IPM scouting in herbaceous perennials > glossary

Apothecia: A small almost mushroomlike structure, shaped like a satellite dish or a saucer on a stalk. Visible with the naked eye. Certain fungi produce these structures and develop spores within them.

Frass: Plant fragments excreted by caterpillars during feeding.

Inoculum: The pathogen or part of the pathogen used to start disease (spore, mycelium, sclerotia, bacterial cell, etc.).

Larva or larvae (plural): Immature stage of insects – between the egg and pupa – that undergo complete metamorphosis (egg, larva, pupa and adult).

Mycelium: Filamentous strands or threadlike structures that make up the vegetative part of a fungus.

Nymph: Immature stage of insects – between the egg and adult – that undergo incomplete or gradual metamorphosis (egg, nymph and adult).

Pycnidia: Flask-shaped reproductive structure produced by some fungi within which spores are produced asexually. Structures may be embedded in the diseased tissue and look like grains of pepper within a lesion or a leaf spot. (See Septoria.)

Sclerotia: Hard, vegetative structure produced by some fungi, which can remain in a dormant state for extended periods of time. Typically found in soil and plant debris.

Setae: Dark-colored, hairlike structures (similar to an eyelash) produced by some fungi. Sometimes visible with a hand lens on infected plant material. (See Anthracnose.)

Sporodochia: A mat or cushionlike reproductive structure produced by some fungi. Sometimes visible with a hand lens on infected plant material. (See Myrothecium.)

Vector: Insect capable of transmitting pathogens such as viruses from one plant to another.