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 (R_o):

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.