Arthropods of Agricultural Importance With the world population projected to increase to > 9 billion by 2050 [1], production of food in a cost effective and environmentally sustainable manner is a high priority. A doubling of current food production will be required [2]. However, an estimated 10-20% of major crops worth billions of dollars are lost to herbivorous insects, representing a major constraint to achieving this goal. In addition, post-harvest losses resulting from insect and mite-associated damage of stored food, cause estimated losses of 30% valued globally at over one hundred billion U.S. dollars [3, 4]. Within the United States, the management of a single pest species, the soybean aphid, which decimated soybean production in the North Central region, has cost an estimated $1.6 billion over a ten year period [5].

Arthropods of Medical Importance Arthropods negatively impact human health and welfare through infliction of injury and transmission of disease. Bed bugs are of significant public health importance with the recent resurgence of bed bugs attributed in part to increased international travel and resistance to multiple pesticides [6, 7]. Bed bugs have caused considerable economic loss to the hotel industry through lawsuits and loss of business, with costs to hotels in New York City estimated at $7,700 per room per year in lost revenue and extermination.

Mosquito-vectored dengue virus and malaria have spread rapidly during the last decade into highly populated urban areas resulting in a dramatic rise in the numbers of clinical cases [8, 9]: There are some 50 million dengue hemorrhagic fever infections per year resulting in 500,000 hospitalizations [10], and 250 million cases of malaria per year, leading to some 1 million deaths worldwide [11, 12]. An estimated $2 billion was spent on malaria control in 2011. Costs associated with morbidity are massive. Vector control is one of the most effective strategies used to prevent the spread of mosquito-borne diseases [5]. In the United States, mosquito-transmitted West Nile virus [13] and tick-transmitted Lyme disease [14] are the primary arthropod vectored disease concerns for public health officials.

Arthropod Management and Current Research Needs

The use of classical chemical insecticides was a major contributing factor to the increase in agricultural productivity in the 20th century [15] and insecticide application remains the primary management practice for the majority of arthropod pests. There are a number of disadvantages associated with their use including development of resistance by pest populations, deleterious impacts on non-target organisms, bioaccumulation in the food chain, environmental pollution and potential effects on the health of humans [16]. Hence, there is ongoing pressure to develop target-specific, environmentally-friendly and biodegradable pest management tools.

Repeated application of chemicals invariably results in the development of insecticide resistance in the targeted pest, with more than 500 species of insects and mites with insecticide resistance recorded, including vectors of human disease [4, 17-19]. As a result, chemicals that were effectively employed in the past are no longer useful against many pest species. Insecticide resistance mechanisms are highly diverse and include enhanced metabolism by detoxifying enzymes, target site insensitivity, reduced insecticide penetration and increased excretion [20-35]. There is a pressing need to find new approaches to manage pests that are resistant to classical chemical insecticides.

Pest tolerant transgenic plants provide a more sustainable approach for crop protection. Toxins derived from the bacterium, Bacillus thuringiensis (Bt), have been highly effective for the management of lepidopteran (moth) and coleopteran (beetle) pests when delivered by transgenic plants [36-39]. Indeed, since their initial introduction in the early 1990s, transgenic plants have been widely adopted [38], with 65% of corn and 73% of cotton planted in U.S. in 2011 expressing Bt toxins [40]. As a result, pesticide use and crop production costs have both been reduced [41-43]. However, resistance to Bt toxins has been documented [44-46] and Bt toxins are not sufficiently toxic for management of the sap-sucking, hemipteran pests [47]. In some cases, the reduced application of chemical insecticides on Bt crops has resulted in increased populations of hemipteran pests [48-51]. Greater flexibility is needed for in planta expression of insecticidal constructs such as Bt toxins, including tissue specific expression, protein and transcript stability. In addition, training of personnel with knowledge of hemipteran pests will be essential for the needs of industrial partners seeking to deal with this emerging group of primary pest arthropods.

In many organisms including insects introduction of double-stranded RNA (dsRNA) results in the specific inactivation of an endogenous gene with sequence identity to the introduced dsRNA; this process is known as RNA interference (RNAi) [52]. RNAi has potential for developing target-specific management methods for insect pests. Injection of dsRNA down-regulates the expression of genes in many insect species [53-60], and the practical application of this approach for arthropod control has been demonstrated [55, 61-63]. However, research is needed to delineate factors that limit the current application of RNAi to certain arthropods to fully exploit the potential of this new approach.

There is an urgent need for development of pest control tools with new target sites. Recent advances in the development of genomic and post genomic technologies provide enhanced means for identifying target sites and for screening assays to rapidly identify chemicals that function through newly identified target sites.  A target site must satisfy several criteria to be acceptable for screening assays:

1. The target site should be necessary for pest survival, present most of the time and respond quickly to intervention leading to death of the pest insect;

2. The presence and functionality of the identified target site in non-targets including beneficial insects, animals and humans should be assessed;

3. The identified target site should have screening potential and be amenable to high throughput screening;

4. The potential for development of resistance to the identified target site should be considered. 

Due to the magnitude of economic loss associated with arthropods and the propensity for arthropods to develop resistance to management strategies in current use, there is a critical need for industry to provide arthropod management products with novel modes of action. However, in many cases, there is insufficient understanding of the basic biology of the pest organisms to provide a foundation for such innovative technological solutions.

Research conducted within the Center falls within five areas of emphasis:

1) Pest tolerant transgenic plants

2) RNA interference

3) Insect resistance

4) Novel target sites

5) Methods.


References Cited

1.            Census, U. S. B. o. t. World Population (February 17, 2012),

2.            Tubiello, F. N.; Soussana, J. F.; Howden, S. M., Crop and pasture response to climate change. Proceedings of the National Academy of Sciences of the United States of America 2007, 104, 19686-19690.

3.            Haines, C. P., IPM for food storage in developing countries: 20th Century aspirations for the 21st Century. Crop Protection 2000, 19, 825-830.

4.            Boyer, S.; Zhang, H.; Lemperiere, G., A review of control methods and resistance mechanisms in stored-product insects. Bull Entomol Res 2011, 1-17.

5.            Kim, C. S.; Schaible, G. D.; Garrett, L.; Lubowski, R. N.; Lee, D. J., Economic impacts of the U.S. soybean aphid infestation: A multi-regional competitive dynamic analysis. Agricultural and Resource Economics Review 2008, 37, 227-242.

6.            Davies, T. G.; Field, L. M.; Williamson, M. S., The re-emergence of the bed bug as a nuisance pest: implications of resistance to the pyrethroid insecticides. Medical and veterinary entomology 2012.

7.            Agency, C. f. D. C. a. P. a. U. S. E. P. Joint statement on bed bug control in the United States from the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Environmental Protection Agency (EPA). ; U.S. Department of Health and Human Services: Atlanta, 2010.

8.            Jansen, C. C.; Beebe, N. W., The dengue vector Aedes aegypti: what comes next. Microbes and Infection 2010, 12, 272-279.

9.            Whitehorn, J.; Farrar, J., Dengue. British Medical Bulletin 2010, 95, 161-173.

10.          Guzman, M. G.; Halstead, S. B.; Artsob, H.; Buchy, P.; Jeremy, F.; Gubler, D. J.; Hunsperger, E.; Kroeger, A.; Margolis, H. S.; Martinez, E.; Nathan, M. B.; Pelegrino, J. L.; Cameron, S.; Yoksan, S.; Peeling, R. W., Dengue: a continuing global threat. Nature Reviews Microbiology 2010, S7-S16.

11.          Enayati, A.; Hemingway, J., Malaria Management: Past, Present, and Future. Annual Review of Entomology 2010, 55, 569-591.

12.          Organization, W. H. World Malaria Report 2011.

13.          Kilpatrick, A. M., Globalization, land use, and the invasion of West Nile virus. Science 2011, 334, 323-327.

14.          Edlow, J. A., Lyme disease and related tick-borne illnesses. Ann Emerg Med 1999, 33, 680-693.

15.          Emden, H. F. v.; Pealall, D. B., Beyond Silent Spring. Chapman & Hall: London, 1996.

16.          Casida, J. E.; Quistad, G. B., Golden age of insecticide research: Past, present or future? Annual Review of Entomology 1998, 43, 1-16.

17.          Devonshire, A. L., Resistance of aphids to insecticides. In Aphids, their biology, natural enemies and control, Minks, A. K.; Harrewijn, P., Eds. Elsevier: Amsterdam, 1989; Vol. C., pp 123-139.

18.          Hemingway, J.; Ranson, H., Insecticide resistance in insect vectors of human disease. Annual Review of Entomology 2000, 45, 371-391.

19.          Li, X. C.; Schuler, M. A.; Berenbaum, M. R., Molecular mechanisms of metabolic resistance to synthetic and natural xenobiotics. Annual Review of Entomology 2007, 52, 231-253.

20.          Rose, R. L.; Brindley, W. A., An evaluation of the role of oxidative-enzymes in Colorado potato beetle resistance to carbamate insecticides. Pesticide Biochemistry and Physiology 1985, 23, 74-84.

21.          Argentine, J. A.; Zhu, K. Y.; Lee, S. H.; Clark, J. M., Biochemical-mechanisms of azinphosmethyl resistance in isogenic strains of Colorado potato beetle. Pesticide Biochemistry and Physiology 1994, 48, 63-78.

22.          Argentine, J. A.; Clark, J. M., Selection, genetics, and biochemistry of abamectin resistance in Colorado potato beetle. Abstracts of Papers of the American Chemical Society 1991, 201, 86-AGRO.

23.          Argentine, J. A.; Clark, J. M.; Ferro, D. N., Genetics and synergism of resistance to azinphosmethyl and permethrin in the Colorado potato beetle (Coleoptera, Chrysomelidae). Journal of Economic Entomology 1989, 82, 698-705.

24.          Ioannidis, P. M.; Grafius, E.; Whalon, M. E., Patterns of insecticide resistance to azinphosmethyl, carbofuran, and permethrin in the Colorado potato beetle (Coleoptera, Chrysomelidae). Journal of Economic Entomology 1991, 84, 1417-1423.

25.          Ioannidis, P. M.; Grafius, E. J.; Wierenga, J. M.; Whalon, M. E.; Hollingworth, R. M., Selection, inheritance and characterization of carbofuran resistance in the Colorado potato beetle (Coleoptera, Chrysomelidae). Pesticide Science 1992, 35, 215-222.

26.          Wierenga, J. M.; Hollingworth, R. M., Inhibition of altered acetylcholinesterases from insecticide-resistant Colorado potato beetles (Coleoptera, Chrysomelidae). Journal of Economic Entomology 1993, 86, 673-679.

27.          Wierenga, J. M.; Hollingworth, R. M., The role of metabolic enzymes in insecticide-resistant Colorado potato beetles. Pesticide Science 1994, 40, 259-264.

28.          Anspaugh, D. D.; Kennedy, G. G.; Roe, R. M., Purification and characterization of a resistance-associated esterase from the Colorado potato beetle, Leptinotarsa-decemlineata (Say). Pesticide Biochemistry and Physiology 1995, 53, 84-96.

29.          Zhu, K. Y.; Lee, S. H.; Clark, J. M., A point mutation of acetylcholinesterase associated with azinphosmethyl resistance and reduced fitness in Colorado potato beetle. Pestic Biochem Physiol 1996, 55, 100-108.

30.          Lee, S.; Clark, J. M., Tissue distribution and biochemical characterization of carboxylesterases associated with permethrin resistance in a near isogenic strain of Colorado potato beetle. Pesticide Biochemistry and Physiology 1996, 56, 208-219.

31.          Lee, S. H.; Clark, J. M., Permethrin carboxylesterase functions as nonspecific sequestration proteins in the hemolymph of Colorado potato beetle. Pesticide Biochemistry and Physiology 1998, 62, 51-63.

32.          Lee, S. H.; Clark, J. M., Purification and characterization of multiple-charged forms of permethrin carboxylesterase(s) from the hemolymph of resistant Colorado potato beetle. Pesticide Biochemistry and Physiology 1998, 60, 31-47.

33.          Lee, S. H.; Clark, J. M., Antibody capture immunoassay for the detection of permethrin carboxylesterase in Colorado potato beetle, Leptinotarsa decemlineata Say. Pesticide Biochemistry and Physiology 1999, 64, 66-75.

34.          Lee, S. H.; Dunn, J. B.; Clark, J. M.; Soderlund, D. M., Molecular analysis of kdr-like resistance in a permethrin-resistant strain of Colorado potato beetle. Pesticide Biochemistry and Physiology 1999, 63, 63-75.

35.          Clark, J. M.; Lee, S. H.; Kim, H. J.; Yoon, K. S.; Zhang, A., DNA-based genotyping techniques for the detection of point mutations associated with insecticide resistance in Colorado potato beetle Leptinotarsa decemlineata. Pest Manag Sci 2001, 57, 968-974.

36.          Shelton, A. M., J.-Z. Zhao, and R. T. Roush. , Economic, ecological, food safety, and social consequences of the development of Bt transgenic plants. Annu. Rev. Entomol. 2002., 47, 845-881.

37.          Christou, P.; Capell, T.; Kohli, A.; Gatehouse, J. A.; Gatehouse, A. M., Recent developments and future prospects in insect pest control in transgenic crops. Trends Plant Sci 2006, 11, 302-308.

38.          Sanahuja, G.; Banakar, R.; Twyman, R. M.; Capell, T.; Christou, P., Bacillus thuringiensis: a century of research, development and commercial applications. Plant biotechnology journal 2011, 9, 283-300.

39.          Gatehouse, J. A., Biotechnological prospects for engineering insect-resistant plants. Plant Physiol 2008, 146, 881-887.

40.          USDA National Agricultural Statistics Service: Growth in adoption of genetically engineered crops continues in the U.S. (February 20, 2012),

41.          Toenniessen, G. H.; O'Toole, J. C.; DeVries, J., Advances in plant biotechnology and its adoption in developing countries. Current Opinion in Plant Biology 2003, 6, 191-198.

42.          Brookes, G.; Barfoot, P., GM Crops the global economic and environmental impact: the first nine years 1996-2004. AgBioForum 2005, 8, 15.

43.          Qaim, M.; Zilberman, D., Yield effects of genetically modified crops in developing countries. Science 2003, 299, 900-902.

44.          Tabashnik, B. E.; Gassmann, A. J.; Crowder, D. W.; Carriere, Y., Insect resistance to Bt crops: evidence versus theory. Nature biotechnology 2008, 26, 199-202.

45.          Wan, P.; Huang, Y.; Wu, H.; Huang, M.; Cong, S.; Tabashnik, B. E.; Wu, K., Increased frequency of pink bollworm resistance to Bt toxin Cry1Ac in China. PLoS ONE 2012, 7, e29975.

46.          Gassmann, A. J.; Petzold-Maxwell, J. L.; Keweshan, R. S.; Dunbar, M. W., Field-evolved resistance to Bt maize by western corn rootworm. PLoS ONE 2011, 6, e22629.

47.          Li, H.; Chougule, N. P.; Bonning, B. C., Interaction of the Bacillus thuringiensis delta endotoxins Cry1Ac and Cry3Aa with the gut of the pea aphid, Acyrthosiphon pisum (Harris). Journal of Invertebrate Pathology 2011, 107, 69-78.

48.          Lu, Y.; Wu, K.; Jiang, Y.; Xia, B.; Li, P.; Feng, H.; Wyckhuys, K. A.; Guo, Y., Mirid bug outbreaks in multiple crops correlated with wide-scale adoption of Bt cotton in China. Science 2010, 328, 1151-1154.

49.          Zhao, J. H.; Ho, P.; Azadi, H., Benefits of Bt cotton counterbalanced by secondary pests? Perceptions of ecological change in China. Environmental monitoring and assessment 2011, 173, 985-994.

50.          Greene, J. K.; Turnipseed, S. G.; Sullivan, M. J.; Herzog, G. A., Boll damage by Southern green stink bug (Hemiptera: Pentatomidae) and tarnished plant bug (Hemiptera: Miridae) caged on transgenic Bacillus thuringiensis cotton. J. Econ. Entomol. 1999, 92, 941-944.

51.          Greene, J. K.; Turnipseed, S. G.; Sullivan, M. J.; May, O. L., Treatment thresholds for stink bugs (Hemiptera: Pentatomidae) in cotton J. Econ. Entomol. 2001, 94, 403-409.

52.          Fire, A.; Xu, S.; Montgomery, M. K.; Kostas, S. A.; Driver, S. E.; Mello, C. C., Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. Nature 1998, 391, 806-811.

53.          Kennerdell, J. R.; Carthew, R. W., Use of dsRNA-Mediated Genetic Interference to Demonstrate that frizzled and frizzled 2 Act in the Wingless Pathway. Cell 1998, 95, 1017-1026.

54.          Misquitta, L.; Paterson, B. M., Targeted disruption of gene function in Drosophila by RNA interference (RNA-i): a role for nautilus in embryonic somatic muscle formation. Proc Natl Acad Sci U S A 1999, 96, 1451-1456.

55.          Price, D. R.; Gatehouse, J. A., RNAi-mediated crop protection against insects. Trends Biotechnol 2008, 26, 393-400.

56.          Hrycaj, S.; Mihajlovic, M.; Mahfooz, N.; Couso, J. P.; Popadic, A., RNAi analysis of nubbin embryonic functions in a hemimetabolous insect, Oncopeltus fasciatus. Evol Dev 2008, 10, 705-716.

57.          Ciche, T. A.; Sternberg, P. W., Postembryonic RNAi in Heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts. BMC Dev Biol 2007, 7, 101.

58.          Eleftherianos, I.; Millichap, P. J.; ffrench-Constant, R. H.; Reynolds, S. E., RNAi suppression of recognition protein mediated immune responses in the tobacco hornworm Manduca sexta causes increased susceptibility to the insect pathogen Photorhabdus. Dev Comp Immunol 2006, 30, 1099-1107.

59.          Cruz, J.; Mane-Padros, D.; Belles, X.; Martin, D., Functions of the ecdysone receptor isoform-A in the hemimetabolous insect Blattella germanica revealed by systemic RNAi in vivo. Dev Biol 2006, 297, 158-171.

60.          Brown, S. J.; Mahaffey, J. P.; Lorenzen, M. D.; Denell, R. E.; Mahaffey, J. W., Using RNAi to investigate orthologous homeotic gene function during development of distantly related insects. Evol Dev 1999, 1, 11-15.

61.          Baum, J. A.; Bogaert, T.; Clinton, W.; Heck, G. R.; Feldmann, P.; Ilagan, O.; Johnson, S.; Plaetinck, G.; Munyikwa, T.; Pleau, M.; Vaughn, T.; Roberts, J., Control of coleopteran insect pests through RNA interference. Nat Biotechnol 2007, 25, 1322-1326.

62.          Runo, S., Engineering host-derived resistance against plant parasites through RNA interference: challenges and opportunities. Bioengineered bugs 2011, 2, 208-213.

63.          Huvenne, H.; Smagghe, G., Mechanisms of dsRNA uptake in insects and potential of RNAi for pest control: a review. J Insect Physiol 2010, 56, 227-235.