Friday, January 30, 2009

Prevention of Larger Animals Entering Homes This Season

As we approach into colder weather, wild animals may move closer to or into our homes. They are ultimately in search of warmth and may invade under homes or in attics. It is always easier to prevent invasion than to remove them. This makes EXCLUSION the key to the prevention of wildlife invaders. Exclusion is the best way to prevent entry. Remember that rats and mice can fit through holes as small as ¼ inch in diameter, so be sure to seal all areas where sunlight can be seen. Exclusion can be accomplished by using steel mesh in the attic to close off possible entry points. The steel mesh can be stapled or nailed around whirly birds, vents and other openings in the attic. Weep holes and cracks and crevices can be sealed using steel wool. If the outside brick is light colored, then non-rust copper steel can be used. Both steel wool and steel mesh can be found at hardware stores. Trees should also be trimmed away from structures. When tree limbs are touching houses, it becomes a perfect bridge for the animals to enter homes.
Also proper sanitation is important to prevent animals from approaching homes. All food containers should be cleaned and properly contained in closed bins, in order to avoid animals entering garbage or recycle containers. Bird seed and other food items should be stored in a sealed container. Clothes, blankets and fleece should also be stored in sealed container, in order to avoid rats and other animals nesting in the materials.
If wild animals are living in or near your home, you must first figure out what animal it is before control should be taken. Mice and rats can be trapped using sticky or snap traps. These traps should be placed perpendicular to the wall, in areas where you see droppings, gnawing, urine stains, or scratch marks.
Call the city or wildlife department if larger animals are believed to be living in homes/structures. Most departments will donate a live cage trap for a period of time and most cities will pick up the trapped animals when they are caged.

Wednesday, January 21, 2009

Using Biological Control to Control Pests

Biological control is an appealing choice to control pests, since there is no persistence of insecticides in the environment or the development of pesticide resistance. The release of natural enemies such as predators, parasites and pathogens to control pests is a type of biological control called augmentation. However, the act of purchasing and releasing natural enemies for the control of insect and mite pests can be disappointing, due to level of the control achieved. Natural enemies are living organisms, so their behavior under different environmental conditions can influence the degree of pest control achieved.
When multiple pests occur within an area, then sometimes natural enemies are needed for each pest. Commercial products available for use to control insects and mites include bacteria, fungi, viruses, nematodes, parasites and predators. Timing of the release of natural enemies is critical, since most require some time to affect the pest populations. Releases of these natural enemies at low pest densities are more effective than releases conducted to reduce high pest densities. Environmental conditions can change dramatically and outdoor releases of natural enemies can be negatively affected by high winds, rain, hot or cold weather and other insects in the ecosystem. In addition, many natural enemies attack only certain life stages, such as egg or larval stage of the pest so multiple releases may be necessary.
Companies selling natural enemies should provide consumers with directions on how to use their products and provide claims of product performance. Also, the purchaser of natural enemies must be aware of legal and biological limitations of augmentive biological control methods.
Sometimes by simply restricting the use of broad-spectrum insecticides will allow naturally occurring beneficial organisms to survive and control the pest. Remember that when insecticides are used, the residues can remain on the crop or site or insecticide drift from adjacent areas can remain toxic to natural enemies long after the insecticide was applied.

Sunday, January 11, 2009

Shore Flies Indoors

Picture of adult shore fly. Photo on:

Shore flies are usually found in greenhouses, since they are attracted to algae growing on potting soil and under greenhouse benches. However, they can be found living on many house plants as well. Shore flies are frequently confused with fungus gnats, since they are usually found together. However shore flies have short antennae, a large head with red eyes, and smokey gray wings with 5 white spots on each wing. Also shore flies are stronger fliers than fungus gnats.
Female shore flies will lay eggs singly on the surface of algae. The eggs will hatch in about 2 to 3 days. The larvae will be found on the top layer of potting soil, feeding on the algae. Shore fly larvae are 1/8 inches in length, with a brownish-yellow, legless body. The larvae do not have a distinct head capsule, but their dark mouthparts and internal organs may be visible. The larvae mature in 3 to 6 days and then pupate. The pupae are also found close to the soil surface. The adult fly will emerge 4 to 5 days later and it will feed on the same materials as the larvae. The adult fly usually stays close to the breeding sites.
Eventhough the shore fly adults and larvae do not feed on plants, they still can present problems. Adults can be a problem, since they can transmit plant pathogens, such as Pythium and other root disease organisms. Also the shore flies’ excrement can land on foliage and leave unsightly black specks.

Some Control Options:

Some Non-chemical Control Options:

1) Avoid over watering and limit fertilizer run-off. Allow soil to dry before watering again.
2) Algae should be removed from under and on benches, walls, and floors.
3) Compost should be aerated often and relocated away from doors and windows.
4) Pasteurized container mix should be used or treat potting soil with heat or steam before using it.
5) Remove standing water and eliminate any plumbing or irrigation system leaks.

Some Chemical Control Options:

Some chemical control options include using such active ingredients as bifenthrin, permethrin to control adults and azadirachtin, kinoprene, diflubenuron, or cyromazine to control larvae.

Saturday, January 3, 2009

Fungus Gnats Fluttering Around

Picture of fungus gnat. Photo found at Texas A&M University:

Bringing plants indoors could result in another flying insect fluttering around inside, since these plants could have become infested with fungus gnats during the warmer weather. Adult fungus gnats are small, 1/8 to 1/10 inches in length, grayish black in color, have a slender body with long legs and antennae. They also are identified by the Y-shaped wing vein. Fungus gnats are usually weak fliers, so they tend to rest on foliage or growing media.
The female fungus gnats will lay tiny, oval semi-transparent eggs in moist organic debris. The fungus gnat eggs hatch into legless larvae that are white to clear in color, with shiny black heads. They eat organic mulch, compost, root hairs, and fungi. The larvae can damage roots of plants, which causes wilting, poor growth and loss of foliage. The flies then pupate in the soil within silk-like cocoons. The complete lifecycle from egg to adult occurs in around 4 weeks.

Some Suggestions for Control Measures:

1) Inspect plants before purchasing and use sterile potting soil.
2) Allow soil to dry for several days to kill some larvae, since over watering, poor drainage and water leaks can result in a large population of fungus gnats. If the top layer of the soil becomes dry, then the larvae will likely die and the females will be less likely to lay eggs in the soil.
3) Discard heavily infested plants to avoid infesting other plants.

Biological Control
1) Some predators of fungus gnat larvae include Steinernema spp. nematodes and Hypoaspis spp. mites that can be applied to the soil.
2) Bacillus thuringiensis israelensis (Bti) can be applied to the soil to control fungus gnat larvae.

Some Chemical Control Options
Larvae can be controlled by many chemicals, such as those containing azadirachtin and imidacloprid. Adult fungus gnats can be controlled by foliar treatments, such as those containing bifenthrin, permethrin, resmethrin, and neem oils.