BIOLOGICAL CONTROL Flashcards
refers to the action of parasites, predators, pathogens in maintaining another organism density at lower average than would occur in their absence. It plays an important role in integrated pest management and organic agriculture.
Biological control
It may be slow in effect but can last longer: inexpensive and harmless to living organisms and the ecosystem.
Biological control
Term biological pest control first used by ____ at the yr _____ meeting of the American association of economic entomologists at California.
Harry Scott Smith, 1919
The first report of the use of an insect sp. To control an insect pest comes from_____
Nan Fang Cao Mu Zhuang (Plants of the southern region) by Ji han (Botanist).
Biological control started to emerge in _____ in U.S.A.
1870
First international shipment of an insect as a biological control agent was made by ____ in ___. Shipping to France the predatory mites to help fight grape vine disease agent ___
Charles V Riley , 1873.
Phylloxera
The first importation of the parasitoid into U.S. was of ______ imported from Europe to control _____
Cotesia glomerata
cabbage white butterfly.
Father of Modern Biological Control and the first person who import mites to control grapevine Phylloxera.
Charles Valentine Riley
_____includes the use of natural enemies and beneficial microorganisms to reduce insect pest population and disease incidence.
Biological control
three biological control agents namely:
parasitoids. predators and entomopathogens.
It refers to the entomological insect parasite. ____ as opposed to parasites destroy the host. This includes organisms that require only one host to complete their life cycle. ____ usually smaller than the host (pest).
Parasitoids
Classification of Parasitoid Development According to the Insect Life Stages
- Egg parasitoids
- Larval parasitoids
- Nymphal parasitoids
- Pupal parasitoids
- Adult parasitoids
•can adopt and survive year-round in the host environment. •has higher reproductive capacity. has high host seeking ability
•life history synchronized with the host.
•has the ability to disperse equally with the host best to •have no hyperparasitoids
•an advantage if the female can detect parasitized host
parasitoids
parasitizes eggs of the corn borer.
Trichogramma evanescens (Hymenoptera)
parasitizes larvae of striped stem borer
Xanthopimpla stemmator (wasp)
preys on Diamond Back Moth (DBM). A parasitoid of diamond back moth (effective in the highlands or places with cold climates like some parts of the Cordillera Region and some parts of Mindanao).
Diadegma semiclausum (wasp)
preys on DBM, Asian corn borer. A parasitoid of diamond back moth which is effective in the lowlands.
Cotesia glomerata (small dark colored wasp)
Example of Parasitoids;
Trichogramma evanescens (Hymenoptera)
Xanthopimpla stemmator (wasp)
Diadegma semiclausum (wasp)
Cotesia glomerata (small dark colored wasp)
are organisms that kills and devour smaller organisms for survival.
Predators
examples of predators
earwigs, lady beetle, ground beetle, nabid bugs. lace wings, dragonfly, syrphids flies.
_____usually viewed as aggressors, and mechanisms of defense in the disease process have been considered mainly from the perspective of the host.
Plant pathogens
____refer to microorganisms that cause disease to their hosts. These are also termed as entomogenous microorganisms or entomopathogens.
Pathogens
Pathogens includes:
Fungi, Bacteria, Nematodes and virus
•This was used successfully to protect crops from a variety of pests.
• They can infect a wide range of insect hosts.
• There has been only limited success in ____ as biological control agent because____ are slow to kill their host. Whereas some fungi have a broad host range.
Fungi
are known as green muscardine fungi. These are easily recognized a few days after death of the arthropod when the fungus grows out of the arthropod integument and forms reproductive structure.
Metarhizium species
are also known to produce compounds that are toxic to arthropods and presumably aid in killing the host. suppressing host’s immune defenses and fending off potential microbial competitors.
Metarhizium species
is highly potent against various sucking pests. It is known as a “white halo” fungus because of the white mycelial growth on the edges of infected scale insects.
_____ used for control of aphids and white flies.
Verticillium lecanii
a green muscardine fungus characterized by the formation of mono or synnematous conidiophores that bear whorls of phialides. Infection process starts with the adhesion of conidia on the insect cuticle. At the end of the
infection cycle, mycelia emerge from the cuticle and produce conidiophores.
Nomuraea species
also called the white muscardine. When spores of this fungus come in contact with the cuticle of susceptible insect, they germinate and grow directly through the cuticle to the inner body, producing toxins and draining the insect, eventually killing it. It then grows back out through the softer portions of the cuticle, covering the insect with a layer of white mold.
Beauvaria bassiana
a naturally occurring fungus in soils throughout the world. ___ is mass produced and used to manage a wide variety of insect pests including: White flies, Thrips, Aphids, Weevils.
Beauvaria bassiana
certainly more specific and is not a threat to the environment. Each ineffective juvenile carries bacteria in the gut, and releases the bacteria into the body cavity of the insect after penetration. The bacteria kill the host in 24 hours.
Entomopathogenic nematodes
used for biological control infects insects via their digestive tract so they offer only limited options for controlling insects with sucking mouth parts such as aphids and scale insects
Bacteria
Resides in soil, soft bodied, non-segmented. Obligate or facultative parasite on broad range of insects. Introduces new and environmental- friendly way to eliminate plant pest.
Nematodes
These harbors gut bacteria which helps in pathogenesis: symbiotic association with bacteria. Entomopathogenic Nematodes (ENs) in the genera Heterorhabditis and Steinernema are used as biological control agent (BCA) for diverse insect pests.
Nematodes
obligate disease causing organisms that can reproduce within a host insect.
Virus
They can provide safe, effective and sustainable control of a variety insect pests usually attack larvae of lepidoptera or hymenoptera.
Virus
_____ host specific. ____ induced mortality is caused by toxic proteins that accumulate during reproductive cycle of virus after death of insect the integument and internal tissues melt away.
Virus
After Infection larvae initially white then darken.
Nuclear polyhedrovirus
After infection larvae turns milky white and stop feeding.
Granulovirus
Biological Control Approaches
- Importation/ Classical Biological Control
- Augmentation
- Conservation
involves the introduction of pests natural enemy
to a new location where they do not occur naturally.
Importation/ Classical Biological Control
Involves the supplemental release of natural enemies, boosting the naturally occurring population.
All activities designed to increase numbers or effect of existing natural enemies, achieved by releasing additional numbers of a natural enemy into a system or modifying the environment in such a way as to promote greater number or effectiveness.
Augmentation BC
Two types Augmentation
Inoculative release:
Inundative release:
small numbers of the control agents are released at intervals to allow them to reproduce in the hope of setting up longer term control and thus keeping the pest down to a low level; constituting prevention rather than cure.
Inoculative release:
involves mass culture and release of natural enemies to suppress the pest population directly.
Inundative release
It involves avoidance of measures that destroy natural enemies and the use of measure that increase their longevity and reproduction of the natural enemies in an environment.
Conservation Bc
Advantages of Biological Control
Absence of toxic effects
No development of resistance by the pest.
No residues of poison in the soils and rivers.
No build-up of toxins in food chain
No killing of pollinators, or development of secondary pests through the destruction of their environment.
Disadvantages of Biological Control
Control is slow
It is often unpredictable
It is difficult and expensive to develop and apply
It requires expert supervision
