Wednesday, September 3, 2008

Remember to Treat for Fire Ants This Fall

Even though we have been experiencing high temperatures, fire ants are unfortunately still in the area. They can live deep within the soil so their mounds may not always be visible. Since they are a medically important insect pest, control measures should be taken in some cases to decrease their populations.
Before treating for fire ants, one must first survey the area to determine the number of mounds, if possible. If less than 5 mounds are present in a quarter acre plot, then it is advised to treat the individual mounds. Treating individual mounds is the fastest way to get rid of the fire ant mounds, but it is more labor intensive and more costly to apply when compared to the broadcast baits.
If more than 5 mounds are present, then treatment should be broadcasted over the entire area. A fire ant bait or contact insecticide may be used. Fire ant baits are made up of defatted corn grit covered with insecticide and soybean oil. Before broadcasting the fire ant bait, foraging activity should be evaluated. In order to test for foraging activity, place a potato chip or hot dog next to the mound. If fire ants find the chip or hot dog within fifteen minutes, then it is an appropriate time to broadcast the fire ant bait. Fire ants will typically actively forage when the soil surface temperature is between 70 and 90° F. The delivery process of fire ant baits into the colony is so effective, that the amount of insecticide applied in an area is significantly reduced. Fire ant baits should never be watered into the soil and they should not be used if they smell rancid. Contact insecticides can also be broadcasted over the entire area and these need to be watered into the soil. One contact insecticide containing fipronil can be used for fire ant control and will usually provide 9 to 12 months control.
Both fire ant baits and contact insecticides can be broadcast using a hand-held spreader for small areas or a Herd Seeder can be mounted onto a truck or ATV for larger areas.
Before applying any type of pesticide, always be sure to read and follow the pesticide label. Also, never use harmful toxins, such as gasoline to control fire ants. These products are illegal and dangerous. In addition, never leave insecticide baits on streets or walkways after application, in order to avoid unnecessary entrance into the water supply.

For more information, please visit the fire ant webpage at

Red imported fire ant lifestages. Photo by Dr. Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Irritating Fleas Jumping Around

The most common type of flea is the cat flea. However, there are a number of other flea species which occur in Texas, including the dog flea, Ctenocephalides canis (Curtis), and the oriental rat flea, Xenopsylla cheopis (Rothschild). All of these fleas are around 1/8 inches in length, dark brown in color and have a wingless flattened body. Mated female fleas lay eggs that are white and round, after consuming host blood. Eggs fall to the ground in the area where the host spends time and rests. Whitish, legless larvae hatch from eggs in 2 to 3 weeks. The larvae develop in 9 to 15 days under optimum conditions. Fully developed larvae will then pupate by spinning a cocoon of silk that becomes covered with soil particles and debris. This protects the pupa and makes them hard to detect. The pupal stage lasts from 7 days up to a year before adults emerge. Under optimum temperature and humidity conditions, fleas can complete their lifecycle from egg to adult in 30 to 75 days.
Adult mouthparts are modified for piercing and sucking blood and they can bite repeatedly. Not only are flea bites irritating due to an itchy reaction, but they can also transmit diseases such as murine typhus.
Sometimes buildings can become infested with fleas even when there are no pets around. Other animals such as bats, roof rats, squirrels, raccoons, and wild dogs and cats commonly have fleas and may bring them within structures. The building should be inspected and all openings should be sealed so wildlife can not enter.

Non-Chemical Control Suggestions:

Change pet bedding regularly and vacuum thoroughly. Vacuum under furniture, cushions, chairs, beds, and along walls. Make sure to discard vacuum cleaner bags at least once a week, since fleas can continue to develop inside vacuum cleaner bags.

Some Chemical Control Suggestions:

Treat your pets. One suggestion is to use a product containing an insect growth regulator that are available as sprays, spot-ons, pills or food additives. Insect growth regulators work by disrupting the normal development of flea eggs and larvae. With all products, read and follow label directions carefully. Products designed for use on adult dogs should not be used on puppies or cats, unless specified on the label.

Treating homes. The pet’s living area should be treated at the same time that the pet is treated. This will hopefully kill immature and newly emerging fleas and will prevent re-infestation of the pet. Citrus sprays containing d-limonene is one suggestion that can be applied to rugs, carpeting and pet bedding. Also, insect growth regulators such as methoprene and pyriproxyfen can be used indoors. Methoprene is unstable in sunlight so it is an effective indoor treatment. However pyriproxyfen sprays, can be applied both indoors and outdoors. Outdoors, treat areas where pets spend most of their time, such as bedding areas or under shade trees.

Remember to inspect your pet for fleas regularly and carefully follow the label directions on the insecticide products.

Photo of a cat flea, Ctenocephalides felis (Bouche) (Siphonaptera: Pulicidae),
larva, pupa, adult and pupal case (bottom).
Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Crouching Chinch Bugs

As we walk onto our lawns this summer, we might come across browning, dying patches of turfgrass due to chinch bugs. The southern chinch bug, Blissus insularis, is one of the most damaging insects to St. Augustine grass in Texas. Even though these insects are only 1/5 inches in length, they can cause damage to large area s of turfgrass.

Chinch bugs develop through incomplete metamorphosis with an egg, nymph and adult stage. The nymphal stage appears orange-red in color with a pale white band across the third part of their bodies (the abdomen). As they molt, the nymphs will change in color from orange-red to black and develop wings. The adult chinch bugs have black bodies with fully developed white wings that contain black triangular markings on the outer margins. The entire life cycle from egg to adult can occur in about 7 to 8 weeks, so more than one generation can occur in a year.
St. Augustine grass is the primary host of the southern chinch bug, but they can also attack bermudagrass, bahiagrass and zoysiagrass. Both nymphs and adults remove sap from the base of plants and inject a toxic substance that prevents transportation of water within the plant. Damage appears as irregular patches of dead or stunted grass surrounded by a halo of yellowing, dying grass. Damage can develop rapidly, especially during hot, dry weather.

One way to detect chinch bug infestations is to use an open-ended can immersed in the soil filled with water. The water causes the chinch bugs to float to the top of the can. The can should be placed in different locations within the damaged grass, totaling a square foot sample area. If 20 to 25 chinch bugs are found in random samples equaling a square foot, then control is needed. Also when infestations exist, chinch bugs may be seen walking on leaves or adjacent sidewalks on hot days.

Some Control Suggestions:

Non-Chemical Control Options:

1) Keeping thatch to a minimum will reduce protective breeding areas for chinch bugs. Lawn aeration and top-dressing, such as compost, can also reduce thatch.
2) Too little or too much water also can cause chinch bug problems. Over-watering results in saturated, oxygen-deprived soils which contain few microbes needed to decompose thatch. Dry lawns should be watered immediately when edges of grass blades begin to curl or if the grass does not spring back quickly when stepped on.
3) Keep beneficial insects in the lawn such as big-eyed bugs (Geocoris spp.) and minute pirate bugs (Xylocoris spp.).

Chemical Control Options:

A variety of liquid and granular insecticides are available to control chinch bugs. Granular insecticides can be applied with a standard fertilizer spreader and should be watered in with 1/4 inch of water to activate the insecticide. Liquid sprays are usually applied using a hose-end sprayer, so be sure to spray back and forth across the same area to ensure the entire area is treated.

If chinch bugs are in an isolated area of the lawn, spot treatments can be used. The off-colored turf and all surrounding infested areas should be treated. Spot treatments can minimize the impact of insecticides on beneficials and help avoid environmental contamination.
Products containing such chemicals as acephate, imidacloprid, lambda-cyhalothrin, bifenthrin and permethrin can be used to control chinch bugs.

Photo: Chinch bugs, Blissus spp. (Hemiptera: Lygaeidae), nymphs and adults. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.