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Survival of Neozygites cf. floridana (Zygomycetes: Entomophthorales) in mummified cassava green mites and the viability of its primary conidia

Abstract

The survival of Neozygites cf. floridana (Weiser and Muma) as dry hyphal bodies in mummified cassava green mites, Mononychellus tanajoa (Bondar), at 5.0% RH in the dark was affected by storage temperature. Survival of the fungus in mummies kept at 24±1.0°C could be demonstrated for 6–7 months. When stored at 4°C, the fungus sporulated from 90% of the mummies liberating an average of 186.9 primary conidia per mummy even after a storage period of 16 months, when the experiment was terminated. The temperature, humidity and light condition significantly affected the viability of primary conidia. The percent viability across all factors dropped from 98.4% after 0 h (beginning of the experiment) to 23.4% after a 1 h exposure to the conditions tested. Lower temperatures maintained higher viabilities with 86.3% of the conidia surviving after 18 h at 18°C, whereas almost all conidia died after 12 h at 33°C. Conidia survived less than 1 h when exposed to SDs (saturation deficit) of 2.0 mm Hg or higher at any tested temperature.

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References

  1. Benz, G. 1987. Environment. In Epizootiology of insect diseases, J.R., Fuxa and Y., Tanada (eds), pp. 177–214. John Wiley and Sons, New York.

    Google Scholar 

  2. Carner, G.R. 1976. A description of the life cycle of Entomophthora sp. in the two spotted spider mite. J. Invertebr. Pathol. 28: 245–254.

    Google Scholar 

  3. Clerk, G. C. and Madelin, M. F. 1965. The longevity of conidia of three insect-parasitising hyphomycetes. Trans. Br. Mycol. Soc. 48: 193–209.

    Google Scholar 

  4. Kenneth, R., Wallis, G., Gerson, U. and Plautt, H.N. 1972. Observations and experiments on Triplosporium floridanum (Entomophthorales) attacking spider mites in Israel. J. Invertebr. Pathol. 19: 366–369.

    Google Scholar 

  5. Nemoto, H. and Aoki, J. 1975. Entomophthora floridana (Entomophthorales: Entomophthoraceae) attacking the sugi spider mites, Oligonychus hondoensis (Acari: Tetranychidae) in Japan. Appl. Entomol. Zool. 10: 90–95.

    Google Scholar 

  6. Newmann, G.G. and Carner, G.R. 1975. Factors affecting the spore form of Entomophthora gammae. J. Invertebr. Pathol. 26: 29–34.

    Google Scholar 

  7. Page, R.M., Sherf, A.F. and Morgan, T.L. 1947. The effect of temperature and relative humidity on the longevity of the conidia of Helminthosporium oryzae. Mycologia 39: 158–164.

    Google Scholar 

  8. Pell, J.K. and Wilding, N. 1992. The survival of Zoophthora radicans (Zygomycetes: Entomophthorales) isolates as hyphal bodies in mummified larvae of Plutella xylostella (Lepidoptera: Yponomeutidae). Entomophaga 37: 649–654.

    Google Scholar 

  9. SAS Institute, Inc. 1988. SAS/STATtm User's Guide. Release 6.03, ed. SAS Institute, Cary, N.C.

  10. Sawyer, W.H. 1931. Studies on the morphology and development of an insect destroying fungus, Entomophthora sphaerosperma. Mycologia 23: 411–432.

    Google Scholar 

  11. Shimazu, M. 1979. Resting spore formation of Entomophthora sphaerosperma (Entomophthorales: Entomophthoraceae) in the brown planthopper, Nilaparvata lugens (Stahl) (Homoptera: Delphacidae). Appl. Entomol. Zool. 14: 383–388.

    Google Scholar 

  12. Shimazu, M. and Soper, R.S. 1986. Pathogenicity and sporulation of Entomophaga maimaiga (Entomophthorales: Entomophthoraceae) on larvae on the gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae). Appl. Entomol. Zool. 21: 589–596.

    Google Scholar 

  13. Steinkraus, D. C. and Slaymaker, P. H. 1994. Effect of temperature and humidity on formation, germination and infectivity of conidia of Neozygites fresenii (Zygomycetes: Neozygitaceae) from Aphis gossypii (Homoptera: Aphididae). J. Invertebr. Pathol. 64: 130–137.

    Google Scholar 

  14. Tanada, Y. and Fuxa, J.R. 1987. The pathogen population. In Epizootiology of insect diseases, J.R., Fuxa and Y., Tanada (eds), pp. 113–157. John Wiley and Sons, New York.

    Google Scholar 

  15. Tyrrell, D. 1988. Survival of Entomophaga aulicae in dried insect larvae. J. Invertebr. Pathol. 52: 187–188.

    Google Scholar 

  16. Watanabe, H. 1987. The host population. In Epizootiology of insect diseases, J.R., Fuxa and Y., Tanada (eds), pp. 71–112. John Wiley and Sons, New York.

    Google Scholar 

  17. Wilding, N. 1973. The survival of Entomophthora spp. in mummified aphids at different temperatures and humidities. J. Invertebr. Pathol. 21: 309–311.

    Google Scholar 

  18. Wilding, N. and Lauckner, F.B. 1974. Entomophthora infecting wheat bulb fly at Rothamstead, Hertfordshire, 1967–71. Ann. Appl. Biol. 76: 161–170.

    Google Scholar 

  19. Zar, J.H. 1984. Biostatistical Analysis. Prentice-Hall, Englewood Cliffs NJ.

    Google Scholar 

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Oduor, G.I., Yaninek, J.S., van der Geest, L.P.S. et al. Survival of Neozygites cf. floridana (Zygomycetes: Entomophthorales) in mummified cassava green mites and the viability of its primary conidia. Exp Appl Acarol 19, 479–488 (1995). https://doi.org/10.1007/BF00052916

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Key words

  • Neozygites cf. floridana
  • Mononychellus tanajoa
  • mummy
  • survival
  • primary conidia
  • germination
  • viability
  • temperature
  • humidity
  • saturation deficit
  • light condition