insecticides necessary.

“Damage in apple in the mid-Atlantic region inflicted by H. halys (brown marmorated stink bug) resulted in losses in excess of 37 million dollars in 2010. In addition, H halys is a serious nuisance pest in residential areas because it uses human-made structures as overwintering sites.”

“Because the brown marmorated stink bug is a newly established invasive pest in the United States, insecticides will play a key role in managing this pest on various crops at least in the short term. Indeed, the use of insecticides has substantially increased in commercial orchards because of the damage inflicted by H. halys and subsequent economic loss in the mid-Atlantic region.”

Authors: T.C. Leskey, D.-H. Lee, B.D. Short and S.E.Wright
Affiliation: USDA Agricultural Research Services, Kearneysville, WV
Title: Impact of insecticides on the invasive Halyomorpha halys (Hemiptera: Pentatomidae): Analysis of insecticide lethality.
Publication: Journal of Economic Entomology. 2012. 105(5):1726-1735.

Devastating New Potato Disease Has Growers Spraying at First Sign of Vector

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Potato psyllids in the Pacific Northwest are spreading a new disease, Zebra chip. Beginning in 2011, psyllid feeding has spread a virus that reduces potato yields and renders tubers unmarketable with bands that darken when fried. Immediate spraying to control the insect vector is required.

“Researchers say populations of potato psyllids – vectors of zebra chip, a crop disease new to the region – are growing dramatically in the Columbia Basin.”

“Despite the increasing psyllid pressure during the past couple of weeks, Phil Hamm, an Oregon State University plant pathologist, believes the disease shouldn’t cause major problems for growers who stick with insecticide programs. … ‘When the region has psyllids, you treat,’ Hamm said.”

Author: John O’Connell
Headline: Psyllid populations growing dramatically
Publication: Capital Press. August 31, 2012.

Leafhoppers Transmit Deadly Grapevine Disease in Italy

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The grapevine disease Flavescence dorée has been called “catastrophic.” Impacts include yield reductions, and reduced wine quality. The disease spreads rapidly and can affect 80-100% of the vines in a few years. The disease is spread by leafhoppers who acquire the organism while feeding on infected plants and then spread the disease when they feed on healthy plants. Spraying to control the leafhopper is mandatory in regions where the disease is known to exist.

“The leafhopper Scaphoideus titanus Ball (Hemiptera: Cicadellidae) is a serious pest of grapevines in Europe as it transmits the phytoplasmas of Flavenscence dorée (FD). … the eggs start to hatch in the middle of May, and nymphs can be found until the middle of July… The adults are present from the end of June until the middle of October.”

“Nymphs from the third instar onward acquire phytoplasmas by piercing the leaves and stems of infected grapevines. After a latency period of 4-5 weeks, during which time they become adults, they can transmit FD phytoplasmas to healthy grapevines. In Italy, insecticide treatment against S. titanus are mandatory in the districts where FD is present. The active ingredients include neonicotinoids and organophosphates; in vineyards subject to organic farming S. titanus is controlled with pyrethrum.”

Authors: F. Lessio, E.B. Mondino and A. Alma
Affiliations: University of Turin, Grugliasco, Italy
Title: Spatial patters of Scaphoideus titanus (Hemiptera: Cicadellidae): a geospatial and neural network approach.
Publication: International Journal of Pest Management. 2011. 57(3):205-216.

Chinese Rice Farmers Use Insecticides to Control Invasive US Pest

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The rice water weevil is an insect native to the southern US, where its native food was grass. Following the introduction of rice into the US, the weevil shifted from grasses to feed on rice. This shift was first reported in the 1880s. In the late 1950s, the insect was found in northern California rice fields. From there, the weevil was carried across the Pacific into Asia in the mid-1970s. First detected in China in 1988, the rice water weevil has become a major rice pest and has spread all across the country.

“The rice water weevil was recognized as an important invasive pest immediately after its discovery in mainland China because of the severe rice yield losses. The adults feed on the upper leaf surfaces producing longitudinal scars. Larval feeding on roots causes stunted growth, yellowing of the leaves (chlorosis) and plants that are easily uprooted, resulting in few tillers and low grain yield. In mainland China yield losses typically exceeded 10% in the established paddies, but approached over 80% in newly infested areas.”

“Insecticides provide the most effective means of controlling the weevil in China as they do in the United States and Japan.”

Authors: Chen, H.¹, Z. Chen² and Y. Zhou²
Affiliation: ¹ Department of Biology, SUNY-Buffalo; ² Plant Quarantine Institute, Beijing, China
Title: Rice water weevil (Coleoptera: Curculionidae) in mainland China: Invasion, spread and control.
Publication: Crop Protection. 2005. 24:695-702.

Hazelnuts Free of Filbertworm Damage Require Insecticide Sprays

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The cultivated hazelnut was introduced to the west coast of the US during the late 1800s. Oregon’s hazelnut orchards account for 99% of US production and 5% of world production. The filbertworm, which is a native insect generally found on acorns and oaks, is the most severe pest of hazelnuts in Oregon. The females lay eggs on leaves and the new worms penetrate the nut and feed voraciously inside. Consumers prefer hazelnuts free of insect damage – insecticide sprays are necessary.

“In untreated orchards, 20-50% of nuts can become infested with filbertworm larvae. Filbertworm larvae attack hazelnuts in Oregon from June through October, when neonates bore into developing nuts and feed on kernels. … Current filbertworm management relies heavily on synthetic insecticides targeting adults, eggs, and neonate larvae. Growers often apply between one and three sprays per season to keep infestation levels below the economically acceptable threshold of 1%.”

“No effective biological control methods are currently available for this pest.”

Authors: Chambers, U.¹, D.J. Bruck², J. Olsen³ and V.M. Walton¹.
Affiliation: ¹Department of Horticulture, Oregon State University; ²USDA-ARS Horticultural Crops Research Laboratory, Corvallis, OR; ³Yamhill County Extension Service, Oregon State University.
Title: Control of overwintering filbertworm( Lepidoptera: Tortricidae) larvae with Steinernema carpocapsae.
Publication: Journal of Economic Entomology. 2010. 103(2):416-422.

Insecticide Use on Brinjal Reduces Poverty in Rural Areas of India

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Brinjal, also known as eggplant or aubergine, is native to India. A total of 1.4 million small family farms grow brinjal, which provides a steady income from market sales for most of the year. The biggest threats to brinjal are insects that can damage 95% of the crop. Worms feeding inside the fruit result in destruction of the fruit tissues. The feeding tunnels become clogged with excreta. This makes even slightly damaged fruit unfit for marketing.

“Brinjal is the most common, popular and principal vegetable crop grown in many geographical parts in India. … Brinjal is mainly cultivated on small family farms and it is a source of cash income for resource-poor farmers. … Farmers use large quantities of chemical insecticides singly or in combination to get blemish free fruits, which fetch premium prices in the market.”

Author: S. Dhas and M. Srivastava
Affiliation: Laboratory of Entomology, Department of Biology, Government Dungar College, Bikaner, Rajasthan, India
Title: An assessment of Carbaryl residues on brinjal crop in an agricultural field in Bikaner, Rajasthan (India)
Publication: Asian Journal of Agricultural Science. 2010. 2(1):15-17.

 

 

Cancellation of Effective Insecticides Puts Carrots at Risk of Rejection by Food Companies

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The carrot weevil is native to northeastern North America. Each female can lay 300 eggs. After hatching and entering the carrot, the larvae tunnel through the carrot, filling the tunnels with excreta. The epidermal cells around the tunnels die and become dark brown. The presence of larvae, excreta and feeding damage are of major concern to carrot processors because of strict FDA quality control in processed foods. Processors are unwilling to accept carrots if they find one live larva in a sample or if the carrots have more than 1% damage. Since the 1940s, effective broad spectrum insecticides kept carrot weevil damage to a minimum; however, the most effective insecticides have been cancelled for use in the US.

“Adults [carrot weevils] overwinter in and near carrot fields where carrots were grown the previous year, emerging in late April to early May in New Jersey. The adults feed directly on the leaves and crowns of carrots, and females oviposit from the beginning of May until late June in carrot roots. Larvae tunnel extensively throughout the upper third of the roots, damaging 80% or more of the carrots in untreated processing carrot fields.”

“Consequently, pesticide applications are directed at adult weevils to prevent or reduce oviposition. … However, during the past several years, carrot weevil damage has been increasing in New Jersey carrot farms, and the damage has been as high as 90% loss on farms in Salem County. These losses are partly due to the cancellation of broad-spectrum insecticides, such as parathion, azinphos-methyl, and phosmet during the early 1990s.”

Authors: G.M. Ghidiu¹, E. Hitchner², M. Zimmerman¹ and E. Rossell¹
Affiliations: ¹Rutgers University; ²Virginia Tech
Title: Effect of two different nozzle arrangements on control of carrot weevil, Listronotus oregonensis (LeConte), in processing carrots.
Publication: Plant Health Progress. April 3, 2006.

European Hop Production has Relied on Insecticides for 150 Years

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A key pest of hops in Europe is the hop aphid, which feeds directly on the hop plant, extracting cell sap and nutrients with its sucking mouth-part. Hop aphids excrete prolific amounts of honeydew. Sooty mold grows on the honeydew and can destroy a crop’s value, as mold renders hop cones unacceptable for brewing. How do European growers cope?

“Dried female flowers (cones) of hops are used for flavoring and as a preservative of beer and related beverages. They provide bitterness and aroma. … Feeding by large numbers of aphids can debilitate hop plants and may induce premature defoliation, sometimes followed by a total loss of yield. Because of the threat posed by [hop aphids], treating hops with pesticides was already being recommended in England by the end of the 17th century and has been used regularly since about 1865.”

Authors: A. Barber, C.A.M. Campbell, H. Crane, P. Darby and R. Lilley
Affiliation: Horticultural Research International, Kent, UK
Title: Cost-benefits of reduced aphicide usage on dwarf hops susceptible and partially resistant to damson-hop aphid.
Publication: Annals of Applied Biology. 2003. 143:35-44.

Lack of Insecticides for Radishes Would Cause Significant Economic Loss in France

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France is the second largest European producer, behind Germany, of radishes. Each year, France produces 48,000 tons of radishes. Damage to radishes from root maggots must be prevented in order to produce a marketable crop. But since 2007 no insecticide has been registered in France for use against root maggots. Emergency uses of unregistered insecticides have preserved the industry. A recent analysis calculated the economic costs of not having effective insecticides available.

“The additional costs caused to replace a chemical treatment by a manual operation (manual sorting at harvest) is calculated at 6,905 €/ha. At the sector level, the lack of availability of a registered plant protection product against vegetable flies would thus lead to a direct loss of 18,600,000 €. This loss in profitability seriously impacts the viability of the radish production sector in France and puts at the stake the employment directly and indirectly involved in this sector. To give an indication, in Loire-Atlantique this sector has significant weight representing 2,500 FTEs (Full Time Equivalent). … The risk of distortion of competition in the French radish production sector is real vis-à-vis other European countries where pressure of the vegetable flies is less.”

Publication: Economic damage caused by the lack of plant protection products against root maggots in radish production in France. In: Study on the Establishment of a European Fund for Minor Uses in the Field of Plant Protection Products. June 2011.
Project Leader: ARCADIA International

“Organic Blueberries Don’t Come Easily”

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The New York Times ran an article with this title in 2011 to inform readers why there are so few organic blueberries grown in New Jersey – “the blueberry capital of the world”. It seems that the organic blueberry growers are powerless to prevent massive feeding on their berries by insects that call New Jersey home. On the other hand, blueberry growers who use chemical insecticides are able to control the insect problem and harvest 2 to 4 times more blueberries per acre.

“New Jersey is one of the country’s top producers of blueberries, yet only a small number of farms are organic. And considering all the obstacles presented by nature, it’s not hard to see why. Insects like the root grub and the plum curculio, as well as some fungi, contribute to organic farmers’ loss of up to 50 percent of their berries a season, whereas conventional farmers may lose 5 percent or 6 percent, said Peter Oudemans, a Rutgers professor and a plant pathologist at the Philip E. Marucci Center for Blueberry and Cranberry Research in Chatsworth, Burlington County. Blueberry plants are native to New Jersey, Dr. Oudemans said, which makes them a natural food choice for native insects. ‘Planting a solid acre of organic blueberries in New Jersey is like throwing a peanut butter sandwich into a room full of kindergartners,’ said Dr. Oudemans, of Hammonton, ‘the blueberry capitol of the world,’ according to a local highway sign. ‘Everything around is going to go for them.'”

“‘We have to do twice the work of conventional growers,’ Mr. Condo [an organic grower] said. ‘It’s a lot harder and much more labor-intensive. Conventional farmers probably get around two or three thousand crates per acre. We’re lucky if we get 700 to 900.'”

Authors: Tammy La Gorce
Title: Organic blueberries don’t come easily.
Publication: The New York Times. June 17, 2011.