With the beef cattle industry in Panola County worth an estimated $62 million annually, controlling external parasites is important to avoid financial losses from your livestock operations.
Commonly referred to as ectoparasites, external parasites cost livestock owners in Panola County, Texas millions of dollars each year. Untreated, these parasites make animals suffer and lose weight. Additionally, these pests transmit diseases and suck blood, reducing meat and milk production in cattle and lowing the quality of animal products.
Integrated Pest Management (IPM)
Efficient pest management requires that cattle operators understand the three components of integrated pest management (IPM) and how they work together. IPM uses cultural, biological and chemical control methods to more effectively suppress insect pests.
Biological Control Methods
For the purpose of this article, we will focus on using biological control methods, otherwise referred to as augmentation. The release of natural enemies (predators, parasites and pathogens) to control pests. Augmentation uses commercially available species applied in a timely manner to prevent population increases or to suppress a pest population. As with any control method, we must first identify insect populations accurately, then we can better use selected beneficial insects to control pest insects through predation.
A few examples of predation are:
- Fire ants preying on any available larvae
- Black dump fly larvae feeding on housefly larvae developing in the same manure
- Small fish and immature dragonflies, damselflies and mayflies feeding on mosquito larvae
Beneficial insects can also control pest populations through competition:
- Soldier fly maggots eat more manure than horn fly or housefly maggots
- Dung beetles remove manure to house their larvae
- Parasitic wasps lay eggs inside immature horn flies, houseflies and stable flies
It is important to note that natural enemies can be released all at once or over time to suppress pests or keep their numbers low. Also, the environment can be enhanced to favor natural enemies.
"Timing of the release of natural enemies is critical."
Although research has shown releasing natural enemies can be very effective in greenhouses, outdoor releases are affected by unpredictable environmental conditions.
Furthermore, if a second pest is unaffected by the released organism, pesticides used to control the second pest often eliminate the natural enemy of the first pest.
Commercial products available for use as biological control options include:
- Microbial insecticides (bacteria, fungi and viruses)
- Multicellular animals (predators, parasites and nematodes)
- Flowers to attract and conserve beneficials in and around pest-prone or pest-infested sites
- Traps using colors or scents as attractants
Best Practices for Pest Control
Purchasing and releasing natural enemies for pest suppression is a rapidly developing technology, but there is still much to be learned to assure effective use of these methods. Results can be inconsistent because of variable conditions such as environmental change. The behavior of these natural predators under different environmental conditions can influence the degree of pest control. Outdoor releases of natural enemies can be negatively affected by high winds, rain, hot or cold weather and other insects in the ecosystem.
Timing of the release of natural enemies is critical, since most require some time to affect the pest population. Releases at low pest densities are more effective than attempts to reduce high pest densities. In addition, many natural enemies attack only certain life stages of the pests, such as egg or larva. Multiple releases may also be necessary to maintain pest suppression, and the practice demands intensive scouting to monitor both pest and beneficial population numbers and effectiveness.
Support from Companies Selling Pest Control Products
Most companies will provide the consumer with directions on how to use their products and support their claims of product performance. Insectaries and brokers, the companies producing and marketing parasites and predators, assure the delivery of viable natural enemies of the stated species or strain. They usually do not guarantee results from releases of these biological control agents, even when used as directed.
Lee Dudley is the County Extension Agent for agriculture and natural resources for Panola County. His email address is firstname.lastname@example.org.