Insects+Use+for+Pest+Management

By: G. Alexopoulos

Insects use for pest management have been utilized for years as a way to naturally combat pest species utilizing their natural predators.


 * Background:**

Humans have been confronting insects as pests for thousands of years. Carrying numerous diseases, insects also have the ability to decimate agricultural crops and cause famine or infect humans with diseases like malaria, yellow fever, or even eggs of their young like the Bot fly. Homemade pesticides of the past became highly developed chemical pesticides. Humans have also been able to develop more pest resistant crop species (a very controversial topic regarding Genetically Modified Organisms)! In efforts to control pests and also limit the use of pesticides University of California developed Integrated Pest Management in the 1950s which utilized the best chemical and biological control for a given pest species. focusing more on when to apply a pesticide to do the greatest amount of good for a small environmental and financial impace.

More interestingly to myself is the biological control of pest species. That is to say, utilizing the predatory and parasitic nature of one species of insect to control the numbers of a pest species. Nature is a cruel place where numerous insect species can fall victim to predation or parasitism.


 * Why use them?**

Chemical pesticides are used widespread and frequently on farms and in your home bug sprays, deterrents, and poisons. The problems occur when these pesticides end up in harming what they shouldn't. Eventually, the nearly complete reliance on insecticides for the control of pests produced problems of their own. Outbreaks of secondary pests, increase of the pest species following the unintended loss of beneficial insects and other arthropods, dramatic failures in pest control following insecticide resistance, and the general toxic nature of these chemicals harming pesticide applicators, consumers, and wildlife (Smith,1970). These problems are still issues today, while insecticide usage has decreases throughout the years especially in the agricultural industry in the United States. The topic of genetically modified plants is fairly controversial. Those against cite reasons ranging from insect resistance to unknown allergens. While other sources show no real affect to the wildlife or any long term effects from GMO use. It is still unknown whether GMO use can cause increasingly resistant "superpests" or cause other unintentional harm. Benedict and Altman (2001) used the results of their study to show that the use of insect protected cotton in 2001 reduced pesticide use by 6.6 million kg of formulated product. Regardless a more natural way for pest control limiting the potential unknown consequences of GMO or chemical pesticide use appears to be the greenest and most environmentally friendly option.

Insect based pest control is useful in decreasing the number of pest species. This is accomplished by releasing or attracting the natural predators of these pest insects. Then, you let nature run it's course. Predator finds prey and eventually an infestation can be decreased to near eradication.


 * Benefits****?**

Using insects to control pests has been done for many years. It happens naturally in the environment as it exists currently. As plants grow they face a number of challenges; diseases, predation, even parasitism can seriously affect the growth of plants. Using insects for pest management means you introduce a natural predator to these pest species. This does not necessarily mean that the introduced insects will prey on your pest. Some predator species have unique abilities to parasitically utilize their prey to lay their eggs in or on them. Their larval young then hatch and feed externally or internally when ready to pupate.


 * What Pests!**

__Aphids:__

Aphids are small an interesting insects that have the potential to cause millions of dollars in crop damage. As Hemipterans, aphids have a tubelike structure called a rostrum which sheaths their sucking mouth parts called a stylet. A majority of their life if not spent mating is spent sucking plant sap also called phloem. These insects can suck plants dry. That is with a large enough infestation a plant can become overwhelmed and eventually die. Additionally, aphids carry numerous plant diseases that can easily be passed from plant to plant by aphids. Aphids can even caused famine from crop failure like the Irish potato famine of the 1840s which killed about 1 million people in Ireland.

__Whitefly__

Whiteflies are small hemipterans that feed on plant veins carrying phloem on the undersides of leaves. Whiteflies usually congregate in large numbers and plants die when overwhelmed by They comprise the family Aleyrodidae with nearly 1550 species described. Able to spread and carry diseases whiteflies impact food production globally. The whitefly problem is most serious in the tropics and subtropic zones. Aleyrodidae cause hundreds of millions of dollars in economic losses. Shown to be able to transmit almost 60 viral plant diseases, whiteflies sometimes carry viruses able to infect a number of different plant species.


 * What Insects?**

Below are a few examples of the types of insects used when controlling pest species with insects.

__Ladybugs (Lady beetles or Ladybird beetles)__

Within the order Coleoptera and under the family Coccinellidae lies the voracious pest consuming Ladybug. While it's name may seem tame for this predator, which is able to consume hundreds of aphids in their lifetime. Additionally, they devour insect eggs, mealybugs, and other soft-bodied insects and mites. Some species of coccinellidae develop a taste for certain prey species. Overwintering as adults in sheltered areas ladybugs are able to live for 11 months some extending two or three years. Throughout the United States as the cold fall months approach Ladybird beetles invade homes and buildings near fields and woods for warmth. Typically swarming on the sides of buildings on periods following cold weather in the late afternoon with temperatures warming in the mid-60s F.

__ Parasitic Wasps __

Part of the Ichneumonoidea family within the order Hymenoptera which contains other families of bees, wasps, and ants. //Encarsia formosa// is one example that lays it's eggs on a whitefly nymph. Parasitic wasps use their host as protection, incubation, and location to lay their eggs. How is this useful with controlling pest species? If your pest happens to be a favorite host for these parasitic wasps the host species won't survive long. These wasps target a number of pest types including aphids, caterpillars, cicadas, lace bugs, scale insects, whiteflies, sawfly larvae, ants, leafminers, and various insect pupae and eggs.

Parasitoid insects are one of the most widely used biological control agents. Commercial production can produce upwards of 4-1000 million female parasitic wasps per week. These facilities run into problems when shipping their live cargo. Conditions in transit can be too hot or cold, and even vibrations from planes and trucks can disrupt the insects(Smith ,1996).

__Lacewings__

Green and brown lacewings are another beneficial insect in the family Chrysopidae and the order Neuroptera containing mantidflies and antlions as well. Able to eat 150 prey items in their lifetime or upwards of 100 aphids a week, millions of lacewings are reared in several countries for biological control. Lacewing larvae are able to consume a number of pest species including aphids, mites, and other small insect pests. While the adults are able to feed off pollen, nectar and even honeydew. While these insects can be bought as a safe, nonchemical, pest control commercially it can be costly. Homeowners can attract theses insects by using companion plants in their gardens. specifically Chrysopidae are attracted to cosmos, sunflowers, dill, and dandelion


 * How can you get beneficial insects at home?**

Believe it or not but beneficial insects are available for sale online. You can purchase different size treatments and also different methods of treatment. You could get a box of hungry Ladybugs ready to devour some Aphids, or you could get a box of female lacewings filled with eggs and ready to lay them.

>  Pp. 137-201.
 * sources**
 * 1)  Smith, R.F., 1970. Pesticides: Their use and limitations in pest management. In: Concepts of Pest Management, R.L. Rabb and F.E. Guthrie, eds., North Carolina State University, Raleigh, NC, USA, pp. 103–118.
 * 2)  Smith,SM (1996) Biological control with Trichogramma:advances, successes, and potential of their use. in 'Annual Reviem of Entomology' pp. 375-406
 * 3) Benedict, J.H., Altman, D.W., 2001. Commercialisation of transgenic cotton expressing insecticidal crystal protein. In J.J. Jenkins and S. Saha (ed) Genetic improvement of cotton: Emerging technologies. Science Pub., Enfield, NH Betz, F. S.,