Adams, H

Adams, H. S., and S. L. Stephenson. 1983. A description of the vegetation on the south slopes of Peters Mountain, southwestern Virginia. Bulletin of the Torrey Botanical Club 110:18-22.

Adams, H., S. Stephenson, T. Blasing, and D. Duvick. 1985. Growth-trend declines of spruce and fir in mid-appalachian subalphine forests. Envir. and Exp. Bot 25:315-325.

Notes: MLBS?

Adams, H., and S. Stephenson. 1989. Old-Growth Red Spruce Communities in the Mid-Appalachians. Vegetatio 85:45-56.

Notes: Article

Dec 15

Adams, H. S., and S. L. Stephenson. 1991. High-elevation coniferous forests in Virginia. Virginia Journal of Science 42:391-399.

Adams, H. S., S. L. Stephenson, S. Ware, and M. Schnittler. in press. Forests of the central and southern Appalachians and eastern Virginia having beech as a major component. Castanea .

Adler, K. 1965. Three new frogs of the genus Hyla from the Sierra Madre del Sur of Mexico. Occasional Papers of the Museum of Zoology, Univeristy of Michigan 642:1-18.

Adler, K. 1968. Extra-optic light entrainment of circadian rhythm in salamanders, (Plethodon glutinosis). Abstr. J. Herp. .

Adler, K. 1968. Pseudemys scripta in West Virginia: Archeological and modern records. Journal of Herpetology 2:117-120.

Adler, K. 1969. Extraoptic phase shifting of circadian locomotor rhythm in salamanders. Science 164:1290-1292.

Adler, K. 1970. How do trained frogs find a goal box? (Abstract). Journal of Herpetology 2:198.

Adler, K. 1970. The role of extraoptic photoreceptors in amophibian rhythms and orientation: a review. Journal of Herpetology 4:99-112.

Adler, K. 1980. Individuality in the use of orientation cues by green frogs. Animal Behavior 28:413-425.

Agrawal, A., and S. L. Stephenson. 1995. Recent successional changes in a former chestnut-dominated forest in southwestern Virginia. Castanea 60:107-113.

Akhter, S., and J. Antonovics. 1999. Use of ITS primers and fungicide treatments to study the anther-smut disease (Ustilago violacea = Microbotryum violaceum) of white campion (Silene alba = S. latifolia). International Journal of Plant Science 160:1171-1176.

Alexander, H. 1987. Inhibition of Pineus floccus colonization by volatile compounds found in leaf tissue of red spruce. Va. J. Sci 38:27-34.

Alexander, H. M. 1987. Pollination Limitation in a Population of Silene-Alba Infected By the Anther-Smut Fungus, Ustilago-Violacea. Journal of Ecology 75:771-780.

Notes: Sep

Alexander, H. M. 1987. The Implications of Intraspecific Variation For Ecological and Evolutionary Interactions Between Silene-Alba and Its Fungal Pathogen Ustilago-Violacea. American Journal of Botany 74:632-632.

Notes: May

Alexander, H. M., and J. Antonovics. 1988. Disease Spread and Population-Dynamics of Anther-Smut Infection of Silene-Alba Caused By the Fungus Ustilago- Violacea. Journal of Ecology 76:91-104.

Notes: Mar

Alexander, H. M. 1989. An Experimental Field-Study of Anther-Smut Disease of Silene- Alba Caused By Ustilago-Violacea - Genotypic Variation and Disease Incidence. Evolution 43:835-847.

Notes: Jul

Alexander, H. M., and A. Maltby. 1990. Anther-Smut Infection of Silene-Alba Caused By Ustilago- Violacea - Factors Determining Fungal Reproduction. Oecologia 84:249-253.

Alexander, H. M. 1990. Epidemiology of Anther-Smut Infection of Silene-Alba Caused By Ustilago-Violacea - Patterns of Spore Deposition and Disease Incidence. Journal of Ecology 78:166-179.

Notes: Mar

Alexander, H. M., J. Antonovics, and A. W. Kelly. 1993. Genotypic Variation in Plant-Disease Resistance - Physiological Resistance in Relation to Field Disease Transmission. Journal of Ecology 81:325-333.

Keywords: anther-smut; inoculation; pathogen; silene-alba; ustilago- violacea

anther-smut infection; ustilago-violacea; silene-alba; hyphal growth; pollination; population; fungus; avena

Abstract: 1. Cloned genotypes of Silene alba differed in the percentage of plants that became diseased following floral and bud inoculation with six isolates of the fungus Ustilago violacea. 2. The three flower and bud inoculation methods used in the study had little effect on the resistance ranking of the genotypes. 3. No differences in virulence were found among the six fungal isolates. 4. Multiple regression analyses revealed that the percentage of diseased plants following inoculation was an important predictor of disease levels of the same genotypes in a field experiment with natural disease transmission. This result validates the use of inoculation methods for large-scale resistance testing in this system. 5. Floral phenology, a plant trait that affects the likelihood of spore deposition in the field, also accounted for a significant portion of the genotypic variation in field disease levels. 6. Thus, both physiological resistance and factors affecting transmission should be considered when interpreting patterns of disease incidence in nature.

Notes: Jun

Alexander, H. M., and J. Antonovics. 1995. Spread of Anther-Smut Disease (Ustilago-Violacea) and Character Correlations in a Genetically Variable Experimental Population of Silene Alba. Journal of Ecology 83:783-794.

Keywords: cost of resistance; demography; epidemiology; host; pathogen; microbotryum violaceum

quantitative genetics; genotypic variation; spore deposition; infection; epidemiology; transmission; patterns; fungus

Abstract: 1 The anther-smut fungus Ustilago violacea produces spores in diseased flowers of the dioecious plant Silene alba; spores are transferred to healthy plants by insect pollinators. 2 To study the ecological and genetic determinants of disease spread and its demographic consequences, an experimental population of S. alba was created that contained both anther- smut inoculated plants (as an inoculum source) and uninoculated plants which were the progeny of crosses between genotypes with high or low disease resistance. 3 Genetic analyses confirmed that variation in resistance is heritable. 4 Total disease incidence increased over the 3-year study, but rates of establishment of new infections decreased and estimates of the latent period increased each year. By the end of the study, the remaining healthy plants were more likely to be from resistant parents, suggesting that changes in genetic structure of the healthy plants may contribute to the decline in new infections over time. 5 Diseased plants were significantly more likely than healthy plants to die during the first winter of the study but there was no difference in the second year. A compilation of several data sets suggests that diseased plants have higher mortality than healthy plants only in winters with overall high plant survivorship. 6 Phenotypic correlations revealed that plants with early flowering dates and high rates of flower production are more likely to become diseased. 7 There was evidence for a genetic correlation between disease resistance and flowering date in males, such that early flowering families were more prone to infection. Such a relationship suggests that resistance could have a fitness cost, since earlier flowering plants are likely to have high fitness in the absence of disease.

Notes: Oct

Alexander, H. M., P. H. Thrall, J. Antonovics, A. M. Jarosz, and P. V. Oudemans. 1996. Population Dynamics and Genetics of Plant Disease - a Case Study of Anther-Smut Disease. Ecology 77:990-996.

Keywords: Anther-smut

Coexistence

Disease ecology

Host

Pathogen

Population ecology

Population genetics

Silene alba

Transmission

Ustilago violacea

Ustilago-violacea

Spore deposition

Genotypic variation

Infection

Patterns

Epidemiology

Transmission

Fungus

Abstract: A model by Levin and Udovic (1977) emphasizes the need for integration of studies of the numerical abundances and genetic composition of host and pathogen species. We use their conceptual framework to summarize our collaborative research on the ecological genetics of the anther-smut disease of Silene alba caused by the fungus Ustilago violacea. Our theoretical investigations have revealed the importance of the rate and mode of disease transmission on the likelihood of coexistence between host and pathogen. Our empirical studies have quantified patterns of disease spread on local and regional spatial scales and have shown that host genotypes differ greatly in resistance. Comparable genetic variation in pathogen virulence has not yet been demonstrated. The genetic composition of host populations alters numerical dynamics in experimental populations: disease declines in resistant populations, while host and pathogen appear to coexist in susceptible populations. Ecological outcomes also may be affected by the negative relationship between disease incidence and host flowering time, which may constitute a ''cost'' to resistance. We are currently expanding our work on the ecology and genetics of metapopulation dynamics of host and pathogen. [References: 40]

Altig, R., and M. Christensen. 1981. Behavioral characteristics of the tadpoles of Rana heckscheri. Journal of Herpetology 15:151-154.

Altig, R., and L. Branch. 1981. Nocturnal stratification of three species of Ambystoma larvae. Copeia 4:870-873.

Altizer, S., P. H. Thrall, and J. Antonovics. 1998. Pollinator behavior and disease transmission of the anther-smut disease of Silene alba. American Midland Naturalist 139:147-163.

Angleberger, M. A. P. 1974. Dimorphism in the red-backed salamander, Plethodon cinereus (Green) at Mountain Lake Virginia. Univeresity of Virginia, Charlottesville, Virginia. Thesis: Masters.

Angleberger, M. A. P., and C. J. P. 1975. Dimorphism in the Red-Backed Salamander Plethodon-Cinereus At Mountain Lake Virginia Usa. Virginia Journal of Science 26:153-158.

Keywords: Vegetation Habitat

*07508 Ecology; Environmental Biology-Animal *11103 Anatomy and Histology, General and Comparative-Comparative Anatomy (1971- ) *62514 Chordata, General and Systematic Zoology-Amphibia

07200 Circadian Rhythms and Other Periodic Cycles 07504 Ecology; Environmental Biology-Bioclimatology and Biometeorology 10614 External Effects-Temperature as a Primary Variable (1971- ) 10620 External Effects-Humidity (1972- ) 16501 Reproductive System-General; Methods

11000 Plantae-Unspecified 85304 Caudata

Plants; Animals; Chordates; Vertebrates; Nonhuman Vertebrates; Amphibians

Abstract: A five mile NS cline located in Giles County, Virginia USA, in which the frequency of the unstriped morph of the salamander P. cinereus decreases from 0.13-0.00, is described and analyzed. There is no correlation between the frequency of unstriped and altitude, type of vegetation, surface moisture, type of cover preferred or the season of sampling. Unstriped salamanders were found at higher frequencies in areas with a lower average daily temperature and less fluctuation between daily high and low temperature extremes. Analysis of egg clutches tends to support the hypothesis that the striped phenotype is dominant.

Anthony, C. D., W. J. A., and J. R. G. 1997. Social interactions in two sympatric salamanders: Effectiveness of a highly aggressive strategy. Behaviour 134:71-88.

Keywords: factor influencing distributions; red-backed salamander; terrestrial salamanders; territorial behavior; agonistic behavior; body-size; competition; interference; evolution; intruders

Abstract: In terrestrial plethodontid salamanders, aggressive behaviour is thought to function in the spacing of territorial residents among contested cover objects on the forest floor. Such behaviour, when exhibited toward heterospecifics, plays an important role in the competitive interactions between species. We compared levels of aggressive behaviour in intra- and interspecific contexts in two species of sympatric salamanders (Plethodon ouachitae and P. albagula) that have similar ecological requirements but differ in adult size. We also tested the effectiveness of such behaviour in holding cover objects (territorial foci) in the laboratory and on the forest floor. We predicted that if one species were more aggressive than the other, then that species would have greater success in obtaining and holding cover objects. In laboratory trials, residents of P. ouachitae (the smaller species) were extremely aggressive in both intra- and interspecific contexts. Individuals of P. ouachitae delivered bites at a rate 14 times that of previously studied species of Plethodon and were significantly more likely to escalate to biting when tested as territorial residents (in intra- and interspecific trials) and as intruders (in interspecific trials). Plethodon albagula exhibited a lower level of aggression, similar to other species of Plethodon. In laboratory trials, in which salamanders competed for cover objects of differing quality, residents of P. ouachitae were effective in expelling conspecific intruders, and they were marginally effective at expelling intruding P. albagula. Residents of P. albagula were less effective in expelling conspecific intruders and did not expel intruding P. auachitae. We conclude that the extreme aggression exhibited by P. ouachitae enabled it to expel intruders from artificial cover objects and to invade cover objects held by larger heterospecific residents. Field data supported intraspecific defence of cover objects by P. ouachitae, but results for Il albagula were inconclusive. These results are consistent with the geographic distributions of these species (P. ouachitae typically outnumbers P. albagula in the Ouachita Mountains) and provide an example of a behavioural mechanism overcoming a size-related disadvantage.

Notes: Article

Feb

Antonovics, J., and H. M. Alexander. 1992. Epidemiology of Anther-Smut Infection of Silene-Alba (= S- Latifolia) Caused By Ustilago-Violacea - Patterns of Spore Deposition in Experimental Populations. Proceedings of the Royal Society of London Series B-Biological Sciences 250:157-163.

Keywords: disease incidence; plant-disease; competition; dispersal; dynamics; mixtures; biology; density; spread; pollen

Abstract: Experimental populations of Silene alba consisting of healthy individuals and individuals infected by the anther-smut fungus Ustilago violacea were used to examine the effect of density and frequency of diseased individuals on spore deposition on healthy flowers. The results showed increasing spore deposition with increasing frequency but not density. Similar trends were observed for pollen deposition on females. The results support the hypothesis that spore transmission is via pollinators that adjust their flight distances to compensate for host density. Frequency-dependent transmission, characteristic of vector borne and venereal diseases, may by an important component of disease transmission of U. violacea in nature.

Notes: Nov 23

Antonovics, J., and P. H. Thrall. 1994. Cost of Resistance and the Maintenance of Genetic-Polymorphism in Host-Pathogen Systems. Proceedings of the Royal Society of London Series B-Biological Sciences 257:105-110.

Keywords: anther-smut infection; parasite population interactions; ustilago-violacea; disease transmission; genotypic variation; spore deposition; epidemiology; dynamics; coexistence; stability

Abstract: By using models which incorporate both numerical and gene- frequency dynamics, we investigate the conditions for a stable polymorphism in host disease resistance when there is a genetically uniform pathogen. We show that polymorphism is more likely when the difference in resistance conferred by alternative alleles is large rather than small. This conforms with the frequent observation of major gene effects on resistance. Moreover, when allelic differences in resistance are large, polymorphism is possible over a wide range of costs, including situations where costs approach values close to zero. The actual resistance cost that can be sustained in such polymorphic populations is dependent on the transmission mode and the intensity of disease-independent population regulation. Expectations regarding resistance costs in any particular host-pathogen system will be dependent on knowledge of the epidemiological and genetic characteristics of that system.

Notes: Aug 22

Antonovics, J., Y. Iwasa, and M. P. Hassell. 1995. A generalized model of parasitoid, venereal, and vector-based transmission processes. The American Naturalist 145:661-675.

Antonovics, J., S. D., T. P. H., and J. A. M. 1996. An anther-smut disease (Ustilago violacea) of fire-pink (Silene virginica): Its biology and relationship to the anther- smut disease of white campion (Silene alba). American Midland Naturalist 135:130-143.

Keywords: genotypic variation; spore deposition; infection; populations; patterns; isozyme; epidemiology; transmission; virulence

Abstract: In the southeastern United States, anther-smut disease (Ustilago violacea) was observed on the native fire pink (Silene virginica), and on the introduced white campion (Silene alba). Fungal isolates from the two host species showed fixed differences at allozyme loci, and isolates from S. alba were similar to isolates from S. alba in Europe. Fungal isolates from S. virginica did not produce disease on S. alba; crosses between fungal isolates from the two hosts showed reduced inoculation success on S. alba. Teliospores from hybrids between the isolates showed abnormal sporidial development. We conclude that the anthersmuts from each of the host species are genetically distinct and partially reproductively isolated ''host-races.'' Ustilago violacea occurs on S. virginica throughout its range, and far beyond the range of diseased S. alba. Rates of infection of healthy flowering individuals in natural populations of S. virginica were very low but a large fraction of plants were already diseased when they first flowered, suggesting disease is transmitted by spares that fall on seedlings or rosettes. There was substantial heterogeneity in disease incidence even among local populations in the same vicinity, but evidence suggests that the disease was not rapidly spreading in S. virginica.

Notes: Jan

Antonovics, J., P. H. Thrall, and A. M. Jarosz. 1998. Genetics and the spatial ecology of species interactions: the Silene-Ustilago system. Pages 158-180 in D. Tilman and P. Kareiva, eds. Spatial Ecology: The Role of Space in Population Dynamics and Interspecific Interactions. Princeton University Press.

Antonovics, J., J. O'Keefe, and M. E. Hood. 1998. Theoretical population genetics of mating-type linked haplo-lethal polymorphisms. International Journal of Plant Sciences 159:192-198.

Antonovics, J. 1999. Pathogens and plant population dynamics: the effects of

resistance genes on numbers and distribution. Pages 49-55 in P. M. Traynor and H. Westwood, eds. Ecological Effects of Pest Resistance Genes in Managed Ecosystems. Information Systems for Biotechnology, Blacksburg, Virginia, USA.

Arnold, G. 1997. The genetics of small populations of Silene alba. University of Virginia, Charlottesville, Virginia, USA. Thesis: Masters.

Asami, T. 1988. Temporal segregation of two sympatric species of land snails. Venus 47:278-297.

Athey, L. A., and E. F. Connor. 1989. The Relationship Between Foliar Nitrogen-Content and Feeding By Odontota-Dorsalis Thun On Robinia-Pseudoacacia L. Oecologia 79:390-394.

Notes: Article

Band, H. T., and R. N. Band. 1987. Amino-Acid and Allozyme Frequency Changes in Overwintering Chymomyza-Amoena (Diptera, Drosophilidae) Larvae. Experientia 43:1027-1029.

Notes: Note

Sep 15

Band, H. T. 1988. Chymomyza amoena (Diptera: Drosophilidae), An unusual urban drosophilid. Va. J. Sci 39:242-249.

Band, H. T. 1988. Chymomyza amoena (Diptera: Drosophilidae) in Virginia. Va. J. Sci 39:378-392.

Band, H. T. 1988. Behavior and taxonomy of Chymomyzid amoena. The International Journal of Comparative Psychology 2:3.

Band, H. T. 1988. Host Shifts of Chymomyza-Amoena (Diptera, Drosophilidae). American Midland Naturalist 120:163-182.

Notes: Jul

Band, H. T. 1988. Host Shifts of Chymomyza-Amoena Diptera Drosophilidae. American Midland Naturalist 120:163-182.

Keywords: Drosophila-Melanogaster Apple Crabapple Black Walnut Plum Courtship Mating Larval Stage Overwinter Oviposition Speciation

*01500 Evolution *07003 Behavioral Biology-Animal Behavior *07504 Ecology; Environmental Biology-Bioclimatology and Biometeorology *07508 Ecology; Environmental Biology-Animal *16504 Reproductive System-Physiology and Biochemistry *60006 Economic Entomology-Fruits and Nuts *60010 Economic Entomology-Trees, Ornamentals and Wood Products *63574 Invertebrata, General and Systematic Zoology-Insecta-Diptera

07506 Ecology; Environmental Biology-Plant 25502 Developmental Biology-Embryology-General and Descriptive 53002 Horticulture-Temperate Zone Fruits and Nuts 53500 Forestry and Forest Products

26215 Juglandaceae 26675 Rosaceae 75314 Diptera

Plants; Vascular Plants; Spermatophytes; Angiosperms; Dicots; Animals; Invertebrates; Arthropods; Insects

Abstract: Chymomyza amonena (Loew) is a domestic species that has expanded its host niche to breed and overwinter in apples in Michigan and the mid-South. Populations remain mutivoltine throughout the latitudes investigated, East Jordan, Mich. (45.10.degree.N) to Eden, N.C. (36.29.degree.N). A new generation can be produced within a month during the breeding season. Populations remain polymorphic for developmental time. The polymorphism has been investigated in apples, but lengthy emergence from crabapples indicates it predated in invasion of apples. Populations overwinter in the larval stage in Michigan; the pupal stage may be the overwintering stage in milder climates or it may be entered early in spring. Populations within Michigan and between Michigan, Missouri and mid-South have been interfertile. This species has a longer prefertile period than Drosophila melanogaster. Comparisons of the oviposition rate of pairs captured in nature with laboratory crosses involving aged and nonaged parents indicate that females in nature do not approach males until past their prefertile period. Multiple use of endemic host plants for breeding has been investigated in mid-Michigan. Females emerging from black walnut husks prefer to oviposit on softened, overwintered native crabapples; females emergining from crabapples early in summer can breed in immature, unripe fallen domestic apples or plums. Females rely on pest species to attack firm substrates first and oviposit in scars, holes or directly in frass when available. Both males and females are attracted to sites where other C. amoena have oviposited. Later in summer females will also oviposit on unfallen fruits. Larvae pupate within the substrate or in soil. Studies at Mt. Lake Biological Station where other chymomyzid species occur show that males will court inter- or intraspecifically. Capture-in-the-air is an alternate mating system in this species to the assault-type mating predominant in this, other drosophilids and other Diptera. The simple courtship and other behaviors are described. Population size is small and, to date, there is no evidence of sympatric of allopatric speciation.

Band, H. 1989. Behavior Of The Chymomyza Aldrichii Species Group (Diptera:Drosophilidae) In Virginia's Allegheny Mountains. Virginia Journal of Science 40:230-237.

Band, H. T. 1989. Aggregated Oviposition By Chymomyza-Amoena (Diptera, Drosophilidae). Experientia 45:893-895.

Notes: Article

Sep 15

Band, H. 1991. Thomas Henry Huxley's Opposition To Evolutionary Ethics. Michigan Academician 23:345-367.

Band, H. 1991. Why Engels Linked Marx And Darwin At Marx's Graveside. Michigan Academician 23:285-294.

Band, H. T. 1991. Thomas Henry Huxley's opposition to evolutionary ehics. Michigan Academician 23:345-367.

Band, H. T. 1991. Acorns As Breeding Sites For Chymomyza-Amoena (Loew) (Diptera, Drosophilidae) in Virginia and Michigan. Great Lakes Entomologist 24:45-50.

Abstract: Chymomyza amoena is the only chymomyzid fly emerging from white oak acorns in Virginia. An average of 2-3 adult flies emerged from a single acorn in July while emergence declined to 0.4 adults/acorns in September. In fall, Drosophila melanogaster was also present. The incidence of drosophilid (Drosophila, Chymomyza) larvae in parasitized acorns in Virginia (40%) in autumn was significantly greater than in Michigan (14%). The Chymomyza larvae present in the parasitized acorns in Michigan most likely were C. amoena, from the known adaptation of this species in Michigan to frass- breeding.

Notes: Spr

Band, H. T. 1994. More on the Mate Recognition Controversy. Michigan Academician 26:83-99.

Notes: Reprint on file

Band, H. T. 1995. A note on the sympatric collection of chymomyza (Diptera: Drosophilidae) in Virginia's Allegheny Mountains. Great Lakes Entomologist 28:217-220.

Keywords: Research Article; Chymomyza Procnemoides; Chymomyza Aldrichii; Sex Ratio; Geographic Distribution; Usa

*53500 Forestry and Forest Products *60010 Economic Entomology-Trees, Ornamentals and Wood Products *62800 Animal Distribution (1971- ) *63574 Invertebrata, General and Systematic Zoology-Insecta-Diptera *64076 Invertebrata, Comparative and Experimental Morphology, Physiology and Pathology-Insecta-Physiology

75314 Diptera

Animals; Invertebrates; Arthropods; Insects

Abstract: The attraction of two Chymomyza species C. procnemoides and C. aldrichii, to the same damaged tree over 19 days in summer 1987 near Mt. Lake Hotel, Giles Co., Virginia is documented, confirming a previous report that Chymomyza species may be sympatric on the same fresh damaged tree/cut wood. A total of 17 males and 7 females were captured. An excess of males to females captured has been reported in Japan and Hungary.

Notes: Fal-win Biological Abstracts Vol. 101 Iss. 011 Ref. 159580

Barr, T. C. J. 1981. Pseudanophthalmus From Appalachian Caves Coleoptera Carabidae the Pseudanophthalmus-Engelhardti Complex. Brimleyana 0:37-94.

Keywords: Pseudanophthalmus-Spp New-Species Pseudanophthalmus-Delicatus New-Status Pseudanophthalmus-Virginicus New-Combination Pseudanophthalmus-Hirsutus-Delicatus Aphanotrechus-Virginicus Description Evolution 29 New Species Pleistocene Virginia Kentucky Georgia Tennessee Alabama Usa

*11103 Anatomy and Histology, General and Comparative-Comparative Anatomy (1971- ) *62800 Animal Distribution (1971- ) *63573 Invertebrata, General and Systematic Zoology-Insecta-Coleoptera *64074 Invertebrata, Comparative and Experimental Morphology, Physiology and Pathology-Insecta-Morphology, Comparative

01500 Evolution 06400 Subterranean Bioresearch (1972- ) 64726 Geological Periods-Pleistocene (1971- )

*75304 Coleoptera

*Animals; *Invertebrates; *Arthropods; *Insects

Abstract: The P. engelhardti complex includes .apprx. 55 spp. of the cave beetle genus Pseudanophthalmus, here arranged in 7 species groups with the following new species described and illustrated: engelhardti group: P. deceptivus of Virginia (VA), USA; P. wallacei of Tennessee (TN), USA; TN; P. nortoni, TN; P. fastigatus of Georgia (GA), USA; P. nickajackensis, TN/AL Alabama, USA); P. sequovah, AL; P steevesi, AL; tennesseenis group: P. pusillus, TN; P. paynei, TN; P. unionis, TN; hirsutus group: P. sericus, VA; P. paulus, TN; P. ventus, TN; P. assimilis, AL; hubrichti group: P. sanctipauli, VA; P. paradoxus, TN; jonesi group: P. scutilus, TN; P. rogersae, KY; P. seclusus, VA: P. pallidus, TN; P. longiceps, VA/TN; P. thomasi, VA; P. cordicollis, VA; hypolithos group: P. hypolithos, KY; P. scholasticus, KY; P frigidus, KY; P calcareus, KY; P. praetermissus, VA; and alabamae group: P. georgiae, GA. Other taxonomic changes are: P. delicatus Valentine, stat. nov. (full species [from P. hirsutus delicatus Valentine 1932]), and P. virginicus, comb. nov. (Aphanotrechus virginicus Barr). The species of the P. engelhardti complex occupy the Appalachian valley from Giles County, southwest Virginia through east Tennessee to northwest Georgia and north Alabama, including karst islands near the eastern Allegheny front .sbd. Pine Mountain (KY/TN), Grassy Cove (TN), Sequatchie Valley (TN), Lookout Valley (TN/GA), and Wills Valley (AL). The hypothesis is offered that a majority of species groups of Pseudanophthalmus are descendants of lineages evolving in the Allegheny plateau and surviving in an Allegheny refugium during the Pleistocene.

Barrington, D. S., C. H. Haufler, and C. R. Werth. 1989. Hybridization, reticulation, and species concepts in the ferns. American Fern Journal 79:55-64.

Barry, R. E., M. A. Botje, and L. B. Grantham. 1984. Vertical stratification of Peromyscus leucopus and P. maniculatus in Sounthwestern Virginia. Journal of Mammology 65:145-148.

Beaty, M. H., and P. B. C. 1993. Evaluation of Trophic State Changes in Mountain Lake. , .

Keywords: Abstract Oligotrophic Mesotrophic Eutrophication Lake Aging Virginia Usa

*07514 Ecology; Environmental Biology-Limnology

00520 General Biology-Symposia, Transactions and Proceedings of Conferences, Congresses, Review Annuals

Beaty, M. H., and P. B. C. 1994. Investigations of Eutrophication in Mountain Lake, Giles County, Virginia. Virginia Polytechnic Institute and State University Water Resources Research Center Bulletin 0:I-X, 1-66.

Keywords: Research Article; Natural Lake; Pollution; Nitrogen; Phosphorus; Primary Production

*07506 Ecology; Environmental Biology-Plant *07514 Ecology; Environmental Biology-Limnology *10069 Biochemical Studies-Minerals *13003 Metabolism-Energy and Respiratory Metabolism *37015 Public Health: Environmental Health-Air, Water and Soil Pollution *51510 Plant Physiology, Biochemistry and Biophysics-Growth, Differentiation

11000 Plantae-Unspecified

Plants

Abstract: Mountain Lake, Giles County, is one of only two natural lakes in Virginia and is the only natural lake in the unglaciated southern Appalachians. Since its discovery by Gist in 1751, the lake has been considered relatively clean and unspoiled. Recent data on nitrate-nitrogen, orthophosphate-phosphorus, hypolimnetic oxygen deficit, and the phytoplankton community suggest that the lake may be shifting toward a more eutrophic state. This paper reviews the existing data for Mountain Lake, then examines various trophic state indices in an attempt to establish whether the Mountain Lake ecosystem may be undergoing eutrophication.

Notes: Biological Abstracts Vol. 099 Iss. 012 Ref. 169968

Beaty, M. H., and P. B. C. 1995. Relative importance of pico-, nano-, and micro-plankton, algae in Mountain Lake, Virginia. , .

Keywords: Meeting Abstract; Aphanocapsa; Sphaerocystis; Chroococcus; Chlamydomonas; Volvox; Ph; Nitrogen; Phosphorus; Grazing; Usa

*07506 Ecology; Environmental Biology-Plant *07514 Ecology; Environmental Biology-Limnology *51504 Plant Physiology, Biochemistry and Biophysics-Nutrition

00520 General Biology-Symposia, Transactions and Proceedings of Conferences, Congresses, Review Annuals 10069 Biochemical Studies-Minerals 13206 Nutrition-Minerals 64002 Invertebrata, Comparative and Experimental Morphology, Physiology and Pathology-Protozoa

09210 Chroococcales (1992- ) 13300 Chlorophyta 35200 Flagellata

Microorganisms; Bacteria; Eubacteria; Cyanobacteria; Plants; Nonvascular Plants; Algae; Animals; Invertebrates; Protozoans

Notes: Biological Abstracts/RRM Vol. 047 Iss. 009 Ref. 155540

Beaty, M. H., and P. B. C. 1995. Eutrophication of Mountain Lake, Virginia. , .

Keywords: Meeting Abstract; Nitella; Phytoplankton Productivity; Growth; Hypolimnetic Oxygen Depletion; Phosphate; Ammonium; Nitrate; Usa

*07506 Ecology; Environmental Biology-Plant *07514 Ecology; Environmental Biology-Limnology *10012 Biochemistry-Gases (1970- ) *37015 Public Health: Environmental Health-Air, Water and Soil Pollution *51504 Plant Physiology, Biochemistry and Biophysics-Nutrition *51510 Plant Physiology, Biochemistry and Biophysics-Growth, Differentiation

00520 General Biology-Symposia, Transactions and Proceedings of Conferences, Congresses, Review Annuals 10069 Biochemical Studies-Minerals 13206 Nutrition-Minerals

13000 Algae-Unspecified 13100 Charophyta

Microorganisms; Plants; Nonvascular Plants; Algae

Notes: Biological Abstracts/RRM Vol. 047 Iss. 009 Ref. 155539

Beaty, M. H. 1995. Limnological Investigations of a Natural, Subalpine Lake in the Stages of Eutrophication: Mountain Lake, Giles County, Virginia. VIRGINIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY, . Thesis: Ph.D.

Abstract: Comprehensive year-round limnological investigations of Mountain Lake, Virginia were conducted from November 1992 through October 1994. Monthly physical, chemical, and biological measurements suggest that this ecosystem has shifted toward a more eutrophic condition. A trend in whole lake mean annual orthophosphate-phosphorus and inorganic nitrogen increases have occurred over the past decade, although primary productivity, cell densities, and chlorophyll a values indicate no consistent trends. Hypolimnetic oxygen deficits, however, have continued to increase over time, and in October 1994 the first measure of anoxic deep water was observed.^Concurrently with the chemical changes, shifts in macrophytes and phytoplankton have occurred. Most notably were reductions in Nitella megacarpa and Dinobryon spp., an increase in Ceratophyllum sp., and a summer dominance of Sphaerocystis schroeteri and Aphanocapsa elachista. These two species represent algal classes, Chlorophyceae and Cyanophyceae, which have also increased in relative abundance and seasonal persistence in Mountain Lake.^Nutrient addition studies conducted in 1994 indicated limiting concentrations of both phosphorus and inorganic nitrogen during most periods of thermal stratification. Significant increases in primary productivity occurred within 48 hrs with the addition of K$\sb2$HPO$\sb4$ and/or NH$\sb4$NO$\sb3$ in the pico-, nano-, and microplankton size classes. The smaller size fractions (pico- and nanoplankton) responded more strongly to the N enrichment, whereas the microplankton responded more with the P enrichment. In all cases, ammonium-N was the preferred inorganic nitrogen source during these studies, as suggested from earlier studies of methylamine uptake in this lake.^Studies of the importance of various phytoplankton size classes (pico-, nano-, micro-, and macro-) during thermal stratification indicated that the microphytoplankton were the most important size class in cell number, cell diversity, and contributed $\sim$95% of the total primary productivity. The picophytoplankton were second in importance constituting $\sim$5% of total primary productivity, whereas the relatively small numbers of nano- and macrophytoplankton contributed little primary productivity. This finding contrasts to many other oligotrophic ecosystems where the pico- and nanophytoplankton have demonstrated significantly greater importance.^Increasing nutrient concentration, increasing hypolimnetic oxygen deficit, and shifting phytoplankton community structure suggest that Mountain Lake is entering the early stages of eutrophication. Continuation of increasing nutrient loads in this natural lake will potentially further shift this ecosystem toward eutrophic conditions.

Notes: <vo> 56/06-b of dissertation abstracts international.

<pg> page 3014

Beaty, M. H., and B. C. Parker. 1996. Response of Phytoplankton Primary Productivity to Nutrient Enrichment At Mountain Lake, Virginia. Journal of Freshwater Ecology 11:421-431.

Keywords: Oligotrophic lake

Eutrophication

Abstract: Mountain Lake, Virginia is a natural subalpine oligo-mesotrophic lake in the unglaciated southern Appalachians. Recent evidence suggests that this ecosystem is entering early stages of eutrophication. Noticable increases in inorganic N and P concentrations in the water column have occurred over the past decade along with increasing hypolimnetic oxygen deficits. Although the causes of this increased nutrient load are not clearly defined, we show here with nutrient enrichment studies the potential impact of nutrient enhancement on the current phytoplankton community with respect to primary productivity and size class. [References: 18]

Beaty, M. H., and B. C. Parker. 1996. Relative Importance of Pico-, Nano-, and Microplankton to the Productivity of Mountain Lake, Virginia. Hydrobiologia 331:121-129.

Keywords: Lake phytoplankton

Size class

Productivity

Picoplankton

Autotrophic picoplankton

Phytoplankton communities

Oligotrophic lake

Nanoplankton

Abundance

Dynamics

Cyanobacteria

Gradient

Ontario

Light

Abstract: Studies of the relative importance of various phytoplankton size classes (pico-, nano-, micro-, and macro-) during thermal stratification at oligomesotrophic Mountain Lake, Giles County, Virginia were conducted from March through October 1994. A detailed time- and depth-series study was conducted to compare C-14-fixation rates in these phytoplankton size fractions. Data indicated that on average the microplankton were the most important size class in cell number and cell volume and contributed approximate to 95% of the total primary productivity. The picoplankton ranked second in importance constituting approximate to 5% of total primary productivity, whereas the relatively small numbers of nano- and macroplankton contributed little primary productivity. No obvious relationships were apparent among cell densities, cell volumes, and chlorophyll a values during late summer thermal stratification, possibly due to shifts in community structure at that time. The findings contrast with many other oligo- to mesotrophic ecosystems where the pico- and nanoplankton have demonstrated significantly greater importance, especially in summer. [References: 41]

Beaty, M. H., and P. B. C. 1996. Response of phytoplankton primary productivity to nutrient enrichment at Mountain Lake, Virginia. Journal of Freshwater Ecology 11:421-431.

Keywords: Research Article; Algae; Phytoplankton; Primary Productivity; Nutrient Enrichment; Freshwater Ecology; Nitrogen; Nutrient; Phosphorus; Mountain Lake; Virginia; Usa

*07506 Ecology; Environmental Biology-Plant *07514 Ecology; Environmental Biology-Limnology *10069 Biochemical Studies-Minerals *51504 Plant Physiology, Biochemistry and Biophysics-Nutrition

13000 Algae-Unspecified

Microorganisms; Plants; Nonvascular Plants; Algae

Notes: Biological Abstracts Vol. 103 Iss. 002 Ref. 019189

Beaty, M. H., and P. B. C. 1996. Relative importance of pico-, nano-, and microplankton to the productivity of Mountain Lake, Virginia. Hydrobiologia 331:121-129.

Keywords: Research Article; Organism; Nanoplankton; Microplankton; Picoplankton; Primary Productivity; Freshwater Ecology; Thermal Stratification; Carbon-14; Fixation; Eutrophication; Biomass Production; Chlorophyll; Total; Phytoplankton Size Fraction; Oligomesotrophic; Giles County; Mountain Lake; Virginia; Usa

*07502 Ecology; Environmental Biology-General; Methods *10060 Biochemical Studies-General *13002 Metabolism-General Metabolism; Metabolic Pathways *23001 Temperature: Its Measurement, Effects and Regulation-General Measurement and Methods *50504 Botany, General and Systematic-Algae

00500 Organisms-Unspecified

Abstract: Studies of the relative importance of various phytoplankton size classes (pico-, nano-, micro-, and macro-) during thermal stratification at oligomesotrophic Mountain Lake, Giles County, Virginia were conducted from March through October 1994. A detailed time- and depth-series study was conducted to compare 14C-fixation rates in these phytoplankton size fractions. Data indicated that on average the microplankton were the most important size class in cell number and cell volume and contributed apprxeq 95% of the total primary productivity. The picoplankton ranked second in importance constituting apprxeq 5% of total primary productivity, whereas the relatively small numbers of nano- and macroplankton contributed little primary productivity. No obvious relationships were apparent among cell densities, cell volumes, and chlorophyll a values during late summer thermal stratification, possibly due to shifts in community structure at that time. The findings contrast with many other oligo- to mesotrophic ecosystems where the pico- and nanoplankton have demonstrated significantly greater importance, especially in summer.

Notes: Biological Abstracts Vol. 103 Iss. 002 Ref. 018951

Beaty, M. H., and B. C. Parker. 1996. Relative Importance of Picoplankton, Nanoplankton, and Microplankton to the Productivity of Mountain Lake, Virginia. Hydrobiologia 331:121-129.

Keywords: Author Keywords: LAKE PHYTOPLANKTON ; SIZE CLASS ; PRODUCTIVITY ; PICOPLANKTON

KeyWords Plus: AUTOTROPHIC PICOPLANKTON; PHYTOPLANKTON COMMUNITIES; OLIGOTROPHIC LAKE; NANOPLANKTON; ABUNDANCE; DYNAMICS; CYANOBACTERIA; GRADIENT; ONTARIO; LIGHT

94-3227 001 (ruminal fermentation in lactating dairy-cows; neutral detergent fiber digestion; steers grazing intermediate wheatgrass; hypertrophic lake; protein systems)

Notes: Article

Bell, C., and W. Justice. 1968. Wild Flowers of North Carolina. University of North Carolina Press.

Bell, C. 1969. Variation and selection pressure in Aquilegia caerulea James (Ranunculaceae). ASB Bulletin 16.

Bell, C. 1970. Abstract: Fertility patterns in Gerardia L. sensu Fernald. ASB Bulletin 17:30.

Bell, C. 1971. Breeding systems and floral biology of the umbelliferae. Linnean Society Supplement 64:93-108.

Bell, C. 1974. Abstract: pollen production in relation to ovule number in two species of Asclepias. ASB Bulletin 21:38.

Bell, C., C. Dubay, and R. Robins. 1975. Inflorescence size as a factor in pollination efficiency in Asclepias syriaca L. (Asclepiadaceae). ASB or VAS? .

Bell, C. R. 1976. Abstract: Inflorescence shape and pollinator activity in Daucus carota L. (Apiaceae). ASB Bulletin 23:42.

Bell, C., and A. Lindsey. 1977. Abstract: umbellet number and pollination efficiency in Daucus carota L. Apiaceae. ASB Bulletin 24:36.

Bell, C., and A. Lindsey. 1977. Abstract: floral structure and pollinator specialization in three genera of Apiaceae. Botanical Society of American Misc. Series Publication 154:4.

Bell, C., and A. Lindsey. 1978. The umbel as a reproductive unit in Apiaceae. Contributions Pluridisciplinaires a la Systematique" Paru 1978, .

Bell, C. 1978. Abstract: Variation in pollinator efficiency in five populations of Asclepias syriaca L. (Asclepiadaceae). Botanical Society of America, Miscl. Series Publication 156:83.

Bell, C., and J. Morley. 1979. Floodplain tree species: a bibliographic literature search with abstracts. US Army Corps of Engineers ETL-0193, . . ETL-0193.

Bell, C., and A. Lindsey. 1980. Pollinator activity and fruit set in sympatric populations of Osmorhiza (Apraceae). Botanical Society of America, Miscelaneous Series Publications 158:11.

Bell, C., and A. Lindsey. 1980. Protogyny and associated reproductive characteristics in Apiaceae. Second International Congress of Systematic and Evolutionary Biology. Abstracts :269.

Bell, C., and J. Farmer. 1980. Dynamics of pollen flow in Asclepias syriaca L. (Asclepiadaceae). Second International Congress of Systematic and Evolutionary Biology. Abstracts :145.

Bell, C. R., and K. R. 1981. An Anomalous Rhizomatous Population of Cicuta-Maculata At Mountain Lake Virginia Usa. Castanea 46:4-7.

Keywords: Monocarpic Perennial Clone Poisonous Tuber Gemmi Parous Asexual Reproduction Storage Flowering

*07506 Ecology; Environmental Biology-Plant *50528 Botany, General and Systematic-Floristics and Distribution *51000 Morphology, Anatomy and Embryology of Plants *51510 Plant Physiology, Biochemistry and Biophysics-Growth, Differentiation

03504 Genetics and Cytogenetics-Plant 03509 Genetics and Cytogenetics-Population Genetics (1972- ) 10060 Biochemical Studies-General 22501 Toxicology-General; Methods and Experimental 51512 Plant Physiology, Biochemistry and Biophysics-Reproduction

26915 Umbelliferae

Plants; Vascular Plants; Spermatophytes; Angiosperms; Dicots

Abstract: Observations on a population of > 1000 plants of C. maculata in the mountains of southwest Virginia show the population to be clonal by means of an extensive system of shallow, slender, elongate rhizomes. Although the fleshy poisonous tubers that form on the roots of the larger of these plants may occasionally function to a limited degree in gemmiparous asexual reproduction, they probably are storage structures associated primarily with the ultimate production of a flowering stalk in the sexual reproductive cycle of these short-lived monocarpic perennials.

Bell, C., and L. Musselman. 1982. Unilateral hybridization in Aureolaria Raf. (Scrophulariaceae). American Journal of Botany 69:647-649.

Bergman, C., and B. Von Holle. in prep. The influence of natural and anthropogenic disturbances in the invasion of species. Natural Area Journal .

Biere, A., and H. S. J. 1996. Impact of flowering phenology of Silene alba and S-dioica on susceptibility to fungal infection and seed predation. Oikos 77:467-480.

Keywords: anther-smut infection; ustilago-violacea; spore deposition; experimental populations; disease transmission; genotypic variation; life-history; patterns; caryophyllaceae; epidemiology

Abstract: Timing of the production of susceptible host stages can have a large impact on a plant's probability of infection by pathogens and on the extent of damage caused by herbivores. In the closely related plant species Silene alba and S. dioica, flowers are the site of infection by the host-sterilizing anther smut fungus Ustilago violacea, as well as the site of oviposition by the noctuid Hadena bicruris. In diseased populations of the two host species, the noctuid can act as pollinator, fruit predator, and vector of fungal spores. Hence, host traits that enhance or reduce visitation rates by the noctuid could affect fruit set, fruit predation and infection probability. A field study was conducted to investigate the magnitude and direction of effects of the timing of anthesis on reproductive success via these pollinator-mediated processes. More than 50% of the Silene fruits produced in a sympatric population of S. alba and S. dioica were predated by the noctuid. Predation was two times higher in S. alba than in S. dioica, annihilating the two times higher flower and fruit production by the former species. This finding emphasizes the potential impact of biotic factors on the relative fecundity of related plant species in natural populations. Onset of flowering was 4-8 weeks earlier in S. dioica than in S. alba. Tn S. dioica, early flowering individuals produced the largest fraction of undamaged fruits per flower because of their high fruit set, and their low rates of fruit abortion and predation. By contrast, in S. alba, late flowering individuals produced the highest fraction of undamaged Fruits per flower, because of a monotonic decrease in Fruit predation with time and the absence of a significant impact of phenology on fruit set. In principle, pollinator-mediated selection could thus favour earlier flowering plants in S. dioica and later flowering plants in S. alba, and an evolutionary response to such selection would increase the average difference in onset of flowering between the two species. However, differences in fitness among phenology classes were more strongly determined by differences in flower production per plant than by differences in the average reproductive success per flower. A response to pollinator-mediated selection is therefore only expected if effects of age, size, or other factors that determine differences in flower production per plant are averaged out over progeny. In both host species, ca 20% of the hosts only produced sterile flowers as a result of systemic infection by the fungal pathogen U. violacea. In S. alba, the impact of phenology on fungal infection was in the same direction as for fruit predation (decreasing with later onset of flowering). In S. dioica, phenology had no effect on the probability of infection. In both species, associations between infection and predation tended to be positive but were not statistically significant, suggesting that the presence of alternative vectors or variation in resistance unrelated to traits affecting vector contact map prevent a tight association between damage caused by a vector-herbivore and its vectored disease.

Notes: Dec

Biere, A., and H. S. 1996. Host adaptation in the anther smut fungus Ustilago violacea (Microbotryum violaceum): Infection success, spore production and alteration of floral traits on two host species and their F1-hybrid. Oecologia 107:307-320.

Keywords: host manipulation; host specialization; plant-pathogen interactions; Silene; Ustilago violacea

silene-alba; linum-marginale; experimental populations; pollinator visitation; pathogen interactions; natural- populations; genotypic variation; viscaria-vulgaris; melampsora-lini; disease spread

Abstract: It is often assumed that host specialization is promoted by trade-offs in the performance of parasites on different host species, but experimental evidence for such trade-offs is scant. We studied differences in performance among strains of the anther smut fungus Ustilago violacea from two closely related host plant species, Silene alba and S. dioica, on progeny of (1) the host species from which they originated, (2) the alternative host species, and (3) inter-specific hybrids. Significant intra-specific variation in the pathogen was found for both infection success on a range of host genotypes (virulence) and components of spore production per infected host (aggressiveness) (sensu Burden 1987). Strains did not have overall higher virulence on conspecifics of their host of origin than on strains from the heterospecific host, but they did have a significantly (c. 3 times) higher spore production per infected male host. This finding suggests that host adaptation may have evolved with respect to aggressiveness rather than virulence. The higher aggressiveness of strains on conspecifics of their host of origin resulted both from higher spore production per infected flower (spores are produced in the anthers), and greater ability to stimulate flower production on infected hosts. The latter indicates the presence of adaptive intraspecific variation in the ability of host manipulation. As transmission of the fungus is mediated by insects that are both pollinators of the host and vectors of the disease, we also assessed the effect of strains on host floral traits. Infection resulted in a reduction of inflorescence height, flower size, and nectar production per flower. Strains did not differ in their effect on nectar production, but infection with strains from S. alba resulted in a stronger reduction of inflorescence height and petal size on both host species. Vectors may therefore in principle discriminate among hosts infected by different strains and affect their efficiency of transmission. Contrary to assumptions of recent hypotheses about the role of host hybrids in the evolution of parasites, hybrids were not generally more susceptible than parental hosts. It is therefore unlikely that the rate of evolution of the pathogen on the parental species is slowed down by selection for specialization on the hybrids.

Notes: Aug

Biere, A., and A. J. 1996. Sex-specific costs of resistance to the fungal pathogen Ustilago violacea (Microbotryum violaceum) in Silene alba. Evolution 50:1098-1110.

Keywords: costs of resistance; genetic polymorphisms; host phenology; male reproductive success; plant-pathogen interactions; Silene latifolia

anther-smut infection; disease resistance; experimental populations; genotypic variation; spore deposition; annual legume; evolution; patterns; dynamics; spread

Abstract: Costs of resistance are often invoked to explain the maintenance of polymorphisms for resistance to fungal pathogens in natural plant populations. To investigate such costs, 27 half-sib families of Silene alba, collected from a single host population, were grown in experiment populations in the presence and absence of the anther-smut fungus Ustilago violacea, a host-sterilizing pathogen transmitted by insects that are both pollinators and vectors of the disease. I lost families differed significantly in resistance to inoculation, indicating the presence of genetic variation for mechanisms that impede fungal growth once the disease is encountered (''biochemical'' resistance) within the host population. in addition. host families differed significantly in onset of flowering and in flower production in the absence of the disease. Path analysis revealed that late onset of flowering In male host families made a direct contribution to high field resistance (P < 0.01), probably due to a reduced rate of contact between hosts and vectors carrying high spore loads (avoidance. or ''phenological'' resistance). The contribution of low flower production to field resistance only approached significance (P < 0.10). There was a significantly positive genetic association between biochemical and phenological resistance, suggesting that delayed flowering is either a pleiotropic effect of biochemical resistance, or that genes governing these traits art in linkage disequilibrium. Path analysis revealed that biochemical resistance made both a direct contribution to field resistance (P < 0.01) and a positive indirect contribution via its association with phenology and flower production (P < 0.05) in male hosts. Costs of resistance were sex specific. Male host families with high field resistance had significantly lower reproductive success in healthy populations, indicating a fitness cost of field resistance (P < 0.01), whereas no costs were detected for female hosts. Path analysis revealed thar the biochemical component of field resistance made: no direct contribution to the observed fitness cost in male hosts, whereas its indirect effect through phenology was only marginally significant (P < 0.10). This finding indicates that fitness costs were mainly due to the phenological component of field resistance. Because the host population had no known history of disease. it is not clear whether the fitness costs are responsible for maintenance of the resistance polymorphism or whether the polymorphism is present for reasons unrelated to pathogen infection. interactions between host families and pathogen strains with respect to inoculation success were not significant. Hence, there was no evidence for indirect costs of biochemical resistance, that is, reduced resistance to alternative strains. infection rates in experimental populations with an initially patchy distribution of the pathogen were lower than in populations with a uniform pathogen distribution, suggesting that the effective pathogen pressure and hence the relative success of susceptible and resistant individuals may, in addition to fitness costs of resistance, depend on the spatial population structure of the pathogen.

Notes: Jun

Bogert, C. 1952. Relative abundance, habitats and normal thermal levels of some Virginian salamanders. Ecology 33:16-30.