Sunday, December 19, 2010

How Cockroaches Are Helping Farmers

Cockroaches are well known for their role as decomposers, but the Asian cockroach (Blattella asahinai) is actually helping Texas cotton farmers to reduce populations of cotton bollworms. In 2006, cotton farmers in Texas discovered these cockroaches in cotton fields. Recently, scientists found that these cockroaches eat cotton bollworm eggs, instead of the plants.
German and Asian cockroaches are almost identical. However, Asian cockroaches have longer and narrower wings and smaller egg cases. In addition, the German cockroaches live indoors, while Asian cockroaches like to burrow in mulch or compost outdoors.
Eventhough this cockroach preys on agricultural pests, scientists are hesitant to make recommendations to mass release this cockroach for the control of lepidopteran pests. Since the Asian cockroaches have been recorded to fly 120 feet in a single flight, they can easily fly into nearby residential neighborhoods. They are attracted to light-colored surfaces or brightly lit surfaces at night and they can enter into structures under doorways or window sills.

Asian Cockroach. Photo posted on USDA website: http://www.ars.usda.gov/is/ar/archive/jan08/roaches0108.htm

Friday, December 10, 2010

Tarantulas Helping People Get Over Fears

According to Reuters Life!, scientists are using tarantulas to determine how the human brain responds to fear based on the proximity, direction and preconceived assumptions of a terrifying object. Researchers from the Cognition and Brain Sciences Unit in Cambridge, England used functional magnetic resonance imaging to follow brain activity in 20 volunteers as they watched a video of a tarantula. Scientists found that different parts of the brain control different parts of the “fear network,” so when the spider moves closer, the brain changes from anxiety to panic. Their results could help scientists diagnose and treat patients who suffer from phobias.
For more information, please visit: http://www.reuters.com/article/idUSTRE6A74KI20101108

Sunday, November 21, 2010

Squash Vine Borers are Active in Gardens

Squash vine borers are the most common and can be the most damaging pests of squash. The larvae tunnel into the stems of squash and other plants, including melons and cucumbers. This causes the stems to wilt and die. The adult moths resemble a wasp, with a red abdomen surrounded with black bands at each segment; their front wings are covered with metallic brown scales and their back wings are clear with a brown band. Adult females lay eggs on the leaves and stems of primarily squash. The larvae hatch and begin burrowing into host plant stems. The larvae are white in color with a brown head and they grow to be an inch in length. The larvae will produce sawdust like frass near the base of the plant as they tunnel and then climb from the stem to pupate in the soil.

Some Control Suggestions:

Some Non-Chemical Controls:


Keep natural enemies in the garden such as parasitic wasps that will attack squash vine borer eggs and larvae. Also adult ground beetles (Family Carabidae) will attack squash vine borer larvae.
When wilting is noticed, a sharp knife can be used to cut a slit into the stem so the larva can be removed. New roots may grow along the cut stem, allowing the plant to survive. Split vines should be covered with soil immediately after the larvae have been removed.
Also remove vines soon after harvest to destroy any larvae that still might be inside the stems.

Some Chemical Controls:

Some chemical suggestions include using such active ingredients as pyrethrins, permethrin, or carbaryl. Apply the dusts or sprays to the base of the plant.

Photo of a southwestern squash vine borer, Melittia calabaza (Lepidoptera: Sessidae), larva. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Tuesday, November 9, 2010

Boxelder Bug Sightings

Boxelder trees are sometimes planted in landscapes, since they grow quickly, reaching heights of 30 to 50 feet. However, they are prone to attack by boxelder bugs. These bugs feed primarily on the female seed-bearing boxelder trees by sucking sap from the leaves, twigs and developing seeds. They will also feed on other trees such as ash, maple, plum and apple, causing scarring of fruits.
Adult boxelder bugs are ½ inches in length, brownish-black in color with three lengthwise red stripes near their heads. Under their wings, their abdomen is red. The immature boxelder bugs resemble the adults in shape, except they are smaller, wingless and bright red in color.
During the fall months, adults and immature boxelder bugs tend to congregate on the female boxelder trees and then begin migrating to a place to overwinter. Only adults overwinter by moving to hibernation sites either by crawling or flying. These bugs tend to cluster in large numbers on the sides of trees and structures, so they can easily enter structures under windows sills or through open doors or vents. If they do invade structures, their feces can stain curtains, paper and other home furnishings. Also their mouthparts can penetrate human skin, so beware when touching them.
The boxelder bugs that happen to enter indoors, will not live more than a few days indoors, do not breed inside, and are essentially harmless.


Some Options for Control:

Some Non-Chemical Control Options:
Removal of the female boxelder trees from the landscape would decrease this insect’s population.
Eliminate hiding places such as piles of boards, rocks, leaves, grass and other debris close to the house.
Caulk and close openings where boxelder bugs can enter the house such as around light fixtures, doors and windows, utility pipes and air conditioners.
Screen all windows, doors, crawl spaces, roof vents, since boxelder bugs are attracted to light and can fly in through doors and windows.

Some Chemical Control Options:
If you do not wish to remove female boxelder trees from the landscape, then the exposed immature boxelder bugs can be chemically treated in the spring and early summer. Insecticides containing the active ingredients such as neem, pyrethrin, rotenone, cyfluthrin, deltamethrin, esfenvalerate and malathion can be used. Specialized equipment may be required to treat tall trees.

Photo of boxelder bug. Photo by Elizabeth “Wizzie” Brown, Program Specialist-IPM, Texas AgriLife Extension.

Thursday, October 21, 2010

Scorpionflies Swarm Woods in North Texas

As you stroll through the woods this fall, you might notice an interesting insect called a scorpionfly, Panorpa nuptialis. This insect is found in the South Central U.S. in wooded areas, near water or in grasslands. Their bodies are around 1 inch in length with snout-like mouthparts and yellow bands on their wings. The male’s genitalia resemble a scorpion’s stinger, hence the common name. They are not strong fliers so they are easy to capture.
Adults feed mainly on dead insects but they can also feed on pollen and nectar; while the larvae feed on dead insects. Before mating, the males will emit a pheromone from their abdomen to attract females. The males will then offer the attracted female a gift. Females often select their mating partners based on this gift offering of prey.
Although scorpionflies may appear scary, especially the males, they do not sting or bite.

Photo of a scorpion fly, Panorpa nuptialis Gerst (Mecoptera: Panorpidae), female. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Monday, October 11, 2010

Can Cockroaches Be Used To Heal People?

Scientists have found that cockroaches might be a good option to fend off dangerous, drug-resistant bacterial infections. British researchers at the University of Nottingham's School of Veterinary Medicine and Science have found 9 different molecules from the tissues of cockroaches and locusts to combat bacteria like E. coli and drug-resistant staph infections (MRSA). These molecules found in the brain and nervous tissues of cockroaches are able to kill 90% of E. coli and MRSA in lab tests, without harming human cells. Since cockroaches live in unsanitary environments, they produce these molecules combat infection. Health experts are afraid that existing bacterial infections will become resistant to current modes of treatment so new ways to kill these bacteria are definitely needed. For the complete story, please visit: http://esciencenews.com/articles/2010/09/07/cockroach.brains.could.be.rich.stores.new.antibiotics

Saturday, September 25, 2010

Fall Webworms Are Likely to be Found Soon

The fall webworm, Hyphantria cunea (Drury), is usually noticed when the light gray silk webs are discovered on trees in late summer and early fall. They are considered pests of shade and ornamental trees in urban areas, by attacking more than 88 plants as they enclose leaves and small branches with their webs. Four generations occur in the south Texas, with 2 to 3 generations occurring in north Texas. The last generation in the fall is usually the most damaging.
The caterpillars build webs soon after hatching and they will remain inside the web consuming the tender parts of the leaves. If the caterpillars eat all of the leaves within the web, then new foliage will be enclosed within the webbing. These caterpillars are 1 inch in length, pale yellow or green in color, and covered with white and black tufts of long hair. The caterpillars will molt 6 or 7 times before dropping to the ground to pupate. The pupae overwinter and the adult moths emerge the following spring.

Some Control Options:

Some Non-Chemical Control Options:
1)Small webs can be removed by pruning and destroying the infested portions of branches.
2) A stick or pole can be used to snag individual webs to allow natural enemies such as yellow jackets, paper wasps and birds to eat the webworms.
3)Bacillus thuringiensis, B.t,. is effective against fall webworms if it is applied when the caterpillars are small. It is better to apply after the eggs hatch and the web is not dense.

Some Chemical Control Options:
Chemicals should be applied after eggs hatch, since they are most effective on young caterpillars. Insecticides such as those containing spinosad and tebufenozide as active ingredients can be used. Multiple applications may be needed as generations continue.

Fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), web on pecan. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Monday, September 20, 2010

Remember to Treat for Fire Ants This Fall

Remember that the end of summer means treating for fire ants! Since the weather has been so hot this summer, we might not necessarily see the fire ant mounds in our yards. However, they are still in the area and are living deep in the soil. Since fire ants are a medically important insect pest, we need to treat this fall to decrease their populations next spring.
Before treating for fire ants, one must first survey the area to determine the number of mounds. If less than 5 mounds are present in a quarter acre plot, then it is advised to treat the individual mounds with a bait, drench or dust.
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 comprised of defatted corn grit covered with an insecticide and soybean oil. Before broadcasting the fire ant bait, foraging activity should be evaluated by placing a potato chip or hot dog next to a mound. If fire ants find the food within fifteen minutes, then it is an appropriate time to broadcast the fire ant bait. Fire ants will typically forage when the soil surface temperature is between 70 and 90° F. 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 the active ingredient 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 to treat larger areas.
For more information, please visit the fire ant webpage at http://fireant.tamu.edu.

Fire ant mound in a landscape. Photo by Dr. Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Sunday, August 29, 2010

Are Flies Biting You Outside?

Have you ever wandered what types of flies can bite you outside, besides a female mosquito? Well there are plenty of other biting flies, including deer flies, horse flies, stable flies, black flies, biting midges and sand flies. All biting flies locate humans and other animals by sensing things in the environment, such the carbon dioxide, dark colors, movement, warmth and perspiration. Once a host is located, a biting fly inserts its piercing mouthparts and injects its saliva with anticoagulants to keep the blood flowing. In sensitive individuals, the fly’s saliva can cause life-threatening allergic reactions. In addition, some flies can transmit disease.
Deer flies are about ¼-inches in length and are typically yellow-brown to black in color with dark bands on their wings. The larvae of deer flies are aquatic so the adult flies are usually found around streams, lakes, ponds, marshes and swamps. The adult flies have scissor-like mouthparts that cut into skin, causing blood flow which they lap up. Deer flies (Chrysops discalis) can transmit tularemia, which is a bacterial disease.
Horse flies are over 1 inch in length and black in color or light brown with shiny green eyes. They are strong, fast fliers and use their scissor-like mouthparts to cut into skin. The larvae of horse flies usually live in water or in moist locations where they prey on other insects. As the larvae grow and then pupate, they move to dryer soils.
The stable fly is ¼-inches in length, and gray in color with four dark stripes on its thorax. This fly has pointed mouthparts that it uses to suck blood, causing a sharp pain when it bites. Stable flies lay their eggs in piles of decaying vegetable matter, such as haystacks, grass clippings and manure.
Black flies are around ⅛ inches in length with broad wings and a hump-backed appearance. They prefer wet environments so they are found near ponds, creeks and rivers. Even though black flies do not transmit disease to humans in the U.S, they can threaten the lives of livestock and humans from inhalation of large swarms or by allergic reactions and blood loss from many bites.
Biting midges, also called “punkies,” and “no-see-ums,” are around 1/32 inches in length. Due to their small size, they can sometimes fly through window and door screens. The larvae of biting midges live in moist sand or soil, decaying vegetation, tree holes and near ponds, rivers, creeks or marshes so the adult flies can be pests around these waterways.
Sand flies are around ⅛ inches in length, hairy and brown to gray in color, with wings that form a “v” when at rest. The sand fly larvae live in moist, decaying vegetation, moss, mud or in water. Most feed on the blood of mammals, reptiles and amphibians. In many parts of the world, including south Texas, certain sand fly species are suspected of transmitting cutaneous leischmaniasis to humans, which is a disfiguring protozoan disease.

Ways to Prevent Bites
Repellents such as those containing DEET (N,N-diethyl-meta-toluamide) or picaridin are suggested to prevent most flies from bitings. Also avoiding wet areas inhabited by the biting flies and wearing light-colored long-sleeve shirts, long pants and hats will prevent some flies from biting.

Controlling Biting Flies:

Some Non-Chemical Controls:
Biting flies can be difficult to control due to all the moist habitats where the larvae can develop. However sanitation is always important, so all potential sites for larval development should be eliminated and decaying vegetation should be disposed of. Also, screens should be installed and maintained on windows and doors and finer mesh should be installed to keep out tiny biting flies, where these flies are a problem. Fans can also be used indoors and outdoors to keep areas free of flies, especially smaller flies that can not fly into the air currents.

Some Chemical Controls:

Ultra-low volume (ULV) treatments and sprays of non-residual pesticides can be used where flies are clustered in a small area. Residual pesticides can be used to spray surfaces where flies are resting, such as in vegetation and along the exterior walls of structures. Also applications of Bacillus thuringiensis israelensis (Bti) or insect growth regulators, such as methoprene, have been used to control some fly larvae.

A deer fly, Chrysops sp. (Diptera: Tabanidae), adult female. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Saturday, July 31, 2010

Field Crickets Out and About Early This Year

As you may have noticed, the field crickets are showing their faces a little earlier this year. Crickets are normally an outdoor insect, usually found under rocks, logs or any crack or crevice. However, they can sometimes enter our homes, mainly under doorways and windows. Crickets feed on all organic matter, including decaying plant material and fungi. Since crickets breakdown plant materials, they are considered beneficial by renewing soil minerals. They are also a food source for many animals such as spiders, ground beetles, birds, lizards and small rodents. However due to their large populations and the male’s mating song, some people wish to control them.

Some Control Options:

Non-Chemical Suggestions:


1) Caulk or seal cracks and gaps that are found in the foundation, around doors, windows, and garage doors.

2) Trim weeds and tall grass growing near the foundation.

3) Remove firewood, brush, rotting wood, boxes, bricks, stones and other objects from around the structure, in order to reduce the number of harborage areas.

4) For crickets found inside the home, vacuum or sweep up and then discard them.


Chemical Control Suggestions:

If a severe infestation exists, there are granular products that can be used for control, such as those containing hydramethylnon. There are also chemicals that can be sprayed outdoors to provide a barrier around homes, such as those containing pyrethrins or bifenthrin. There are also products that can be applied in indoor and outdoor cracks and crevices, such as those containing boric acid. Remember to dispose of dead crickets to reduce the smell and decrease the likelihood of ants feeding on the dead crickets.

A field cricket, Gryllus sp. (Orthoptera: Gryllidae). Photo by Dr. Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Thursday, July 22, 2010

Large Numbers of Bagworms Found on All Sorts of Hosts

This insect is usually first detected by observing the larval bags made up of bits and pieces of host plant leaves and twigs that are woven together with silk. As the larvae grow and feed in the spring and summer, so do their bags. The bags can vary in length from ¼ to 2 inches. Many broadleaf and evergreen trees and shrubs can serve as hosts for bagworm species, including arborvitae and other ornamental conifers, cedar, cypress, elm, fruit and nut trees, juniper, oak, locust, maple, persimmon, pines, sycamore, willow and many other ornamental plants.
Although bagworm species vary slightly in habits and life cycle, the bagworm usually spends the winter months in the egg stage within the bag produced by the female from the previous fall. Very small larvae spin strands of silk and are carried by the wind onto other plants, or larger larvae can crawl to adjacent plants. Full grown caterpillars pupate within their bags usually in the late summer. The male moths emerge out of the bag. The male moths are black in color with ½ inch clear wings and feathery antennae. The male flies to mate with a female. The females remain inside their bags and do not have eyes, legs, mouthparts or antennae. After mating, the females produce between 500 to 1,000 eggs inside their bag and then die.
Infested plants develop more bagworms each year since the female stage does not fly. When there are large populations, the larvae can defoliate plants. Heavy infestations over several years, especially when added to other environmental stresses, can lead to plant death.

Some Control Options:

Non- Chemical Controls:
If only a few small trees or shrubs are infested, handpicking and destroying bags is recommended. During the winter months, the bags contain eggs and during the late spring and summer, the bags will contain a larva.


Chemical Control Options:
When many small bagworms, less than ½ inches are present, then it is recommended to treat with an insecticidal spray such as those containing acephate, azadiractin, spinosad, Bacillus thuringiensis var. kurstaki, permethrin, or bifenthrin.

Bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: Psychidae), larval "bag" on arborvitae. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Tuesday, June 29, 2010

Are Fuzzy Caterpillars Safe To Touch?

It is true, that it is not wise to pick up a fuzzy caterpillar with your bare hands! Usually if the caterpillar has hairs or is brightly colored, they can harm you. These features are meant to protect them from predators. If a predator such as a bird or lizard eats a fuzzy or brightly colored insect, it either tastes bad, gives the predator an upset stomach, or hurts the predator in some other way. This causes the predator to avoid eating another one in the future. Some fuzzy caterpillars such as the Woolly Bears and Tussock Moth Caterpillars have urticating hairs. These hairs can irritate the digestive tract of their predators, and can irritate your skin feeling like fine cactus needles. Puss caterpillars or Asps are more painful when touched. They are blonde in color and extremely hairy. These caterpillars have poison glands that produce an itchy skin rash when touched and hypersensitive individuals may require medical attention.

Puss caterpillar or "asp", Megalopyge opercularis (J. E. Smith) (Lepidoptera: Megalopygidae). Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Monday, June 21, 2010

What Is Making You Itch This Summer?

As we enjoy the warm outdoors, we need to protect ourselves from a small red mite, also know as a chigger. Chiggers develop through four lifestages: egg, larva, nymph and adult. Six-legged larvae hatch from the eggs and climb up onto vegetation, so they can crawl onto a passing host. This is the only stage that feeds on humans and animals. Chigger larvae prefer to bite people in places where clothing fits tightly over the skin such as around the waistline, under socks, or where the skin is thin or creased such as around the ankles or the back of knees. Chigger larvae insert their mouthparts into a skin pore or hair follicle, and then inject a digestive fluid to dissolve skin cells. This results in itchy, reddish welts on the skin. After feeding, the larvae drop off of the host to molt into eight-legged nymphs which then molt into adults. Chigger nymphs and adults feed on eggs of springtails, isopods, and mosquitoes. Under favorable conditions, most chiggers complete their development from egg to adult in 40 to 70 days.

Suggestions for Prevention:

Avoid sitting on the ground when camping, picnicking, or working outdoors. Wear tightly woven socks, long pants, long sleeved shirts, and high shoes. Also tuck pant legs inside boots and button cuffs and collars as tightly as possible to prevent chiggers from climbing inside your clothes. Apply repellents such as DEET or permethrin to both the skin and clothing. Powdered sulfur is another repellent that can be dusted around the opening of your pants, socks, and boots or rubbed on skin such as over legs, arms and waist.

Suggestions for relief after exposure to chiggers:
Wash clothes in hot, soapy water to kill chigger larvae. Take a hot bath or shower and soap repeatedly after chigger exposure. Creams or ointments such as hydrocortisone or calamine lotion can be applied to relieve itching temporarily.

Suggestions for Use of Insecticides:
Chiggers sometimes become a problem in home lawns, so chemical control may be desirable. Insecticide sprays may provide some temporary reduction of chiggers and they are effective when applied in areas where chiggers and their animal hosts are living and/or roaming. Insecticides containing carbaryl, permethrin, cyfluthrin are some suggestions for control.

Photo of chigger bites. Photo by Michael Merchant, Professor and Extension Entomologist, Texas A&M University.

Thursday, May 27, 2010

Attack of the Yucca Bugs


This year you many have noticed abundant numbers of yucca bugs, Haticotoma spp. (Hemiptera: Miridae), if you have yucca in your landscape. The adults are about ¼ inches in length with a red head and pronotum and grayish-black wings. The yucca bugs are usually found in large groups on the upper leaf surface and will tend to move quickly when disturbed. The immature stage or nymphal stage (those without wings), will also be present on the leaves. The yucca bugs have piercing sucking mouthparts so their feeding causes small pale spots or blotches on leaf surfaces where the green chlorophyll has been removed.
Some control options for the immature stage include insecticidal soap or pyrethrins. Systemic insecticide products, such as those containing acephate, dinotefuran or imidacloprid, are also effective for control of these bugs.

Haticotoma (Hemiptera: Miridae) species on yucca. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Friday, May 21, 2010

Possible New Scale Found on Crape Myrtles in North Texas


This bark scale in the genus Eriococcus, is thought to be an exotic insect pest that has infested North Texas crape myrtles. These bark scales appear as white, waxy encrustations near pruning wounds or in branch crotches. Larger female scales “bleed” a pink liquid when crushed. Since this scale excretes honeydew, the limbs and leaves become sticky. In heavy infestations, black sooty mold will begin to grow on the truck and branches of the crape myrtle.
Currently, the crape myrtle bark scale has only been observed infesting crape myrtles in north Texas area (from South Dallas to Sherman). If you live outside this area and believe you have an infestation of this scale, please submit your sample or a picture of the infested crape myrtle to your local county Extension office or to Dr. Mike Merchant (m-merchant@tamu.edu) or myself (k-schofield@tamu.edu) at the Texas AgriLife Research and Extension Center, 17360 Coit Road, Dallas, TX 75252.

Some Control Options:

For heavily infested crape myrtles, it is recommended to wash the trunk and limbs with a soft brush and dishwashing soap solution to remove female scales and egg masses. Also, washing with the soapy water will remove some of the black mold.
Systemic insecticides such as those containing imidacloprid or dinotefuran as a drench applied to the root zone have shown good control when applied between the months of May and July. Also winter applications of dormant oil to the bark and crotches of the plants where scales shelter is an effective control option.

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 http://fireant.tamu.edu.

Aftermath of many fire ant stings!

Fire ants stinging in a circular pattern.

Wednesday, March 31, 2010

Mosquitoes or Midges?

Large numbers of non-biting midge flies (Family Chironomidae) are being reported this time of year. These midges can be easily confused with mosquitoes, since these midges are small, between ⅛- ½ inches in length. However midges lack scales on their wings and do not have a piercing mouthpart, like mosquitoes. Adult midges are humpbacked, are brown, black, or gray in color, and male midges have very feathery antennae. Sometimes in urban environments, where structures are built next to lakes, rivers, stagnant ditches and ponds, adult midges can emerge in extremely large numbers. These swarms tend to occur just after sunset, as the adults become active and fly towards outdoor lights. Adults are attracted to lights and may accumulate in large numbers on window screen, around porch and street lights. Swarms of adults may be so dense that they interfere with outdoor activities and can stain walls and other surfaces when they rest. They can also enter into structures through small cracks or deep piles of dead midges can accumulate underneath outdoor lights.

Chironomid midge eggs are laid on the surface of the water, and then the eggs sink to the bottom and hatch. The larvae burrow into the mud and construct small tubes to live in. The organic matter in the water and in the mud serves as food for the developing larvae. Some larvae are known as "bloodworms" due to the presence of hemoglobin in the blood that allows the larvae to breathe in low oxygen conditions in the mud. Larvae transform into pupae while still in their tubes and then the pupae swim to the surface where the adult emerges. Adults mate in swarms soon after emerging. The males swarm at dusk and mating occurs after females enter the swarm. The adults only live for a few days since they do not feed.

Some Control Options

Some Non-Chemical Control Options:

1) Fertilizer run-off from residential lawns and garden, golf courses and agricultural fields are sometimes responsible for the development of larger populations of midges; so the proper use of fertilizers can avoid excess run-off into lakes, ponds and streams.
2) Locating the source of breeding is advised so all areas of standing water should be eliminated. Midges may fly as far as a quarter of a mile from the breeding site such as a drainage ditch, standing water, lake or pond.
3) High intensity white light has been found to be highly attractive to adult midges so by keeping blinds closed and porch lights off will help to reduce the number of adults attracted to these outdoor lights.

Some Chemical Control Options:

Bacillus thuringiensis var. israelensis (Bti), is registered for use against chironomid midge larvae. Also insect growth regulators such as methoprene can be used to control midge larvae. In addition, applications of residual insecticides such as those containing permethrin can be applied to porches, carports, under the eaves of structures to control adult midges.

Photo of a midge, Family Chironomidae. Photo by Marilyn Sallee, Master Gardener Entomology Specialist, Tarrant County.

Friday, March 19, 2010

New Learning Module for Chilli Thrips

Chilli thrips, Scirtothrips dorsalis, is an invasive insect that has an extremely wide host range, attacking more than 40 plant families. The National Plant Diagnostic Network has released an e-learning module to provide an introduction to the distribution, life history, and pest status potential of chilli thrips. In order to view the chilli thrips e-learning module, please go to and click on ‘take the online modules’. If you do not have an account set up with the National Plant Diagnostic Network , you will need to do so to view the module. As of March 2010, a certificate of completion for the chilli thrips module will be available once the module post test has been completed at 70% or higher.
The chilli thrips training module was developed by Amanda Hodges, Lance Osborne, Howard Beck (University of Florida/IFAS), and Scott Ludwig (Texas AgriLife Extension Service).

Wednesday, March 10, 2010

Amount of Sleep Linked to Premature Aging

If you are like me and are lucky to sleep 4 hours a night, you might want to take action to correct this potentially serious situation. A new study published in the journal of Aging by scientists from Oregon State University found a key gene that helps control circadian rhythms can improve the health of aging fruit flies, if it is unharmed. However, significant health impacts, including early death could occur if the gene is absent. The "period" gene in fruit flies (also found and expressed in almost every cell in the human body) was examined in this study. This gene is one of four primary genes that help control the biological clock in many animals. The study used normal fruit flies compared to mutant flies where the "period" gene was absent. In their experiments, researchers caused a mild metabolic stress to the flies at various times, that corresponded to youth, middle age and old age. They found no significant change in the young flies; however in middle-age and older flies, significant damage occurred. The mutant flies lost some of their motor skills and their brains showed higher levels of neuronal degeneration, similar to Alzheimer's disease in humans. When exposed to a single stressful event, the middle age mutant flies had a 12% shorter lifespan compared to normal flies exposed to the same stress; and when exposed to a single stress in old age, mutant flies had a 20% shorter lifespan.
The scientists theorized that the "period" gene is regulating pathways involved in removal of oxidative damage. Those flies without this gene experienced the symptoms of aging more quickly. These findings could have impacts on neurological damage, heart disease and even cancer research. The work was done under the leadership of Jadwiga Giebultowicz, an OSU professor of zoology, in collaboration with Dr. Doris Kretzschmar from the Oregon Health and Sciences University. For more information, please visit

Monday, February 22, 2010

For all those coffee drinkers out there!

Coffee is one of the biggest cash crops in many parts of the world, and the coffee berry borer is one of the most widespread pests of the coffee berry. The female borer drills a hole into the berry and then lays her eggs. The eggs hatch and the larvae complete their development by feeding on the berry. These tiny beetles cause economic losses estimated at $500 million. Recently, however, a group of scientists discovered a thrips species, Karnyothrips flavipes, which is a natural enemy of the coffee borer. This thrips was identified as feeding on the eggs and larvae of the coffee borer inside the coffee berry. Scientists found the highest percentage of thrips preying on borer larvae and eggs early in the growing season, which coincides with the coffee borer populations being the highest. More research is needed to determine how effective this predator is at controlling the coffee borer and to see if this thrips is preying on the coffee berry borers in other coffee producing countries. For the full story, please view http://www.sripmc.org/news_popover.cfm?id=4153.

Photo of green Arabica coffee berries growing in Kona, Hawaii.

Friday, February 5, 2010

New Entomology Curriculum

The waiting is over...the 4-H Entomology curriculum has been revised! The new curriculum is more engaging for younger audiences and will give all visitors a competitive advantage for college entomology or biology courses. The online material has been redesigned and now consists of printable workbooks in addition to web-based html pages. Web tools now contain more and larger photos of pinned and preserved insects, which will greatly aid contest participants as they prepare for the entomology contest as well as help aspiring entomologists learn insect orders. In addition, the taxonomy used in the new curriculum is being taught in most colleges in the world, and it matches that being taught in the Department of Entomology at Texas A&M University. There are also several digital videos on insect collecting that have been added as supplemental material for those who wish to make an insect collection. The new 4-H entomology resources can be found at insects.tamu.edu/youth/4h/index.html.

Monday, January 25, 2010

Use of Oils to Manage Insects

The use of oils as part of a control program is becoming more favored instead of using synthetic pesticides. Oils can be distilled from petroleum such as horticultural oils, Volck oils, summer oils, dormant oils or mineral oils or oils can be extracted from plants and animals such as neem oil or fish oils. Oils are generally effective against aphids, scale crawlers, mealybugs, spider mites, whiteflies and small caterpillars.
When oils are applied, a thin layer covers the insect or mite. The oil clogs the spiracles or pores through which they breathe causing death by suffocation. Oils can also disrupt membrane function or structure or disrupt feeding. Multiple applications may be needed for control.
Sometimes oils can injure a plant causing leaf scorching, defoliation, reduced flowering and stunted growth however there are some items on the label to be aware of such as unsulfonated residues, viscosity, and distillation. Usually the higher the unsulfonated residue (UR), the less likely for plant injury. Also the lower the viscosity, the less likelihood for plant injury. In addition, the distillation range is a measure of the purity of the oil fraction so distillation ranges of 80°F or less are considered appropriate.
It is best to apply oils when conditions are lower than 85°F and 90% humidity is recommended, since the longer the wet oil remains on the foliage, the greater the chance of phytotoxicity. Also it is not advised to treat stressed plants with oils and some plants are sensitive to oil such as azalea, hibiscus, impatiens, photinia, and spruce so they should not be treated.

Wednesday, January 13, 2010

Whiteflies on Houseplants

The silverleaf whitefly is the most economically important whitefly species in Texas, with a host range of more than 500 plant species, including poinsettias. Adults are 1/16 inches in length with white wings and pale yellow bodies. They will flutter around when disturbed and tend to be more active during the late morning and afternoon, compared to early morning and evening.
The female whitefly will lay oblong, smooth, yellow to amber-brown colored eggs randomly on the underside of leaves. The eggs hatch into flat, greenish-yellow, oval nymphs that begin to suck the sap of plants. Both the nymphs and adults remove phloem from leaves, which causes the leaves to turn pale and die or drop off. Since whiteflies remove phloem, they also excrete honeydew. This honeydew is a perfect media for sooty mold to grow. In addition, plant disorders and virus transmission can result from whitefly feeding.

Some Suggestions for Control Options:

Some Non-Chemical Control Options:

1) Inspect new plants before purchase and treat any infested material.
2) Remove and destroy heavily infested plants from the landscape or interiorscape.
3) Introduce and preserve natural enemies, such as ladybeetles, green lacewings, minute pirate bugs, big eyed bugs and damsel bugs that are predators of whiteflies and minute wasps, such as Encarsia formosa and Eretmocerus eremicus are parasitoids of whiteflies.
4) Beauveria bassiana, a fungus sold commercially can be used to control whiteflies.

Some Chemical Control Options:

Insecticide misuse can result in whitefly populations that cannot be controlled, since chemical overspray can lead to whitefly resistance. Several classes of insecticides are labeled for use against whiteflies and these classes should be rotated in order to avoid resistance. Systemic insecticides can be used such as those containing imidacloprid, dinotefuran or thiamethoxam. Also insecticidal soaps and horticultural oil can be used.

Picture of whitefly. Photo by Dr. Scott Ludwig, Program Specialist-IPM, Texas AgriLife Extension, Texas A&M University System.