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Recently I have been looking into biological pest controls. Most people are familiar with some of these such as lady bugs or predatory mites, however there is a wide range of pest control options from fungi, bacteria, predators or parasitoids. In my search I came across an amazing resource (http://www.biocontrol.entomology.cornell.edu/index.php). It is my plan to read several of these over the next couple of days and compile a list of which predator goes with each pest because the website doesn't seem to do that, and I feel that is a more appropriate way to organize the data. I would also eventually like to compile this into some kind of pdf, but that seems like a rather difficult and lengthy task at the moment. As I've said before, wholesale use of pesticides effects the good and bad organisms alike. I have started a similar topic regarding the use of plant compounds as an effective pest management strategy, Organic Garden Pests-Aside! Predators The arthropod predators of insects and mites include beetles, true bugs, lacewings, flies, midges, spiders, wasps, and predatory mites. Insect predators can be found throughout plants, including the parts below ground, as well as in nearby shrubs and trees. Some predators are specialized in their choice of prey, others are generalists. Some are extremely useful natural enemies of insect pests. Unfortunately, some prey on other beneficial insects as well as pests. Insect predators can be found in almost all agricultural and natural habitats. Each group may have a different life cycle and habits. Although the life history of some common predators is well studied, information on the biology and relative importance of many predatory species is lacking. In this document, we have included the more common and better understood beneficial predators. Major characteristics of arthropod predators: adults and immatures are often generalists rather than specialists they generally are larger than their prey they kill or consume many prey males, females, immatures, and adults may be predatory they attack immature and adult prey Relative Effectiveness Most beneficial predators will consume many pest insects during their development, but some predators are more effective at controlling pests than others. Some species may play an important role in the suppression of some pests. Others may provide good late season control, but appear too late to suppress the early season pest population. Many beneficial species may have only a minor impact by themselves but contribute to overall pest mortality. Often too, the role of the beneficial predators has not been adequately studied. Surveys of agricultural systems give an indication of the potential number and diversity of predators in a crop. For example, over 600 species of predators in 45 families of insects and 23 families of spiders and mites have been recorded in Arkansas cotton. Eighteen species of predatory insects (not including spiders and mites) have been found in potatoes in the northeastern United States. There may be thousands of predators per acre, in addition to many parasitoids. Although the impact of any one species of natural enemy may be minor, the combined impact of predators, parasitoids, and insect pathogens can be considerable. Predators Table of Contents Pathogens and Antagonists of Plant Disease and Post-Harvest Decay Insects and mites, like plants, humans, and other animals, can be infected by disease-causing organisms such as bacteria, viruses, and fungi. Under some conditions, such as high humidity or high pest abundance, these naturally occurring organisms may multiply to cause disease outbreaks or epizootics that can decimate an insect population. Diseases can be important natural controls of some insect pests. Some pathogens have been mass produced and are available in commercial formulations for use in standard spray equipment. These products are frequently referred to as microbial insecticides, biorational, or bio-insecticides. Some of these microbial insecticides are still experimental, others have been available for many years. Formulations of the bacterium, Bacillus thuringiensis or Bt, for example, are widely used by gardeners and commercial growers. Most insect pathogens are relatively specific to certain groups of insects and certain life stages. The microbial products do not directly affect beneficial insects and none are toxic to wildlife or humans. Specificity, ironically, can be a disadvantage to the commercialization of these products because their small market may limit profitability. Unlike chemical insecticides, microbial insecticides can take longer to kill or debilitate the target pest. This may limit their use to crops that can sustain some insect damage. To be effective, most microbial insecticides must be applied to the correct life stage of the pest, and some understanding of the target pest's life cycle is required. Some microbial insecticides must be eaten by the insect to be effective. Good spray coverage is therefore important. Major characteristics of insect pathogens: they kill, reduce reproduction, slow growth, or shorten the life of pests they usually are specific to target species or to specific life stages their effectiveness may depend on environmental conditions or host abundance the degree of control by naturally occurring pathogens may be unpredictable they are relatively slow acting; they may take several days or longer to provide adequate control they may cause epizootics Microbial insecticides are compatible with the use of predators and parasitoids, which may help to spread some pathogens through the pest population. Beneficial insects are not usually affected directly because of the specificity of a microbial product, but some parasitoids may be affected indirectly if parasitized hosts are killed. Insecticide applicators should note that although microbials are non-toxic to humans in the conventional sense, safety precautions should be followed to minimize exposure. Pathogens Table of Contents Antagonists Antagonists of plant disease and food spoilage microorganisms are not yet well understood. However, the research that has been done has yielded exciting and promising results, and the study of antagonists has become a rapidly expanding field in plant pathology. Worldwide, diseases of crop plants cause losses estimated to be 12%, and post harvest losses due to food spoilage have been estimated to be between 10% and 50%. In the United States, these figures are estimated to be 12% and 9%, respectively. Finding ways to prevent microorganisms from causing these losses would help ensure a stable food supply for the world's ever expanding population. Outside of agriculture, diseases can cause the destruction of entire stands of plants in marshes, forests, or other natural settings, and in other plant systems. Knowledge of the interactions among microorganisms and ways to manipulate microbiota is growing as research in this field rapidly expands. Antagonists have been successfully used to suppress tomato mosaic, foot and butt rot of conifers, citrus tristeza disease, and crown gall of several crops. Seeds have been coated with antagonists that reduce infection by pathogens and also enhance plant growth. Brown rot of peaches in storage was controlled under simulated commercial conditions by incorporating the antagonist Bacillus subtilis into wax used in the packing process. Inoculation of hosts with antagonists has been used with good results against a common fungal pathogen of conifers and chestnut blight. The future also holds much promise for the suppression of plant-parasitic nematodes by microbiota. Growers have applied antagonists to the above-ground parts of plants, to the soil (and roots), and to plant seeds. The above-ground environment is the least stable for antagonists because of the extreme variability in moisture and nutrients. Soil is a more stable environment for microbiota, but soil in most fields is generally nutrient poor, pH may range from 4-8, and temperatures and moisture may vary widely. In contrast, greenhouse planting mixes can be managed more effectively to promote antagonist colonization. Finally, it is practical to treat seeds to favor microbial antagonists. To be most effective, antagonists of plant disease and food spoilage should be: genetically stable effective at low concentrations easy to culture and amenable to growth on an inexpensive medium effective against a wide range of pathogens in a variety of systems prepared in an easily distributable form non-toxic to humans resistant to pesticides compatible with other treatments (physical and chemical) non-pathogenic against the host plant Relative Effectiveness Under ideals conditions, such as in the laboratory, antagonists can completely protect plants from pathogens. In the field, disease control is likely to be less successful. Proper deployment of the antagonist appears to be crucial. Critical factors include moisture and nutrient availability and pH. If the deployment system can meet the needs of the antagonist, successful colonization is more likely. Careful selection of an aggressive strain of the antagonist is also important. Parasitoids Insect parasitoids have an immature life stage that develops on or within a single insect host, ultimately killing the host, hence the value of parasitoids as natural enemies. Adult parasitoids are free-living and may be predaceous. Parasitoids are often called parasites, but the term parasitoid is more technically correct. Most beneficial insect parasitoids are wasps or flies, although some rove beetles (see Predators) and other insects may have life stages that are parasitoids. Most insect parasitoids only attack a particular life stage of one or several related species. The immature parasitoid develops on or within a pest, feeding on body fluids and organs, eventually leaving the host to pupate or emerging as an adult. The life cycle of the pest and parasitoid can coincide, or that of the pest may be altered by the parasitoid to accommodate its development. The life cycle and reproductive habits of beneficial parasitoids can be complex. In some species, only one parasitoid will develop in or on each pest while, in others, hundreds of young larvae may develop within the pest host. Overwintering habits may also vary. Female parasitoids may also kill many pests by direct feeding on the pest eggs and immatures. Major characteristics of insect parasitoids: they are specialized in their choice of host they are smaller than host only the female searches for host different parasitoid species can attack different life stages of host eggs or larvae are usually laid in, on, or near host immatures remain on or in host; adults are free-living, mobile, and may be predaceous immatures almost always kill host Relative Effectiveness Whereas insect predators immediately kill or disable their prey, pests attacked by parasitoids die more slowly. Some hosts are paralyzed, while others may continue to feed or even lay eggs before succumbing to the attack. Parasitoids, however, often complete their life cycle much more quickly and increase their numbers much faster than many predators. Parasitoids can be the dominant and most effective natural enemies of some pest insects, but their presence may not be obvious. It is often necessary, to determine the extent of parasitism, to dissect or rear samples of pest insects to see if any adult parasitoids emerge. Parasitoids can be parasitized by other parasitoids. This phenomenon, known as hyperparasitism, is a natural occurrence, can be common, and may reduce the effectiveness of some beneficial species. Little can be done to manage hyperparasitism. Pesticide Susceptibility Parasitoids are often more susceptible to chemical insecticides than predators. Adult parasitoids are usually more susceptible than their hosts. Immature parasitoids, especially if protected within the egg of their host or in their own cocoon, may tolerate pesticides better than adults, but immature parasitoids will usually die if their host is killed. Parasitoids Table of Contents