Monday, September 21, 2009

Larger Populations of Dragonflies in 2009?

Have you been noticing more dragonflies in your landscape lately? According to Dr. Forrest Mitchell, Professor and Entomologist with Texas AgriLife Research in Stephenville, “of the 231 species of dragonflies and damselflies in Texas, 26 species may be migratory, including the brown-and-yellow wandering glider (Pantala flavescens) and the spot-winged glider (Pantala hymenaea). Both are known as rainpool gliders since they are adapted to breeding in temporary water. Rainpool gliders will lay eggs in nearly anything that can hold water including buckets, flower pots, water troughs, puddles, ditches and swimming pools. They will even attempt to lay eggs on shiny car hoods, wet asphalt and wet concrete.
We have had several cool fronts along with heavy localized rain to make rainpools and either or both may be what accounts for the presence of so many dragonflies in our region. I am noticing them mostly over stretches of roads and parking lots or wide open fields where the hunting is good. They may be in other places as well, but harder to see.
However, just as fronts can bring dragonflies, fronts can also take them away. Work in the last decade on the eastern seaboard of the U.S. shows that moving dragonflies are swept together and collected by weather fronts. These concentrations may then be deposited elsewhere and a long way off, so enjoy watching them while you have a chance.”
For more information regarding dragonflies, please visit Dr. Mitchell’s Digital Dragonflies website: or check out A Dazzle of Dragonflies by Forest Mitchell and James L. Lasswell (Texas A&M University Press, 2005). Also Odonata Central posts a checklist of species for Texas:

Photo of female wandering glider, Pantala flavescens. Photo by Dr. Forrest Mitchell, Professor and Entomologist with Texas AgriLife Research (

Tuesday, September 8, 2009

Fire Ant Awareness Week

More than 10 years ago, the second week of September was declared statewide as Fire Ant Awareness Week. This week was established to help Texas residents realize the importance of a fall treatment for fire ants, since it is also important to treat in the fall to keep the fire ants from returning the following 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 a fire ant bait or contact insecticide can be broadcasted over the entire area. 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 chip or hot dog 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 65 and 95° 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 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 for larger areas.
For more information, please visit the fire ant webpage at

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

Friday, September 4, 2009

Fireflies or Lightening Bugs?

"Lightening beetle" is the correct common name since these insects are neither flies, in the Order Diptera or true bugs, in the Order Hemiptera. Adult male lightening beetles are long and narrow and ½- inches in length; they have a black head with a reddish section behind the head and dark brown wing covers edged with yellow. The underside of their last abdominal segments is colored greenish-yellow, since they are capable of producing flashes of light. Few other insects can be confused with lightning beetles, since no other insect possess the light-producing structures on their abdomens. The larvae and wingless adult female lightening beetles are flattened and spindle-shaped. They do have structures that produce light, so they are called "glow worms." The light produced is due to the reaction of two substances, luciferin and the enzyme, luciferase.
Adults produce light to find mates and some species use it to attract other lightning bugs as prey. Immature stages of lightning beetles are predatory on other small insects, earthworms, slugs and snails. Larvae and adults are active at night and inject toxic digestive enzymes into prey before sucking out the liquefied body contents.
Winter is spent in the larval stage in chambers formed in the soil. They pupate in the spring and emerge in early summer. Lightning beetles can be found in early summer beginning at dusk and are mostly found in wooded areas. After mating, females lay eggs in the damp soil. The eggs hatch into larvae in about 4 weeks and the larvae develop through several stages before pupating. The life cycle from egg to adult in most lightening beetle species takes two years.

A lightening beetle, Photinus sp. (Coleoptera: Lampyridae). Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.