Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-25T06:27:17.907Z Has data issue: false hasContentIssue false

ABUNDANCE OF THE FIR ENGRAVER, SCOLYTUS VENTRALIS, AND THE DOUGLAS-FIR BEETLE, DENDROCTONUS PSEUDOTSUGAE, FOLLOWING TREE DEFOLIATION BY THE DOUGLAS-FIR TUSSOCK MOTH, ORGYIA PSEUDOTSUGATA1

Published online by Cambridge University Press:  31 May 2012

L. C. Wright
Affiliation:
Department of Entomology, Washington State University, Pullman 99164
A. A. Berryman
Affiliation:
Department of Entomology, Washington State University, Pullman 99164
B. E. Wickman
Affiliation:
Department of Entomology, Washington State University, Pullman 99164

Abstract

Fir engraver and Douglas-fir beetle numbers were monitored during and after an outbreak of the Douglas-fir tussock moth. The population behavior of the two species of bark beetles was similar. Number of emerged offspring/female was highest during the years of defoliation and declined afterward. Total number of beetle attacks peaked 1 to 2 years after defoliation ended and then declined. During and 1 year after defoliation, beetles generally infested trees that had greater than 90% defoliation. After this time infestations were not as strongly associated with heavily defoliated trees. Life tables were constructed for beetles within trees and for beetles per area of forest land. Key mortality factors acting on beetles within trees occurred during the larval and pupal stages. Mortality during adult dispersal was a key factor when beetle density per area of land was considered. Although beetle offspring emerging per dm2 of bark surface was relatively low in defoliated trees, defoliation appeared to reduce host resistance which enabled beetles to successfully attack at lower densities, reducing intraspecific competition, and resulting in increased emergence of offspring/female parent.

Résumé

Le scolyte Scolytus ventralis et le dendroctone du Douglas, Dendroctonus pseudotsugae ont été suivis pendant et après une infestation de la chenille à houppes du Douglas. L'évolution des populations des deux coléoptères s'est avérée similaire. Le nombre de progénitures/femelle était maximal pendant les années de défoliaison et a baissé par la suite. Le nombre total d'attaques a atteint son sommet un à deux ans après l'arrêt de la défoliaison et a chuté ensuite. Pendant la défoliaison et jusqu'à un an après, les coléoptères ont généralement infesté des arbres défoliés à plus de 90%. Par après, les infestations n'étaient pas aussi clairement associées aux arbres sévèrement défoliés. Des tables de survie ont été préparées sur la base des nombres de coléoptères par arbre et par unité de surface du couvert forestier. Les facteurs-clés expliquant la mortalité intra-arbre ont agi pendant les stades larvaires et pupal. La mortalité durant la dispersion par le vol est apparue comme un facteur-clé lorsque la densité des coléoptères par unité de surface était considérée. Bien que le nombre de progénitures émergées par dm2 de surface de l'écorce était relativement basse pour les arbres défoliés, la défoliaison a semblé réduire la résistance de l'hôte ce qui a favorisé l'attaque à basse densité, réduisant ainsi la compétition intraspécifique et causant une augmentation du nombre de progénitures émergeant par femelle.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1984

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

Ashraf, M. and Berryman, A. A.. 1969. Biology of Scolytus ventralis (Coleoptera: Scolytidae) attacking Abies grandis in Northern Idaho. Melanderia 2. 23 pp.Google Scholar
Belyea, R. M. 1952. Death and deterioration of balsam fir weakened by spruce budworm defoliation in Ontario. II. An assessment of the role of associated insect species in the death of severely weakened trees. J. For. 50: 729739.Google Scholar
Berryman, A. A. 1968. Distributions of Scolytus ventralis attacks, emergence, and parasites in grand fir. Can. Ent. 100: 5768.CrossRefGoogle Scholar
Berryman, A. A. 1973. Population dynamics of the fir engraver, Scolytus ventralis (Coleoptera: Scolytidae). I. Analysis of population behavior and survival from 1964 to 1971. Can. Ent. 105: 14651488.CrossRefGoogle Scholar
Berryman, A. A. 1974. Dynamics of bark beetle populations: Towards a general productivity model. Environ. Ent. 3: 579585.Google Scholar
Berryman, A. A. and Ashraf, M.. 1970. Effects of Abies grandis resin on the attack behavior and brood survival of Scolytus ventralis (Coleoptera: Scolytidae). Can. Ent. 102: 12291236.Google Scholar
Berryman, A. A. and Pienaar, L. V.. 1973. Simulation of intraspecific competition and survival of Scolytus ventralis broods (Coleoptera: Scolytidae). Environ. Ent. 2: 447459.Google Scholar
Berryman, A. A. and Wright, L. C.. 1978. Defoliation, tree condition, and bark beetles. In Brookes, M. H., Stark, R. W., and Campbell, R. W. (Eds.), The Douglas-fir Tussock Moth: A Synthesis. U.S. Dep. Agric. Forest Serv., Tech. Bull. 1585. 331 pp.Google Scholar
Craighead, F. C. 1940. Some effects of artificial defoliation on pine and larch. J. For. 38: 885888.Google Scholar
Evenden, J. C. 1940. Effects of defoliation by the pine butterfly upon ponderosa pine. J. For. 38: 949955.Google Scholar
Ferrell, G. T. 1973. Weather, logging, and tree growth associated with fir engraver attack scars in white fir. U.S. Dep. Agric. Forest Serv. Res. Pap. PSW-92. 11 pp.Google Scholar
Furniss, M. M. 1962. Infestation patterns of Douglas-fir beetle in standing and windthrown trees in southern Idaho. J. econ. Ent. 55: 486491.Google Scholar
Furniss, M. M., McGregor, M. D., Foiles, M. W., and Partridge, A. D.. 1979. Chronology and characteristics of a Douglas-fir beetle outbreak in northern Idaho. U.S. Dep. Agric. Forest Serv., Gen. Tech. Rep. INT-59. 19 pp.Google Scholar
Hertert, H. D., Miller, D. L., and Partridge, A. D., 1975. Interaction of bark beetles (Coleoptera: Scolytidae) and root-rot pathogens in grand fir in northern Idaho. Can. Ent. 107: 899904.CrossRefGoogle Scholar
Johnson, N. E. 1967. The influence of temperature and moisture on the overwintering mortality of the Douglas-fir beetle, Dendroctonus pseudotsugae, in western Washington (Coleoptera: Scolytidae). Ann. ent. Soc. Am. 60: 199204.Google Scholar
Lejeune, R. R., McMullen, L. H., and Atkins, M. D.. 1961. The influence of logging on Douglas-fir beetle populations. For. Chron. 37: 308314.Google Scholar
Marsden, M. A., Furniss, M. M., and Kline, L. N.. 1981. Modeling seasonal abundance of Douglas-fir beetle in relation to entomophagous insects and location in trees. U.S. Dep. Agric. Forest Serv., Gen. Tech. Rep. INT-111. 22 pp.Google Scholar
McMullen, L. H. and Atkins, M. D.. 1961. Intraspecific competition as a factor in the natural control of the Douglas-fir beetle. For. Sci. 7: 197203.Google Scholar
Podoler, H. and Rogers, D.. 1975. A new method for the identification of key factors from life-table data. J. Anim. Ecol. 44: 85114.Google Scholar
Rudinsky, J. A. 1966. Host selection and invasion by the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, in coastal Douglas-fir forests. Can. Ent. 98: 98111.CrossRefGoogle Scholar
Schmitz, R. F. and Rudinsky, J. A.. 1968. Effect of competition on survival in western Oregon of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Scolytidae). School For. Oreg. St. Univ. Res. Pap. 8. 42 pp.Google Scholar
Scott, B. A. and Berryman, A. A.. 1971. Laboratory rearing techniques for Scolytus ventralis (Coleoptera: Scolytidae). Wash. agric. Exp. Stn Bull. 741. 9 pp.Google Scholar
Southwood, T. R. E. 1966. Ecological Methods with Particular Reference to the Study of Insect Populations. Methuen, London. 391 pp.Google Scholar
Vité, J. P. and Rudinsky, J. A.. 1957. Contribution toward a study of Douglas-fir beetle development. For. Sci. 3: 156167.Google Scholar
Webb, W. L. and Karchesy, J. J.. 1977. Starch content of Douglas-fir defoliated by the tussock moth. Can. J. For. Res. 7: 186188.CrossRefGoogle Scholar
Wickman, B. E. 1958. Mortality of white fir following defoliation by the Douglas-fir tussock moth in California, 1957. U.S. Dep. Agric. Forest Serv. Res. Note 137. 4 pp.Google Scholar
Wickman, B. E. 1963. Mortality and growth reduction of white fir following defoliation by the Douglas-fir tussock moth. U.S. Dep. Agric. Forest Serv., Res. Pap. PSW-7. 15 pp.Google Scholar
Wickman, B. E. 1978. Tree mortality and top-kill related to defoliation by the Douglas-fir tussock moth in the Blue Mountains outbreak. U.S. Dep. Agric. Forest Serv. Res. Pap. PNW-233. 47 pp.Google Scholar
Wright, L. C. and Berryman, A. A.. 1978. Effect of defoliation by the Douglas-fir tussock moth on moisture stress in grand fir and subsequent attack by the fir engraver beetle (Coleoptera: Scolytidae). U.S. Dep. Agric. Forest Serv. Res. Note PNW-323. 14 pp.Google Scholar
Wright, L. C., Berryman, A. A., and Gurusiddaiah, S.. 1979. Host resistance to the fir engraver beetle, Scolytus ventralis (Coleoptera: Scolytidae). 4. Effect of defoliation on wound monoterpene and inner bark carbohydrate concentrations. Can. Ent. 111: 12551262.Google Scholar