Monitoring and Economic Thresholds

Hagstrum and Subramanyam (2006) Fundamentals of Stored Product Entomology reviewed sampling plans developed between 1985 and 2004 for bulk storage, processing, transportation, and marketing facilities. They discuss the relationship between variance and mean insect density which is widely used to calculate the number of samples needed to estimate the mean with a given accuracy and to develop sequential sampling plans. This relationship is curvilinear and consistent between insect species and commodities. A linear approximation of the curve can be used when data are collected for insect densities ranging over five orders of magnitude (0.1 to 1,000) is used to fit the curve. Otherwise, the slope varies with the range of insect densities considered.

The random distribution of insects among sampling units explains the probability of insect detection and the relationship between variance and mean insect density. As the first insects arrive, the number of sampling units with one insect increases logarithmically. The fraction of sampling units with one insect determines how fast the variance increases. At some insect densities, a sampling unit will eventually have more than one insect. At this point, the variance will begin to increase more rapidly as the number of sampling units with more than one insect begins to increase logarithmically. In many studies, as a result of these relationships, aggregation appears to increase as insect density increases.

Accurate estimation of insect density often requires more sampling than can be justified economically. However, determining whether a pest population is near the density at which economic losses are likely to occur generally is more practical using a sequential sampling plan. Economic thresholds have been determined for 11 stored product pest species that infest raw commodity storages, processing plants, or retail businesses. Most of the following cited papers were not included in Hagstrum and Subramanyam (2006) Fundamentals of Stored Product Entomology. Most were published more recently than this book.

Sampling Plans

Amoah, Barbara, M. W. Schilling and Thomas W. Phillips. 2016. Monitoring Tyrophagus putrescentiae (Acari: Acaridae) With Traps in Dry-Cured Ham Aging Rooms. Environmental entomology 45(4): 1029-1039.

Carvalho, M., J. de Carvalho, L. Torres, and A. Mexia. 2006. Developing sequential sampling plans for classifying Lasioderma serricorne (F.) (Coleoptera, Anobiidae) status in a cigarette factory. J. Stored Prod. Res. 42:42-50.

Carvalho, M. O., A. Mexia and L. M. Torres. 2007. Sequential sampling plans for classifying Lasioderma serricorne (F) (Coleoptera : Anobiidae) status in a cigarette factory on the Cape Verde islands. Journal African Entomology 15: 37-44.

Carvalho, M.O., Faro, A. and Subramanyam, B. 2013. Insect population distribution and density estimates in a large rice mill in Portugal – A pilot study. J. Stored Prod. Res. 52: 48–56.

Carvalho, Maria Otilia 2016. Developing and Validating Sequential Sampling Plans for Integrated Pest Management on Stored Products. Advanced Techniques in Biology & Medicine 4: 183. doi: 10.4172/2379-1764.1000183

Jansson, R. K. and R. McSorley. 1990. Sampling Plans for the Sweetpotato Weevil (Coleoptera: Curculionidae) on Sweet Potato in Southern Florida. J. Econ. Entomol. 83: 1901-1906.

Jian, F., R. Larson, D. S. Jayas and N. D. G. White. 2011. Evaluation of sampling units and sampling plans for adults of Cryptolestes ferrugineus (Coleoptea: Laemophloeidae) in stored wheat under different temperatures, moisture contents, and adult densities. Journal of Stored Products Research 47(4): 334-340.

Jian, F., D. S. Jayas, and N. D. G. White. 2014. How many kilograms of grain per sample unit is big enough? Part I – comparison of insect detection and density estimation between manual probe sampling and Insector® system. Journal of Stored Products Research 56: 60-66.

Jian, F., D. S. Jayas, and N. D. G. White. 2014. How many kilograms of grain per sample unit is big enough? Part II – simulation of sampling from grain mass with different insect densities and distribution patterns. Journal of Stored Products Research 56: 67-80.

Opit, G.P., Throne, J.E. and Flinn, P.W. 2009. Sampling Plans for the Psocids Liposcelis entomophila and Liposcelis decolor (Psocoptera: Liposcelididae) in Steel Bins Containing Wheat. Journal of Economic Entomology 102: 1714-1722.

Park, J. J. and T. M. Perring. 2010. Development of a Binomial Sampling Plan for the Carob Moth (Lepidoptera: Pyralidae), a Pest of California Dates. J. Econ. Entomol. 103: 1474-1482.

Wakefield, M., Dunn, J. 2005. Effectiveness of the BT mite trap for detecting the storage mite pests, Acarus siro, Lepidoglyphus destructor and Tyrophagus longior. Experimental and Applied Acarology 35: 17-28.

Economic Thresholds

Amoah, Barbara Amoh. 2016. Monitoring populations of the ham mite, Tyrophagus putrescentiae (Schrank) (Acari: Acaridae): research on traps, orientation behavior, and sampling techniques. PhD dissertation, Department of Entomology, Kansas State University

Amoah, Barbara, David Hagstrum, Bhadriraju Subramanyam, James F. Campbell, M. Wes Schilling and Thomas W. Phillips. 2017.  Sampling methods to detect and estimate populations of Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) infesting dry-cured hams. J. Stored Prod. Res. 73: 98-108.

Arthur, F.H., Campbell, J.F. and Toews, M.D. 2013. Distribution, abundance, and seasonal patterns of Plodia interpunctella (Hübner) in a commercial food storage facility. J. Stored Prod. Res. 53: 7–14.

Baier, A.H., and Webster, B.D. 1992. Control of Acanthoscelides obtectus Say (Coleoptera: Bruchidae) in Phaseolus vulgaris L. seed stored on small farms. I. Evaluation of damage. J. Stored Prod. Res. 28(4): 289–293.

Caliboso, F. M. 1990. Corn weevil, Sitophilus zeamais Motsch (Coleoptera: Curculionidae): a population model. MS thesis, Faculty of the Graduate School, University of the Philippines at Los Baños, Los Baños

Campbell, J.F., Toews M.D., Arthur F.H., Arbogast R.T. 2010. Long-term monitoring of Tribolium castaneum populations in two flour mills: rebound after fumigation. J. Econ. Entomol. 103(3): 1002–1011.

Carvalho, M.O., Passos de Carvalho, J., Torres, L.M.and Mexia, A. 2006. Developing sequential sampling plans for classifying Lasioderma serricorne (F.) (Coleoptera: Anobiidae) status in a cigarette factory. J. Stored Prod. Res. 42 (1): 42–50.

Carvalho, M.O., Faro, A. and Subramanyam, B. 2013. Insect population distribution and density estimates in a large rice mill in Portugal – A pilot study. J. Stored Prod. Res. 52: 48–56.

Chen, P, Zhang, H, Lu, Q. and Zheng, L. 2008. Survey and analysis of economic thresholds for insect pest control in grain storage in the Fujian area of China. See Ref. 57, pp. 493–97 In Guo DL, Navarro S, Jian Y, Cheng T, Zuxun J, et al., eds. 2008. Proc. Int. Conf. Control. Atmos. Fumigation Stored Prod. 8th, Chengdu, Sept. 21–26. Chengdu, China: Sichuan Publ. Group

Chen, P., H. Zhang, Q. Lu and L. Zheng. 2010. Survey and analysis of economic thresholds for stored insect pest control in Fujian area of China. Grain Storage 39: 10-13.

Compton, J.A.F., Floyd, S., Magrath, P.A., Addo, S., Gbedevi, S.R., Agbo, B., Bokor, G., Amekupe, S., Motey, Z., Penni, H. and Kumi, S. 1998. Involving grain traders in determining the effect of postharvest insect damage on the price of maize in African markets. Crop Prot. 17(6): 483–489.

Flinn, P.W., Hagstrum, D.W., Reed, C.R. and Phillips, T.W. 2007. Stored Grain Advisor Pro: Decision support system for insect management in commercial grain elevators. J. Stored Prod. Res. 43(4): 375–383.

Hagstrum DW, Flinn PW. 2014. Modern stored-product insect pest management. J. Plant Prot. Res. 54: 205–210. (Review of economic thresholds for nine species)

Haouel-Hamdi, Soumaya, Faten Titouhi, Emna Boushih, Mohamed Zied Dhraief, Moez Amri and Jouda Mediouni-Ben Jemâa. 2017. Population Demographic and Reproductive Parameters of the Cowpea Seed Beetle Callosobruchus maculatus Infesting Stored Lentil and Chickpea Commodities. Tunisian Journal of Plant Protection 12(1): 67-81.

Hodges, R.J., Smith, M., Madden, A., Russell, D., Gudrups, I. and Halid, H. 1997. Development of a decision support system for the fumigation of milled-rice bag-stacks in the tropics. p. 425–434. In: Proc. Int. Conference on Controlled Atmosphere and Fumigation in Stored Products (E.J. Donahaye, S. Navarro, A. Varnava eds. Cyprus, April 1996. Printco Ltd., Nicosia, Cyprus.

Luo F, Li Z, Yu J, Lu X. 2008. Application of economic threshold level in stored grain fumigation for controlling of pests. See Ref. 57, pp. 530–532. In Guo DL, Navarro S, Jian Y, Cheng T, Zuxun J, et al., eds. 2008. Proc. Int. Conf. Control. Atmos. Fumigation Stored Prod. 8th, Chengdu, Sept. 21–26. Chengdu, China: Sichuan Publ. Group

Meikle, W.G., Holst, N., Degbey, P. and Oussou, B. 2000. Evaluation of sequential sampling plans for the larger grain borer (Coleoptera: Bostrichidae) and the maize weevil (Coleoptera: Curculionidae) and of visual grain assessment in West Africa. J. Econ. Entomol. 93 (6): 1822–1831.

Nansen, C., and W. G. Meikle. 2011. The economic injury level and action threshold in stored-product systems, doi: 10.2212/spr.2011.3.3 ed.

Sabio, G. C., F. M. Caliboso, R. L. Tiongson, and E. A. Benigno. 1984. Establishment of economic threshold levels in stored grains, and preliminary trial of methacrifos as a stack spray, pp. 65-93. In R. L. Semple and A. S. Frio (eds.), Health and Ecology in Grains Post Harvest Technology. Proceedings of the 7th ASEAN Technical Seminar on Grain Post-Harvest Technology, 21-24 August 1984, Kuala Lumpur. ASEAN Crops Post-Harvest Programme.

Santos AK, Faroni LRA, Guedes RN, dos Santos JP, Rozazdo AF. 2002. Nıvel de dano economico de Sitophilus zeamais (M.) em trigo armazenado. Rev. Bras. Eng. Agrıc. Ambient. 6(2): 273–279.

Subramanyam, B., Hagstrum, D.W., Meagher, R.L., Burkness, E.C., Hutchinson, W.D. and Naranjo, S.E. 1997. Development and evaluation of sequential sampling plans for Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae) infesting farm stored wheat. J. Stored Prod. Res. 33 (4): 321–329.

Toews, M., Subramanyam, Bh. and Roesli, R. 2003. Development and validation of sequential sampling plans for Sitophilus species associated with pet specialty stores. p. 115–120. In: Advances in Stored Product Protection (P.F. Credland, D.M. Armitage, C.H. Bell, P.M. Cogan, E. Highley, eds.). Proc. 8th Int. Working Conference on Stored Product Protection, York, UK, 22–26 July 2002. CABI International, Wallingford, UK.

Vela-Coiffier, E. L., W. S. Fargo, E. L. Bonjour, G. W. Cuperus & W. D. Warde, 1997. Immigration of insects into on-farm stored wheat and relationships among trapping methods. Journal of Stored Products Research 33: 157–166.

Zakladnoi GA. 1991. Modern technologies for stored-grain protection against insect pests in the USSR. p. 1983–1990. In Proc. Intern.Work. Conf. Stored-Prod. Prot. 5th, Bordeaux, Sept. 9–14, Bordeaux, France:M´edoc

Other Sampling and Detection Studies

Armitage DA. 2003. Grain sampling methods to achieve consumer confidence and food safety. Home-Grown Cereal Authority Research Review (UK) No. 50, 21 p.

Brabec, D., Pearson, T., Flinn, P., Katzke, D., 2010. Detection of internal insects in using a conductive roller mill and estimation of insect fragments in the resulting flour. J. Stored Prod. Res. 46, 180-185.

Buckman, K.A., Campbell, J.F. 2013. How varying pest and trap densities affect Tribolium castaneum capture in pheromone traps. Entomologia Experimentalis et Applicata 3: 404-412.

Cogan, P.M., Stubbs, M.R. and Wakefield, M.E. 1985. Detection of insects in large bulks of grain. M.A.F.F.,A.D.A.S. Slough Lab. Rep. 14. 22 p.

Elmouttie, D., Kiermeier, A. and Hamilton, G. 2010. Improving detection probabilities in stored grain. Pest Management Science 66: 1280-1286.

Elmouttie, David, Hammond, Nicole Elana and Hamilton, Grant S. 2013. A review of current statistical methodologies for in storage sampling and surveillance in the grains industry. Bulletin of Entomological Research, 103(02), pp. 140-147.

Elmouttie, David, Paul Flinn, Andreas Kiermeier, Bhadriraju Subramanyam, David Hagstrum and Grant Hamilton. 2013. Sampling stored-product insect pests: a comparison of four statistical sampling models for probability of pest detection. Pest Manag. Sci. 69: 1073–1079.

Fleurat-Lessard, Francis 2011. Monitoring insect pest populations in grain storage: the European context. Stewart Postharvest Review doi: 10.2212/spr.2011.3.4

Flinn, P.W., Opit, G.P. and Throne, J.E. 2009. Predicting stored grain insect population densities using an electronic probe trap. Journal of Economic Entomology 102: 1696-1704.

Hamilton, G., and D. Elmouttie. 2011. Insect distributions and sampling protocols for stored commodities. Stewart Postharvest Review doi: 10.2212/spr.2011.3.2.

Jian, F., R. Larson, D. S. Jayas, and N. D. G. White. 2011. Three-dimensional spatial distribution of adults of Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) in stored wheat under different temperatures, moisture contents, and adult densities. J. Stored Prod. Res. 47:293-305.

Jian, F., R. Larson, D. S. Jayas and N. D. G. White. 2012. Three dimensional temporal and spatial distribution of adult Oryzaephilus surinamensis and Sitophilus oryzae in stored wheat under different temperatures, moisture contents, and adult densities. J. Stored Prod. Res. 49: 155-165.

Jian, Fuji, Ron Larson, Digvir S. Jayas and Noel D. G. White. 2012. Three-Dimensional Temporal and Spatial Distribution of Adult Rhyzopertha dominica in Stored Wheat and Corn Under Different Temperatures, Moisture Contents, and Adult Densities. J. Econ. Entomol. 105(4): 1194-1204.

Jian, F., D. S. Jayas, N. D. G. White, P. G. Fields, and N. Howe. 2014. An evaluation of insect expulsion from wheat samples by microwave treatment for disinfestation. Biosyst. Eng. 130:1-12.

Jian, F., D. S. Jayas, N. D. G. White and P. G. Fields. 2014. Insect detection and density estimation in stored grain bins: is it a needle in a haystack or an elephant in a room?, p. 230-245. In F. H. Arthur, R. Kengkanpanich, W. Chayaprasert and D. Suthisut (eds.), Proceedings of the 11th International Working Conference on Stored Product Protection, 24-28 November 2014, Chiang Mai, Thailand.

Jian, F., Jayas, D.S., Fields, P.G. and White, N.D.G. 2015. A new method to rapidly detect the rusty grain beetle, Cryptolestes ferrugineus, in stored grain. J. Stored Prod. Res. 63: 1-5.

Jian, Fuji, Sara Doak, Digvir S. Jayas , Paul G. Fields, Noel D.G. White. 2016. Comparison of insect detection efficiency by different detection methods. Journal of Stored Products Research 69: 138-142. (Berlese funnel, shaking grain on a metal sieve, shaking grain on an acrylic device, microwave heating)

Knight, J., R. Wilkin, and J. Rivett. 2004, Grain Sampling and Assessment: Sampling Grain in Lorries. Home-Grown Cereals Authority (HGCA) Project Report, London Project Report 339

Knight, J. D., and R. Wilkin. 2006. Assessment of three commercial automatic grain samplers fitted to front loader buckets.” HGCA Project Report 407, 20 p.

Knight, J. D., and D. R. Wilkin. 2010. Development and validation of on-farm sampling methods for the collection of marketing (quality) samples at harvest. Journal of stored products research 46(4): 221-227.

Krizkova-Kudlikova, I., Hubert, J. 2008. Development of polyclonal antibodies of the detection of Tribolium castaneum contamination in wheat grain. J. Agric. Food Chem. 56: 8035-8040.

Laopongsit, W., Srzednicki, G., Craske, J., 2014. Preliminary study of solid phase micro-extraction (SPME) as a method for detecting insect infestation in wheat grain. J. Stored Prod. Res. 59, 88-95.

Manickavasagan, A., Jayas, D.S. and White, N.D.G. 2008. Thermal imaging to detect infestation by Cryptolestes ferrugineus inside wheat kernels. J. Stored Prod. Res. 44: 186-192.

Minkevich, J.M., Demianyk, C.J., White, N.D.G., Jayas, D.S. and Timlick, B. 2002. A rapid method to detect Cryptolestes ferrugineus (Coleoptera: Cucujidae) larvae in stored grain. Can. J. Plant Sci. 82: 591-597.

Nawrocka, A., Stepien, E., Grundas, S., Nawrot, J. 2012. Mass loss determination of wheat kernel infested by granary weevil from X-ray images. J. Stored Prod. Res. 48: 19-24.

Nansen, C., Meikle, W.G., Campbell, J., Phillips, T.W. and Subramanyan, B. 2008. A binomial and species-independent approach to trap capture analysis of flying insects. Journal of Economic Entomology. 101: 1719-1728.

Neethirajan S., Karunakaran, C., Jayas, D.S. and White, N.D.G. 2007. Detection techniques for stored-product insects in grain. Food Control 18: 157–162.

Obrepalska-Steplowska, A., K. Nowaczyk, M. Holysz, M. Gawlak & J. Nawrot 2008. Molecular techniques for the detection of granary weevil (Sitophilus granarius L.) in wheat and flour. Journal Food Additives & Contaminants: Part A  25(10): 1179-1188.

Pearson, T.C. and Brabec, D.L. 2007. Detection of wheat kernels with hidden insect infestations with an electrically conductive roller mill. Appl. Eng. Agric. 19: 727-733.

Pearson, T.C., Brabec, D.L. and Schwartz, C.R. 2003. Automated detection of internal insects infestations in whole wheat kernels using a Perten SKCS 4100. Appl. Eng. Agric. 19: 727-733.

Reed, J.T., Adams, L.C., Abel, C.A., 2010. Comparison of three insect sampling methods in sweet potato foliage in Mississippi. Journal of Entomological Science 45: 111-128.

Savoldelli, S. 2006. Correlation between Plodia interpunctella Hübner (Lepidoptera: Pyralidae) males captured with a wing trap and the real density of moth’s population.  p. 487-491. In Lorini, I., Bacaltchuk, B., Beckel, H., Deckers, D., Sundfeld, E., Biagi, J.P., Santos, J.D., Celaro, J.C., Faroni, L.R.D’A., Bortolini, L.de O.F., Sartori, M.R., Elias, M.C., Guedes, R.N.C., Fonseca, R.G.da, Scussel, V.M. (eds.). Proceedings of the Ninth International Working Conference on Stored Product Protection, 15-18 October 2006, Brazil. Campinas, Sao Paulo, Brazilian Post-Harvest Association – ABRAPOS, Passo Fundo

Singh, C.B., Jayas, D.S., Paliwal, J., White, N.D.G., 2009. Detection of insect-damaged wheat kernels using near-infrared hyperspectral imaging. J. Stored Prod. Res. 45, 151-158.

Stejskal, V., Aulicky, R., Kucerova, Z. and Lukas, J. 2008. Method of sampling and laboratory extraction affects interpretation of grain infestation by storage pests. Journal of Plant Diseases and Protection 115: 129-133.

Thind, B. 2005. A new versatile and robust trap for detection and monitoring of stored product pests in the cereal and allied industries. Experimental and Applied Acarology 35: 1-15.

Toews M.D. and Nansen C. 2011. Chapter 21, Trapping and interpreting captures of stored grain insects. p. 243-261. In: Hagstrum, D.W., Phillips, T.W., Cuperus, G., (Eds.), Stored Product Protection. Manhattan, Kansas, K-state Research and Extension, Manhattan, KS, USA

Wakefield, M. 2006. Storage arthropod pest detection – current status and future directions. p. 371-384. In Lorini, I., Bacaltchuk, B., Beckel, H., Deckers, D., Sunfeld, E., Dos Santos, J.P., Biagi, J.D., Celaro, J.C., Faroni, L.R.D.A., Bortolini, L.O.F., Sartori, M.R., Elias, M.C., Guedes, R.N.C., Da Fonseca, R.G., Scussel, V.M. (eds.) Biology, behavior, and pest detection on stored grain. Proceedings of the Ninth International Working Conference on Stored Product Protection, 15-18 October 2006, Campinas, São Paulo, Brazil

Wilkin, D. R. 1982. Sampling bulk grain. Ministry of Agriculture, Fisheries and Food (MAFF)

Wilkin, D. R. 1982. Detection of infestation in grain. Ministry of Agriculture, Fisheries and Food (MAFF)

Wilkin, D. R. and V. J. Wright. 1984. Sampling bulk grain to check infestation. Slough Laboratory Rpt. No 6569, Ministry of Ag., Fish, and Food, Slough, U.K.

Wilkin, D. R., and B. B. Thind. 1984. Stored product mites detection and loss assessment in animal feed. p. 608-620. In R. B. Mills, V. F. Wright, J. R. Pedersen, W. H. McGaughey, R. W. Beeman, K. J. Kramer, R. D. Speirs and C. L. Storey (eds.), Proceedings of the 3rd International Working Conference on Stored-Product Entomology, 23-28 October, 1983, Manhattan, Kansas. Kansas State University

Wilkin, D. R., Cowe, I. A., Thind, B. B., McNicol and Cuthbertson, D. C. 1986. The detection and measurement of mite infestation in animal feed using near infrared reflectance. Journal of Agricultural Science (Cambridge) 107: 439-448.

Wilkin, D. R. 1990. Detection of insects in bulk grain. Journal of the Kansas Entomological Society 63: 554-558.

Wilkin, D.R., Fleurat-Lessard, F., 1991. The detection of insects in grain using conventional sampling spears. In: Fleurat-Lessard, F., Ducom, P. (Eds.), Proceedings of the Fifth International Working Conference on Stored Product Protection, September 9-14, 1990, Bordeaux, France, pp. 1445-1453.

Wilkin, D.R. 1991. An assessment of methods of sampling bulk grain. HGCA Project Report No. 34. Home Grown Cereals Authority, London.

Wilkin, D. R. 1993. An assessment of practical methods for collecting samples from lorry-loads of grain. Home Grown Cereals Authority (HGCA) Project Report no. 79, 23 p.

Wilkin, D. R., D. Catchpole, and S. Catchpole. 1993. The development of a practical method for removing insects from large samples of grain. Project Report no. 82. Home Grown Cereals Authority, London

Wilkin, D.R., Catchpole, D. and Catchpole, S. 1994. The detection of insects in grain during transit-an assessment of the problem and the developmentof a practical solution. p 463-469. In Highley, E.; Wright, E.J.; Banks, H.J.; Champ, B.R. (Eds.), Stored Product Protection, Proceedings of the 6th International Working Conference on Stored-Product Protection, 17-23 April 1994, Canberra, Australia. CAB International, Wallingford, United Kingdom

Wilkin, D.R. 2003. An alternative approach to assessing pest problems in stored grain. p. 464-467. In: Credland, P.F., Armitage, D.M., Bell, C.H., Cogan, P.M. and Highley, E (Eds.) Proceedings of the 8th International Working Conference on Stored Product Protection, York, July 2002 CABI publishing, Wallingford, UK