Category Archives: Insecticides

Zebra Stripes on Potato Chips? No Way.

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Zebra Chip Disease

Zebra Chip Disease

5.4 billion pounds of potatoes are used to make potato chips in the U.S. every year. 50% of the potatoes grown in the U.S. come from the Pacific Northwest states of Washington, Oregon, and Idaho. The first appearance of a new potato disease known as “zebra chip” in the Pacific Northwest in 2011 caused great concern. The bacterium that causes zebra chip is transmitted to potato by an insect, the potato psyllid which transmits the bacterium within hours of colonizing a potato plant. Thus, psyllid controls must begin immediately upon detection of the insect in a field. The disease is not harmful to humans when they eat a potato chip, but the bacterium discolors the chips making them unmarketable. In regions where zebra chip has been a problem (Texas, New Zealand, Mexico, Honduras) entire fields have been abandoned.

“Potato producers and researchers, alike, were caught by surprise in late summer 2011 when zebra chip showed up for the first time in Washington, Oregon and Idaho, affecting most of the major cultivars grown in the region. Zebra chip, a disease spread by potato psyllids infected with the liberibacter bacterium, causes dark streaks in the tuber flesh. The discoloration is intensified when the infected tubers are processed into chips or fries. …At this point, the only way you’re going to control zebra chip is to manage your potato psyllids. …Nowhere where this thing has shown up, has it gotten better except by huge applications of insecticides.”

Authors: D. Keller
Affiliation: Field Editor, Potato Country.
Title: Zebra Chip Strikes Pacific Northwest.
Publication:  Potato Country. January 2012. 28-31.

Onion Plants Die Without Insecticide Treatments

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Onion Maggot Damage

Onion Maggot Damage

100,000-300,000 onion maggots overwinter on every acre of onions in northern states. The average number of eggs laid by a single female in the spring is about 50. The emerging maggots seek out the roots and bulbs of onions and tunnel into the bulb. Maggots feed for two to three weeks. Damaged plants are usually so severely injured that they wilt, dry out and soon disappear.

“Management of onion maggot Delia antiqua is an integral component of onion production in the northern United States and Canada. There are three generations of D. antiqua per year in the northern United States and infestations of first-generation D. antiqua typically cause the most serious damage because maggot feeding kills seedlings. If onion seedlings are not protected with an insecticide applied during planting, D. antiqua can reduce plant stands by one-half to near 100%.”

Authors: B. Nault, J.Z. Zhao, R. Straub, J. Nyrop and M.L. Hessney.
Affiliation:  Department of Entomology, NYSAES, Cornell University.
Title: Onion Maggot (Diptera: Anthomyiidae) Resistance to Chlorpyrifos in New York Onion Fields.
Publication: Journal of Economic Entomology. 2006. 99(4):1375-1380.

30 million Insects per Acre in Chinese Rice Fields Means Growers Must Spray

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Rice Stripe on Leaf

Rice Stripe on Leaf

Insects often transmit diseases when they fed on a crop plant. Rice is fed on by planthoppers which transmit viruses. In one outbreak in China, 30 million planthoppers were estimated to infest each of 50 million acres. Major losses were prevented thanks to insecticide sprays.

“Laodelphax striatellus Fallén (Hemoptera: Delphacidae) is an economically important sap-sucking pest in rice. The leaves infested by L. striatellus turn yellow, wilt, and even die, resulting in yield loss and quality reduction. In addition, L. striatellus transmits rice viral diseases such as Rice black-streaked dwarf virus and Rice stripe virus, which are two of the most serious diseases and often cause major yield losses. In recent years, the damage caused by L. striatellus feeding injury and the diseases transmitted by this planthopper has been increasing in China. When the outbreak occurred in Jiangsu and Anhui provinces in 2004 and 2005, the density of L. striatellus reached 30 million per acre, and 50 million acres of rice was infested, causing 30% of yield reduction in areas without pesticide treatment.”

Authors: C-X Duan1, J-M Wan1, H-Q Zhai2, Q Chen1, J-K Wang1, N Su1 and C-L Lei1
Affiliation:
1Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China; 2Chinese Academy of Agricultural Sciences, Beijing, China
Title: Quantitative trait loci mapping of resistance to Laodelphax striatellus (Hemoptera: Delphacidae) in rice using recombinant inbred lines.
Publication: Journal of Economic Entomology. 2007. 100(4):1450-1455.

Chilean Apple Growers Must Use Insecticides to Control Quarantine Pests

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Codling Moth Frass

Codling Moth Frass

Chile is a major exporter of apples to other Latin American and Asian countries. Some of these countries do not have populations of the codling moth and they want to keep the insect out. Codling moth is present in Chilean apple orchards which means that growers must spray insecticides to assure that their export fruit shipments will not be rejected.

“Regular applications of insecticides have been the main management practice against codling moth in Chile. … Pest management in Chilean apple orchards with fruit grown for export is dependent on intensive pesticide use, mainly because of strong quarantine restrictions toward the codling moth from Asian and Latin America countries. In this production scenario, even low levels of fruit damage at harvest (<0.5%) are a major concern for growers. To avoid quarantine rejection of exports, an increase in the frequency of insecticide sprays has been observed.”

Authors: E. Fuentes-Contreras1, M. Reyes2, W. Barros1 and B. Sauphanor2

Affiliation:
1Department de Producción Agrícola, Universidad de Talca, Talca, Chile; 2PSH-Ecologie de la Production Intégrée, INRA Site Agroparc, Avignon Cedex, France
Title: Evaluation of azinphos-methyl resistance and activity of detoxifying enzymes in codling moth (Lepidoptera: Tortricidae) from central Chile.
Publication: Journal of Economic Entomology. 2007. 100(2):551-556.

Japanese Consumers Have High Standards for Rice Quality Making Insecticide Use Necessary

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Damaged Rice

Damaged Rice

Rice Bug

Rice Bug

The feeding of rice bugs on rice plants results in black marks on the rice grains. Japanese consumers demand perfect rice, which means that farmers must prevent the insects from feeding.

“A complex of Hemiptera, commonly referred to as rice bugs, are considered to be important insect pests in rice-growing regions of the world. Many species of Hemiptera, from families including Alydidae, Pentatomidae, Coreidae, and Miridae, have been reported as rice bugs.”

“Rice bugs cause yield loss, decrease the quality of grain, and reduce the germination rate. Among these problems, decrease in the quality of grain is considered to be the most important problem in Japanese rice. Infestations cause brown or black marks on the grain. Contamination of as little as 0.1% of such stained grain has reduced commercial value according to Japanese rice quality regulations, and thus the economic injury level is very low. This has led rice farmers to a dependence on insecticide use for rice bug control.”

Authors: H. Takeuchi1,2 and T. Watanabe1
Affiliation: 1Department of Entomology and Nematology, National Agricultural Research Center, Tsukuba, Japan; 2National Agricultural Research Center for Kyushu Okinawa Region, Kumamoto, Japan.
Title: Mortality factors of eggs of Leptocorisa chinensis (Hemiptera: Alydidae) in rice fields.
Publication: Journal of Economic Entomology. 2006. 99(2):366-372.

Insect Saliva Lowers the Quality of Italian Bread Wheat

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Damaged Grain

Damaged Grain


Sunn Pest

Sunn Pest

Italian bread dough is famous for its high quality. Several insect species feed on the wheat plants in the field and when they do, they leave a little saliva behind, which would lower the quality of the bread if insecticides aren’t used.

“Several species known as sunn pests or cereal bugs, have long been recognized as detrimental to wheat bread-making quality in south central Europe, western Asia, and northern Africa. … In Italy, severe infestations of sunn pests have been reported in southern regions and also, although seldom, in the Po Valley.”

“For a long time, it has been recognized that damaged grains can show a discolored area around the point of stylet penetration and that flour derived from damaged kernels produces sticky dough and poor bread. The detrimental effect on baking quality is obvious even in presence of 3-5% damaged kernels and dramatically increases for values higher than 10%. The quality depletion is due to proteolytic enzymes injected in the kernels by insects via their saliva that persist in the flour after milling and cause breakdown of gluten structure in the dough.”

“Presently, no sources of resistance to E. Maura in Italian germplasm are known; thus the only way of reducing the damage is chemical pest control in the field.”

Authors: P. Vaccino1, M. Corbellini1, G. Reffo1, G. Zoccatelli2
, M. Migliardi3 and L. Tavella3
Affiliation: 1Instituto Sperimentale per la Cerealicoltura, Angelo Lodigiano, Italy; 2Dipartmento Scientifico e Tecnologico, University of Verona, Italy; 3University of Torino, Grugliasco, Italy.
Title: Impact of Eurygaster maura (Heteroptera: Scutelleridae) feeding on quality of bread wheat in relation to attack period.
Publication: Journal of Economic Entomology. 2006. 99(3):757-763.

Pecan Weevils Feast on Pecans in Orchards

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Pecan Weevil Larva

Pecan Weevil Larva

Pecan Weevil Adult

Pecan Weevil Adult

The pecan weevil is a late season nut pest that feeds only on pecans and hickory. The female drills a hole in the nut with her snout and places one to four fertilized eggs within the kernel. The pecan weevil larvae are creamy, white legless grubs with soft fleshy bodies. Heavy populations of weevils can destroy all nuts on a tree.

“The pecan weevil is a major pest of pecans throughout the southeastern United States, as well as portions of Texas and Oklahoma. … Adults emerge from soil in late July-August to feed on and oviposit in developing nuts. Larval development is completed within the ripening kernel of the nut.”

“Current control recommendations for pecan weevil consist mainly of aboveground applications of chemical insecticides (e.g., carbaryl) to suppress adults. Application of chemical insecticides is recommended every 7-10 days during peak weevil emergence (generally up to at least a 6 week period).”

Authors: D.I. Shapiro-Ilan1, W.A. Gardner2, T.E. Cottrell1, R. W. Behle3 and B.W. Wood1

Affiliation:
1USDA-ARS, Southeastern Fruit and Tree Nut Research Laboratoy, Byron, GA; 2Department of Entomology, University of Georgia, Griffin, GA; 3USDA-ARS-NCAUR, Peoria, IL
Title: Comparison of application methods for suppressing the pecan weevil (Coleoptera: Curculionidae) with Beauveria bassiana under field conditions.
Publication: Environmental Entomology. 2008. 37(1):162-171.

Zero Tolerance for Maggots in Cherries Means Growers Must Spray

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Cherry Maggot

Cherry Maggot

Pairs of cherry fruit flies have been observed copulating for 18 hours at a time. Each female may deposit 100 to 300 eggs under the fruit skin over a period of thirty days. Eggs hatch in 3-7 days and young maggots feed on cherry flesh, mainly around the pit. Maggots and their frass within the fruit render the product unsalable.

“Insecticides continue to be vital in efforts to control the western cherry fruit fly, the most serious insect pest of commercial sweet and sour cherries in the western United States. … The zero tolerance for fly larvae in cherries has necessitated the use of these highly toxic insecticides in commercial orchards. Isolated homeowner or abandoned trees can be heavily infested and also need to be treated with these insecticides to reduce chances of flies dispersing to commercial orchards.”

Authors: W.L. Yee1 and D.G. Alston2
Affiliation: 1USDA-ARS, Yakima Agricultural Research Laboratory, Wapato, WA; 2Department of Biology, Utah State University, Logan, UT
Title: Effects of spinosad, spinosad bait, and chloronicotiny insecticides on mortality and control of adult and larval western cherry fruit fly (Diptera: Tephritidae).
Publication: Journal of Economic Entomology. 2006. 99(5):1722-1732.

Chinese Farmers Must Kill an Insect Native to America in Order to stay as the #1 Potato-Growing Country in the World

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Colorado Potato Beetle

Colorado Potato Beetle

The native home of the Colorado Potato Beetle is the American West from which it has spread around the world eating potato plants. After adult beetles mate, each female deposits 500 eggs on a potato leaf. The larvae emerge and eat the leaves for about three weeks. Feeding by the beetles can defoliate plants, killing them, or significantly reducing their yields.

“The Colorado potato beetle (CPB), native to the south-west United States and Mexico, is the most important agricultural insect pest throughout North America, Europe and parts of Asia. … The beetle invaded China in the 1990s from Kazakhstan. Since then, it has spread eastwards by more than 40 km per year and is currently distributed throughout most of the northern Xinjiang Uygur Autonomous Region. Foliage damaged by the CPB is a serious threat to potato crops in northern Xinjiang.”

“The beetles consume the leaves of the potato plants, causing a 30-50% reduction in yield each year, with no gain at all in some fields. … Insecticide treatments are currently indispensable and effective in CPB control.”

“Increasing the scale of potato farming is now seen as an important measure in resolving the food crisis and overcoming poverty in provinces such as Gansu, the Inner Mongolia Autonomous Region and the Ningxia Hui Autonomous Region… where the acreage of potato crop reaches over 1 million ha. Therefore, controlling the damage and spread of the CPB has become an important issue in China.”

Authors: Zhaoxu Zhou, Jinhuan Pang, et al.
Affiliation: State Key Laboratory of Plant Genomics, Chinese Academy of Sciences, Beijing, China
Title: Evaluation of the resistance of transgenic potato plants expressing various levels of Cry3A against the Colorado potato beetle (Leptinotarsa decemlineata Say) in the laboratory and field.
Publication: Pest Management Science. 2012. 68(12):1595-1604.

Consumers Don’t Want Bugs with Berries, Making Insecticides Necessary

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Japanese beetles are often present in blueberry fields and are collected along with the berries at harvest. Because of zero consumer tolerance for bugs in blueberry products, insecticides are necessary to remove the beetles from the blueberry fields before harvest.

“The Japanese beetle, Popillia japonica Newman, is an invasive pest of fruit and vegetable crops, turfgrass, and ornamentals in eastern and central North America. … During the adult emergence period of June to September in Michigan beetles can be observed feeding and mating in clusters on host plants.”

“Much of the food industry maintains a zero tolerance standard for insect contamination at pack-out, which places added pressure on growers of fruit crops such as cherry, peach, plum, and blueberry that may be harvested when beetles are present. The majority of commercial blueberry producers use over-the-row mechanical harvesters for collecting fruit from their fields. This harvesting method does not effectively discriminate between beetles and berries, so adult Japanese beetles are a significant contamination risk in fields being harvested where Japanese beetle has not been controlled.”

“Color sorting technology has been adopted by many large processors to detect and remove beetles, providing >95% removal. Even with these management components available to help minimize the risk of fruit contamination with adult beetles, conventional insecticides remain the primary approach to in-field management of Japanese beetles in fruit crops.”

Authors: J. Wise¹, C. Vandervoort² and R. Isaacs¹.
Affiliation: ¹Department of Entomology, Michigan State University; ²Pesticide Analytical Laboratory, Michigan State University.
Title: Lethal and sublethal activities in imidacloprid contribute to control of adult Japanese beetle in blueberries.
Publication: Journal of Economic Entomology. 2007. 100(5):1596-1603.