Alarm pheromones signals

Within Hymenoptera, pheromones produced by workers in social colonies are the best studied across many genera, principally in ants [6], with those eliciting trail following most extensively studied. The distinct behavior and the relative ease of the bioassay have resulted in chemical identifications in many species [ 113,114]. Those that have been recently identified are listed in Table 5. In addition, several alarm and recruitment signals have recently been identified. Many of the compounds recently identified in ants have previously been reported as trail or alarm pheromones in other ant species. For example, methyl 4-methylpyrrole-2-carboxylate 64, 3-ethyl-2,5-dimethylpyrazine 65, (9Z)-hexadec-9-enal 66,4-methylheptan-3-ol 67, and methyl 6-methylsalicy-late 68 have been identified as trail pheromone components, and heptan-2-one 69,4-methylheptan-3-one 70, formic acid 71, undecane 61,4-methylheptan-3-ol 67, methyl 6-methylsalicylate 68, and citronellal 72 have been identified as alarm pheromone components [6]. The use of the same chemicals across genera, with some used for very different functions, is an interesting phenomenon. 

There is some evidence that a compound may serve different signaling functions depending on the context and concentration in which it is released. For example, neral (2) functions as an alarm pheromone for Schwiebea elongata at higher doses (Kuwahara et al., 2001), whereas at lower doses, it has been shown to attract (and possibly arrest) females (Nishimura et al., 2002). 

Alarm Pheromones. Ants utilize a wide variety of methyl and ethyl ketones to generate alarm signals (5). These compounds, which are present in relatively large quantities, are produced by species in most of the major subfamilies of ants. 2-Alkanones such as 2-heptanone, 6-methyl-5-hepten-2-one, and 4-methyl-2-hexanone are primarily produced by dolichoderine species (117,... 

In addition to acyclic ketones, dolichoderine ants in the genus Azteca generate an alarm signal with 2-methylcyclopentanone (xxxi),cis-l-acetyl-2-methylcyclopentane (XXXII), and 2-acetyl-3-methylcyclopentene (XXXIII) (128). That some ant species utilize aromatic compounds as alarm pheromones is demonstrated by the identification of methyl 6-methyl salicylate (XXXIV) in the... 

Alarm pheromones. Many mammals live in family groups that are prone to attack. Some of these species have evolved chemical signaling systems that are triggered when danger is perceived. This is best described perhaps in deer, which release a series of odorants from their tarsal glands when startled, although the active component(s) have not yet been definitively isolated and identified.96... 

In aquatic environments, chemical cues serve as an important source of information for the detection of predation risk. Chemical signals released by disturbed or injured conspecifics may provide prey animals with an early warning of danger.2 115 We now discuss two kinds of well-established alarm pheromones from sea anemone and sea slug. 

Semiochemicals can be placed into two distinct classes Pheromones control intraspecific interactions. These semiochemicals provide information regarding a range of behaviours including mate selection, aggregation, dispersal (alarm pheromones), oviposition and food sources (trail pheromones). Allelochemicals control interspecific interactions such as host and non-host identification by primary colonizers (plant or animal) and whether a food source is already exploited through tritrophic interactions (signals indicating the presence of primary colonizers). 

Camphor and <7-limonene are allomones in that the trees which produce them are protected from insect attack by their presence. For instance, Arthur Birch, one of the great terpene chemists of the twentieth century, reported finding d-limonene in the latex exuded by trees of the species Araucaria bidwilli.1 2 These trees are protected from termite attack because the d-limonene they produce is an alarm pheromone for termites that live in the same area. Similarly, antifeedants could be considered to be allomones since the signal generator, the plant, receives the benefit of not being eaten. Myrcene is a kairomone, in that it is produced by the ponderosa pine and its presence attracts the females of the bark beetle, Dendroctonous brevicomis. Geraniol is found in the scent of many flowers such as the rose. Its presence attracts insects to the flower and it can be classified as a synomone since the attracted insect finds nectar and the plant obtains a pollinator. 

GH3)jGHGH2GH200GGH3, which is a bee alarm pheromone that signals danger to a honey bee. If this compound is warmed with aqueous sodium hydroxide, a slow reaction takes place to produce sodium ethanoate and 3-methylbutan-l-ol. The reaction is first order with respect to both 3-methylbutyl ethanoate and the aqueous hydroxide ion. Explain the term first order and give experimental details showing how this information could be obtained. [8]... 

Brown GE, Adrian JC Jr, Kaufman IH, Erickson JL, Gershaneck D (2001) Responses to nitrogen-oxides by chariciform fishes suggest evolutionary conservation in Ostariophysian alarm pheromones. In Marchlewska-Koj A, Lepri J, Muller-Schwarze D (eds) Chemical signals in vertebrates. Plenum, New York, pp 305-312... 

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