Chinch Bugs & Mole Crickets

Chapter 2

Section VII

of the

Pest Bear & AffiliatesService Personnel Development Program

2005

Copyright @ 2005-2006, Central Fla Duplicating, Inc. All rights reserved

While the Southern Chinch Bug is the most serious pest of St Augustine grasses, it not a serious pest of any other grasses.

Their life cycle will vary depending on the area of the State:In North Florida the eggs hatch in late April and they have 3-4 generations each yearIn South Florida the eggs begin hatching in February and they may have 7 generations each year

Southern Chinch Bugs

Life Cycle

Chinch Bugs have a gradual metamorphosis

Egg

Nymph - 5 molts

Adult

The first instar nymphs are about the size of the head of a pin and bright red in color with a white band across the back

Older nymphs and adults are about 1/5 “ long and black

Adults have white wings contrasting a black body

All stages, except the egg stage, damage the grass

Feeding Habits

Chinch Bugs damage St Augustine grass by sucking the plant juices from the stems

Chinch Bug damage first appears as yellowish or brownish patches in the lawn

Damaged areas are often found in water stressed areas along the outer edges of the lawn

Chinch Bug damage is particularly apparent during periods of drought

Use of Cultural Practices

Studies have shown that certain cultural practices can drastically reduce the need for pesticide applications for the control of Chinch Bugs

Some cultural practices are

Do not mowing St Augustine lower than 3”

Keeping the mower blade sharp

Irrigate with 3/4” of water and do not rewater until wilting is noted

Fertilize only following a soil test and apply fertilizer designed for your grass

Controlling Chinch Bugs Requires Monitoring

Inspect the lawn regularly, weekly is recommended but not necessarily practical

Look for off-color areas, particularly in areas that are not shaded or are along walks or driveways

Visual inspection is necessary and requires parting the grass the find and identify the nymphs and adults

Examine the base of the grass next to the soil

When heavy infestations occur, Chinch Bugs can often be seen crawling on grass blades and sidewalks

Using a Water Float to Find Chinch Bugs

Use a 2-3 pound coffee can with both ends cut outPush 2-3” into the soil at the margin of the yellowed area

You may need to cut through the rootsFill the can with waterIf present, the Chinch Bugs will float to the top in about 5

minutesMay need to add water to keep the level above the grassCheck all suspected areas

Do Not Assume Yellowing is Chinch Bugs - It could be nutritional or disease related

Resistant Varieties of St Augustine

Floratam, Floralawn and Floratine varieties of St Augustine offer varying degrees of Chinch Bug Resistance

Floratam and Floralawn provide true antibiosis, the Chinch Bugs do not develop while feeding on them

Floratine is only tolerant to reduced infestations

Using Pesticides for Control

Pesticides should not be applied unless a high level of infestations, 20-25 Chinch Bugs per square foot has been noted

Since residual treatments are basically non-effective in controlling Chinch Bugs, spot treatments are recommended.

Treat the infested areas and a 5 foot buffer around the target area

Apply the treatment as needed or biweekly until the infestation is controlled.

Treat the entire yard when a severe infestation is noted

Chinch Bugs and Resistance

In some areas of Florida, Chinch Bugs are resistant to organo-phosphate and carbamate insecticides

Resistance has been enhanced by misapplications of pesticides and the Chinch Bugs tremendous reproductive potential

Where resistance has occurred, synthetic pyrethrins should be applied

Mole Crickets - General Information

The two most destructive species of mole crickets in Florida are the:

Southern Mole Cricket

Tawny Mole Cricket

The Short-winged Mole Cricket occurs in South Florida

The Northern Mole Cricket is found throughout Florida but is not numerous

Mole Crickets - General Information

Mole Cricket adults are about 1 1/2” long and light brown in color.

Their fore legs are short and stout and well adapted for tunneling through the soil.

Tawny, Southern and Short-winged Mole Crickets are South American species and hitch-hiked to the United States in ship’s ballast.

All three species became established about 1900 in Brunswick, GA.

Mole Crickets - Import ant Pests

Mole Crickets have no native parasites to limit their development and spread.

In Florida, there are about 4.4 million acres of bahiagrass, which is their favorite host.

Most bahiagrass is in roadsides and pastures and is not highly managed.

Florida’s sandy soils are are an ideal habitat

Mole Crickets - How Damage Occurs

Mole Crickets tunnel through the soil near the surface.

Tunneling loosens the soil so that the grass is uprooted and dies due to desiccation to the root system.

Mole Crickets damage the grass roots causing thinning of the turf and eventually completely bare soil.

Bahiagrass is more susceptible to Mole Cricket damage because of the open-growth habit and presence of sandy soils.

Mole Crickets - Oviposition

Mole Crickets deposit their eggs in chambers hollowed out in the soil.

Chambers are found in the upper 6” of the soil unless the weather is cool and the soil is very dry.

A female will average constructing 3-5 chambers.A female will usually deposit around 35 eggs in

each chamber.

Mole Crickets - Egg Laying

Oviposition usually begins in the latter part of March.

The peak egg-laying is May to mid-June.

Approximately 75% of the eggs are laid in May and June.

Eggs hatch in about 20 days if the weather is warm.

Mole Crickets - Feeding Habits

Nymph Mole Crickets burrow to the surface and feed on organic matter and small organisms.

Most Mole Crickets feed at night, particularly after a rain or irrigation.

Coming to the surface causes damage due to tunneling and tunnels may be 20 feet in length per night.

Mole Crickets are strongly attracted to lights at night.

Mole Crickets - Inspection

Visual inspection is necessary to determine level of Mole Cricket infestation.

“Soap Flush” is a very effective way to find Mole Crickets.Use 1 1/2 fluid ounces of liquid dishwasher detergent in 2 gallons of water, applied with a sprinkling can over 4 square feet.If 3-4 Mole Crickets appear on the surface within 3 minutes, treatment is probably needed.

Mole Crickets - Cannibalism, Predators, and Biological Control

Southern Mole Crickets are very cannibalistic and nymphs devour other nymphs and eggs.

When they come to the surface, numerous predators feed on them and often damage the lawn in the process.

Research is underway and attempting to control mole crickets with parasitic nematodes, fungal pathogens and viruses, and predatory larvae.

Mole Crickets - Cultural Control

Proper irrigation and fertilization practices greatly reduce the damage done by Mole Crickets.

Do not mow bahiagrass lower than 3” and keep the mower blade sharp.

Do not let turf to dry out too much, and when watering, apply 3/4” of water.

Do not irrigate until grass begins to wilt.Monitor the levels of nutrients and apply only

what is needed to maintain the grass.

Mole Crickets - Chemical Control

Apply pesticides if damage from previous infestations is noted in the spring.

Apply pesticides when adults are at the surface and tunneling.

Use the soapy-water locating method to determine the amount of the infestation.

Pesticides may need to be applied 2-3 times a year if infestations are heavy.

Mole Crickets - Applying Pesticides

Mole Crickets may be controlled with sprays, granules or baits.

Apply product when the overnight temperature is expected to be 60 degrees or higher.

Make sure the lawn is moist when making the application.

Irrigation following application sometimes encourages the Mole Crickets to come to the surface to feed.

Mole Crickets - General Pesticide Info.

Be sure the pesticide selected is labeled for use on lawns.

Read and understand the directions on the container regarding dosage rates, application information and precautions.

When applying liquids, use ample amounts of water.

Follow label instructions concerning post treatment precautions and procedures.

Use adequate safety precautions and equipment.