How to Use This Booklet
Go to the tab that best exemplifies the damage observed on ornamental plants or turfgrass. Some insects are not easily seen. Sometimes a magnifying glass or a microscope is needed. The type of damage caused can provide evidence of the culprit. Not all insects cause damage and many benefit your garden. You will find many of these insects in the beneficial insects section of this book.
Insect Guide Key
Size of the insect:
🔎 – needs magnification to be observed
> ⅛” – 1/8” to 1/2” long
> ½” – 1/2” long or more
Practice Integrated Pest Management (IPM)
Before choosing a course of action about an insect in the garden,
remember the four principles of IPM:
- Monitor the garden
- Identify the insect or problem
- Evaluate the situation and predict the impact of the
damage, if any - Make a decision about the best course of action and choose
your control methods
Consult your county Extension agent and state pest control handbook regarding the choice of control methods. Always follow pesticide labels and use proper precautions before handling pesticides.
Pretty or pest?
Some insects, especially those that cause chewing damage to plants, are beautiful additions to the garden at later stages in their life. Take a look at the caterpillars and see what they become before you decide to take action.
Chewing damage
Clues: Scraped or chewed leaves or flowers. Frass and webbing.
Examples
Beetles
Caterpillars
Grasshoppers & Sawflies
Dieback damage
Clues: Unusual wilting, drying or death of a branch or twig on an otherwise healthy plant.
Examples
Scales
Soft Scales
More clues: In addition to unusual wilting or drying, look for frass in branch crotches or frass ‘toothpicks.’
Examples
Borers
Distortion damage
Clues: Abnormally shaped or colored deformation of plant parts. Some of these can also be symptoms of plant diseases.
Galls
Insects & mites that make galls
Leaf curling
Leaf mines
Stippling damage
Clues: Chlorotic spots. Also look for frass, cast skins and webbing.
Examples
Lace bugs
Mites
Pest insects of turfgrass
While visual evidence of insect damage to turfgrass is often seen above ground, damage can be caused by insects that live either above ground or below ground. Proceed to the tabbed section that best exemplifies observable damage.
Sampling
Several techniques are used to confirm the presence of insects in turgrass:
Flotation sampling
Soap flush sampling
Soil sampling
Above ground pests
Chewed or shredded leaves, leaves with shot-holes, cut stems, abnormal yellowing or drying of leaves. Also look for frass, webbing or spittle-like substance on leaves.
Examples of damage
Chewing pests
Sucking pests
Below ground pests
Example
Possible culprits
Beneficial insects in the landscape
Beneficial insects include predators and parasitoids. They prey on pest insects or use them as hosts for the parasitoids’ young. Such insects are beneficial because they remove pests from the environment.
Predators
Predators prey on pest insects. Predators are generally larger, faster and stronger than their prey and often capture and eat many individuals during their life cycle.
Example
Beetles
Dragonflies
Damselflies
Flies
Lacewings
Mantids
Wasps
Spiders & Mites
True bugs
Parasitoids
Parasitoids at work
Flies & Wasps
Useful terms
Bugs
“True bugs” are insects belonging to the suborder Heteroptera, under order Hemiptera. Sometimes “bugs” is misused as a generic term for insects.
Cast skins
Dried skins left by immature insects after they molt.
Chlorotic spots
Pale yellow, green or white spots on leaves caused when sucking pests draw out plant sap.
Frass
Insect fecal matter.
Larva(e)
Immature insects that do not resemble the adult(s).
Nymph(s)
Immature insects that resemble the adult.
Predator
Insects or other organisms that prey on other insects. Predators are generally larger, faster and stronger than their prey and often capture and eat many individuals during their life cycle.
Parasitoids
Insects that live and develop as parasites on other insects (hosts) and eventually kill them. Parasitoids usually complete their development on a single individual host.
Flotation sampling
Method to sample turf insects (e.g., chinch bugs), done by inserting one end of a hollow, cylindrical container into the turfgrass and filling it with water. Insects, if present, will float to the top and can be counted.
Soap flush sampling
Method to sample turf insects (e.g., sod webworms and other caterpillars), done by drenching a unit area of turfgrass (e.g., 2’ x 2’) with soapy water (2 fl. oz. liquid dish detergent in 1 gal. water). Caterpillars, if present, get irritated by the soap and
crawl to the surface, and can be counted and identified.
Soil sampling
Method to sample soil-dwelling insects (e.g., white grubs and bill bug grubs), done by digging about 6 inches deep into a unit area of soil (e.g., 1’ x 1’), at several points over the turfgrass. Grubs, if present, will be exposed and can be counted.
