Hostname: page-component-76fb5796d-r6qrq Total loading time: 0 Render date: 2024-04-26T20:18:04.352Z Has data issue: false hasContentIssue false
  • English
  • Français

HOST ASSOCIATIONS, PHENOTYPIC VARIATION, AND MATING COMPATIBILITY OF CHORISTONEURA OCCIDENTALS AND C. RETINIANA (LEPIDOPTERA: TORTRICIDAE) POPULATIONS IN SOUTH-CENTRAL OREGON

Published online by Cambridge University Press:  31 May 2012

W. Jan A. Volney ,
Andrew M. Liebhold  and
William E. Waters
W. Jan A. Volney
Affiliation:
Division of Entomology and Parasitology, University of California, Berkeley 94720
Andrew M. Liebhold
Affiliation:
Division of Entomology and Parasitology, University of California, Berkeley 94720
William E. Waters
Affiliation:
Division of Entomology and Parasitology, University of California, Berkeley 94720
Get access Rights & Permissions [Opens in a new window]

Abstract

Brown larval morphs, diagnostic of Choristoneura occidentalis Freeman, and green larval morphs, diagnostic of C. retiniana (Walsingham), were found on both Douglas-fir and white fir in mixed stands in south-central Oregon. The rank proportion of brown morphs in stands was strongly correlated with the rank proportion of Douglas-fir in host species basal area component. Despite considerable overlap in most phenotypic characters, differences in phenotypic frequencies between sympatric green and brown morphs were found in larval head capsule pigmentation, thoracic shield pigmentation, pupal coloration, and adult forewing ground color. In laboratory matings, neither larval host nor larval color morph influenced the mating success, as assessed by the production of viable eggs. Crosses between females reared from brown larval morphs and males from green morphs produced a slightly lower proportion of viable eggs when compared with intramorph matings. Larval host had little effect on either the fecundity of females or the viability of their progeny. Females reared from brown larval morphs produced significantly more eggs than their green counterparts from the same stand. The occurrence of intermediates in all mixed stands and the production of families with anomalous morph frequencies indicate that these two species hybridize in nature. The lack of much structural differentiation and varying efficacy of reproductive barriers indicate that relatively little differentiation of the regulatory genome has occurred between these two species.

Résumé

Des larves brunes caractéristiques de Choristoneura occidentalis Freeman et des larves vertes caractéristiques de C. retiniana (Walsingham) ont été trouvées à la fois sur le sapin Douglas et le sapin du Colorado dans des boisés mixtes du centre méridional de l'Oregon. La proportion de larves brunes dans les boisés s'est avérée fortement corrélée à la proportion de Douglas exprimée en termes de surface terrière. Malgré un chevauchement considérable pour la plupart des caractères phénotypiques, des différences sont apparues entre des populations sympatriques des morphes brune et verte pour la pigmentation de la capsule céphalique, la pigmentation de l'écusson thoracique, la coloration pupale et la couleur de fond de l'aile antérieure. Lors d'accouplements en laboratoire, le succès d'accouplement n'a été affecté ni par l'hôte larvaire, ni par la couleur larvaire, tel qu'établi à partir de la production d'oeufs viables. Des croisements entre des femelles obtenues de larves brunes et des mâles provenant de larves vertes ont donné une proportion légèrement inférieure d'oeufs viables, comparés à des croisements intra-morphe. L'hôte larvaire n'a eu que peu d'effets sur la fécondité des femelles ou la viabilité de leur progéniture. Des femelles issues de larves brunes ont produit significativement plus d'oeufs que celles issues de larves vertes provenant du même boisé. La présence d'intermédiaires dans tous les boisés mélangés et la production de familles montrant des fréquences anormales des morphes indiquent que les deux espèces se croisent en nature. L'absence de différenciation structurale substantielle et l'efficacité variable des barrières reproductives montrent qu'il y a eu relativement peu de différenciation du génome régulateur entre ces deux espèces.

Type
Articles
Information
The Canadian Entomologist , Volume 116 , Issue 6 , June 1984 , pp. 813 - 826
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

Beckwith, R. C. and Burnell, D. G.. 1982. Spring larval dispersal of the western spruce budworm (Lepidoptera: Tortricidae) in north-central Washington. Environ. Ent. 11: 828–832.CrossRefGoogle Scholar
Carolin, V. M. Jr., and Coulter, W. K.. 1975. Comparison of western spruce budworm populations and damage on grand fir and Douglas-fir trees. U.S.D.A. For. Serv. PNW For. & Range Exp. Stn. Res. Pap. PNW-195. 16 pp.Google Scholar
Dolph, R. E. 1980. Budworm activity in Oregon and Washington 1947–1979. U.S.D.A. For. Serv., Pacific Northwest Region R6-FIDM-033. 54 pp.Google Scholar
Freeman, T. N. 1967. On coniferophagous species of Choristoneura (Lepidoptera: Tortricidae) in North America I. Some new forms of Choristoneura allied to C. fumiferana. Can. Ent. 99: 449–455.CrossRefGoogle Scholar
Grizzle, J. E., Starmer, C. F., and Koch, G. G.. 1969. Analysis of categorical data by linear models. Biometrics 25: 489–504.CrossRefGoogle ScholarPubMed
Harvey, G. T. and Roden, P. M.. 1979. Special collection of coniferophagous Choristoneura species and hybrids at the Great Lakes Forest Research Centre, Sault Ste. Marie, Canada. Environment Canada, Forestry Service Great Lakes Forest Research Centre Info. Rep. O-X-293. 27 pp. + Appendix.Google Scholar
Harvey, G. T. and Stehr, G.. 1967. On coniferohagous species of Choristoneura (Lepidoptera: Tortricidae) in North America. III. Some characters of immature forms helpful in the identification of species. Can. Ent. 99: 464–481.CrossRefGoogle Scholar
Liebhold, A. M. and Volney, W. J. A.. Effect of foliage proximity on attraction of Choristoneura occidentalis and C. retiniana (Lepidoptera:Tortricidae) to pheromone sources. J. Chem. Ecol. (in press).Google Scholar
Liebhold, A. M., Volney, W. J. A., and Waters, W. E.. 1984. Evaluation of cross-attraction between sympatric Choristoneura occidentalis and C. retiniana (Lepidoptera: Tortricidae) populations in south-central Oregon. Can. Ent. 116: 827–840.CrossRefGoogle Scholar
Little, E. L. Jr.,, 1971. Atlas of United States Trees. Vol. I. Conifers and important hardwoods. U.S. Dep. Agric. For. Serv. Misc. Publ. 1146. 9 pp. + Maps.Google Scholar
Oliver, C. G. 1979. Genetic differentiation and hybrid viability within and between some Lepidoptera species. Am. Nat. 114: 681–694.CrossRefGoogle Scholar
Powell, J. A. 1980. Nomenclature of Nearctic conifer-feeding Choristoneura (Lepidoptera: Tortricidae): historical review and present status. U.S.D.A. For. Serv. PNW For. & Range Exp. Stn. Gen. Tech. Rep. PNW-100. 18 pp.Google Scholar
Robertson, J. L. 1979. Rearing the western spruce budworm. U.S.D.A. Misc. Publ., Canada/United States spruce Budworms Program. 18 pp.Google Scholar
Sanders, C. J. 1971. Sex pheromone specificity and taxonomy of budworm moths (Choristoneura). Science 171: 911–913.CrossRefGoogle ScholarPubMed
Sanders, C. J., Daterman, G. E., and Ennis, T. J.. 1977. Sex pheromone responses of Choristoneura spp. and their hybrids (Lepidoptera: Tortricidae). Can. Ent. 109: 1203–1220.CrossRefGoogle Scholar
Smith, S. G. 1953. Reproductive isolation and the integrity of two sympatric species of Choristoneura (Lepidoptera: Tortricidae). Can. Ent. 85: 141–151.CrossRefGoogle Scholar
Smith, S. G. 1954. A partial breakdown of temporal and ecological isolation between Choristoneura species (Lepidoptera:Tortricidae). Evolution 8: 206–224.CrossRefGoogle Scholar
Steel, R. D. G. and Torrie, J. H.. 1960. Principles and procedures of statistics. McGraw-Hill, N.Y.481 pp.Google Scholar
Stehr, G. W. 1967. On coniferophagous species of Choristoneura (Lepidoptera: Tortricidae) in North America II. Geographic distribution in accordance with forest regions. Can. Ent. 99: 456–563.CrossRefGoogle Scholar
Stock, M. W. and Castrovillo, P. J.. 1981. Genetic relationships among representative populations of five Choristoneura species: C. occidentalis, C. retiniana, C. biennis, C. lambertiana, and C. fumiferana (Lepidoptera: Tortricidae). Can. Ent. 113: 857–865.CrossRefGoogle Scholar
Volney, W. J. A., Waters, W. E., Akers, R. P., and Liebhold, A. M.. 1983 a. Variation in spring emergence patterns among western Choristoneura spp. (Lepidoptera: Tortricidae) populations in southern Oregon. Can. Ent. 115: 199–209.CrossRefGoogle Scholar
Volney, W. J. A., Liebhold, A. M., and Waters, W. E.. 1983 b. Effects of temperature, sex, and genetic background on coloration of Choristoneura (Lepidoptera: Tortricidae) populations in south-central Oregon. Can. Ent. 115: 1583–1596.CrossRefGoogle Scholar
Waters, W. E. and Volney, W. J. A.. Sampling and analysis of endemic western spruce budworm populations. In Site Characteristics and Population Dynamics of Lepidopteran and Hymenopteran Forest Pests. Brit. For. Comm. (In press).Google Scholar