Tag Archives: insecticides

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.

Residents Protest Organic Farm’s Mishandling of Pests

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In September 2011, the situation in Jacumba, California got so out of hand that residents planned to protest the neighboring organic farm. Why? Eye gnats. Since Bornt & Sons Organic Farm can’t use chemical insecticides to control gnats, humans and animals in the small town of Jacumba are continually plagued with them flying around their eyes. East County Magazine reported on the issue…

“The gnats serve as a vector for diseases including pink eye and summer mastitis, causing swelling and burning of the protective membrane lining the eyelids and discharge from the eyes. … Chelsea Russell, a teacher at Jacumba School, says for the past seven years, her students have suffered. …’I ask myself, do I teach in a third world country?'”

“Eye gnats are very common in warm, dry areas. They grow in light, well drained sandy soils that are freshly plowed and contain abundant organic matter. Conditions at Bornt’s farms are ideal and because the farm is organic, Bornt is limited to the types of pesticides he can use.”

As a follow up to this story, Bornt & Sons Organic Farm planned to cease operations as of June 2012. Because they have removed their non-chemical eye gnat controls in preparation to close, the eye gnat swarms have been growing in Jacumba this summer.

Title: Jacumba residents call for shut-down of organic farm over eye gnat infestation; plan protest march on Sept. 17.
Publication: East County Magazine. September 11, 2011.

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

Heavy Thrips Infestations in Virginia and North Carolina Cotton

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Thrips have many hosts, including grasses, grains and alfalfa. Large populations often develop on these hosts and fly into cotton fields when the cotton seedlings are developing. Thrips feeding causes severe deformation and stunting of the developing cotton leaves. The Upper Southeast cotton region (Virginia and North Carolina) could be designated “Thrips Central” for the Cotton Belt. Jack Bacheler, a North Carolina Extension Entomologist, explains…

“With the exceptionally warm winter and good moisture levels, at this point it looks like thrips flights into cotton should be both large and early this year. … Our region has earned the distinction of having the highest levels of thrips and greatest potential damage to seedling cotton of anywhere in the U.S. In some tests, with the help of a microscope, we sometimes count as many as 200 to 500 thrips per 5 seedlings! That’s a “ton” of thrips, especially if seedlings are unprotected. So it’s probably not a surprise that Virginia and North Carolina have the highest ratio of surrounding host vegetation to small average cotton field size.”

“Over the past eight years, more than 85 percent of our cotton acreage has been over-sprayed [i.e. sprayed over] following a seed treatment. With the potential for thrips damage lasting up to 5 or 6 weeks after planting and seed treatments varying from about 2 to 3 weeks in their activity, a high percentage of foliar follow-up treatments for thrips is not surprising.”

Author: Jack Bacheler
Affiliation: North Carolina Extension Entomologist
Title: Heavy thrips populations anticipated.
Publication: Southeast Farm Press, April 18, 2012. Available: http://connection.ebscohost.com/c/articles/76291692/thrips-pressure-heavy-mississippi-cotton

Grape Mealybug Control in California Depends on Insecticides

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Four species of mealybug feed on grapes in California. They suck out plant content and excrete unused plant material. The result is a layer of sticky, wet honeydew on which thick, black, sooty mold grows. The strict quality standards set by the grape industry and demanded by consumers have led to a dependence on insecticides for controlling mealybug populations.

“Although more vineyards are becoming infested, populations within infested areas are declining because the judicious use of insecticides has successfully lowered mealybug populations in areas that are infested.”

“Season-long control programs for vine mealybug are typically comprised of a combination of insecticide treatments assisted by biological control. … Promoting parasites is very important because they are active late in the growing season and can reduce vine mealybug populations before the pest begins to move to the lower part of the trunk after harvest [where they are protected from insecticides].”

Authors: Chuck Ingels, David Haviland and Steve Quashnick*
Affiliation: UC Cooperative Extension and *Wilbur Ellis
Title: Vine mealybug management in wine grapes in the northern San Joaquin Valley.
Publication: CAPCA Adviser (2012) April:34-37.

Consumer Expectations for High Quality Lettuce Require Insecticide Use

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Fresh market lettuce production in the desert growing areas of Southern California and Arizona is a billion dollar industry and the region annually produces >95% of the leafy vegetables consumed in the U.S. in the fall and winter months. Consumers desire lettuce without any blemishes or insect damage. Consumer standards result in the annual use of insecticides on the lettuce crop as described by Arizona entomologists John Palumbo and Steve Castle…

“In desert vegetable production systems, growers have been delivering high-quality safe produce to the fresh market for decades, and this has been accomplished almost exclusively through the use of insecticides.”

“…western lettuce growers and consultants have reported that chemical control is the only effective IPM tactic available for the control of most major insect pests. Naturally occurring biotic control agents are simply not capable of providing the level of crop protection necessary for meeting the marketing demands for fresh produce. … Because of the short time these crops are in the field, minor feeding activity may render the product unmarketable because of high consumer standards.”

“More recently, the fresh produce industry has experienced significant growth in the value-added market, where lettuce and other leafy greens are prepared and sold as fresh-cut lettuce packs and ready-to-eat, bagged salad mixes. The growth of this industry has also resulted in higher cosmetic standards for leafy vegetable crops, often to the point where virtually no insect contaminants or feeding blemishes are tolerated.”

Authors: John C. Palumbo and Steve J. Castle
Affiliation: University of Arizona Department of Entomology
Title: IPM for fresh-market lettuce production in the desert southwest: the produce paradox
Publication: Pest Management Science (2009) 65:1311-1320.