Glossary
abiotic:
physical properties of an environment, such as climate, soils, atmospheric gases.
adventive:
nonindigenous species which has recently arrived or which appears to be a temporary resident in a new range; its persistence has not been determined.
allele dynamics:
the interactions of alleles with each other.
alleles:
any number of variants of a single gene.
allelopathy:
the production and emittance of organic compounds by an organism that causes detrimental consequences for its neighbors.
allopatric:
two or more species having nonoverlapping ranges of distribution.
annual:
an organism that completes its life cycle in a year or less.
antipodal:
opposites; refers to any objects (such as chromosomes) that are at diametrically opposite extremes.
apomixis:
the development of a seed without fertilization.
arrhenotokous:
capable of producing male offspring only, as in worker bees and some sawflies.
asexual reproduction:
any reproduction not involving the fusion of gametes.
autotroph:
an organism capable of self-nourishment, such as a plant nourishing itself by photosynthesis.
avirulence gene:
a gene that infers the inability to infect another organism.
basic reproduction number (Ro):
the average number of offspring or infectious units from a single organism or infectious agent.
biological control:
control of an invasive species by the introduction of a predator, grazer, or pathogen of that species.
biotic:
any process or phenomenon that is caused by living organisms.
carrying capacity:
the theoretical maximum number of individuals in a population that can be supported by a defined set of conditions in an environment.
cline:
a geographic gradient in the frequency of a gene.
confamilial:
belonging to the same family.
congeners:
members of the same genus.
congeneric:
referring to members of the same genus.
conspecific:
referring to members of the same species.
cryptogam:
plants and plant-like organisms that do not reproduce with seeds and do not produce flowers, such as ferns, mosses, fungi, and algae.
demographic:
refers to any attribute or process relating to a population.
deterministic growth rate (λ):
a growth rate that has only one outcome as defined by the parameters or conditions under which the population occurs.
diapause:
a state of arrested growth or development, usually applied only to insects.
dichogamy:
flowers that are functionally male first, then develop female structures.
dioecious:
producing male and female structures on two separate plants within the same species.
dioecy:
in plants, the possession of male and female structures on separate individuals.
diploid:
possession of two full sets of genes and two sets of chromosomes; one set from the mother, one from the father.
dsRNA:
double stranded ribonucleic acid.
ectophagous:
feeding on the outside of the host.
endophagous:
feeding on the internal organs or at least within the body of the host.
endophytic:
fungi that reside within plant cells, or plants that live within other plants.
entomophagous:
insect-feeding.
epiphyte:
a plant that grows on another plant nonparasitically, or grows on an object.
establishment:
permanent self-maintenance of a population without additional members arriving through immigration.
exploitation competition:
competition in which resources obtained by one organism, population, or species results in a lowered resource availability to another organism, population, or species.
floras/faunas:
the collective assembly of all plants (floras) or animals (faunas) within a prescribed area and within a prescribed taxonomic group (for example all insect species in the United States).
founder:
an organism which gives rise to a new populations.
genetic drift:
changes in allelic frequency due to sampling error; that is, changes in frequency that result because the genes appearing in offspring are not
a perfectly representative sampling of the parental genes (such as occurs in small populations).
genotypes:
the genetic constitution of an individual or group.
haustellate:
having a tubular organ adapted for sucking blood or the juices of plants.
herbivorous:
refers to those animals that feed or graze on living plant material, usually in reference to non-reproductive tissue (i.e., leaves, stems).
heterogamy:
alteration of sexual reproduction with parthenogenesis.
hermaphrodite:
an organism that possesses the reproductive organs of both sexes.
heterozygosity:
the proportion of the individuals in a population that are heterozygotes; that is, those individuals that have two different alleles at a locus.
homozygous:
having two copies of the same allele at a genetic locus.
indigenous:
native to a prescribed geographic range.
interference competition:
competition between any two individuals in which one physically excludes or prohibits another from gaining a resource in short supply.
intrinsic rate of increase (r):
maximum growth rate of a population, estimated as a birth rate minus the death rate; the net increase in the population.
inverse density dependence:
increase in fitness with increases in density (birth rates rise, mortality rates drop).
invasion (biotic or biological):
a phenomenon in which a nonindigenous species arrives in a new range in which it establishes, proliferates, spreads, and causes broadly-defined detrimental consequences in the environment.
lag phase:
phase in the typical cycle of population growth, when there is little or no growth, between introduction of an organism and exponential (log) growth.
larval:
in connection with arthropods, the immature instars, that is, stages in development.
logistic curve:
growth curve characterized by oscillation of population growth at a level below the carry capacity.
log phase:
phase in the typical cycle of population growth, between lag phase and decline, when a population grows exponentially.
mandibulate:
chewing, in reference to insects that chew prey with those mouth-parts called mandibles.
mean population growth rate:
the average rate by which a population changes size.
mesic:
having or characterized by a moderate amount of moisture.
mesophytic:
referring to intermediate environmental conditions.
monoecious:
bearing the reproductive structures of both parents on the same plant.
monophagous:
feeding on a single prey or forage species.
Moran effect:
a spatially correlated density independent perturbation, such as weather, which occurs across populations.
multilocus genotype:
a genotype that results in a trait or traits from the expression of genes at multiple locations within the genome of an organism.
mutational variance:
variance in the genetic make-up of a population due to mutations in individuals’ chromosomal DNA.
naturalization:
the establishment of a nonindigenous population in a new range; used mainly in connection with plants.
net reproductive rate:
average number of offspring an individual in a population will produce in his/her lifetime.
nonindigenous:
not native; refers to a species, population, organism that occurs at a locale that is not part of its native range.
oligophagous:
feeds on a few or several prey or forage species.
oviposition:
passage of the arthropod egg from the oviducts to outside the arthropod; egg-laying.
pathotype:
an infrasubspecific classification of a pathogen distinguished from others of the species by its pathogenicity on a specific host(s).
parasitoids:
insects that initially behave as a parasite but eventually act as a predator and devour their host.
parthenogenetic:
production of individuals from unfertilized eggs.
perennials:
organisms that may (and usually must) survive several years in order to reproduce.
phenological synchrony:
correspondence between traits in becoming active at the same season.
phenotype:
the observable characteristics of an organism.
phenotypic plasticity:
the phenomenon of organisms displaying a range of phenotypes from the same genotype.
phytophagous:
feeding on plants.
phytosanitary:
related to ensuring plant health.
plasticity:
the capacity of organisms with the same genotype to vary in developmental pattern, in phenotype, or in behavior according to varying environmental conditions.
polyphagous:
feeds on many prey or forage species.
polyploidy:
possessing more than two sets of genes and chromosomes.
population:
a group of genetically related members of the same species living within a prescribed space or range within a prescribed time frame.
propagules:
seeds, eggs, spores or other resting stages that are capable of being transported.
physiognomic:
literally the morphology of a plant community; refers to the number and characteristic shape of the layers of plants if the community were viewed in cross-section.
predatory guild:
a group of several types of predators that feed on a particular developmental stage of a pest.
race:
a genetically or geographically distinct subgroup of a species.
ruderal:
highly disturbed areas, such as rubbish heaps.
selfer:
an organism that does not require a sexual partner to contribute either egg or sperm; the organism contains both sexes.
stochastic:
random, involving chance or probability.
sympatric:
referring to speciation within the same geographical area.
true annual population:
a population that replicates one time per year.
univoltine:
one generation per year, used in connection with arthropods.
voltinism:
the frequency or number of annual broods.
