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