CPRT Lec 4.2 - SemioChemicals Flashcards
betlog
Chemicals emitted by living organisms that induce a behavioral or physiological response in other individuals.
Semiochemicals
A Greek word that means sign or signal emitted by one individual that causes a response in another individual
Semeion
Insects use _____ to locate a mate, a host, and a food source, avoid competition, escape natural enemies, and overcome their hosts’ natural defense system
Semiochemicals
2 main groups of semiochemicals
Pheromones and Allelochemicals
Chemicals that mediate interaction between individuals within the species or intraspecific interactions.
Pheromones
Produced by females to attract males during mating
Sex Pheromones
Produced by male butterflies to seduce females during courtship
Sex pheromones
The most studied pheromones are from what insect group?
Lepidoptera
Semiochemicals released by insects to attract members of the same species after locating a source of food or mating site.
- Beetles and weevils mainly emit them
Aggregation pheromones
Semiochemicals released by an insect to alert members of the same species when there are threats to disperse them.
- social insects like aphids, thrips produce this to escape from natural enemies
Alarm pheromones
Social insects produce this to indicate the trail to be followed when some members locate food sources. (e.g. ants and termites)
Trail marking pheromones
Parasitoids produce __________________ to mark a host in which they have laid an egg; used to avoid ovipositing on hosts they or somebody else have oviposited already
Host marking pheromones
“Secondary metabolites” produced by organism such as plants, animals, or microorganisms
Allelochemicals
Similar to pheromones, but acts between two individuals of the different species (interspecific)
Kairomones
Allelochemicals released by one and taken up or recognized by another organism.
- Kairomones
- Allomones
- Synomones
True or False: Kairomones favor the emitter of the chemical signal but not the receiver
False.
found inside the host body serving as indicators for the host’s suitability for laying parasitoid eggs
Internal Kairomones
Located outside of the host body that could be host frass or glue used to attach eggs to a substrate
External Kairomones
This allelochemical benefits the producer but has neutral effects on the recipient (e.g. insect repellant and deterrents).
Allomones
Kairomones in plants also emit _____ upon herbivore damage and can be used for pest control
plant volatiles
Substance produced by an individual of one species that benefits both producer and recipient, a different species.
Synomone
A substance that deters or inhibits insects from finding, feeding on, or ovipositing on an attractive host substrate. (e.g. neem oil, critonella oil, Bordeaux mixture)
Repellent
It is a use of pheromones in PM in detecting the potentially invasive presence of insects; estimate insect population’s relative density
Insect Monitoring
It is a use of pheromones in PM to lure and trap insects before being destroyed by physical/chemical means (attract-and-kill)
Trapping
It is a use of pheromones in PM which involves affecting male’s behavior in their search for females for mating by releasing high quantities of synthetic female pheromones in the atmosphere
Mating disruption
It is a use of pheromones in PM consisting of a combination of repellent and attracttive stimuli modifying insect’s behaviour and their natural enemies
Push-pull strategy
insects are deterred or repelled away from the crops
push strategy
insects attracted by lures and concentrated in other areas where they are trapped/killed in a controlled manner
pull strategy
Benefits of semiochemicals?
- Highly selective
- Virtually no detectable residue
- No accumulation in wildlife or groundwater
- Neglible health risks to humans and other animals
What was used for semiochemical research against rice green leafhopper?
leaf discs of tagbak
