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.

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).

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

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.

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.

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.

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.