Friday, April 30, 2010

Spring Weather Means Attack of the Aphids!

Aphids are small, soft-bodied winged or wingless insects about 1/25 to 1/8 inches in length, with relatively long legs and antennae. Aphids can vary in color from black, green, yellow to even pink. Some aphids lay eggs, while others give birth to live young that can mature in as little as 7 to 8 days. Aphids have piercing-sucking mouthparts that remove phloem from the plant, which can cause distortions in young leaves and stunt new growth. They can also feed on flower buds, which cause deformities.
Since aphids feed on phloem they excrete honeydew, which is a sticky waste product that collects onto lower lying leaves. Once deposited, the honeydew is a nice food source for sooty mold which may grow on the underlying foliage. Sooty mold will inhibit photosynthesis, so its growth can potentially cause severe harm to the plants.

Some Control Options

Some Non-Chemical Control Options: Conserve beneficial insects, such as spiders, praying mantids, assassin bugs, lacewings, ladybird beetle larvae and adults and parasitic wasps in outdoor landscapes. Also spraying water streams is effective to dislodge aphids feeding on plants.

Some Chemical Control Options: Insecticidal soaps and oils can be used to control aphids and are considered low impact insecticides. Other foliar insecticides containing such active ingredients as permethrin, cyfluthrin, carbaryl, deltamethrin, pyrethrins and tebufenozide or systemic insecticides such as those containing imidacloprid or acephate can also be used.

Yellow sugarcane aphid, Sipha flava (Forbes) (Homoptera: Aphididae). Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Thursday, April 15, 2010

Time to Treat for Fire Ants

Red imported fire ants, Solenopsis invicta Buren, are an invasive species that has infested over 360 million acres in the southern United States, and they are continuing to spread. Fire ants are aggressive ants and within seconds after being disturbed, will begin to bite and sting. The fire ant workers bite first and then sting repeatedly, since they have a smooth stinger. After the first sting, it can rotate its stinger and sting again, leaving a circular pattern of stings. Most people who are not highly allergic develop welts and pustules. Fire ant stings can be fatal to those who are severely allergic. Symptoms of a severe allergic reactions include excessive swelling, shortness of breath, and thickening of the tongue. Those who are severely allergic to fire ant stings should seek medical attention immediately.
The use of chemicals is needed to manage their populations, in order to allow the native ant species back into the landscape. Fire ant baits, drenches, dusts and contact granular insecticides may be applied to control fire ants. It is advised to treat the individual fire ant mounds directly if less than 5 mounds are found within a 1/4 acre or less than 20 mounds within 1 acre, since this is not considered an infestation. However, if more than 5 mounds are present within a ¼ acre or 20 mounds within an acre, then a fire ant bait or contact insecticide should be broadcasted over the entire infested area. 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 assessed, by placing a potato chip or hot dog next to the mound. If fire ants find the chip or hot dog within twenty minutes, then it is a suitable time to broadcast the bait. Fire ants will typically actively forage when the soil surface temperature is between 70 and 90° F, which is between May and September. Fire ant baits should never be watered into the soil and they should not be applied if they smell rancid. On the other hand, contact granular insecticides can also be broadcasted over the entire infested area and need to be watered into the soil. Control using contact granular insecticide generally lasts for 6 to 12 months, depending on the active ingredient within the insecticide.
Both fire ant baits and contact insecticides can be broadcasted using a hand-held spreader for small areas or a Herd Seeder can be mounted onto a truck or ATV for larger areas.
For more information, please visit the fire ant webpage at

Aftermath of many fire ant stings!

Fire ants stinging in a circular pattern.