[Image: Spider, Centipede, Millipede]Bugs, Bugs, Bugs July 2009
There are always a lot of questions about how the weather affects the insect populations. Does it increase the populations? Does it kill them out? A good example of this action can be seen now that we are hot and extremely dry. Have you noticed any increase in insect population? Have you noticed any declines? First, many of us are probably staying inside where it is cool to keep away from the burning rays of the sun, and we’re finding that there seem to be more insects and other relations trying to join us indoors, such as spiders, millipedes, centipedes, ants and sow bugs. Pests such as snails are accumulating on walls, plants and even mailboxes. Honeybees are accumulating at our swimming pools and hummingbird feeders; wasps and yellow jackets are visiting our trash cans more often and in larger numbers. Mosquitoes and fire ants appear to have gone into hiding. Wooly bears and crickets have also shown an increase in numbers. All of this is due, in part, to our present weather situation.
Most of the visitors coming indoors are looking for some type of relief from the heat and drought. Many are being attracted to the areas around the house that are being watered. The watering attracts other insects that are the primary food sources for the spiders, ants and centipedes (Figure 1). They also are attracted to the outside light sources, which are excellent insect attractants and therefore provide good food sources. They come indoors because they can feel the coolness escaping under doors that are not properly sealed by the sweeps, and this makes it easy for them to come in and cool down. Management of this situation is easy. First, change the outside lights to bug or yellow lights to reduce the insect attraction to them. Then, treat the plant beds with a pyrethroid to kill potential food sources and drive out or kill the spiders, ants and centipedes. Last fix the sweeps on the doors and make sure they fit the length of the door and have a good seal. This will keep the pests out and save you money by reducing the loss of your air conditioning. Many of these pests are in the lawns feeding on other insects that come to the decomposing thatch left after mowing your lawn. Periodic thatch removal will remove this food source and help your grass put its roots in the soil and not in this decomposing material where droughts as we’re having can cause it to die back.
Snails are likewise attracted to the moisture from watering the plants or lawn to keep them alive. The condensation on the plants as the temperatures cool in the evening and condensation on mailboxes all act like magnets to these plant-feeding pests. The snails and slugs can be treated with several materials to help eliminate them. Beer traps, Niban, Mesurol or Methaldehyde baits can all be used for management of slugs and snails.
Honeybees are foragers, and when the weather dries, the nectar sources and pollen sources in plants dry up. This causes honeybees to forage anywhere they can find a food source. Sometimes those are insect populations that excrete honeydew, sometimes trash cans that are uncovered and sometimes foods left outdoors – especially drinks and sweets, even beer. Your pool is an excellent source of water that the honeybees use to “air condition” their hives – even insects can get overheated. And hummingbird feeders are an excellent source of nectar for honey production. All of these situations can create problems for the homeowners, so corrective measures need to be addressed. Honeydew-excreting insects – like aphids and scales – can be treated with any number of oils, soaps or insecticides. In some cases, predators and parasites are capable of easily controlling these populations but do on occasion need assistance. Be sure to do it correctly, or you could kill the beneficials and release the pest populations. Trash cans can be covered and simply moved away from the house to prevent interaction. Hummingbird feeders can have little cages placed over the feeding sites to prevent the bees from feeding there – and periodically clean the outside of the feeders to remove drippings the hummingbirds leave. As for the swimming pool, it’s hard to completely remove the attraction for the bees, but sometimes a bird path filled with water or some of the pool water will draw the honeybees away from the pool and allow for uninterrupted pool fun. Try to place the water between the pool and the bee hive if you know where it is. Honeybees are excellent pollinators and are very beneficial to both vegetable and flower gardens as well as to the other plants and animals around the neighborhood. Honeybees can be a problem by building their hive in the walls of your home. Information about honeybee removal and swarm collection is available on the LSU AgCenter Web Site. This will provide you with a [Image: Mosquito and Larvae]lection.htm">list of beekeepers and their phone numbers to assist you with their removal. Unless you have experience working with honeybees, this can become a big stinging problem for you and the neighborhood.
Yellow jackets, on the other hand, can be much more aggressive and can build very large nests. Although they are beneficial by feeding on many soft-bodied insects, when disturbed they can sting several times and are sometimes aggressive without being disturbed. They will forage in open trash cans and on unguarded food and drinks. They are very aggravated by someone taking a drink from a soda and trying to swallow them while they are getting a drink from inside the can or bottle. They will be more aggressive during the heat and drought when you clean fish outdoors. In this environment they will build their nest in some unusual protected places more than normal, such as under raised houses or trailers. In the wild they are easy-going until disturbed, but when they build their nest next to living or working situations, they become a problem. In the woods they are excellent beneficials, but around the home they need to be removed. Pyrethroid sprays with oil or soap usually can be very effective.
Mosquito populations are down but not out with the lack of water. With the accumulations of rainfall in some areas, we will see the populations come back very strong. Where water stands or collects needs to be watched closely after a good rain. It only takes a short time for the mosquitoes to develop and cause havoc, swarming around and biting. Dump any containers that hold stagnant rainfall and use mosquito dunks in areas where possible – small ponds, water kettles, etc. Various mosquito repellents are available. Use the one that works best for you. Put mosquito fish in water sources where possible to feed on the larva.
Fire ants have not gone away but are waiting for the right time to swarm out and begin new colonies. The hot weather makes it difficult for them to dig in the hard soil, but once it rains and the round is wet, they will swarm out of the mounds and begin to establish new colonies. Do not treat until you have checked for foraging activity. This is the best indicator of the times to treat for fire ants. Use something with a high oil content, placing it in the yard for about 30 minutes, then check for activity. If covered in fire ants, this is the time to treat. Baits, growth regulators and contact materials abound on the market. Use what fits your goal best. The Web page has loads of information and our number to call if you have questions. If you desire, we can come to a community or subdivision meeting to present the program on how to set up the communitywide programs. If you’re treating a large area, the[Image: Woolbear of Flower]re are spreaders available to you through the county agents. Check the map on the Web site to see where these spreaders are located and make arrangements to have one ready when you are.
Wooly bear-salt marsh caterpillars are not usually a problem in gardens and fields, but with the dry hot weather the only lush green are young plants and watered vegetables and flowers. These caterpillars have been causing problems for all of these. Again, the problem is the young, succulent plants and the watered plants make prime targets for these hungry caterpillars. They can be easily managed in the home flower and vegetable gardens with pyrethroids, but in young soybeans and other crops, it’s difficult to justify treatment. In some cases the damage is done very quickly and replanting could be a better option than spraying.
Large populations of black field crickets, devil horses and some grasshoppers have shown up, creating a nuisance and eating plants. The field crickets gather around lights, get in buildings and get mashed around doorways, making things slippery. The constant chirping from the crickets indoors can be very aggravating. The feeding on plants by the devil horses and grasshoppers – usually not a problem – is increased because of numbers. All of these can be managed with Sevin or pyrethroids with timely applications. The devil horses are a little early because populations normally occur in late July and August.