Ecological Research

, Volume 4, Issue 2, pp 199–208 | Cite as

Principal component analyses of bagged wheat infested withSitotroga cerealella (Lepidoptera: Gelechiidae) andSitophilus oryzae (Coleoptera: Curculionidae)

  • Osamu Imura
  • Ranendra N. Sinha


Interrelations among biological and abiological variables over 22 weeks at 28°C and 60% RH were revealed by principal component analysis (PCA) on data collected from simulated bagged wheat (Triticum aestivum L.) which was not infested by insects (control system), was infested bySitophilus oryzae (L.) (SO system), bySitotroga cerealella (Olivier) (SC system) or by both species (SC+SO system). The variables measured were temperature, grain moisture, CO2, dust weight, fat acidity value, grain weight, germination, insect numbers and frequency of occurrence of microfloral species. The analysis indicated the interrelations among variables involved in degradation of the wheat. In the control system, the dominant interrelations were those among abiological variables, indicating that deterioration of the wheat was minimal. In the SO system, principal components which represented insect effects, seed quality and temperature-fungal relationships, were predominant. Similar factor-loading patterns were extracted both in the SC and SC+SO systems; the principal components suggested thatS. cerealella was mainly responsible for heavy deterioration of the wheat. The principal components, which were rotated orthogonally by 45δ, indicated that the process of wheat degradation in both systems proceeded gradually until week 10 or 15 and thereafter the rate of degradation was accelerated and serious grain quality loss occurred.

Key words

Bagged wheat Principal component analysis Sitophilus oryzae Sitotroga cerealella Stored-grain ecosystem 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Calderon, M. (1981) The ecosystem approach for apprehending the extent of postharvest grain losses. Phytoparasitica9: 157–167.Google Scholar
  2. Christensen, C. M. (1972) Microflora and seed deterioration. “Viability of seeds” (ed. Roberts, E. H.), 59–93. Chapman and Hall Ltd. London.Google Scholar
  3. — (1969) Grain storage—the role of fungi in quality loss. 153 pp. Univ. Minnesota Press, Minneapolis.Google Scholar
  4. DeLucca, A. J. &Ory, R. L. (1987) Effects of microflora on the quality of stored rice. Trop. Sci.27: 205–214.Google Scholar
  5. Dixon, W. J. (ed.) (1983) BMDP statistical software 1983 printing with additions. Univ. California Press, Berkeley.Google Scholar
  6. Imura, O. &Sinha, R. N. (1984) Effect of infestation bySitotroga cerealella (Lepidoptera: Gelechiidae) andSitophilus oryzae (Coleoptera: Curculionidae) on the deterioration of bagged wheat. Environ. Entomol.13: 1471–1477.Google Scholar
  7. Matsushita, S., Terao, K. &Ishima, T. (1980) Studies on the preference for prepared foods (Part 1). Sampling test of preference for prepared foods and its statistical analysis. J. Home Econ. Japan31: 75–83 (In Japanese with English summary).Google Scholar
  8. Misra, C. P., Christensen, C. M. &Hodson, A. C. (1961) The Angoumois grain moth,Sitotroga cerealella, and storage fungi. J. Econ. Entomol.54: 1032–1033.Google Scholar
  9. Multon, J. L. (1982) Les mécanismes d'altération des grains et graines dans l'éco-système postrécolte, les pertes qui en résultent et les stratégies des défence des stocks. “Conservation et stockage des grains et graines et produits derivés Vol. 1” (ed. Multon, J. L.), 1–57. Tech. Docum. Lav., Paris.Google Scholar
  10. Okuno, T., Kume, H., Haga, T. &Yoshizawa, T. (1985) Multivariate analysis methods, rev. ed. 430 pp. JUSE Press, Tokyo (In Japanese).Google Scholar
  11. Prakash, A., Pasalu, I. C. &Mathur, K. C. (1981) Population fluctuations of insect pests in stored paddy under natural and controlled conditions. Oryza18: 90–92.Google Scholar
  12. Semeniuk, G. (1954) Microflora. “Storage of cereal grains and their products” (ed. Anderson, J. A. & Alcock, A. W.), 77–151. AACC, St. Paul.Google Scholar
  13. Sinha, R. N. (1973a) Interrelations of physical, chemical, and biological variables in the deterioration of stored grains. “Grain storage: part of a system” (ed. Shinha, R. N. & Muir, W. E.), 15–47. AVI Publ. Comp., Inc., Westport.Google Scholar
  14. — (1973b) Ecology of storage. Ann. Technol. Agric.22: 351–369.Google Scholar
  15. — (1977) Uses of multivariate methods in the study of stored-grain ecosystems. Environ. Entomol.6: 185–192.Google Scholar
  16. — (1970) Maximum likelihood factor analysis of natural arthropod infestations in stored grain bulks. Res. Popul. Ecol.12: 51–60.Google Scholar
  17. — (1969a) Principal-component analysis of interrelations among fungi, mites, and insects in grain bulk ecosystems. Ecology50: 536–547.Google Scholar
  18. ——— (1969b) Canonical correlation between groups of acarine, fungal and environmental variables in bulk grain ecosystems. Res. Popul. Ecol.11: 92–104.Google Scholar
  19. —— (1979) Interrelations of arthropods and microorganisms in damp bulk stored wheat—a multivariate study. Res. Popul. Ecol.21: 40–67.Google Scholar
  20. — (1985) Insect pests of flour mills, grain elevators, and feed mills and their control. 290 pp. Can. Govern. Publ. Center, Ottawa.Google Scholar
  21. Sokal, R. R. &Rohlf, F. J. (1981) Biometry, 2nd ed. 859 pp. Freeman and Co., San Francisco.Google Scholar
  22. van Bronswijk, J. E. M. H. &Sinha, R. N. (1971) Interrelations among physical, biological, and chemical variables in stored-grain ecosystems; a descriptive and multivariate study. Ann. Entomol. Soc. Am.64: 789–803.Google Scholar
  23. White, N. D. G. &Sinha, R. N. (1980a) Principal component analysis of interrelations in storedwheat ecosystems infested with multiple species of insects. Res. Popul. Ecol.22: 33–50.Google Scholar
  24. —— (1980b) Canonical correlation analysis of interrelations in insect-infested stored wheat. Environ. Entomol.9: 106–112.Google Scholar
  25. Zeleny, L. (1954) Chemical, physical, and nutritive changes during storage. “Storage of cereal grains and their products” (ed. Anderson, J. A. & Alcock, A. W.), 46–76. AACC, St. Paul.Google Scholar

Copyright information

© the Ecological Society of Japan 1989

Authors and Affiliations

  • Osamu Imura
    • 1
  • Ranendra N. Sinha
    • 2
  1. 1.Stored-Product Entomology LaboratoryNational Food Research InstituteTsukuba, IbarakiJapan
  2. 2.Research StationAgriculture CanadaWinnipegCanada

Personalised recommendations