Module 15: Pests of the Acadian Forest

Appendix B - Glossary

Gall: Plant galls are abnormal outgrowths on tree parts and can be caused by various parasites, fungi, bacteria, insects and mites.

Instar: A stage in larval development of an insect, between two moults.

Moult: When the insect sheds its outer layer during growth.

Nymph: The larval form of certain insects usually resembling the adult form but smaller and lacking fully developed wings.

Pheromone: A chemical compound, produced and secreted by an animal, that influences the behavior and development of other members of the same species.

Pupa: The non-feeding stage between the larva and adult in insects, during which the larva typically undergoes complete transformation within a protective cocoon or hardened case.

Biological Control: A method of controlling pests using other living organisms; knowledge of natural predators, parasites, and other interactions are used to manage pest populations. Biological control may be a component of Integrated Pest Management.

Btk: Bacillus thuringiensis var. kurstaki (Btk) is a type of bacteria found naturally in the soil that is known to cause illness in various insect larvae, including caterpillars of pest species such as gypsy moth, spruce budworm, and cabbage looper. It is used as a form of biological insecticide.

Cocoon: a casing spun of silk by many moth caterpillars and other insect larvae as a protective covering while in pupa stage. Cocoons may be tough or soft, opaque or translucent, solid or mesh-like, and of various colours and layers depending on the type of insect larva producing it.

Defoliator: an adult or larval insect which strips all the leaves from a tree or shrub.

Larva: a juvenile form of an organism before morphing into adult stage.