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Field guide to exotic pests and diseases: Glossary
6. Glossary
Angiosperms – (flowering plants) a class of vascular plants, all characteristically bearing seeds within enclosing carpellary systems (eg. oaks and eucalypts).
Anterior - at or towards the front of an insect.
Bole – the trunk of a tree up to the first main branches.
Cambium – the meristematic tissue that gives rise to secondary wood (xylem) and secondary inner bark (phloem).
Canker – a disease of woody plants characterised by sharply delimited necrosis of the cortical tissues and malformation of the bark caused by recurring localised killing of the cambium layer.
Castes – any set of individuals in a given colony that are both morphologically distinct and specialised in behaviour (eg. workers, soldiers, queens etc.).
Crown – leafy upper part of a tree.
Defoliation – the shedding of leaves, either as a seasonal normality or as a consequence of disease.
Dorsal - on the upper surface of an insect.
Dunnage – off-cuts of timber used for packaging and stabilising cargo to protect it from damage during shipping and transport. Often very poor quality timber is used for dunnage.
Foliage – leaves.
Frass – solid insect excrement.
Galleries – tunnels and chambers formed by insects eating wood or composed of silk and debris, usually faecal.
Green timber – timber which is newly cut and still has high moisture content. Technically referred to as unseasoned timber.
Gymnosperms – Gymnosperms differ from the angiosperms in having naked seeds with no enclosing carpellary structures (eg. pines and cypress).
Host – a plant or other organism that furnishes subsistence to, or harbours a parasite.
Incipient decay – the early stage of wood decay in which the wood is invaded and may show discolouration but is not otherwise structurally altered.
Larva – the second stage in the life cycle of an insect between egg and pupa. Also known as a grub or caterpillar.
Ovipositor - specialised structure at the rear end of female insects which is used for depositing eggs.
Perennial – a plant that lives for several years.
Posterior - at or towards the rear of an insect.
Pronotum – is the upper and dorsal part of the prothorax of an insect - insects generally have three segments: head, pronotum and abdomen.
Pupa – the third stage of the insect life cycle, in which the larva undergoes transformation into the adult.
Resin – a substance exuded by certain plants when wounded. On exposure to air components evaporate leaving a solid or semi-solid residue protecting the damaged area.
Rostrum – the elongated snout that extends the mouthparts of some insects.
Seasoned timber – timber dried to a moisture content that is stable.
Spore – reproductive structure from which a new organism arises, produced by some plants, fungi, bacteria, and protozoa.
Timber in-service - timber that is used in buildings and field structures, including constructional timbers such as building structures, utility poles, railway sleepers, bridge timbers and other outdoor service timber.
Vector – an agent that carries a disease to a host (eg. insects, animals, wind, rainsplash and infected tools).
Ventral - towards or at the lower surface of an insect.