University of Florida

Appendix 14: Glossary

action threshold

pest density at which a management tactic is implemented to avoid economic loss.


business ventures revolving around agricultural production, such as marketing pesticides, fertilizer or pest population information.

apical meristem

the growing point (bud) of the stem through which vertical growth occurs.


a disease characterized by general and rapid killing of leaves, flowers and stems.


the collection of outermost floral leaves or sepals that enclose the remaining floral parts until flower maturity.


a definite, sunken or cracked dead area on the stem or branch that is surrounded by living tissues.


a yellowing or bleaching of normally green tissues due to the decline in chlorophyll production; often a common disease symptom but may be due to unavailable nutrients.


pair of tubular processes on the posterior part of an aphid's abdomen, looking like two "pipes".


pertaining to the top surface or "back" of insects.


solid waste of insects (fecal material).


the enlargement of a canker or other wound about a stem, completely cutting off water and/or nutrient supply resulting in plant death.

Integrated post management (IPM)

an approach to controlling pests which emphasizes minimizing crop losses by all means at the grower's disposal - resistant and tolerant varieties, cultural methods, biological control, and application of chemicals.

larva - (larvae pl.)

the immature stage between the egg and the pupa of an insect with complete metamorphosis.


a localized area of diseased tissue, such as a leaf spot or canker.


a legless larva of a fly, without a well defined head region.


very short hairlike appendages covering the body of certain caterpillars; usually requires magnification to be seen.


characteristic symptom of viral diseases where variegated patterns of dark green to yellow form in leaves.


an irregular pattern of light and dark areas in foliage.

myceilum - (mycelia pl.)

the hypha or mass of hyphae that make up the body of a fungus.


a rapid, localized destruction of all tissue structures resulting in death; rots and cankers are necrotic symptoms.


egg laying organ of the female insect.


an organism that is partially or wholly dependent upon living tissue for survival; an example of particular interest to an IPM practitioner is the beneficial insect which lives in or on other living organisms (hosts); are usually smaller than their host, many insect pest parasites are small wasps.


the measure of a plant's developmental stage.


a beneficial insect that is usually larger than its prey and which kills and devours more than one host during its lifetime.


a fleshy, non-jointed protrusion on the underside of a caterpillar's abdomen, which functions as a leg.

pupa - (pupae pl.)

the inactive stage between larva and adult in insects with complete metamorphosis.

pyonidium - (pycnidia pl.)

a spherical or flask-shaped asexual fruiting body of a fungus that can be resolved easily with a hand lens.

scierotlum (sclerotia pl.)

small, fungal resting structure composed of a mass of interwoven funnel strands; these are usually dark colored and variable in shape.


a hard, triangular plate on the dorsal surface of true bugs, between the base of the wings.

shot hole

a symptom in which small diseased fragments of leaves fall off and leave small holes in their place.

stoma (stomata pl.)

opening usually in the lower leaf epidermis that connect to intercellular space where gas exchange occurs between the spongy tissue and the outside air.


a groove or seam in the external skeleton on an insect.


a compound leaf with three leaflets arising from the same rachis or leaf axis.

true legs

appendages on ventral portion of thorax; insects have six such structures.

vein banding

a viral disease symptom in which areas along leaf veins are darker green than the tissue between these veins.


a target or bulls eye-like symptom on plant tissue that is diagnostic of certain diseases.