Lecture Definitions Flashcards
Alternate Host
One or the other of the 2 different hosts of a host alternating (heteroecious) rust
Basal Cups
Cuplike structures of dwarf mistletoe that remain on the branches of the host tree after he aerial shoots fall off
define:apothecia
cuplike structure containing asci
Basidiospore
A spore produced on a basidium
define asci/ascus
sack like structure containing a definite number of ascospores, usually 8
Canker
caused by?
An area of dead tissue in a woody stem caused by fungi, bacteria or dwarf mistletoes. It is marked by sloughing of tissue that leaves an open wound surrounded by zones of callus
ascospore
spore produced in ascus
Chlorosis
An unseasonable yellowing of the foliage, symptomatic of a chlorophyll deficiency in the leaf tissues
brown cubical rot
rot in which the causal fungi generally made a more concentrated attack on cellulose than lignin. the brown friable residue splits along rectangular planes in the advanced stage of decay
Conk
The fruiting body or spore-producing structure of a wood decay fungus forming externally on the host
catface
(1) a defect on the surface of a tree or log resulting from a wound(2)a well defined healing or healed wound on the bole of a tree, usually at the base
Dieback
Death of extremities of the branches or leaves
damping off
death of seeds or seedlings, usually by soil-borne fungi
Endemic
An agent or disease present in a population or geographical area at all times
facultative parasite
the ability of normally saprophytic organisms to parasitize, i.e. to live on living material
Epidemic
Widespread high level of disease incidence beyond normal proportions
facultative saprophyte
the ability of normally parasitic organisms to live on dead material
Gall
caused by:(4)
Small, local swelling on the stem or branch of a tree caused by fungi, bacteria, insects or physiological disorders
hip canker(affects 3 things)
ridges in stem sapwood, affect form of tree, lumber content, and growth rate
Heart Rot
Decay in the heartwood (centre) of a tree
lesion
a definite, localized area of dead tissue, a circumscribed diseased area
Hypha, Hyphae
A fungus filament
obligate parasite
a parasite that is incapable of existing independently of living tissues
Laminate
Separated into sheets or layers
obligate saprophyte
inability of a pathogen to live on anything but dead material
Mycelium
Collective term for hyphae or fungus filaments
vector
an organism (usually an insect) that can transmit disease
Pathogen
An organism capable of causing disease
virulence
degree of pathogenicity
Parasite
An organism that lives in or on another living organism (host) and benefits by deriving nutrients at the hosts expense
Red Belt
Winter drying of conifers in mountainous areas producing bands of reddened trees at specific elevations
Resinosis
An abnormal exudation of resin or pitch from conifers
An abnormal flow or resin or pitch from conifers
Rhizomorph
Strand or chord of compact mycelium, often dark in colour
Saprophyte
An organism which lives off of lifeless organic matter
Sign
Expression of the casual agent of a disease
Symptom
Expression of the host indicating the presence of a disease
Sunscald
Heat injury to bark and cambium resulting from exposure to intense sunlight
Aggregating Phermones
Phermones released by either sex of an insect which attracts both males and females to a location. Used by bark beetles to ensure that sufficient beetles are at a susceptible tree to overcome its resistance
Boring Dust
Fine, light coloured powdered wood, cast out of tunnels made by burrowing bark beetles or other wood boring insects. An early sign of attack by bark beetles.
Chitin
A polymer that constitutes a major component inside an exoskeleton and fungal cell walls
Egg Gallery
A groove excavated by a female bark beetle under the bark. Eggs are laid in niches or groups along the side of the egg gallery. When larvae hatch, they excavate feeding galleries in the phloem at right angles to the gallery
Frass
Dry excremement of wood boring insects consisting chiefly of wood particles or other plant material. Solid larval insect excrement
Instar
The immature insect. The first instar is the insect after hatching but before its first molt. The second instar is the insect after the first molt but before its second molt etc.
Any post-egg stage, initiated or terminated by molting, indicated growth stages.
Larva
An individual that emerges from the egg and differs markedly from the adult form
Metamorphasis
The change in form during development
Nymph
The immature stage of a hemimetabolous insect (one with incomplete metamorphasis); it usually resembles the adult.
Parthenogenesis
Development of an egg without fertilization
Pitch Tubes
A combination of boring dust, insect frass, and tree pitch that amasses around the entrance hole of an egg galleryas the adult female beetle excavates under the bark
Pupa
The stage of insect development between the last larval instar and the emergence of a new adult.
Decay
The process by which sound wood is destroyed by the action of fungi
Inoculum
Spores or tissue of a pathogen that serve to initiate disease in a plant. Infectious material.
