Week.10.Beneficial Microorganisms & Insects in Pest Management Flashcards
Beneficial Organisms Include -Natural Enemies- which include (2)…
-Invertebrates
-Vertebrates
Beneficial Organisms Include -Micro Organisms- which include (5)…
-Diseases
-Viruses
-Bacteria
-Protozoa
-Fungi
-It is important to understand natural enemies so that they can be manipulated to our advantage.
-Consider the target pest natural enemies before formulating control strategy.
-Chemical control may affect populations of beneficial organisms or natural enemies.
Biological Control is…
Pest management tactic involving the deliberate use of natural enemies to reduce a pest’s population.
Natural Control may…
may involve other agents other than natural enemies and no purposeful manipulation is involved. Its efficacy may be affected by weather, food, etc.
Biological Control has a history of…
-One of the oldest most effective methods of pest control.
-Earliest records date to fourth century China where ants were used to suppress pests in citrus.
-Many other forms of control were documented. These varied from the use of insects, lizards, birds and toads to control insects.
In was not until ….. that biological control was firmly established as a control method in the USA. That year marked the successful introduction of a predatory insect, the vedalia beetle, Rodolia cardinalis.
1888
The object of biocontrol is to introduce natural enemies or manipulate existing ones to cause pest populations to drop below economic injury level.
A goal of many of the programs is to establish a -self-sustaining system-. A natural enemy is introduced with the hope it will become established, and will continue to hold the population down indefinitely.
Agents of Biological Control include (4)
-Parasites.
-Parasitoids.
-Non-beneficial parasites (or Hyper-parasites).
-Predators.
A Parasite is…
an animal that lives on or within a larger animal called the host.
-The parasite feeds on its host, usually weakening it sometimes killing it.
Parasites with the greatest impact on insect populations are… (2) and kinda as (3)
Insects or Nematodes
-Mites- also parasitize insects but have a lesser impact on populations.
Nematode parasites are available commercially for several horticultural and agricultural applications. The primary genera used for biological control is …… and ….. .
Steinernema and Hetertorhabditis
-Commercial formulation include alginate gels, clays, flowable gels, and water dispersed granules.
-Commercial formulation include alginate gels, clays, flowable gels, and water dispersed granules.
Parasitoids are…
Insects that parasitize other insects and arthropods are most appropriately called parasitoids.
At what stage is a parasitoid, parasitic?
A parasitoid is parasitic in its immature stages but is free living as an adult.
-In all instances parasitoids kill their hosts, but in some circumstances the host may live much of its full life before dying.
-Parasitoids may attack many host stags, but the adult stage is the least frequently parasitized.
The most significant group of parasitoids are the….. and ….. .
Hymenoptera and Diptera
In Hymenoptera the most significant group of insects are small parasitic wasps belonging to several families.
In Diptera the Tachinidae family stands out.
-Either penetrate the body wall and lay eggs inside host or attach eggs to the outside of the host’s body.
-If larvae eggs are laid outside the newly emerged larvae will have to burrow inside the insect’s exoskeleton to feed.
-If larvae eggs are laid outside the newly emerged larvae will have to burrow inside the insect’s exoskeleton to feed.
-Populations can be sustained in low numbers.
-Only one host is required for development of a parasitoid, and most have a narrow host range resulting in good control of specific pests.
-Host searching capacity may be strongly reduced by weather or other abiotic factors.
-Only females search.
-Often the best searchers lay few eggs.
-Like pests, natural enemies have enemies themselves. Parasitoids have parasites, most often tiny wasps, that kill them while feeding on their host.
-This phenomenon has been termed hyperparasitism. The parasite attacking the beneficial parasite is considered a hyperparasite.
-Parasites can also affect predatory insects introduced as biological control or insects used to suppress weeds.
-Introduction of new parasitic species needs careful study to determine ecological impact of these releases.
Predators are…
are free living organisms that feed on other animals.
-Predators may attack both immatures and adults, and more than one individual is needed for a predator to reach maturity.
-Major predators of insects include birds, fish, amphibians, reptiles, mammals, arthropods including spiders, mites and other insects. Even some plants.
-Many of the important predators used in biological control are insects and mites.
Nearly ever insect order has important predatory species. Some notable predatory insects include lady beetles, ground beetles, lacewings, ants, flower flies, damsel bugs, and assassin bugs.
-Some of the most successful instances of biological control have been with insect predators and insect pests.
Some predators that feed on single species are called ….. .
monophagous.
Insects with a narrow range of pray feeding on a few species are called ….. .
oligophagous.
Insects with a wide range of prey are called ….. .
polyphagous.
Insects with a polyphagous habit may not respond as well to changing pest densities and may have limited success in controlling a specific pest.
:)
Characteristics of Predators are:
-Kills prey rapidly
-Often all individuals in the population (males, females, immatures, and adults) search for prey.
-Synchronization of predator/prey life cycle is not critical aspect of timing control.
Some Predator Insects Are:
-Hemiptera (Like Damsel Bug & Assasin Bug).
-Lacewing, Neuroptera: Chrysopidae
-Coleoptera: Carabidae Ground Beetles
-Coleoptera: Coccinellidae Lady beetles
Lady Beetles are predators in ….. & ….. stages.
Larvae & Adult.
Lady Beetles eat a wise range of prey including (4)…
aphids, scales, mites, and thrip.
<Pathogenic>
-Insects contract diseases. They have been recognized as far back as 2700 BC in China with honeybee.
-The idea of using a microorganism (Fungus) to control a pest dates back to the eighteenth century.
</Pathogenic>
-Today insect pathology is an established discipline that contributes to the modern biological control programs.
The major microorganism causing diseases in insects include: (4)
-Bacteria
-Viruses
-Protozoans
-Fungus
-Most of these have been studied for the use as microbial insecticide.
-More than twelve insect pathogens have been registered with the EPA (necessary step to be able to sell them) since the first the first registration of Bacillus popilliae in 1948 now know as Paenibacillus popilliae or Milky Spore. It is a soil dwelling gram positive bacteria
-Milky spores are used commercially to control the white grubs of Japanese beetles.
-Applications of product in August, when the grubs are close to the surface and feeding, they are vulnerable to infestation by milky spore.
-Spores in the soil are swallowed by grubs during their normal feeding of roots. This ingestion of the spore by the host activates reproduction of the bacteria inside the grub. Within 7–21 days the grub will eventually die and as the grub decomposes, billions of new spores are released into the soil.
-Milky spore is not harmful to beneficial insects, birds, bees, pets, or people. Like other bacteria, survives drought conditions, but suffers in temperatures of Zone 5 and colder.
Keep It Going :)
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