Alarm and defense

The vast majority of formicid species use chemical secretions for defensive purposes. However, within many groups of ants, the proteinaceous venom typical of other Hymenoptera has been superceded by mixtures of structurally simpler organic compounds, and in many cases a communicative function has been added to the defensive or offensive properties. In this section we will concentrate upon the role of alarm communication within colonies, and leave intercolony and interspecies effects aside. However, it must be pointed out that 

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The chains of some fliranoid famesane derivatives are terminated by furan rings. Dendrolasin from sweet potatoes, also isolated from some marine snails, for example, is an alarm and defense pheromone of the ant Dendrolasius fulginosus. Ses-quirosefuran and longifolin occur in the leaves of Actinodaphne longifolia. 

In a similar manner, the alicyclic precursor of multistriatin may be 4,6-dimethyl-7-octen-3-one (301, Scheme 55). Similar compounds have been obtained in alarm and defensive secretions of certain insects. Pales et al. (451) found that the mandibular gland secretion of the ant Manica mutica contained mainly 4,6-dimethyl-4-octen-3-one. Meinwald et al. (452) identified 4,6-dimethyl-6-octen-3-one in the defensive secretion of the daddy long legs, Leiobunum vittatum. 

In a defensive strategy that is based on the detection of a chemical/biological agent in order to initiate a response, the time required for authorities to respond to an attack has three components the inherent response time of the detection system, the time required to verify the validity of a detector alarm, and the time required to decide on what action to take in response to the alarm. These three elements are discussed in more detail below. 

Stingless bees lay chemical trails with mandibular gland constituents which have been identified as normal aliphatic alcohols or monoterpene aldehydes. Trigona spinipes generates a trail with a mixture of 2-heptanol, 2-undecanol, and 2-tridecanol, and it has been possible to successfully lay artificial trails with these alcohols (136). Trail following in workers of Trigona subterranea is released by citral (130), the stereoisomers of which are also utilized as alarm pheromones and defensive compounds. Such pheromonal parsimony appears to be especially typical of eusocial bees and ants. 

Fatty acids Formic acid (C 3.2) Alarm pheromone (and defense substance) of ants (Formica sp.)... 

Alarm pheromones (and defense substances) of the skunk Mephitis mephitis... 

An important principle is that security must be built in depth - otherwise known as defense in depth. In this context, it may be helpful to think of security as a set of concentric rings, where the target is located at the center. Each ring represents a level of physical protection (perimeter fence, building shell, security case) but the number of rings and security resistance will vary relative to the risk. The spaces between the rings may represent other defensive measures such as closed-circuit television (CCTV), security lighting, intruder alarm systems, etc. 

Terpenoid substances are of broad distribution and diverse function in insects. One set, elaborated by the mandibular glands of Acanthomyops claviger, acts both as a defensive secretion and as an alarm releaser. When fed Cu-labeled acetate or mevalonate, laboratory colonies of these ants produce radioactive citronellal and citral, providing unambiguous evidence for de novo synthesis of these terpenes by the ant. The incorporations of these precursors implicate the mevalonic acid pathway as the likely biosynthetic route. 

Finding 4 Although the rapid detection of a chemical/ biological attack and identification of the agent used are worthwhile objectives, a defensive strategy that depends exclusively on a detection-system alarm before action is taken (i.e., employment of a detect and react strategy) has several serious limitations. 

Alarm pheromones, consisting of typical components of bug defensive secretions (e.g., simple aldehydes and esters), have been reported for Leptoglos-sus zonatus [122] and Leptocorisa oratorius [123]. 

The pheromone of Leptocorisa chinensis illustrates the critical importance of the interplay between attractive and inhibitory chemicals [21]. Headspace extracts from males and females were qualitatively similar. From the eight compounds in headspace extracts that elicited strong antennal responses from males, four were discounted as being defensive chemicals or alarm pheromones. The remaining group of four chemicals, consisting of octanol,... 

Activate Emergency Alarm Notification System and take defensive action until relieved by a more qualified employee. (Use Site notification system) First Responder... 

Predatory fish may also be affected by alarm pheromones (Section 7.2) of the prey, both directly and indirectly. The alarm odor may act as defense compoimd that inhibits predator attack or reduces capture rate by inducing predator avoidance in school members of the prey species. 

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