Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-24T04:25:45.008Z Has data issue: false hasContentIssue false
  • English
  • Français

TRANSMISSION OF THE PITCH CANKER FUNGUS, FUSARIUM SUBGLUTINANS F. SP. PINI, TO MONTEREY PINE, PINUS RADIATA, BY CONE- AND TWIG-INFESTING BEETLES

Published online by Cambridge University Press:  31 May 2012

Kelli Hoover ,
David L. Wood ,
Andrew J. Storer ,
Joseph W. Fox  and
William E. Bros
Kelli Hoover
Affiliation:
Department of Entomology, University of California, Davis, California, USA 95616
David L. Wood*
Affiliation:
Division of Insect Biology, University of California, Berkeley, California, USA 94720
Andrew J. Storer
Affiliation:
Division of Insect Biology, University of California, Berkeley, California, USA 94720
Joseph W. Fox
Affiliation:
Division of Insect Biology, University of California, Berkeley, California, USA 94720
William E. Bros
Affiliation:
Department of Biological Sciences, San Jose State University, San Jose, California, USA 95192
*
1 Address for reprint requests.
Get access Rights & Permissions [Opens in a new window]

Abstract

Conophthorus radiatae Hopkins, Ernobius punctulatus Fall, and Pityophthorus spp. infest cones and twigs of Monterey pines (Pinus radiata D. Don) and thus may be important vectors of the pitch canker fungus Fusarium subglutinans f. sp. pini in the central coast of California. Fifteen percent of 1st-year Monterey pine conelets infested with C. radiatae prior to August 1990 developed pitch canker by May 1991. Conophthorus radiatae, E. punctulatus, and Pityophthorus spp. were dissected from some of these conelets and found carrying F. s. pini. Between June 1990 and May 1991, 16% of 695 randomly selected uninfested 1st-year conelets from a total of 329 separate cone whorls were infested by at least one of the above beetle species, and F. s. pini was isolated from 42% of the attacked conelets. Average percentage contamination of beetles per conelet was highest for adults of Pityophthorus spp. (38%), followed by adults of C. radiatae (33%), larvae of E. punctulatus (24%), and larvae of Pityophthorus spp. (5%). There were significant associations between conelets that contained contaminated C. radiatae, Pityophthorus spp., and/or E. punctulatus and conelets with F. s. pini.

Under experimental conditions, C. radiatae and E. punctulatus transmitted the fungus to healthy cones. Ernobius punctulatus required an entrance tunnel by C. radiatae to enter and infect the cone. Artificially wounded cones did not develop pitch canker. Intra- and interspecific transmission of F. s. pini was demonstrated among these beetle species. In infested branch tips without cones, interspecific transmission of F. s. pini between E. punctulatus and Pityophthorus spp. was also demonstrated.

The roles of C. radiatae and E. punctulatus as vectors of F. s. pini and of Pityophthorus spp. as potential vectors are discussed in relation to the epidemiology of pitch canker disease. The spread of pitch canker to California’s native pines as well as other conifers may be enhanced by interspecific transmission of F. s. pini between E. punctulatus and C. radiatae in cones and between E. punctulatus and Pityophthorus spp. in branch tips. Ernobius punctulatus provides a pathway for the fungus to potential insect vectors that attack several hosts and a variety of plant parts.

Résumé

Conophthorus radiatae Hopkins, Ernobius punctulatus Fall, et Pityophthorus spp. infestent les cônes et les rameaux du pin de Monterey (Pinus radiata D. Don) au centre de la côte californienne et peuvent donc être d’importants vecteurs de la nécrose causée par Fusarium subglutinans f. sp. pini. Quinze pour-cent des cônes de première année infestés par C. radiatae avant août 1990 étaient porteurs de la maladie en mai 1991. Des coléoptères, C. radiatae, E. punctulatus, et Pityophthorus spp., prélevés dans certains de ces jeunes cônes étaient porteurs du champignon. Entre juin 1990 et mai 1991, 16% de 695 jeunes cônes sains de première année choisis au hasard parmi 329 groupes de cônes ont été infestés par au moins une des espèces de coléoptères et la maladie a été décelée chez 42% des jeunes cônes attaqués. Ce sont les adults de Pityophthorus spp. qui causent le pourcentage moyen de contamination par jeune cône le plus élevé (38%), suivis des adults de C. radiatae (33%), puis des larves d’E. punctulatus (24%), et des larves de Pityophthorus spp. (5%). Des relations significatives ont été constatées entre la fréquence des jeunes cônes infestés par des C. radiatae, Pityophthorus spp., et (ou) E. punctulatus et la fréquence des jeunes cônes porteurs de la maladie.

Dans des conditions expérimentales, C. radiatae et E. punctulatus ont réussi à propager le champignon à des cônes sains. Ernobius punctulatus nécessite l’existence d’un tunnel creusé par C. radiatae pour pénétrer à l’intérieur du cône et l’infecter. Des cônes ont été meurtris artificiellement et ils n’ont pas été affectés par la maladie. Les coléoptères se transmettent le vecteur de maladie entre individus d’une même espèce et d’une espèce à l’autre. La propagation interspécifique de F. s. pini entre E. punctulatus et Pityophthorus spp. a été observée aux extrémités de rameaux sans cônes infectés.

Le rôle de C. radiatae et E. punctulatus comme vecteurs de F. s. pini et des espèces de Pityophthorus comme vecteurs potentiels de la maladie est examiné en fonction de ce que l’on connaît de l’épidémiologie de la nécrose. La propagation de la maladie aux pins californiens indigènes de même qu’à d’autres conifères peut être facilitée par la transmission interspécifique du vecteur entre E. punctulatus et Pityophthorus spp. aux extrémités des rameaux. Ernobius punctulatus constitue une voie de transmission du champignon à des insectes vecteurs potentiels qui s’attaquent à une variété d’hôtes et à diverses parties de plantes.

[Traduit par la Rédaction]

Type
Articles
Information
The Canadian Entomologist , Volume 128 , Issue 6 , December 1996 , pp. 981 - 994
Copyright
Copyright © Entomological Society of Canada 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adams, D. 1989. Incidence of Pine Pitch Canker in California. California Department of Forestry and Fire Protection. 25 pp.Google Scholar
Bright, D.E. Jr., and Stark, R.W.. 1973. The Bark and Ambrosia Beetles of California. Bulletin California Insect Survey 16: 169 pp.Google Scholar
Correll, J.C., Gordon, T.R., McCain, A.H., Fox, J.W., Koehler, C.S., Wood, D.L., and Schultz, M.E.. 1991. Pitch canker in California: Pathogenicity, distribution, and canker development on Monterey pine (Pinus radiata). Plant Disease 75: 676–682.CrossRefGoogle Scholar
Dallara, P.L. 1993. Interrelationships among twig beetles (Scolytidae: Pityophthorus spp.), pitch canker disease, and conifers in central coastal California. Appendix pp. xliv–xlv in Adams, D.H., Rios, J.E., and Storer, A.J. (Eds.), Proceedings of the 42nd Annual Meeting of the California Forest Pest Council. Rancho Cordova, CA, Nov. 17–18, 1993. 101 pp.Google Scholar
Dallara, P.L., Seybold, S.J., Francke, W., Wood, D.L.. 1994. The chemical ecology of Pityophthorus spp. (Coleoptera: Scolytidae), in central coastal California. Appendix pp. lxvii–lxix in Adams, D.H., Rios, J.E., and Storer, A.J. (Eds.), Proceedings of the 43rd Annual Meeting of the California Forest Pest Council. Rancho Cordova, CA, Nov. 16–17, 1994. 112 pp.Google Scholar
Dallara, P.L., Storer, A.J., Wood, D.L., and Gordon, T.R.. 1995. Current Status of Pitch Canker Disease in California. California Department of Forestry and Fire Protection. Tree Note 20: 4 pp.Google Scholar
Fox, J.W., Wood, D.L., and Koehler, C.S., 1990. Distribution and abundance of engraver beetles (Scolytidae: Ips species) on Monterey pines infected with pitch canker. The Canadian Entomologist 122: 1157–1166.CrossRefGoogle Scholar
Fox, J.W., Wood, D.L., Koehler, C.S., and O'Keefe, S.T.. 1991. Engraver beetles (Scolytidae: Ips species) are capable of vectoring the pitch canker fungus, Fusarium subglutinans f. sp. pini. The Canadian Entomologist 123: 1355–1367.CrossRefGoogle Scholar
Fransen, J.J., and Buisman, C.. 1935. Infectieproven op verschillende ipensooten met behulp iepen spintkevers. Tijdschrift over plantenziekten 41: 221–239.Google Scholar
Furniss, R.L., and Carolin, V.M.. 1977. Western Forest Insects. USDA Forest Service Miscellaneous Publication 1339: 654 pp.Google Scholar
Hedlin, A.F., Yates, H.O. III, Tovar, D.C., Ebel, B.H., Koerber, T.W., and Merkel, E.P.. 1981. Cone and Seed Insects of North American Conifers. Canadian Forestry Service, United States Forest Service. 122 pp.Google Scholar
Hoover, K. 1992. Interrelationships between Conophthorus radiatae (Coleoptera: Scolytidae) and Ernobius punctulatus (Coleoptera: Anobiidae), Vectors of Pitch Canker Fungus in California. MS thesis, San Jose State University, San Jose, CA. 57 pp.Google Scholar
Hoover, K., Wood, D.L., Fox, J.W., and Bros, W.E.. 1995. Quantitative and seasonal association of the pitch canker fungus, Fusarium subglutinans f. sp. pini with Conophthorus radiatae (Coleoptera: Scolytidae) and Ernobius punctulatus (Coleoptera: Anobiidae) which infest Pinus radiata. The Canadian Entomologist 127: 79–91.CrossRefGoogle Scholar
Leach, J.G. 1940. Insect Transmission of Plant Diseases. McGraw-Hill Book Co., Inc., New York, NY. 423 pp.Google Scholar
McCain, A.H., Koehler, C.S., and Tjosvold, S.A.. 1987. Pitch canker threatens California pines. California Agriculture 41(11): 22–23.Google Scholar
Ohmart, C.P. 1981. An Annotated List of Insects Associated with Pinus radiata D. Don in California. Division of Forest Research, Commonwealth Scientific and Industrial Research Organization. Division Report 8: 50 pp.Google Scholar
Ruckes, H. Jr., 1958. Some observations on the Monterey pine cone beetle, Conophthorus radiatae Hopkins (Coleoptera: Scolytidae). Annals of the Entomological Society of America 51(2): 214–215.CrossRefGoogle Scholar
Schaefer, C.H. 1962. Life history of Conophthorus radiatae (Coleoptera: Scolytidae) and its principal parasite, Cephalonomia utahensis (Hymenoptera: Bethylidae). Annals of the Entomological Society of America 55(5): 569–577.CrossRefGoogle Scholar
Sokal, R.R., and Rohlf, F.J.. 1981. Biometry, 2nd ed. W.H. Freeman and Co., New York, NY. 859 pp.Google Scholar
Storer, A.J., and Dallara, P.L.. 1992. Pitch Canker Disease in California. California Department of Forestry and Fire Protection. Tree Note 15: 2 pp.Google Scholar
Storer, A.J., Dallara, P.L., Wood, D.L., and Gordon, T.R.. 1994. Pitch canker in California: Geographic and host range expansion. California Agriculture 48: 9–13.CrossRefGoogle Scholar
Storer, A.J., Gordon, T.R., Wood, D.L., and Dallara, P.L.. 1995. Entomological and pathological aspects of pitch canker disease in California. pp. 573–586in Hain, F.P., Salom, S.M., Ravlin, W.F., Payne, T.L., and Raffa, K.F. (Eds.), Proceedings of a Joint IUFRO Working Party Conference, Maui, Hawaii, February 6–11, 1994.Google Scholar
Webber, J.F. 1987. The influence of the d2 factor on survival and infection by the Dutch elm pathogen Ophiostoma ulmi. Plant Pathology 36: 531–538.CrossRefGoogle Scholar
Webber, J.F., and Brasier, C.M.. 1984. The transmission of Dutch elm disease: A study of the processes involved. pp. 271–306in Anderson, J.M., Rayner, A.D.M., and Walton, D. (Eds.), Invertebrate–Microbial Interactions. Cambridge University Press, Cambridge, UK.Google Scholar
Webber, J.F., and Gibbs, J.N.. 1989. Insect dissemination of fungal pathogens to trees. pp. 161–193in Wilding, N., Collins, N.M., Hammond, P.M., and Webber, J.F. (Eds.), Insect–Fungus Interactions. Academic Press, Oxford, UK.CrossRefGoogle Scholar
Winer, B.J., Brown, D.R., and Michels, K.M.. 1991. Statistical Principles in Experimental Design, 3rd ed. McGraw-Hill, New York, NY. 1057 pp.Google Scholar
Wood, D.L., Gordon, T.R., Fox, J.W., Koehler, C.S., McCain, A.H., and Schultz, M.E.. 1990. Epidemiology and control of pitch canker in California 1989–1990. University of California, Berkeley Report: 26 pp.Google Scholar
Wood, S.L. 1982. Great Basin Naturalist Memoirs: The Bark and Ambrosia Beetles of North and Central America (Coleoptera: Scolytidae): A Taxonomic Monograph. Brigham Young University, Provo, UT. 1359 pp.Google Scholar
Zar, J.H. 1984. Biostatistical Analysis. Prentice-Hall, Inc., Englewood Cliffs, NJ. 718 pp.Google Scholar