Pheromones categories

The Pherobase database is an extensive compilation of behavior-modifying compounds listed in the various pheromone categories aggregation, alarm, releaser, primer, territorial, trail, sex pheromones, and others. The database contains over 30,000 entries. Jmol images of molecules are shown. The molecules can be projected as either space-filling or wire-frame models. They can be rotated in 3-dimensional space. In addition, the database includes mass spectral, NMR, and synthesis data for more than 2,500 compounds. This is a fun site ... 

By means of intracellular recording and staining methods, we have examined the responses of AL neurons to stimulation of the ipsilateral antenna with each of the sex pheromone components as well as partial and complete blends (75). In accordance with results of behavioral and sensory-receptor studies, components A and B are the most effective and potent sex pheromone components for eliciting physiological responses in the male-specific AL neurons. On the basis of these responses, we classified the neurons into two broad categories pheromone generalists and pheromone specialists (76). Pheromone generalists are neurons that respond similarly to stimulation of either the component A input channel or the component B input channel and do not respond differently when the complete, natural pheromone blend is presented to the antenna. In contrast, pheromone specialists are neurons that can discriminate between antennal stimulation with component A and stimulation with component B. There are several types of pheromone specialists. Some... 

Finally, we have the subtlest category the modulator pheromones. These pheromones change stimulus sensitivity, salience, and sensorimotor integration in the recipient. These pheromones may determine how a recipient organism will respond to a signal in a specific context. This adds another level of complexity to pheromone action. 

Pheromones are classified in at least ten different categories. The most conq)lex category involves enantiomers at a specific composition (Mori 2000), implying multiple receptors. Other complex networks of biological events involve terpenoids released by plants in response to grazing by herbivores. These metabolites can be used to attract parasitic wasps for pest control (Tumlinson 1993), or, like the strigolactones (Table 12.1), as useful germination stimulants of root parasites of plants in the families Scrophulariaceae and Orobanchaceae (Welzel 1999 Ryan 2001). 

C. polyphyllae is an example of the first category. This species produces /i-acaridial (13) as the major component of its exudates. This compound functions as the female sex pheromone (Leal et al., 1989f), and males can discriminate... 

S. elongata is an example of the second category. At high doses, neral (2) acts as an alarm pheromone (Kuwahara et al, 2001), whereas at lower doses the compound attracts females (Nishimura et al., 2002). Because females of this species can reproduce parthenogenetically, the reason for this function as an attractant is not clear. Possible function may be as an aggregation pheromone. In addition, there are many other mite species in which the major component of the opisthonotal gland secretions functions as the alarm pheromone, and it is entirely possible that these compounds may be found to have additional pheromonal functions at lower doses. 

From our limited knowledge of spider pheromones, at least three different categories of releaser pheromones can be identified those associated with triggering courtship... 

Recent reviews of mammalian semiochemicals89 and of mammalian pheromones8,90,91 have appeared. Vandenbergh groups mammalian pheromones into various categories, which we have used here as a basis for organization into three main and four subcategories ... 

The existence of chirality in pheromone molecules has been recognized since 1966, but as Silverstein (7) explains, most of us ignored it because the insects responded to the synthesized racemic compounds. Thus the insects response to the chiral pheromones identified in earlier work appeared to fall into the first category described by Silverstein (5), i.e., the insect produced and responded to a single enantiomer and the other enantiomer was inactive. Furthermore, the paucity of natural pheromone obtainable from the insects makes it difficult, and in most cases impossible, to determine the stereochemistry of the natural material. 

The most notable advance in insect pheromone science in the last three decades is the recognition of the importance of chirality in pheromone perception. Fig. (11) [46h] summarizes the stereochemistry-pheromone activity relationships. The relationships are divided into ten categories as detailed below. 

This is the most common relationship, and the majority (about 70%) of the chiral pheromones belongs to this category. Only the (lR,5S,7R)-isomer of exo-brevicomin (entry 41) is bioactive [207]. (3S,4R)-Faranal (entry 19) is the bioactive enantiomer of the trail following pheromone of the pharaoh s ant [208]. 

Pheromones are classified into two categories, releaser pheromones and primer pheromones. Releaser (or signaller) pheromones cause changes of behaviors in the receivers, while primer pheromones cause physiological impacts on the receivers. Releaser pheromones can be further classified as sex pheromones, aggregation pheromones, trail pheromones, etc., according to the type of behavioral change. 

I explained this category in the case of the German cockroach pheromone (104), and also discussed the spined citrus bug pheromone [(3/ ,4S)-74], whose opposite enantiomer was as active as the pheromone itself. Females of the maritime pine scale Matsucoccusfeytaudi) use (3.S ,7R)-118 as the sex pheromone. Its OR,1R )-isomcr also showed bioactivity similar to the natural pheromone, while M. feytaudi males responded very weakly to the two other stereoisomers. It therefore seems that only the stereochemistry at C-7 of 118 is important for the expression of pheromone activity.139... 

Behavior-modifying compounds are divided into two broad categories — pheromones and allelochemicals. A pheromone is a substance secreted by an animal that influences the behavior or development of other animals of the same species. The term was suggested by Butenandt, Karlson, and Liischer in 1959 (Butenandt et al., 1959 Karlson and Butenandt, 1959 Karlson and Liischer, 1959). Allelochemicals act between different species and are often called kairomones, provided that the recipient has an advantage by sensing the substance. If the substance only benefits the emitter species, the allelochemical is called an allomone, and if both emitter and receiver are benefited, the allelochemical is known as a synomone. The scent from flowers that attracts bees may therefore be called synomone. 

The most well-known functions of secondary metabolites among arthropods include the use of pheromones for intraspecific communication, the employment of antipredatorial defensive agents, and the offensive use of paralytic and/or toxic agents, such as in the form of venoms, for the acquisition of prey. In recent years, considerable insight has been gained in all three categories, as well as in the discovery of heretofore unknown interactions (see Section 2.04.4.1). Fossil evidence of chemical defense in the insects reaches as far back as the Early Cretaceous period. The chemical defense of insects has been reviewed as... 

A typical hive atmosphere chromatogram from our TD/GC/MS technique is shown in Figure 2.2. Identified compounds have been systematized into four categories, each with a summary table. Table 2.2 lists compounds reported as honey bee semiochemicals. Semiochemicals are produced in glands that secrete to the exterior of the insect, and include pheromones, which are chemicals used to communication between individuals of the same species. Table 2.3 consists of compounds associated with hive stores. Table 2.4 presents compounds emanating from materials and components from which beehives are assembled. Table 2.5 documents compounds arising from non-bee sources. Within each category, compounds have been listed in formula order. Table 2.6 contains selected levels for hazardous air pollutants that have been collected from hives in our studies in the vicinity of Chesapeake Bay, USA. 

Anonymous e.g., Sex pheromones e.g., Category pheromones (such as immature, adult) usually required... 

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