Nervous And Chemical Integration

CH3- (CH2 )4-COOH E Caproic acid

FIGURE 13.7. Pheromones. (A) Bombykol, the sex attractant of the silk moth, Bombyx mori; (B,C) honey bee queen pheromones; (D) undecane, an alarm pheromone produced by many formicine ants; and (E) caproic acid, a major component of the trail-marking secretion of the termite Zootermopsis nevadensis.

Typically, the pheromone-producing glands of female Lepidoptera are eversible sacs located in the intersegmental membrane behind the eighth abdominal stemite. In the ho-mopteran Schizaphis borealis the glands are probably on the hind tibiae; in Periplaneta the pheromone seems to be produced in the gut and is released from fecal pellets; in the queen honey bee the mandibular glands are the source; and in the house fly sex pheromone is secreted evenly over the second through seventh abdominal segments. In Coleoptera the glands are abdominal.

The components of many male attractants have been identified, especially those of pestiferous Lepidoptera in which they appear generally to be aliphatic straight-chain hydrocarbons, alcohols, acetates, aldehydes, and ketones containing 10-21 carbon atoms (Figure 13.7A). Among Lepidoptera, species in the same family or subfamily tend to produce a "key component." For example, (Z)-11-tetradecenol or its derivative is produced by almost all Tortricinae. Usually the sex pheromone is ablend of two or more components, occurring in species-specific proportions. (Interestingly, the proportions may vary among populations of the same species in different geographic locations.) Further, only one isomeric form of a component is typically attractive in a given species. As a result, under natural conditions males respond only to the pheromone produced by females of their species. Other factors that serve to prevent interspecific attraction between males and females of species producing similar pheromones include differences in the time of day at which males are sensitive to pheromone, differences in geographic location of the species, differences in the time of year when the species are sexually mature, and the need for additional stimuli, perhaps auditory, visual, or chemical, before a male is attracted to a female. For example, the "initial" separation of two species may occur on the basis of their attraction to different host plants. Thus, in the vicinity of a host plant, the chances of being attracted to a conspecific female will be greatly increased. Nevertheless, other stimuli will be necessary to "confirm" the conspecific nature of the partner.

In many species (for lists, see Weatherston and Percy, 1977; Tamaki, in Kerkut and Gilbert, 1985; Fitzpatrick and McNeil, 1988; Birch et al., 1990) it is males that produce a sex pheromone. This may function, like those of females, as a long-distance "attractant" or may trigger close-in behavior such as short-range attraction, female orientation for mating, adoption of the mating posture, and quiescence. For example, the male cockroach, Nauphoeta cinerea, produces seducin, which both attracts and pacifies the unmated female

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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