Cereal Research Communications

, Volume 39, Issue 2, pp 298–305 | Cite as

Pherocon AM trapping and the “Whole plant count” method — A comparison of two sampling techniques to estimate the WCR adult densities in Central Europe

  • R. BažokEmail author
  • I. Sivčev
  • T. Kos
  • J. Igrc Barčić
  • J. Kiss
  • S. Jankovič


Pherocon AM (PhAM) trapping and visual counting are two commonly used methods for identifying maize fields in the USA that contain a sufficient number of adult western corn rootworms (WCR), Diabrotica virgifera virgifera LeConte to cause economic root damage by larvae the following year. Therefore, the estimation of adult WCR population plays an important role in management decisions (rotation or treatment). The goals of this study were (1) to compare adult WCR data obtained by PhAM trapping to “whole plant count” data in different maize developmental stages, (2) to determine the period in which the data obtained by both methods show the highest correlation, (3) to determine the regression curve between capture of WCR on PhAM as an independent variable and number of WCR observed by visual plant count, and (4) to determine if the “whole plant count” method can serve as a substitution for PhAM trapping under European conditions. Three samplings were conducted in 2006 in 38 fields in Croatia and one sampling was conducted in 22 fields in Serbia. Sampling in Croatia was conducted when maize plants were in the R 65-69, R 73-77 and R 79-85 developmental stages according to BBCH identification keys of maize. Sampling in Serbia was conducted when maize plants reached R 69-71 developmental stages. Three to six PhAM traps were placed in each 0.5 to 4 ha maize field seven days prior to sampling. Visual counts were conducted on the same day as trap inspections. Adult WCR densities in the PhAM traps were correlated to adult densities on whole plants. Statistical analyses comparing the results of PhAM trapping with the visual “whole plant count” method showed that there is a significant medium to strong correlation between them. Correlation coefficients varied depending on the data used in the analysis. When sampling was conducted in the first half of August (maize developmental stages R 69-77), the correlation coefficients were the highest (r(R 6971) = 0.8677 and r(R 73-77) = 0.706). Coefficients of determination were the highest as well [r2(R 69-71) = 0.753; r2(R 73-77) = 0.4984]. Therefore, the most appropriate period for sampling is during the first half of August. At that time, the majority of the maize plants were between the R 69 and R 77 developmental stages. According to the results, 0.5–1 visually determined adult/plant corresponds to 40 adults/trap/week. This shows that both methods are equally useful for estimating the population densities of WCR in the Central European region.


correlations Central Europe sampling techniques Pherocon AM traps whole plant counts western corn rootworm 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bača, F. 1994. Novi član štetne entomofaune u Jugoslaviji Diabrotica virgifera virgifera LeConte (Coleoptera, Chrysomelidae). (New member of harmful entomofauna of Yugoslavia Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae)). Zaštita bilja 45:125–131. (Sc. Sum En)Google Scholar
  2. Bažok, R. 2007. Kukuruzna zlatica. (Western corn rootworm). Glasilo biljne zaštite 5:316–321. (Cro. Sum En.)Google Scholar
  3. Bažok, R., Kiss, J., Igrc Barčić, J., Cagan, L., Komaromi, J., Kos, T., Hoffman, P., Terpo, I., Stevo, J. 2008. Economic threshold levels of WCRlarvae based on adult densities in previous maize in 3 different regions in Central Europe. In: Closing EU-project meeting DIABR-ACT “Harmonise the strategies for fighting Diabrotica virgifera virgifera”, Gottingen, Germany, 25–29.05.2008, abstracts (
  4. Boetel, M.A., Fuller, B.W. 2003. Emergence of adult northern and western corn rootworms (Coleoptera: Chrysomelidae) following reduced soil insecticide applications. J. Econ. Entomology 96:714–729.CrossRefGoogle Scholar
  5. Boetel, M.A., Fuller, B.W., Chandler, L.D., Hovland, D.G., Evenson, P.D. 1998. Fecundity and egg viability of northern and western corn rootworm (Coleoptera: Chrysomelidae) adults surviving labeled and reduced soil insecticide applications. J. Econ. Entomology 91:275–279.CrossRefGoogle Scholar
  6. Edwards, C.R., Larry, W.B., Turpin, F.T. 1994. Field Crop Insects. Managing Corn Rootworms 1994. Purdue University, Cooperative Extension Service, E-49, 1–6, West Lafayette, IN, USA.Google Scholar
  7. Furlan, L., Canzi, S., Di Bernardo, A., Edwards, C.R. 2006. The ineffectiveness of insecticide seed coatings and planting time soil insecticides as Diabrotica virgifera virgifera LeConte population suppressors. J. Appl. Entomology 130:485–490.CrossRefGoogle Scholar
  8. Gray, M.E., Felsot, A.S., Steffey, K.L., Levine, E. 1992. Planting time application of soil insecticides and western corn rootworm (Coleoptera: Chrysomelidae) emergence: Implications for long-term management programs. J. Econ. Entomology 64:544–552.CrossRefGoogle Scholar
  9. Hein, G.L., Tollefson, J.J. 1984. Comparison of adult corn rootworm (Coleoptera: Chrysomelidae) trapping techniques as population estimators. Environ. Entomology 13:266–271.CrossRefGoogle Scholar
  10. Hein, G.L., Tollefson, J.J. 1985. Use of the Pherocon AM trap as a scouting tool for predicting damage by corn rootworm (Coleoptera: Chrysomelidae) larvae. J. Econ. Entomology 78:200–203.CrossRefGoogle Scholar
  11. Metcalf, R.L. 1986. Foreword. In: Krysan, J.L., Miller, T.A. (eds), Methods for the Study of Pest Diabrotica. Springer Verlag, New York, USA, pp. 7–15.Google Scholar
  12. Prues, K.P., Witkowski, J.F., Raun, E.S. (1974): Population suppression of western corn rootworm by adult control with ULV Malathion. J. Econ. Entomology 5:651–655.CrossRefGoogle Scholar
  13. Roselle, R.M. 1977. An evaluation of the Nebraska method for predicting corn rootworm (Diabrotica virgifera LeConte) larval damage based on adult sampling. M.S. thesis. University of Nebraska, Lincoln, USA.Google Scholar
  14. Spencer, J.L., Levine, E., Isard, S.A., Mabry, T.R. 2005. Movement, dispersal and behaviour of western corn rootworm adults in rotated maize and soybean fields. In: Vidal, S., Kuhlman, U., Edwards, C.R. (eds), Western Corn Rootworm Ecology and Management. CABI Publishers, U.K., pp. 121–144.CrossRefGoogle Scholar
  15. Stauss, R. 1994. Compendium of Growth Stage Identification Keys for Mono- and Dicotyledonous Plants, Extended BBCH scale. Ciba-Geigy AG.Google Scholar
  16. Sutter, G.R., Branson, T.F., Fischer, J.R., Elliot, N.C. 1991. Effect of insecticide treatments on survival, development, fecundity, and sex ratio in controlled infestations of western corn rootworms (Coleoptera: Chrysomelidae). J. Econ. Entomology 84:1905–1912.CrossRefGoogle Scholar
  17. Szalai, M., Papp Komáromi, J., Bažok, R., Igrc Barčić, J., Kiss, J., Toepfer, S. 2011. The growth rate of Diabrotica virgifera virgifera populations in Europe. J. Pest Sci. 84:133–142.CrossRefGoogle Scholar
  18. Tollefson, J.J., Witkowski, J.F., Owens, J.C., Hinz, P.N. 1979. Influence of sampler variation on adult corn rootworm population estimates. Env. Entomology 8:215–217.CrossRefGoogle Scholar
  19. Vasilj, Đ. 2000. Biometrika i eksperimentiranje u bilinogojstvu (Biometric and experimentation in plant breeding). Hrvatsko Agronomsko štvo, Zagreb, 320 pp. (Cro. No Sum)Google Scholar
  20. Wilde, G.E. 1999. Areawide management of corn rootworm in Kansas. In: Summary of the Abstracts, 4th FAO WCR/TCP meeting, 5th EPPO ad hoc Panel and 6th International IWGO Workshop on Diabrotica virgifera virgifera. LeConte, Paris, France, pp. 26–27.Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest 2011

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • R. Bažok
    • 1
    Email author
  • I. Sivčev
    • 2
  • T. Kos
    • 1
  • J. Igrc Barčić
    • 3
  • J. Kiss
    • 4
  • S. Jankovič
    • 5
  1. 1.Faculty of AgricultureUniversity of ZagrebZagrebCroatia
  2. 2.Institute for Plant Protection and EnvironmentBeogradSerbia
  3. 3.“Chromos-agro” d.d.ZagrebCroatia
  4. 4.Plant Protection InstituteSzent István UniversityGödöllőHungary
  5. 5.Institute for Science Application in AgricultureBeogradSerbia

Personalised recommendations