BIOLOGICAL CONTROL OVERVIEW Flashcards
Biological Control of Insects and Mites
There are far more applications of bio control agent for the management of insects and mites than any other pest group.
More than 40 insect species have been partially or substantially controlled in the state of California alone in the past century.
Includes
Predatory Arthropods: Green and Brown lacewings, syrphid flies, aphid flies, robber flies, damel bugs, big-eyed bugs, assasin bugs, minute pirate bugs, lady beetles, soldier beetles, predaceous ground beetles, wasps, ants and predaceous mite or spiders.
Parasitic Insects: Mainly Hymenoptera (wasps) and Diptera (flies).
Nematodes: The role of naturally occurring nematode enemies continuous to not be well understood. For those that are known to have some control capacities, they are referred to as Entomopathogenic. (Tend to be used as broad spectrum source of control as opposed to specialits)
Pathogens: Include virus, bacteria, fungi, and other microorganisms. Naturally occurring fungi is important in keeping aphid populations low in humid conditions.
Biological Control of Weeds
Most weeds targeted for biological control are specific problem weeds that are toxic to livestock or have some other undesirable quality.
Pathogens: Offer some potential applications, however because many weeds are closely related to desirable species, any release must be carefully considered. One example of successful pathogen establishment was the introduction of Puccinia chondrillina (rust pathogen) against skeletonweed in Australia.
Vertebrate: Plant-eating vertebrates are used to manage weeds in some situations (usually non-specific and rely heavily on the seeds, fruit, roots, and other plant parts as major components of there diet).
-Fish have successfully controlled aquatic weeds.
-Geese in selective grazing mechanisms for cotton, orchards, strawberries and more.
-Cattle, sheep, and goats especially used in rangeland scenarios.
If not managed correctly vertebrates can attack crop.
Allelopathy: Not very well understood, however some plant compounds may be isolated and synthesized to create stronger detracting effects.
Lack of effective weed control with allelochemicals can be partially attributed to the poor stability, high volatility, and strong absorption of these chemicals to soil particles.
Competitions: Tilting any of the growing resources in favor of the crop plant can help it outcompete the weeds. For instance using transplants can give the host plant an advantage by shading certain weed species and a head start.
Biological Control of Plant Pathogens
Disease suppressive soils
In some cases soil solarization, crop rotating, incorporating compost, green manure, or other amendments can increase activities of beneficial soil organisms and reduce disease occurrence.
Mycopesticides are commercially available beneficial microorganism or their by products that control plant pathogens.
Disease Suppressive soils of those where disease incidence remains low even though a pathogen, susceptible host, and environmental condition are all favorable toward disease suppression.
Biological Control of Plant Parasitic Nematodes
Effective use of biological control agents for plant parasitic nematodes is a complicated manners.
Nematodes have man types of natural enemies that regulate their numbers including insects, pathogenic bacteria, competitors and other nematodes.
A famous is example are that of fungi species that capture and trap nematodes in a snare like fashion.
