What are pheromones of insects and what role do they have?
Pheremones of insects are chemicals that insects use to communicate with one another. This is not voluntary communication that the insects control. It is involuntary as a response to whatever is going on with or near the insect.
Some of the more common functions of pheremones are:
- To attract members of the opposite sex
- To leave a trail for other insects to follow
- To alert other insects to danger (as an alarm)
Scientists have learned to use pheremones as a way to try to control insect populations. There are now ways to use pheremones to disrupt mating cycles, for example, and control the population of harmful insects in a particular field.
pheromones are like odors that are created in the body of an insect.Insects use these pheromones to attract other insects of their species to them.Hundreds of pheromones are known with which one sex of an insect species attracts its mate.
Pheromones are chemical messengers used by insects to communicate and are similar to the hormones inside the human body. Insect pheromones are of many types.These are as follows:
Alarm pheromones,trail pheromone,queen mandibular pheromones
Most pheromones consist of blends of two or more chemicals which need to be emitted at exactly the right proportions to be biologically active.
In insects and other animal groups, meeting sexual partners who are capable of physiological copulation is not random, but through complex mechanisms "transceiver" that enable exchanges of information between individuals, sometimes distant enough.
Chemical communication mechanisms play an important ecological role, allowing the specific and precise tracking of partners across the environment.
Communication mechanisms between the individuals of the same species are physical (sound waves, electromagnetic waves, color, etc.) and chemical, which are predominant (chemical compounds).
Sex Pheromones (hormones that carry the message) are chemical compounds that mediate sexual attraction between individuals of different sexes. Name of pheromone was used first in 1959 by P. Karlson and I. LUSCHER. The pheromone generally means a chemical emitted by one individual and received by another individual of the same species, causing a specific reaction to the individual which received it.
Sex pheromones are biologically active compounds, which determine sexual attraction of the other sex, closeness of individuals around and all their precopulator behavior. In most cases, the female is the issuing authority, and the male is the individual receiver. There are also cases where the roles are reversed. Among insects where sex pheromones were identified, most are Lepidopterae followed (in decreasing order) by orders Coleopterae, Hymenopterae, Orthopterae, Dipterae, Isopterae.
From chemical point of view, natural insect pheromones are formed usually from a single chemical compound, it is rarely a mixtures of several compounds. In the latter case, the specific function of the pheromone depends on the proportion of different compounds mixed. The simplest of insect sex pheromone is valeric acid produced by the female of boring worm of the sugar beet, Limonius californicus.
Most pheromones are esters, acids, alcohols and ketones, with long carbon chain, consisting of C-C, with double bonds, which facilitate their isomerization. Molecular conformation of pheromones plays an important role in their biological activity.
Pheromones are a means of communication in the insect family. They convey messages of alarm, set trails to follow, death pheromones, provide sexual attractants, sexual deception, and instruction.
Alarm Pheromones- Insects alert one another to danger by releasing pheromones which act as an alarm alerting other insects that danger is present.
Trail pheromones- Scientists most commonly associate this type of pheromones with trails left by ants. The trails serve to guide other ants to food and back to their homes.
Death pheromones- Death pheromones have recently been defined as scientists have learned more in their role at indicating to insects when an insect has died and needs to be removed from the hive, hill, tree, or wherever the type of insects resides.
Sexual attractants are released by insects to alert other insects that they are ready to mate. This pheromone has been used by farmers to attract insects for pollination. They are also used to prevent certain insects from invading crops.
Sexual deception is used by some insects to fool other insects to come to them. They then feast on the insects.
Instruction pheromones are indicators of what tasks need to be done. For example, a queen bee releases chemicals which instruct her workers. They know when to feed and groom her and it prevents them from creating other queens.